feature: introduce Promethes (#976)

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Changelog
 All notable changes to Ergo will be documented in this file.
 
+## [2.13.0] - TODO
+
+### Config changes
+* Add `prometheus`
+
 ## [2.12.0] - 2023-10-10
 
 We're pleased to be publishing v2.12.0, a new stable release. This is another bugfix release aimed at improving client compatibility and keeping up with the IRCv3 specification process.

default.yaml

@@ -877,6 +877,14 @@ fakelag:
         "MONITOR":     1
         "WHO":         4
 
+# prometheus: exports metrics
+prometheus:
+    # whether to enable prometheus
+    enabled: true
+
+    # listen address
+listen: "localhost:2112"
+
 # the roleplay commands are semi-standardized extensions to IRC that allow
 # sending and receiving messages from pseudo-nicknames. this can be used either
 # for actual roleplaying, or for bridging IRC with other protocols.

go.mod

@@ -23,11 +23,19 @@ require (
 	github.com/xdg-go/scram v1.0.2
 	golang.org/x/crypto v0.5.0
 	golang.org/x/term v0.7.0
-	golang.org/x/text v0.6.0
+	golang.org/x/text v0.9.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/prometheus/client_golang v1.17.0 // indirect
+	github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.11.1 // indirect
 	github.com/tidwall/btree v1.4.2 // indirect
 	github.com/tidwall/gjson v1.14.3 // indirect
 	github.com/tidwall/grect v0.1.4 // indirect
@@ -36,7 +44,8 @@ require (
 	github.com/tidwall/rtred v0.1.2 // indirect
 	github.com/tidwall/tinyqueue v0.1.1 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
-	golang.org/x/sys v0.7.0 // indirect
+	golang.org/x/sys v0.11.0 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
 )
 
 replace github.com/gorilla/websocket => github.com/ergochat/websocket v1.4.2-oragono1

go.sum

@@ -2,8 +2,13 @@ code.cloudfoundry.org/bytefmt v0.0.0-20200131002437-cf55d5288a48 h1:/EMHruHCFXR9
 code.cloudfoundry.org/bytefmt v0.0.0-20200131002437-cf55d5288a48/go.mod h1:wN/zk7mhREp/oviagqUXY3EwuHhWyOvAdsn5Y4CzOrc=
 github.com/GehirnInc/crypt v0.0.0-20200316065508-bb7000b8a962 h1:KeNholpO2xKjgaaSyd+DyQRrsQjhbSeS7qe4nEw8aQw=
 github.com/GehirnInc/crypt v0.0.0-20200316065508-bb7000b8a962/go.mod h1:kC29dT1vFpj7py2OvG1khBdQpo3kInWP+6QipLbdngo=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
+github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815 h1:bWDMxwH3px2JBh6AyO7hdCn/PkvCZXii8TGj7sbtEbQ=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
 github.com/ergochat/confusables v0.0.0-20201108231250-4ab98ab61fb1 h1:WLHTOodthVyv5NvYLIvWl112kSFv5IInKKrRN2qpons=
@@ -28,8 +33,14 @@ github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14j
 github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
 github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd h1:+iAPaTbi1gZpcpDwe/BW1fx7Xoesv69hLNGPheoyhBs=
 github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd/go.mod h1:4soZNh0zW0LtYGdQ416i0jO0EIqMGcbtaspRS4BDvRQ=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
@@ -40,6 +51,14 @@ github.com/onsi/gomega v1.9.0 h1:R1uwffexN6Pr340GtYRIdZmAiN4J+iw6WG4wog1DUXg=
 github.com/onsi/gomega v1.9.0/go.mod h1:Ho0h+IUsWyvy1OpqCwxlQ/21gkhVunqlU8fDGcoTdcA=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.17.0 h1:rl2sfwZMtSthVU752MqfjQozy7blglC+1SOtjMAMh+Q=
+github.com/prometheus/client_golang v1.17.0/go.mod h1:VeL+gMmOAxkS2IqfCq0ZmHSL+LjWfWDUmp1mBz9JgUY=
+github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 h1:v7DLqVdK4VrYkVD5diGdl4sxJurKJEMnODWRJlxV9oM=
+github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16/go.mod h1:oMQmHW1/JoDwqLtg57MGgP/Fb1CJEYF2imWWhWtMkYU=
+github.com/prometheus/common v0.44.0 h1:+5BrQJwiBB9xsMygAB3TNvpQKOwlkc25LbISbrdOOfY=
+github.com/prometheus/common v0.44.0/go.mod h1:ofAIvZbQ1e/nugmZGz4/qCb9Ap1VoSTIO7x0VV9VvuY=
+github.com/prometheus/procfs v0.11.1 h1:xRC8Iq1yyca5ypa9n1EZnWZkt7dwcoRPQwX/5gwaUuI=
+github.com/prometheus/procfs v0.11.1/go.mod h1:eesXgaPo1q7lBpVMoMy0ZOFTth9hBn4W/y0/p/ScXhY=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
@@ -72,20 +91,31 @@ golang.org/x/crypto v0.5.0 h1:U/0M97KRkSFvyD/3FSmdP5W5swImpNgle/EHFhOsQPE=
 golang.org/x/crypto v0.5.0/go.mod h1:NK/OQwhpMQP3MwtdjgLlYHnH9ebylxKWv3e0fK+mkQU=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.5.0 h1:GyT4nK/YDHSqa1c4753ouYCDajOYKTja9Xb/OHtgvSw=
+golang.org/x/net v0.10.0 h1:X2//UzNDwYmtCLn7To6G58Wr6f5ahEAQgKNzv9Y951M=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
 golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.7.0 h1:BEvjmm5fURWqcfbSKTdpkDXYBrUS1c0m8agp14W48vQ=
 golang.org/x/term v0.7.0/go.mod h1:P32HKFT3hSsZrRxla30E9HqToFYAQPCMs/zFMBUFqPY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.6.0 h1:3XmdazWV+ubf7QgHSTWeykHOci5oeekaGJBLkrkaw4k=
 golang.org/x/text v0.6.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=

irc/config.go

@@ -536,6 +536,11 @@ type TorListenersConfig struct {
 	MaxConnectionsPerDuration int           `yaml:"max-connections-per-duration"`
 }
 
+type PrometheusConfig struct {
+	Enabled bool
+	Listen  string
+}
+
 // Config defines the overall configuration.
 type Config struct {
 	AllowEnvironmentOverrides bool `yaml:"allow-environment-overrides"`
@@ -667,6 +672,8 @@ type Config struct {
 
 	Fakelag FakelagConfig
 
+	Prometheus PrometheusConfig
+
 	History struct {
 		Enabled          bool
 		ChannelLength    int              `yaml:"channel-length"`

irc/server.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/ergochat/irc-go/ircfmt"
 	"github.com/okzk/sdnotify"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/tidwall/buntdb"
 
 	"github.com/ergochat/ergo/irc/bunt"
@@ -84,6 +85,7 @@ type Server struct {
 	rehashMutex       sync.Mutex // tier 4
 	rehashSignal      chan os.Signal
 	pprofServer       *http.Server
+	prometheusServer  *http.Server
 	exitSignals       chan os.Signal
 	tracebackSignal   chan os.Signal
 	snomasks          SnoManager
@@ -780,6 +782,7 @@ func (server *Server) applyConfig(config *Config) (err error) {
 
 	server.setupPprofListener(config)
 
+	server.setupPrometheusListener(config)
 	// set RPL_ISUPPORT
 	var newISupportReplies [][]string
 	if oldConfig != nil {
@@ -842,6 +845,33 @@ func (server *Server) setupPprofListener(config *Config) {
 	}
 }
 
+func (server *Server) setupPrometheusListener(config *Config) {
+	promConfig := config.Prometheus
+	if !promConfig.Enabled {
+		return
+	}
+
+	listen := promConfig.Listen
+	if listen == "" {
+		server.logger.Error("prometheus", "Prometheus listener failed", "Prometheus is enabled, but listen is not specified")
+		return
+	}
+
+	promHandler := http.NewServeMux()
+	promHandler.Handle("/metrics", promhttp.Handler())
+	ps := http.Server{
+		Addr:    listen,
+		Handler: promHandler,
+	}
+	go func() {
+		if err := ps.ListenAndServe(); err != nil {
+			server.logger.Error("server", "Prometheus listener failed", err.Error())
+		}
+	}()
+	server.prometheusServer = &ps
+	server.logger.Info("server", "Started Prometheus listener", server.prometheusServer.Addr)
+}
+
 func (server *Server) loadDatastore(config *Config) error {
 	// open the datastore and load server state for which it (rather than config)
 	// is the source of truth

vendor/github.com/beorn7/perks/LICENSE

@@ -0,0 +1,20 @@
+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/beorn7/perks/quantile/stream.go

@@ -0,0 +1,316 @@
+// Package quantile computes approximate quantiles over an unbounded data
+// stream within low memory and CPU bounds.
+//
+// A small amount of accuracy is traded to achieve the above properties.
+//
+// Multiple streams can be merged before calling Query to generate a single set
+// of results. This is meaningful when the streams represent the same type of
+// data. See Merge and Samples.
+//
+// For more detailed information about the algorithm used, see:
+//
+// Effective Computation of Biased Quantiles over Data Streams
+//
+// http://www.cs.rutgers.edu/~muthu/bquant.pdf
+package quantile
+
+import (
+	"math"
+	"sort"
+)
+
+// Sample holds an observed value and meta information for compression. JSON
+// tags have been added for convenience.
+type Sample struct {
+	Value float64 `json:",string"`
+	Width float64 `json:",string"`
+	Delta float64 `json:",string"`
+}
+
+// Samples represents a slice of samples. It implements sort.Interface.
+type Samples []Sample
+
+func (a Samples) Len() int           { return len(a) }
+func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
+func (a Samples) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+type invariant func(s *stream, r float64) float64
+
+// NewLowBiased returns an initialized Stream for low-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the lower ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewLowBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * r
+	}
+	return newStream(ƒ)
+}
+
+// NewHighBiased returns an initialized Stream for high-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the higher ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewHighBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * (s.n - r)
+	}
+	return newStream(ƒ)
+}
+
+// NewTargeted returns an initialized Stream concerned with a particular set of
+// quantile values that are supplied a priori. Knowing these a priori reduces
+// space and computation time. The targets map maps the desired quantiles to
+// their absolute errors, i.e. the true quantile of a value returned by a query
+// is guaranteed to be within (Quantile±Epsilon).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
+func NewTargeted(targetMap map[float64]float64) *Stream {
+	// Convert map to slice to avoid slow iterations on a map.
+	// ƒ is called on the hot path, so converting the map to a slice
+	// beforehand results in significant CPU savings.
+	targets := targetMapToSlice(targetMap)
+
+	ƒ := func(s *stream, r float64) float64 {
+		var m = math.MaxFloat64
+		var f float64
+		for _, t := range targets {
+			if t.quantile*s.n <= r {
+				f = (2 * t.epsilon * r) / t.quantile
+			} else {
+				f = (2 * t.epsilon * (s.n - r)) / (1 - t.quantile)
+			}
+			if f < m {
+				m = f
+			}
+		}
+		return m
+	}
+	return newStream(ƒ)
+}
+
+type target struct {
+	quantile float64
+	epsilon  float64
+}
+
+func targetMapToSlice(targetMap map[float64]float64) []target {
+	targets := make([]target, 0, len(targetMap))
+
+	for quantile, epsilon := range targetMap {
+		t := target{
+			quantile: quantile,
+			epsilon:  epsilon,
+		}
+		targets = append(targets, t)
+	}
+
+	return targets
+}
+
+// Stream computes quantiles for a stream of float64s. It is not thread-safe by
+// design. Take care when using across multiple goroutines.
+type Stream struct {
+	*stream
+	b      Samples
+	sorted bool
+}
+
+func newStream(ƒ invariant) *Stream {
+	x := &stream{ƒ: ƒ}
+	return &Stream{x, make(Samples, 0, 500), true}
+}
+
+// Insert inserts v into the stream.
+func (s *Stream) Insert(v float64) {
+	s.insert(Sample{Value: v, Width: 1})
+}
+
+func (s *Stream) insert(sample Sample) {
+	s.b = append(s.b, sample)
+	s.sorted = false
+	if len(s.b) == cap(s.b) {
+		s.flush()
+	}
+}
+
+// Query returns the computed qth percentiles value. If s was created with
+// NewTargeted, and q is not in the set of quantiles provided a priori, Query
+// will return an unspecified result.
+func (s *Stream) Query(q float64) float64 {
+	if !s.flushed() {
+		// Fast path when there hasn't been enough data for a flush;
+		// this also yields better accuracy for small sets of data.
+		l := len(s.b)
+		if l == 0 {
+			return 0
+		}
+		i := int(math.Ceil(float64(l) * q))
+		if i > 0 {
+			i -= 1
+		}
+		s.maybeSort()
+		return s.b[i].Value
+	}
+	s.flush()
+	return s.stream.query(q)
+}
+
+// Merge merges samples into the underlying streams samples. This is handy when
+// merging multiple streams from separate threads, database shards, etc.
+//
+// ATTENTION: This method is broken and does not yield correct results. The
+// underlying algorithm is not capable of merging streams correctly.
+func (s *Stream) Merge(samples Samples) {
+	sort.Sort(samples)
+	s.stream.merge(samples)
+}
+
+// Reset reinitializes and clears the list reusing the samples buffer memory.
+func (s *Stream) Reset() {
+	s.stream.reset()
+	s.b = s.b[:0]
+}
+
+// Samples returns stream samples held by s.
+func (s *Stream) Samples() Samples {
+	if !s.flushed() {
+		return s.b
+	}
+	s.flush()
+	return s.stream.samples()
+}
+
+// Count returns the total number of samples observed in the stream
+// since initialization.
+func (s *Stream) Count() int {
+	return len(s.b) + s.stream.count()
+}
+
+func (s *Stream) flush() {
+	s.maybeSort()
+	s.stream.merge(s.b)
+	s.b = s.b[:0]
+}
+
+func (s *Stream) maybeSort() {
+	if !s.sorted {
+		s.sorted = true
+		sort.Sort(s.b)
+	}
+}
+
+func (s *Stream) flushed() bool {
+	return len(s.stream.l) > 0
+}
+
+type stream struct {
+	n float64
+	l []Sample
+	ƒ invariant
+}
+
+func (s *stream) reset() {
+	s.l = s.l[:0]
+	s.n = 0
+}
+
+func (s *stream) insert(v float64) {
+	s.merge(Samples{{v, 1, 0}})
+}
+
+func (s *stream) merge(samples Samples) {
+	// TODO(beorn7): This tries to merge not only individual samples, but
+	// whole summaries. The paper doesn't mention merging summaries at
+	// all. Unittests show that the merging is inaccurate. Find out how to
+	// do merges properly.
+	var r float64
+	i := 0
+	for _, sample := range samples {
+		for ; i < len(s.l); i++ {
+			c := s.l[i]
+			if c.Value > sample.Value {
+				// Insert at position i.
+				s.l = append(s.l, Sample{})
+				copy(s.l[i+1:], s.l[i:])
+				s.l[i] = Sample{
+					sample.Value,
+					sample.Width,
+					math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
+					// TODO(beorn7): How to calculate delta correctly?
+				}
+				i++
+				goto inserted
+			}
+			r += c.Width
+		}
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
+		i++
+	inserted:
+		s.n += sample.Width
+		r += sample.Width
+	}
+	s.compress()
+}
+
+func (s *stream) count() int {
+	return int(s.n)
+}
+
+func (s *stream) query(q float64) float64 {
+	t := math.Ceil(q * s.n)
+	t += math.Ceil(s.ƒ(s, t) / 2)
+	p := s.l[0]
+	var r float64
+	for _, c := range s.l[1:] {
+		r += p.Width
+		if r+c.Width+c.Delta > t {
+			return p.Value
+		}
+		p = c
+	}
+	return p.Value
+}
+
+func (s *stream) compress() {
+	if len(s.l) < 2 {
+		return
+	}
+	x := s.l[len(s.l)-1]
+	xi := len(s.l) - 1
+	r := s.n - 1 - x.Width
+
+	for i := len(s.l) - 2; i >= 0; i-- {
+		c := s.l[i]
+		if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
+			x.Width += c.Width
+			s.l[xi] = x
+			// Remove element at i.
+			copy(s.l[i:], s.l[i+1:])
+			s.l = s.l[:len(s.l)-1]
+			xi -= 1
+		} else {
+			x = c
+			xi = i
+		}
+		r -= c.Width
+	}
+}
+
+func (s *stream) samples() Samples {
+	samples := make(Samples, len(s.l))
+	copy(samples, s.l)
+	return samples
+}

vendor/github.com/cespare/xxhash/v2/LICENSE.txt

@@ -0,0 +1,22 @@
+Copyright (c) 2016 Caleb Spare
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/cespare/xxhash/v2/README.md

@@ -0,0 +1,72 @@
+# xxhash
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/cespare/xxhash/v2.svg)](https://pkg.go.dev/github.com/cespare/xxhash/v2)
+[![Test](https://github.com/cespare/xxhash/actions/workflows/test.yml/badge.svg)](https://github.com/cespare/xxhash/actions/workflows/test.yml)
+
+xxhash is a Go implementation of the 64-bit [xxHash] algorithm, XXH64. This is a
+high-quality hashing algorithm that is much faster than anything in the Go
+standard library.
+
+This package provides a straightforward API:
+
+```
+func Sum64(b []byte) uint64
+func Sum64String(s string) uint64
+type Digest struct{ ... }
+    func New() *Digest
+```
+
+The `Digest` type implements hash.Hash64. Its key methods are:
+
+```
+func (*Digest) Write([]byte) (int, error)
+func (*Digest) WriteString(string) (int, error)
+func (*Digest) Sum64() uint64
+```
+
+The package is written with optimized pure Go and also contains even faster
+assembly implementations for amd64 and arm64. If desired, the `purego` build tag
+opts into using the Go code even on those architectures.
+
+[xxHash]: http://cyan4973.github.io/xxHash/
+
+## Compatibility
+
+This package is in a module and the latest code is in version 2 of the module.
+You need a version of Go with at least "minimal module compatibility" to use
+github.com/cespare/xxhash/v2:
+
+* 1.9.7+ for Go 1.9
+* 1.10.3+ for Go 1.10
+* Go 1.11 or later
+
+I recommend using the latest release of Go.
+
+## Benchmarks
+
+Here are some quick benchmarks comparing the pure-Go and assembly
+implementations of Sum64.
+
+| input size | purego    | asm       |
+| ---------- | --------- | --------- |
+| 4 B        |  1.3 GB/s |  1.2 GB/s |
+| 16 B       |  2.9 GB/s |  3.5 GB/s |
+| 100 B      |  6.9 GB/s |  8.1 GB/s |
+| 4 KB       | 11.7 GB/s | 16.7 GB/s |
+| 10 MB      | 12.0 GB/s | 17.3 GB/s |
+
+These numbers were generated on Ubuntu 20.04 with an Intel Xeon Platinum 8252C
+CPU using the following commands under Go 1.19.2:
+
+```
+benchstat <(go test -tags purego -benchtime 500ms -count 15 -bench 'Sum64$')
+benchstat <(go test -benchtime 500ms -count 15 -bench 'Sum64$')
+```
+
+## Projects using this package
+
+- [InfluxDB](https://github.com/influxdata/influxdb)
+- [Prometheus](https://github.com/prometheus/prometheus)
+- [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics)
+- [FreeCache](https://github.com/coocood/freecache)
+- [FastCache](https://github.com/VictoriaMetrics/fastcache)

vendor/github.com/cespare/xxhash/v2/testall.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -eu -o pipefail
+
+# Small convenience script for running the tests with various combinations of
+# arch/tags. This assumes we're running on amd64 and have qemu available.
+
+go test ./...
+go test -tags purego ./...
+GOARCH=arm64 go test
+GOARCH=arm64 go test -tags purego

vendor/github.com/cespare/xxhash/v2/xxhash.go

@@ -0,0 +1,228 @@
+// Package xxhash implements the 64-bit variant of xxHash (XXH64) as described
+// at http://cyan4973.github.io/xxHash/.
+package xxhash
+
+import (
+	"encoding/binary"
+	"errors"
+	"math/bits"
+)
+
+const (
+	prime1 uint64 = 11400714785074694791
+	prime2 uint64 = 14029467366897019727
+	prime3 uint64 = 1609587929392839161
+	prime4 uint64 = 9650029242287828579
+	prime5 uint64 = 2870177450012600261
+)
+
+// Store the primes in an array as well.
+//
+// The consts are used when possible in Go code to avoid MOVs but we need a
+// contiguous array of the assembly code.
+var primes = [...]uint64{prime1, prime2, prime3, prime4, prime5}
+
+// Digest implements hash.Hash64.
+type Digest struct {
+	v1    uint64
+	v2    uint64
+	v3    uint64
+	v4    uint64
+	total uint64
+	mem   [32]byte
+	n     int // how much of mem is used
+}
+
+// New creates a new Digest that computes the 64-bit xxHash algorithm.
+func New() *Digest {
+	var d Digest
+	d.Reset()
+	return &d
+}
+
+// Reset clears the Digest's state so that it can be reused.
+func (d *Digest) Reset() {
+	d.v1 = primes[0] + prime2
+	d.v2 = prime2
+	d.v3 = 0
+	d.v4 = -primes[0]
+	d.total = 0
+	d.n = 0
+}
+
+// Size always returns 8 bytes.
+func (d *Digest) Size() int { return 8 }
+
+// BlockSize always returns 32 bytes.
+func (d *Digest) BlockSize() int { return 32 }
+
+// Write adds more data to d. It always returns len(b), nil.
+func (d *Digest) Write(b []byte) (n int, err error) {
+	n = len(b)
+	d.total += uint64(n)
+
+	memleft := d.mem[d.n&(len(d.mem)-1):]
+
+	if d.n+n < 32 {
+		// This new data doesn't even fill the current block.
+		copy(memleft, b)
+		d.n += n
+		return
+	}
+
+	if d.n > 0 {
+		// Finish off the partial block.
+		c := copy(memleft, b)
+		d.v1 = round(d.v1, u64(d.mem[0:8]))
+		d.v2 = round(d.v2, u64(d.mem[8:16]))
+		d.v3 = round(d.v3, u64(d.mem[16:24]))
+		d.v4 = round(d.v4, u64(d.mem[24:32]))
+		b = b[c:]
+		d.n = 0
+	}
+
+	if len(b) >= 32 {
+		// One or more full blocks left.
+		nw := writeBlocks(d, b)
+		b = b[nw:]
+	}
+
+	// Store any remaining partial block.
+	copy(d.mem[:], b)
+	d.n = len(b)
+
+	return
+}
+
+// Sum appends the current hash to b and returns the resulting slice.
+func (d *Digest) Sum(b []byte) []byte {
+	s := d.Sum64()
+	return append(
+		b,
+		byte(s>>56),
+		byte(s>>48),
+		byte(s>>40),
+		byte(s>>32),
+		byte(s>>24),
+		byte(s>>16),
+		byte(s>>8),
+		byte(s),
+	)
+}
+
+// Sum64 returns the current hash.
+func (d *Digest) Sum64() uint64 {
+	var h uint64
+
+	if d.total >= 32 {
+		v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = d.v3 + prime5
+	}
+
+	h += d.total
+
+	b := d.mem[:d.n&(len(d.mem)-1)]
+	for ; len(b) >= 8; b = b[8:] {
+		k1 := round(0, u64(b[:8]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if len(b) >= 4 {
+		h ^= uint64(u32(b[:4])) * prime1
+		h = rol23(h)*prime2 + prime3
+		b = b[4:]
+	}
+	for ; len(b) > 0; b = b[1:] {
+		h ^= uint64(b[0]) * prime5
+		h = rol11(h) * prime1
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+const (
+	magic         = "xxh\x06"
+	marshaledSize = len(magic) + 8*5 + 32
+)
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (d *Digest) MarshalBinary() ([]byte, error) {
+	b := make([]byte, 0, marshaledSize)
+	b = append(b, magic...)
+	b = appendUint64(b, d.v1)
+	b = appendUint64(b, d.v2)
+	b = appendUint64(b, d.v3)
+	b = appendUint64(b, d.v4)
+	b = appendUint64(b, d.total)
+	b = append(b, d.mem[:d.n]...)
+	b = b[:len(b)+len(d.mem)-d.n]
+	return b, nil
+}
+
+// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
+func (d *Digest) UnmarshalBinary(b []byte) error {
+	if len(b) < len(magic) || string(b[:len(magic)]) != magic {
+		return errors.New("xxhash: invalid hash state identifier")
+	}
+	if len(b) != marshaledSize {
+		return errors.New("xxhash: invalid hash state size")
+	}
+	b = b[len(magic):]
+	b, d.v1 = consumeUint64(b)
+	b, d.v2 = consumeUint64(b)
+	b, d.v3 = consumeUint64(b)
+	b, d.v4 = consumeUint64(b)
+	b, d.total = consumeUint64(b)
+	copy(d.mem[:], b)
+	d.n = int(d.total % uint64(len(d.mem)))
+	return nil
+}
+
+func appendUint64(b []byte, x uint64) []byte {
+	var a [8]byte
+	binary.LittleEndian.PutUint64(a[:], x)
+	return append(b, a[:]...)
+}
+
+func consumeUint64(b []byte) ([]byte, uint64) {
+	x := u64(b)
+	return b[8:], x
+}
+
+func u64(b []byte) uint64 { return binary.LittleEndian.Uint64(b) }
+func u32(b []byte) uint32 { return binary.LittleEndian.Uint32(b) }
+
+func round(acc, input uint64) uint64 {
+	acc += input * prime2
+	acc = rol31(acc)
+	acc *= prime1
+	return acc
+}
+
+func mergeRound(acc, val uint64) uint64 {
+	val = round(0, val)
+	acc ^= val
+	acc = acc*prime1 + prime4
+	return acc
+}
+
+func rol1(x uint64) uint64  { return bits.RotateLeft64(x, 1) }
+func rol7(x uint64) uint64  { return bits.RotateLeft64(x, 7) }
+func rol11(x uint64) uint64 { return bits.RotateLeft64(x, 11) }
+func rol12(x uint64) uint64 { return bits.RotateLeft64(x, 12) }
+func rol18(x uint64) uint64 { return bits.RotateLeft64(x, 18) }
+func rol23(x uint64) uint64 { return bits.RotateLeft64(x, 23) }
+func rol27(x uint64) uint64 { return bits.RotateLeft64(x, 27) }
+func rol31(x uint64) uint64 { return bits.RotateLeft64(x, 31) }

vendor/github.com/cespare/xxhash/v2/xxhash_amd64.s

@@ -0,0 +1,209 @@
+//go:build !appengine && gc && !purego
+// +build !appengine
+// +build gc
+// +build !purego
+
+#include "textflag.h"
+
+// Registers:
+#define h      AX
+#define d      AX
+#define p      SI // pointer to advance through b
+#define n      DX
+#define end    BX // loop end
+#define v1     R8
+#define v2     R9
+#define v3     R10
+#define v4     R11
+#define x      R12
+#define prime1 R13
+#define prime2 R14
+#define prime4 DI
+
+#define round(acc, x) \
+	IMULQ prime2, x   \
+	ADDQ  x, acc      \
+	ROLQ  $31, acc    \
+	IMULQ prime1, acc
+
+// round0 performs the operation x = round(0, x).
+#define round0(x) \
+	IMULQ prime2, x \
+	ROLQ  $31, x    \
+	IMULQ prime1, x
+
+// mergeRound applies a merge round on the two registers acc and x.
+// It assumes that prime1, prime2, and prime4 have been loaded.
+#define mergeRound(acc, x) \
+	round0(x)         \
+	XORQ  x, acc      \
+	IMULQ prime1, acc \
+	ADDQ  prime4, acc
+
+// blockLoop processes as many 32-byte blocks as possible,
+// updating v1, v2, v3, and v4. It assumes that there is at least one block
+// to process.
+#define blockLoop() \
+loop:  \
+	MOVQ +0(p), x  \
+	round(v1, x)   \
+	MOVQ +8(p), x  \
+	round(v2, x)   \
+	MOVQ +16(p), x \
+	round(v3, x)   \
+	MOVQ +24(p), x \
+	round(v4, x)   \
+	ADDQ $32, p    \
+	CMPQ p, end    \
+	JLE  loop
+
+// func Sum64(b []byte) uint64
+TEXT ·Sum64(SB), NOSPLIT|NOFRAME, $0-32
+	// Load fixed primes.
+	MOVQ ·primes+0(SB), prime1
+	MOVQ ·primes+8(SB), prime2
+	MOVQ ·primes+24(SB), prime4
+
+	// Load slice.
+	MOVQ b_base+0(FP), p
+	MOVQ b_len+8(FP), n
+	LEAQ (p)(n*1), end
+
+	// The first loop limit will be len(b)-32.
+	SUBQ $32, end
+
+	// Check whether we have at least one block.
+	CMPQ n, $32
+	JLT  noBlocks
+
+	// Set up initial state (v1, v2, v3, v4).
+	MOVQ prime1, v1
+	ADDQ prime2, v1
+	MOVQ prime2, v2
+	XORQ v3, v3
+	XORQ v4, v4
+	SUBQ prime1, v4
+
+	blockLoop()
+
+	MOVQ v1, h
+	ROLQ $1, h
+	MOVQ v2, x
+	ROLQ $7, x
+	ADDQ x, h
+	MOVQ v3, x
+	ROLQ $12, x
+	ADDQ x, h
+	MOVQ v4, x
+	ROLQ $18, x
+	ADDQ x, h
+
+	mergeRound(h, v1)
+	mergeRound(h, v2)
+	mergeRound(h, v3)
+	mergeRound(h, v4)
+
+	JMP afterBlocks
+
+noBlocks:
+	MOVQ ·primes+32(SB), h
+
+afterBlocks:
+	ADDQ n, h
+
+	ADDQ $24, end
+	CMPQ p, end
+	JG   try4
+
+loop8:
+	MOVQ  (p), x
+	ADDQ  $8, p
+	round0(x)
+	XORQ  x, h
+	ROLQ  $27, h
+	IMULQ prime1, h
+	ADDQ  prime4, h
+
+	CMPQ p, end
+	JLE  loop8
+
+try4:
+	ADDQ $4, end
+	CMPQ p, end
+	JG   try1
+
+	MOVL  (p), x
+	ADDQ  $4, p
+	IMULQ prime1, x
+	XORQ  x, h
+
+	ROLQ  $23, h
+	IMULQ prime2, h
+	ADDQ  ·primes+16(SB), h
+
+try1:
+	ADDQ $4, end
+	CMPQ p, end
+	JGE  finalize
+
+loop1:
+	MOVBQZX (p), x
+	ADDQ    $1, p
+	IMULQ   ·primes+32(SB), x
+	XORQ    x, h
+	ROLQ    $11, h
+	IMULQ   prime1, h
+
+	CMPQ p, end
+	JL   loop1
+
+finalize:
+	MOVQ  h, x
+	SHRQ  $33, x
+	XORQ  x, h
+	IMULQ prime2, h
+	MOVQ  h, x
+	SHRQ  $29, x
+	XORQ  x, h
+	IMULQ ·primes+16(SB), h
+	MOVQ  h, x
+	SHRQ  $32, x
+	XORQ  x, h
+
+	MOVQ h, ret+24(FP)
+	RET
+
+// func writeBlocks(d *Digest, b []byte) int
+TEXT ·writeBlocks(SB), NOSPLIT|NOFRAME, $0-40
+	// Load fixed primes needed for round.
+	MOVQ ·primes+0(SB), prime1
+	MOVQ ·primes+8(SB), prime2
+
+	// Load slice.
+	MOVQ b_base+8(FP), p
+	MOVQ b_len+16(FP), n
+	LEAQ (p)(n*1), end
+	SUBQ $32, end
+
+	// Load vN from d.
+	MOVQ s+0(FP), d
+	MOVQ 0(d), v1
+	MOVQ 8(d), v2
+	MOVQ 16(d), v3
+	MOVQ 24(d), v4
+
+	// We don't need to check the loop condition here; this function is
+	// always called with at least one block of data to process.
+	blockLoop()
+
+	// Copy vN back to d.
+	MOVQ v1, 0(d)
+	MOVQ v2, 8(d)
+	MOVQ v3, 16(d)
+	MOVQ v4, 24(d)
+
+	// The number of bytes written is p minus the old base pointer.
+	SUBQ b_base+8(FP), p
+	MOVQ p, ret+32(FP)
+
+	RET

vendor/github.com/cespare/xxhash/v2/xxhash_arm64.s

@@ -0,0 +1,183 @@
+//go:build !appengine && gc && !purego
+// +build !appengine
+// +build gc
+// +build !purego
+
+#include "textflag.h"
+
+// Registers:
+#define digest	R1
+#define h	R2 // return value
+#define p	R3 // input pointer
+#define n	R4 // input length
+#define nblocks	R5 // n / 32
+#define prime1	R7
+#define prime2	R8
+#define prime3	R9
+#define prime4	R10
+#define prime5	R11
+#define v1	R12
+#define v2	R13
+#define v3	R14
+#define v4	R15
+#define x1	R20
+#define x2	R21
+#define x3	R22
+#define x4	R23
+
+#define round(acc, x) \
+	MADD prime2, acc, x, acc \
+	ROR  $64-31, acc         \
+	MUL  prime1, acc
+
+// round0 performs the operation x = round(0, x).
+#define round0(x) \
+	MUL prime2, x \
+	ROR $64-31, x \
+	MUL prime1, x
+
+#define mergeRound(acc, x) \
+	round0(x)                     \
+	EOR  x, acc                   \
+	MADD acc, prime4, prime1, acc
+
+// blockLoop processes as many 32-byte blocks as possible,
+// updating v1, v2, v3, and v4. It assumes that n >= 32.
+#define blockLoop() \
+	LSR     $5, n, nblocks  \
+	PCALIGN $16             \
+	loop:                   \
+	LDP.P   16(p), (x1, x2) \
+	LDP.P   16(p), (x3, x4) \
+	round(v1, x1)           \
+	round(v2, x2)           \
+	round(v3, x3)           \
+	round(v4, x4)           \
+	SUB     $1, nblocks     \
+	CBNZ    nblocks, loop
+
+// func Sum64(b []byte) uint64
+TEXT ·Sum64(SB), NOSPLIT|NOFRAME, $0-32
+	LDP b_base+0(FP), (p, n)
+
+	LDP  ·primes+0(SB), (prime1, prime2)
+	LDP  ·primes+16(SB), (prime3, prime4)
+	MOVD ·primes+32(SB), prime5
+
+	CMP  $32, n
+	CSEL LT, prime5, ZR, h // if n < 32 { h = prime5 } else { h = 0 }
+	BLT  afterLoop
+
+	ADD  prime1, prime2, v1
+	MOVD prime2, v2
+	MOVD $0, v3
+	NEG  prime1, v4
+
+	blockLoop()
+
+	ROR $64-1, v1, x1
+	ROR $64-7, v2, x2
+	ADD x1, x2
+	ROR $64-12, v3, x3
+	ROR $64-18, v4, x4
+	ADD x3, x4
+	ADD x2, x4, h
+
+	mergeRound(h, v1)
+	mergeRound(h, v2)
+	mergeRound(h, v3)
+	mergeRound(h, v4)
+
+afterLoop:
+	ADD n, h
+
+	TBZ   $4, n, try8
+	LDP.P 16(p), (x1, x2)
+
+	round0(x1)
+
+	// NOTE: here and below, sequencing the EOR after the ROR (using a
+	// rotated register) is worth a small but measurable speedup for small
+	// inputs.
+	ROR  $64-27, h
+	EOR  x1 @> 64-27, h, h
+	MADD h, prime4, prime1, h
+
+	round0(x2)
+	ROR  $64-27, h
+	EOR  x2 @> 64-27, h, h
+	MADD h, prime4, prime1, h
+
+try8:
+	TBZ    $3, n, try4
+	MOVD.P 8(p), x1
+
+	round0(x1)
+	ROR  $64-27, h
+	EOR  x1 @> 64-27, h, h
+	MADD h, prime4, prime1, h
+
+try4:
+	TBZ     $2, n, try2
+	MOVWU.P 4(p), x2
+
+	MUL  prime1, x2
+	ROR  $64-23, h
+	EOR  x2 @> 64-23, h, h
+	MADD h, prime3, prime2, h
+
+try2:
+	TBZ     $1, n, try1
+	MOVHU.P 2(p), x3
+	AND     $255, x3, x1
+	LSR     $8, x3, x2
+
+	MUL prime5, x1
+	ROR $64-11, h
+	EOR x1 @> 64-11, h, h
+	MUL prime1, h
+
+	MUL prime5, x2
+	ROR $64-11, h
+	EOR x2 @> 64-11, h, h
+	MUL prime1, h
+
+try1:
+	TBZ   $0, n, finalize
+	MOVBU (p), x4
+
+	MUL prime5, x4
+	ROR $64-11, h
+	EOR x4 @> 64-11, h, h
+	MUL prime1, h
+
+finalize:
+	EOR h >> 33, h
+	MUL prime2, h
+	EOR h >> 29, h
+	MUL prime3, h
+	EOR h >> 32, h
+
+	MOVD h, ret+24(FP)
+	RET
+
+// func writeBlocks(d *Digest, b []byte) int
+TEXT ·writeBlocks(SB), NOSPLIT|NOFRAME, $0-40
+	LDP ·primes+0(SB), (prime1, prime2)
+
+	// Load state. Assume v[1-4] are stored contiguously.
+	MOVD d+0(FP), digest
+	LDP  0(digest), (v1, v2)
+	LDP  16(digest), (v3, v4)
+
+	LDP b_base+8(FP), (p, n)
+
+	blockLoop()
+
+	// Store updated state.
+	STP (v1, v2), 0(digest)
+	STP (v3, v4), 16(digest)
+
+	BIC  $31, n
+	MOVD n, ret+32(FP)
+	RET

vendor/github.com/cespare/xxhash/v2/xxhash_asm.go

@@ -0,0 +1,15 @@
+//go:build (amd64 || arm64) && !appengine && gc && !purego
+// +build amd64 arm64
+// +build !appengine
+// +build gc
+// +build !purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+//
+//go:noescape
+func Sum64(b []byte) uint64
+
+//go:noescape
+func writeBlocks(d *Digest, b []byte) int

vendor/github.com/cespare/xxhash/v2/xxhash_other.go

@@ -0,0 +1,76 @@
+//go:build (!amd64 && !arm64) || appengine || !gc || purego
+// +build !amd64,!arm64 appengine !gc purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+func Sum64(b []byte) uint64 {
+	// A simpler version would be
+	//   d := New()
+	//   d.Write(b)
+	//   return d.Sum64()
+	// but this is faster, particularly for small inputs.
+
+	n := len(b)
+	var h uint64
+
+	if n >= 32 {
+		v1 := primes[0] + prime2
+		v2 := prime2
+		v3 := uint64(0)
+		v4 := -primes[0]
+		for len(b) >= 32 {
+			v1 = round(v1, u64(b[0:8:len(b)]))
+			v2 = round(v2, u64(b[8:16:len(b)]))
+			v3 = round(v3, u64(b[16:24:len(b)]))
+			v4 = round(v4, u64(b[24:32:len(b)]))
+			b = b[32:len(b):len(b)]
+		}
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = prime5
+	}
+
+	h += uint64(n)
+
+	for ; len(b) >= 8; b = b[8:] {
+		k1 := round(0, u64(b[:8]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if len(b) >= 4 {
+		h ^= uint64(u32(b[:4])) * prime1
+		h = rol23(h)*prime2 + prime3
+		b = b[4:]
+	}
+	for ; len(b) > 0; b = b[1:] {
+		h ^= uint64(b[0]) * prime5
+		h = rol11(h) * prime1
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+func writeBlocks(d *Digest, b []byte) int {
+	v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+	n := len(b)
+	for len(b) >= 32 {
+		v1 = round(v1, u64(b[0:8:len(b)]))
+		v2 = round(v2, u64(b[8:16:len(b)]))
+		v3 = round(v3, u64(b[16:24:len(b)]))
+		v4 = round(v4, u64(b[24:32:len(b)]))
+		b = b[32:len(b):len(b)]
+	}
+	d.v1, d.v2, d.v3, d.v4 = v1, v2, v3, v4
+	return n - len(b)
+}

vendor/github.com/cespare/xxhash/v2/xxhash_safe.go

@@ -0,0 +1,16 @@
+//go:build appengine
+// +build appengine
+
+// This file contains the safe implementations of otherwise unsafe-using code.
+
+package xxhash
+
+// Sum64String computes the 64-bit xxHash digest of s.
+func Sum64String(s string) uint64 {
+	return Sum64([]byte(s))
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	return d.Write([]byte(s))
+}

vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go

@@ -0,0 +1,58 @@
+//go:build !appengine
+// +build !appengine
+
+// This file encapsulates usage of unsafe.
+// xxhash_safe.go contains the safe implementations.
+
+package xxhash
+
+import (
+	"unsafe"
+)
+
+// In the future it's possible that compiler optimizations will make these
+// XxxString functions unnecessary by realizing that calls such as
+// Sum64([]byte(s)) don't need to copy s. See https://go.dev/issue/2205.
+// If that happens, even if we keep these functions they can be replaced with
+// the trivial safe code.
+
+// NOTE: The usual way of doing an unsafe string-to-[]byte conversion is:
+//
+//   var b []byte
+//   bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+//   bh.Data = (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+//   bh.Len = len(s)
+//   bh.Cap = len(s)
+//
+// Unfortunately, as of Go 1.15.3 the inliner's cost model assigns a high enough
+// weight to this sequence of expressions that any function that uses it will
+// not be inlined. Instead, the functions below use a different unsafe
+// conversion designed to minimize the inliner weight and allow both to be
+// inlined. There is also a test (TestInlining) which verifies that these are
+// inlined.
+//
+// See https://github.com/golang/go/issues/42739 for discussion.
+
+// Sum64String computes the 64-bit xxHash digest of s.
+// It may be faster than Sum64([]byte(s)) by avoiding a copy.
+func Sum64String(s string) uint64 {
+	b := *(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)}))
+	return Sum64(b)
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+// It may be faster than Write([]byte(s)) by avoiding a copy.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	d.Write(*(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)})))
+	// d.Write always returns len(s), nil.
+	// Ignoring the return output and returning these fixed values buys a
+	// savings of 6 in the inliner's cost model.
+	return len(s), nil
+}
+
+// sliceHeader is similar to reflect.SliceHeader, but it assumes that the layout
+// of the first two words is the same as the layout of a string.
+type sliceHeader struct {
+	s   string
+	cap int
+}

vendor/github.com/golang/protobuf/AUTHORS

@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.

vendor/github.com/golang/protobuf/CONTRIBUTORS

@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.

vendor/github.com/golang/protobuf/LICENSE

@@ -0,0 +1,28 @@
+Copyright 2010 The Go Authors.  All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+

vendor/github.com/golang/protobuf/proto/buffer.go

@@ -0,0 +1,324 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"errors"
+	"fmt"
+
+	"google.golang.org/protobuf/encoding/prototext"
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+const (
+	WireVarint     = 0
+	WireFixed32    = 5
+	WireFixed64    = 1
+	WireBytes      = 2
+	WireStartGroup = 3
+	WireEndGroup   = 4
+)
+
+// EncodeVarint returns the varint encoded bytes of v.
+func EncodeVarint(v uint64) []byte {
+	return protowire.AppendVarint(nil, v)
+}
+
+// SizeVarint returns the length of the varint encoded bytes of v.
+// This is equal to len(EncodeVarint(v)).
+func SizeVarint(v uint64) int {
+	return protowire.SizeVarint(v)
+}
+
+// DecodeVarint parses a varint encoded integer from b,
+// returning the integer value and the length of the varint.
+// It returns (0, 0) if there is a parse error.
+func DecodeVarint(b []byte) (uint64, int) {
+	v, n := protowire.ConsumeVarint(b)
+	if n < 0 {
+		return 0, 0
+	}
+	return v, n
+}
+
+// Buffer is a buffer for encoding and decoding the protobuf wire format.
+// It may be reused between invocations to reduce memory usage.
+type Buffer struct {
+	buf           []byte
+	idx           int
+	deterministic bool
+}
+
+// NewBuffer allocates a new Buffer initialized with buf,
+// where the contents of buf are considered the unread portion of the buffer.
+func NewBuffer(buf []byte) *Buffer {
+	return &Buffer{buf: buf}
+}
+
+// SetDeterministic specifies whether to use deterministic serialization.
+//
+// Deterministic serialization guarantees that for a given binary, equal
+// messages will always be serialized to the same bytes. This implies:
+//
+//   - Repeated serialization of a message will return the same bytes.
+//   - Different processes of the same binary (which may be executing on
+//     different machines) will serialize equal messages to the same bytes.
+//
+// Note that the deterministic serialization is NOT canonical across
+// languages. It is not guaranteed to remain stable over time. It is unstable
+// across different builds with schema changes due to unknown fields.
+// Users who need canonical serialization (e.g., persistent storage in a
+// canonical form, fingerprinting, etc.) should define their own
+// canonicalization specification and implement their own serializer rather
+// than relying on this API.
+//
+// If deterministic serialization is requested, map entries will be sorted
+// by keys in lexographical order. This is an implementation detail and
+// subject to change.
+func (b *Buffer) SetDeterministic(deterministic bool) {
+	b.deterministic = deterministic
+}
+
+// SetBuf sets buf as the internal buffer,
+// where the contents of buf are considered the unread portion of the buffer.
+func (b *Buffer) SetBuf(buf []byte) {
+	b.buf = buf
+	b.idx = 0
+}
+
+// Reset clears the internal buffer of all written and unread data.
+func (b *Buffer) Reset() {
+	b.buf = b.buf[:0]
+	b.idx = 0
+}
+
+// Bytes returns the internal buffer.
+func (b *Buffer) Bytes() []byte {
+	return b.buf
+}
+
+// Unread returns the unread portion of the buffer.
+func (b *Buffer) Unread() []byte {
+	return b.buf[b.idx:]
+}
+
+// Marshal appends the wire-format encoding of m to the buffer.
+func (b *Buffer) Marshal(m Message) error {
+	var err error
+	b.buf, err = marshalAppend(b.buf, m, b.deterministic)
+	return err
+}
+
+// Unmarshal parses the wire-format message in the buffer and
+// places the decoded results in m.
+// It does not reset m before unmarshaling.
+func (b *Buffer) Unmarshal(m Message) error {
+	err := UnmarshalMerge(b.Unread(), m)
+	b.idx = len(b.buf)
+	return err
+}
+
+type unknownFields struct{ XXX_unrecognized protoimpl.UnknownFields }
+
+func (m *unknownFields) String() string { panic("not implemented") }
+func (m *unknownFields) Reset()         { panic("not implemented") }
+func (m *unknownFields) ProtoMessage()  { panic("not implemented") }
+
+// DebugPrint dumps the encoded bytes of b with a header and footer including s
+// to stdout. This is only intended for debugging.
+func (*Buffer) DebugPrint(s string, b []byte) {
+	m := MessageReflect(new(unknownFields))
+	m.SetUnknown(b)
+	b, _ = prototext.MarshalOptions{AllowPartial: true, Indent: "\t"}.Marshal(m.Interface())
+	fmt.Printf("==== %s ====\n%s==== %s ====\n", s, b, s)
+}
+
+// EncodeVarint appends an unsigned varint encoding to the buffer.
+func (b *Buffer) EncodeVarint(v uint64) error {
+	b.buf = protowire.AppendVarint(b.buf, v)
+	return nil
+}
+
+// EncodeZigzag32 appends a 32-bit zig-zag varint encoding to the buffer.
+func (b *Buffer) EncodeZigzag32(v uint64) error {
+	return b.EncodeVarint(uint64((uint32(v) << 1) ^ uint32((int32(v) >> 31))))
+}
+
+// EncodeZigzag64 appends a 64-bit zig-zag varint encoding to the buffer.
+func (b *Buffer) EncodeZigzag64(v uint64) error {
+	return b.EncodeVarint(uint64((uint64(v) << 1) ^ uint64((int64(v) >> 63))))
+}
+
+// EncodeFixed32 appends a 32-bit little-endian integer to the buffer.
+func (b *Buffer) EncodeFixed32(v uint64) error {
+	b.buf = protowire.AppendFixed32(b.buf, uint32(v))
+	return nil
+}
+
+// EncodeFixed64 appends a 64-bit little-endian integer to the buffer.
+func (b *Buffer) EncodeFixed64(v uint64) error {
+	b.buf = protowire.AppendFixed64(b.buf, uint64(v))
+	return nil
+}
+
+// EncodeRawBytes appends a length-prefixed raw bytes to the buffer.
+func (b *Buffer) EncodeRawBytes(v []byte) error {
+	b.buf = protowire.AppendBytes(b.buf, v)
+	return nil
+}
+
+// EncodeStringBytes appends a length-prefixed raw bytes to the buffer.
+// It does not validate whether v contains valid UTF-8.
+func (b *Buffer) EncodeStringBytes(v string) error {
+	b.buf = protowire.AppendString(b.buf, v)
+	return nil
+}
+
+// EncodeMessage appends a length-prefixed encoded message to the buffer.
+func (b *Buffer) EncodeMessage(m Message) error {
+	var err error
+	b.buf = protowire.AppendVarint(b.buf, uint64(Size(m)))
+	b.buf, err = marshalAppend(b.buf, m, b.deterministic)
+	return err
+}
+
+// DecodeVarint consumes an encoded unsigned varint from the buffer.
+func (b *Buffer) DecodeVarint() (uint64, error) {
+	v, n := protowire.ConsumeVarint(b.buf[b.idx:])
+	if n < 0 {
+		return 0, protowire.ParseError(n)
+	}
+	b.idx += n
+	return uint64(v), nil
+}
+
+// DecodeZigzag32 consumes an encoded 32-bit zig-zag varint from the buffer.
+func (b *Buffer) DecodeZigzag32() (uint64, error) {
+	v, err := b.DecodeVarint()
+	if err != nil {
+		return 0, err
+	}
+	return uint64((uint32(v) >> 1) ^ uint32((int32(v&1)<<31)>>31)), nil
+}
+
+// DecodeZigzag64 consumes an encoded 64-bit zig-zag varint from the buffer.
+func (b *Buffer) DecodeZigzag64() (uint64, error) {
+	v, err := b.DecodeVarint()
+	if err != nil {
+		return 0, err
+	}
+	return uint64((uint64(v) >> 1) ^ uint64((int64(v&1)<<63)>>63)), nil
+}
+
+// DecodeFixed32 consumes a 32-bit little-endian integer from the buffer.
+func (b *Buffer) DecodeFixed32() (uint64, error) {
+	v, n := protowire.ConsumeFixed32(b.buf[b.idx:])
+	if n < 0 {
+		return 0, protowire.ParseError(n)
+	}
+	b.idx += n
+	return uint64(v), nil
+}
+
+// DecodeFixed64 consumes a 64-bit little-endian integer from the buffer.
+func (b *Buffer) DecodeFixed64() (uint64, error) {
+	v, n := protowire.ConsumeFixed64(b.buf[b.idx:])
+	if n < 0 {
+		return 0, protowire.ParseError(n)
+	}
+	b.idx += n
+	return uint64(v), nil
+}
+
+// DecodeRawBytes consumes a length-prefixed raw bytes from the buffer.
+// If alloc is specified, it returns a copy the raw bytes
+// rather than a sub-slice of the buffer.
+func (b *Buffer) DecodeRawBytes(alloc bool) ([]byte, error) {
+	v, n := protowire.ConsumeBytes(b.buf[b.idx:])
+	if n < 0 {
+		return nil, protowire.ParseError(n)
+	}
+	b.idx += n
+	if alloc {
+		v = append([]byte(nil), v...)
+	}
+	return v, nil
+}
+
+// DecodeStringBytes consumes a length-prefixed raw bytes from the buffer.
+// It does not validate whether the raw bytes contain valid UTF-8.
+func (b *Buffer) DecodeStringBytes() (string, error) {
+	v, n := protowire.ConsumeString(b.buf[b.idx:])
+	if n < 0 {
+		return "", protowire.ParseError(n)
+	}
+	b.idx += n
+	return v, nil
+}
+
+// DecodeMessage consumes a length-prefixed message from the buffer.
+// It does not reset m before unmarshaling.
+func (b *Buffer) DecodeMessage(m Message) error {
+	v, err := b.DecodeRawBytes(false)
+	if err != nil {
+		return err
+	}
+	return UnmarshalMerge(v, m)
+}
+
+// DecodeGroup consumes a message group from the buffer.
+// It assumes that the start group marker has already been consumed and
+// consumes all bytes until (and including the end group marker).
+// It does not reset m before unmarshaling.
+func (b *Buffer) DecodeGroup(m Message) error {
+	v, n, err := consumeGroup(b.buf[b.idx:])
+	if err != nil {
+		return err
+	}
+	b.idx += n
+	return UnmarshalMerge(v, m)
+}
+
+// consumeGroup parses b until it finds an end group marker, returning
+// the raw bytes of the message (excluding the end group marker) and the
+// the total length of the message (including the end group marker).
+func consumeGroup(b []byte) ([]byte, int, error) {
+	b0 := b
+	depth := 1 // assume this follows a start group marker
+	for {
+		_, wtyp, tagLen := protowire.ConsumeTag(b)
+		if tagLen < 0 {
+			return nil, 0, protowire.ParseError(tagLen)
+		}
+		b = b[tagLen:]
+
+		var valLen int
+		switch wtyp {
+		case protowire.VarintType:
+			_, valLen = protowire.ConsumeVarint(b)
+		case protowire.Fixed32Type:
+			_, valLen = protowire.ConsumeFixed32(b)
+		case protowire.Fixed64Type:
+			_, valLen = protowire.ConsumeFixed64(b)
+		case protowire.BytesType:
+			_, valLen = protowire.ConsumeBytes(b)
+		case protowire.StartGroupType:
+			depth++
+		case protowire.EndGroupType:
+			depth--
+		default:
+			return nil, 0, errors.New("proto: cannot parse reserved wire type")
+		}
+		if valLen < 0 {
+			return nil, 0, protowire.ParseError(valLen)
+		}
+		b = b[valLen:]
+
+		if depth == 0 {
+			return b0[:len(b0)-len(b)-tagLen], len(b0) - len(b), nil
+		}
+	}
+}

vendor/github.com/golang/protobuf/proto/defaults.go

@@ -0,0 +1,63 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// SetDefaults sets unpopulated scalar fields to their default values.
+// Fields within a oneof are not set even if they have a default value.
+// SetDefaults is recursively called upon any populated message fields.
+func SetDefaults(m Message) {
+	if m != nil {
+		setDefaults(MessageReflect(m))
+	}
+}
+
+func setDefaults(m protoreflect.Message) {
+	fds := m.Descriptor().Fields()
+	for i := 0; i < fds.Len(); i++ {
+		fd := fds.Get(i)
+		if !m.Has(fd) {
+			if fd.HasDefault() && fd.ContainingOneof() == nil {
+				v := fd.Default()
+				if fd.Kind() == protoreflect.BytesKind {
+					v = protoreflect.ValueOf(append([]byte(nil), v.Bytes()...)) // copy the default bytes
+				}
+				m.Set(fd, v)
+			}
+			continue
+		}
+	}
+
+	m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		switch {
+		// Handle singular message.
+		case fd.Cardinality() != protoreflect.Repeated:
+			if fd.Message() != nil {
+				setDefaults(m.Get(fd).Message())
+			}
+		// Handle list of messages.
+		case fd.IsList():
+			if fd.Message() != nil {
+				ls := m.Get(fd).List()
+				for i := 0; i < ls.Len(); i++ {
+					setDefaults(ls.Get(i).Message())
+				}
+			}
+		// Handle map of messages.
+		case fd.IsMap():
+			if fd.MapValue().Message() != nil {
+				ms := m.Get(fd).Map()
+				ms.Range(func(_ protoreflect.MapKey, v protoreflect.Value) bool {
+					setDefaults(v.Message())
+					return true
+				})
+			}
+		}
+		return true
+	})
+}

vendor/github.com/golang/protobuf/proto/deprecated.go

@@ -0,0 +1,113 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strconv"
+
+	protoV2 "google.golang.org/protobuf/proto"
+)
+
+var (
+	// Deprecated: No longer returned.
+	ErrNil = errors.New("proto: Marshal called with nil")
+
+	// Deprecated: No longer returned.
+	ErrTooLarge = errors.New("proto: message encodes to over 2 GB")
+
+	// Deprecated: No longer returned.
+	ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof")
+)
+
+// Deprecated: Do not use.
+type Stats struct{ Emalloc, Dmalloc, Encode, Decode, Chit, Cmiss, Size uint64 }
+
+// Deprecated: Do not use.
+func GetStats() Stats { return Stats{} }
+
+// Deprecated: Do not use.
+func MarshalMessageSet(interface{}) ([]byte, error) {
+	return nil, errors.New("proto: not implemented")
+}
+
+// Deprecated: Do not use.
+func UnmarshalMessageSet([]byte, interface{}) error {
+	return errors.New("proto: not implemented")
+}
+
+// Deprecated: Do not use.
+func MarshalMessageSetJSON(interface{}) ([]byte, error) {
+	return nil, errors.New("proto: not implemented")
+}
+
+// Deprecated: Do not use.
+func UnmarshalMessageSetJSON([]byte, interface{}) error {
+	return errors.New("proto: not implemented")
+}
+
+// Deprecated: Do not use.
+func RegisterMessageSetType(Message, int32, string) {}
+
+// Deprecated: Do not use.
+func EnumName(m map[int32]string, v int32) string {
+	s, ok := m[v]
+	if ok {
+		return s
+	}
+	return strconv.Itoa(int(v))
+}
+
+// Deprecated: Do not use.
+func UnmarshalJSONEnum(m map[string]int32, data []byte, enumName string) (int32, error) {
+	if data[0] == '"' {
+		// New style: enums are strings.
+		var repr string
+		if err := json.Unmarshal(data, &repr); err != nil {
+			return -1, err
+		}
+		val, ok := m[repr]
+		if !ok {
+			return 0, fmt.Errorf("unrecognized enum %s value %q", enumName, repr)
+		}
+		return val, nil
+	}
+	// Old style: enums are ints.
+	var val int32
+	if err := json.Unmarshal(data, &val); err != nil {
+		return 0, fmt.Errorf("cannot unmarshal %#q into enum %s", data, enumName)
+	}
+	return val, nil
+}
+
+// Deprecated: Do not use; this type existed for intenal-use only.
+type InternalMessageInfo struct{}
+
+// Deprecated: Do not use; this method existed for intenal-use only.
+func (*InternalMessageInfo) DiscardUnknown(m Message) {
+	DiscardUnknown(m)
+}
+
+// Deprecated: Do not use; this method existed for intenal-use only.
+func (*InternalMessageInfo) Marshal(b []byte, m Message, deterministic bool) ([]byte, error) {
+	return protoV2.MarshalOptions{Deterministic: deterministic}.MarshalAppend(b, MessageV2(m))
+}
+
+// Deprecated: Do not use; this method existed for intenal-use only.
+func (*InternalMessageInfo) Merge(dst, src Message) {
+	protoV2.Merge(MessageV2(dst), MessageV2(src))
+}
+
+// Deprecated: Do not use; this method existed for intenal-use only.
+func (*InternalMessageInfo) Size(m Message) int {
+	return protoV2.Size(MessageV2(m))
+}
+
+// Deprecated: Do not use; this method existed for intenal-use only.
+func (*InternalMessageInfo) Unmarshal(m Message, b []byte) error {
+	return protoV2.UnmarshalOptions{Merge: true}.Unmarshal(b, MessageV2(m))
+}

vendor/github.com/golang/protobuf/proto/discard.go

@@ -0,0 +1,58 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// DiscardUnknown recursively discards all unknown fields from this message
+// and all embedded messages.
+//
+// When unmarshaling a message with unrecognized fields, the tags and values
+// of such fields are preserved in the Message. This allows a later call to
+// marshal to be able to produce a message that continues to have those
+// unrecognized fields. To avoid this, DiscardUnknown is used to
+// explicitly clear the unknown fields after unmarshaling.
+func DiscardUnknown(m Message) {
+	if m != nil {
+		discardUnknown(MessageReflect(m))
+	}
+}
+
+func discardUnknown(m protoreflect.Message) {
+	m.Range(func(fd protoreflect.FieldDescriptor, val protoreflect.Value) bool {
+		switch {
+		// Handle singular message.
+		case fd.Cardinality() != protoreflect.Repeated:
+			if fd.Message() != nil {
+				discardUnknown(m.Get(fd).Message())
+			}
+		// Handle list of messages.
+		case fd.IsList():
+			if fd.Message() != nil {
+				ls := m.Get(fd).List()
+				for i := 0; i < ls.Len(); i++ {
+					discardUnknown(ls.Get(i).Message())
+				}
+			}
+		// Handle map of messages.
+		case fd.IsMap():
+			if fd.MapValue().Message() != nil {
+				ms := m.Get(fd).Map()
+				ms.Range(func(_ protoreflect.MapKey, v protoreflect.Value) bool {
+					discardUnknown(v.Message())
+					return true
+				})
+			}
+		}
+		return true
+	})
+
+	// Discard unknown fields.
+	if len(m.GetUnknown()) > 0 {
+		m.SetUnknown(nil)
+	}
+}

vendor/github.com/golang/protobuf/proto/extensions.go

@@ -0,0 +1,356 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/runtime/protoiface"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+type (
+	// ExtensionDesc represents an extension descriptor and
+	// is used to interact with an extension field in a message.
+	//
+	// Variables of this type are generated in code by protoc-gen-go.
+	ExtensionDesc = protoimpl.ExtensionInfo
+
+	// ExtensionRange represents a range of message extensions.
+	// Used in code generated by protoc-gen-go.
+	ExtensionRange = protoiface.ExtensionRangeV1
+
+	// Deprecated: Do not use; this is an internal type.
+	Extension = protoimpl.ExtensionFieldV1
+
+	// Deprecated: Do not use; this is an internal type.
+	XXX_InternalExtensions = protoimpl.ExtensionFields
+)
+
+// ErrMissingExtension reports whether the extension was not present.
+var ErrMissingExtension = errors.New("proto: missing extension")
+
+var errNotExtendable = errors.New("proto: not an extendable proto.Message")
+
+// HasExtension reports whether the extension field is present in m
+// either as an explicitly populated field or as an unknown field.
+func HasExtension(m Message, xt *ExtensionDesc) (has bool) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return false
+	}
+
+	// Check whether any populated known field matches the field number.
+	xtd := xt.TypeDescriptor()
+	if isValidExtension(mr.Descriptor(), xtd) {
+		has = mr.Has(xtd)
+	} else {
+		mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+			has = int32(fd.Number()) == xt.Field
+			return !has
+		})
+	}
+
+	// Check whether any unknown field matches the field number.
+	for b := mr.GetUnknown(); !has && len(b) > 0; {
+		num, _, n := protowire.ConsumeField(b)
+		has = int32(num) == xt.Field
+		b = b[n:]
+	}
+	return has
+}
+
+// ClearExtension removes the extension field from m
+// either as an explicitly populated field or as an unknown field.
+func ClearExtension(m Message, xt *ExtensionDesc) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return
+	}
+
+	xtd := xt.TypeDescriptor()
+	if isValidExtension(mr.Descriptor(), xtd) {
+		mr.Clear(xtd)
+	} else {
+		mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+			if int32(fd.Number()) == xt.Field {
+				mr.Clear(fd)
+				return false
+			}
+			return true
+		})
+	}
+	clearUnknown(mr, fieldNum(xt.Field))
+}
+
+// ClearAllExtensions clears all extensions from m.
+// This includes populated fields and unknown fields in the extension range.
+func ClearAllExtensions(m Message) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return
+	}
+
+	mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+		if fd.IsExtension() {
+			mr.Clear(fd)
+		}
+		return true
+	})
+	clearUnknown(mr, mr.Descriptor().ExtensionRanges())
+}
+
+// GetExtension retrieves a proto2 extended field from m.
+//
+// If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
+// then GetExtension parses the encoded field and returns a Go value of the specified type.
+// If the field is not present, then the default value is returned (if one is specified),
+// otherwise ErrMissingExtension is reported.
+//
+// If the descriptor is type incomplete (i.e., ExtensionDesc.ExtensionType is nil),
+// then GetExtension returns the raw encoded bytes for the extension field.
+func GetExtension(m Message, xt *ExtensionDesc) (interface{}, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return nil, errNotExtendable
+	}
+
+	// Retrieve the unknown fields for this extension field.
+	var bo protoreflect.RawFields
+	for bi := mr.GetUnknown(); len(bi) > 0; {
+		num, _, n := protowire.ConsumeField(bi)
+		if int32(num) == xt.Field {
+			bo = append(bo, bi[:n]...)
+		}
+		bi = bi[n:]
+	}
+
+	// For type incomplete descriptors, only retrieve the unknown fields.
+	if xt.ExtensionType == nil {
+		return []byte(bo), nil
+	}
+
+	// If the extension field only exists as unknown fields, unmarshal it.
+	// This is rarely done since proto.Unmarshal eagerly unmarshals extensions.
+	xtd := xt.TypeDescriptor()
+	if !isValidExtension(mr.Descriptor(), xtd) {
+		return nil, fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
+	}
+	if !mr.Has(xtd) && len(bo) > 0 {
+		m2 := mr.New()
+		if err := (proto.UnmarshalOptions{
+			Resolver: extensionResolver{xt},
+		}.Unmarshal(bo, m2.Interface())); err != nil {
+			return nil, err
+		}
+		if m2.Has(xtd) {
+			mr.Set(xtd, m2.Get(xtd))
+			clearUnknown(mr, fieldNum(xt.Field))
+		}
+	}
+
+	// Check whether the message has the extension field set or a default.
+	var pv protoreflect.Value
+	switch {
+	case mr.Has(xtd):
+		pv = mr.Get(xtd)
+	case xtd.HasDefault():
+		pv = xtd.Default()
+	default:
+		return nil, ErrMissingExtension
+	}
+
+	v := xt.InterfaceOf(pv)
+	rv := reflect.ValueOf(v)
+	if isScalarKind(rv.Kind()) {
+		rv2 := reflect.New(rv.Type())
+		rv2.Elem().Set(rv)
+		v = rv2.Interface()
+	}
+	return v, nil
+}
+
+// extensionResolver is a custom extension resolver that stores a single
+// extension type that takes precedence over the global registry.
+type extensionResolver struct{ xt protoreflect.ExtensionType }
+
+func (r extensionResolver) FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) {
+	if xtd := r.xt.TypeDescriptor(); xtd.FullName() == field {
+		return r.xt, nil
+	}
+	return protoregistry.GlobalTypes.FindExtensionByName(field)
+}
+
+func (r extensionResolver) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) {
+	if xtd := r.xt.TypeDescriptor(); xtd.ContainingMessage().FullName() == message && xtd.Number() == field {
+		return r.xt, nil
+	}
+	return protoregistry.GlobalTypes.FindExtensionByNumber(message, field)
+}
+
+// GetExtensions returns a list of the extensions values present in m,
+// corresponding with the provided list of extension descriptors, xts.
+// If an extension is missing in m, the corresponding value is nil.
+func GetExtensions(m Message, xts []*ExtensionDesc) ([]interface{}, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return nil, errNotExtendable
+	}
+
+	vs := make([]interface{}, len(xts))
+	for i, xt := range xts {
+		v, err := GetExtension(m, xt)
+		if err != nil {
+			if err == ErrMissingExtension {
+				continue
+			}
+			return vs, err
+		}
+		vs[i] = v
+	}
+	return vs, nil
+}
+
+// SetExtension sets an extension field in m to the provided value.
+func SetExtension(m Message, xt *ExtensionDesc, v interface{}) error {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return errNotExtendable
+	}
+
+	rv := reflect.ValueOf(v)
+	if reflect.TypeOf(v) != reflect.TypeOf(xt.ExtensionType) {
+		return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", v, xt.ExtensionType)
+	}
+	if rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			return fmt.Errorf("proto: SetExtension called with nil value of type %T", v)
+		}
+		if isScalarKind(rv.Elem().Kind()) {
+			v = rv.Elem().Interface()
+		}
+	}
+
+	xtd := xt.TypeDescriptor()
+	if !isValidExtension(mr.Descriptor(), xtd) {
+		return fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
+	}
+	mr.Set(xtd, xt.ValueOf(v))
+	clearUnknown(mr, fieldNum(xt.Field))
+	return nil
+}
+
+// SetRawExtension inserts b into the unknown fields of m.
+//
+// Deprecated: Use Message.ProtoReflect.SetUnknown instead.
+func SetRawExtension(m Message, fnum int32, b []byte) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return
+	}
+
+	// Verify that the raw field is valid.
+	for b0 := b; len(b0) > 0; {
+		num, _, n := protowire.ConsumeField(b0)
+		if int32(num) != fnum {
+			panic(fmt.Sprintf("mismatching field number: got %d, want %d", num, fnum))
+		}
+		b0 = b0[n:]
+	}
+
+	ClearExtension(m, &ExtensionDesc{Field: fnum})
+	mr.SetUnknown(append(mr.GetUnknown(), b...))
+}
+
+// ExtensionDescs returns a list of extension descriptors found in m,
+// containing descriptors for both populated extension fields in m and
+// also unknown fields of m that are in the extension range.
+// For the later case, an type incomplete descriptor is provided where only
+// the ExtensionDesc.Field field is populated.
+// The order of the extension descriptors is undefined.
+func ExtensionDescs(m Message) ([]*ExtensionDesc, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
+		return nil, errNotExtendable
+	}
+
+	// Collect a set of known extension descriptors.
+	extDescs := make(map[protoreflect.FieldNumber]*ExtensionDesc)
+	mr.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		if fd.IsExtension() {
+			xt := fd.(protoreflect.ExtensionTypeDescriptor)
+			if xd, ok := xt.Type().(*ExtensionDesc); ok {
+				extDescs[fd.Number()] = xd
+			}
+		}
+		return true
+	})
+
+	// Collect a set of unknown extension descriptors.
+	extRanges := mr.Descriptor().ExtensionRanges()
+	for b := mr.GetUnknown(); len(b) > 0; {
+		num, _, n := protowire.ConsumeField(b)
+		if extRanges.Has(num) && extDescs[num] == nil {
+			extDescs[num] = nil
+		}
+		b = b[n:]
+	}
+
+	// Transpose the set of descriptors into a list.
+	var xts []*ExtensionDesc
+	for num, xt := range extDescs {
+		if xt == nil {
+			xt = &ExtensionDesc{Field: int32(num)}
+		}
+		xts = append(xts, xt)
+	}
+	return xts, nil
+}
+
+// isValidExtension reports whether xtd is a valid extension descriptor for md.
+func isValidExtension(md protoreflect.MessageDescriptor, xtd protoreflect.ExtensionTypeDescriptor) bool {
+	return xtd.ContainingMessage() == md && md.ExtensionRanges().Has(xtd.Number())
+}
+
+// isScalarKind reports whether k is a protobuf scalar kind (except bytes).
+// This function exists for historical reasons since the representation of
+// scalars differs between v1 and v2, where v1 uses *T and v2 uses T.
+func isScalarKind(k reflect.Kind) bool {
+	switch k {
+	case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
+		return true
+	default:
+		return false
+	}
+}
+
+// clearUnknown removes unknown fields from m where remover.Has reports true.
+func clearUnknown(m protoreflect.Message, remover interface {
+	Has(protoreflect.FieldNumber) bool
+}) {
+	var bo protoreflect.RawFields
+	for bi := m.GetUnknown(); len(bi) > 0; {
+		num, _, n := protowire.ConsumeField(bi)
+		if !remover.Has(num) {
+			bo = append(bo, bi[:n]...)
+		}
+		bi = bi[n:]
+	}
+	if bi := m.GetUnknown(); len(bi) != len(bo) {
+		m.SetUnknown(bo)
+	}
+}
+
+type fieldNum protoreflect.FieldNumber
+
+func (n1 fieldNum) Has(n2 protoreflect.FieldNumber) bool {
+	return protoreflect.FieldNumber(n1) == n2
+}

vendor/github.com/golang/protobuf/proto/properties.go

@@ -0,0 +1,306 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+// StructProperties represents protocol buffer type information for a
+// generated protobuf message in the open-struct API.
+//
+// Deprecated: Do not use.
+type StructProperties struct {
+	// Prop are the properties for each field.
+	//
+	// Fields belonging to a oneof are stored in OneofTypes instead, with a
+	// single Properties representing the parent oneof held here.
+	//
+	// The order of Prop matches the order of fields in the Go struct.
+	// Struct fields that are not related to protobufs have a "XXX_" prefix
+	// in the Properties.Name and must be ignored by the user.
+	Prop []*Properties
+
+	// OneofTypes contains information about the oneof fields in this message.
+	// It is keyed by the protobuf field name.
+	OneofTypes map[string]*OneofProperties
+}
+
+// Properties represents the type information for a protobuf message field.
+//
+// Deprecated: Do not use.
+type Properties struct {
+	// Name is a placeholder name with little meaningful semantic value.
+	// If the name has an "XXX_" prefix, the entire Properties must be ignored.
+	Name string
+	// OrigName is the protobuf field name or oneof name.
+	OrigName string
+	// JSONName is the JSON name for the protobuf field.
+	JSONName string
+	// Enum is a placeholder name for enums.
+	// For historical reasons, this is neither the Go name for the enum,
+	// nor the protobuf name for the enum.
+	Enum string // Deprecated: Do not use.
+	// Weak contains the full name of the weakly referenced message.
+	Weak string
+	// Wire is a string representation of the wire type.
+	Wire string
+	// WireType is the protobuf wire type for the field.
+	WireType int
+	// Tag is the protobuf field number.
+	Tag int
+	// Required reports whether this is a required field.
+	Required bool
+	// Optional reports whether this is a optional field.
+	Optional bool
+	// Repeated reports whether this is a repeated field.
+	Repeated bool
+	// Packed reports whether this is a packed repeated field of scalars.
+	Packed bool
+	// Proto3 reports whether this field operates under the proto3 syntax.
+	Proto3 bool
+	// Oneof reports whether this field belongs within a oneof.
+	Oneof bool
+
+	// Default is the default value in string form.
+	Default string
+	// HasDefault reports whether the field has a default value.
+	HasDefault bool
+
+	// MapKeyProp is the properties for the key field for a map field.
+	MapKeyProp *Properties
+	// MapValProp is the properties for the value field for a map field.
+	MapValProp *Properties
+}
+
+// OneofProperties represents the type information for a protobuf oneof.
+//
+// Deprecated: Do not use.
+type OneofProperties struct {
+	// Type is a pointer to the generated wrapper type for the field value.
+	// This is nil for messages that are not in the open-struct API.
+	Type reflect.Type
+	// Field is the index into StructProperties.Prop for the containing oneof.
+	Field int
+	// Prop is the properties for the field.
+	Prop *Properties
+}
+
+// String formats the properties in the protobuf struct field tag style.
+func (p *Properties) String() string {
+	s := p.Wire
+	s += "," + strconv.Itoa(p.Tag)
+	if p.Required {
+		s += ",req"
+	}
+	if p.Optional {
+		s += ",opt"
+	}
+	if p.Repeated {
+		s += ",rep"
+	}
+	if p.Packed {
+		s += ",packed"
+	}
+	s += ",name=" + p.OrigName
+	if p.JSONName != "" {
+		s += ",json=" + p.JSONName
+	}
+	if len(p.Enum) > 0 {
+		s += ",enum=" + p.Enum
+	}
+	if len(p.Weak) > 0 {
+		s += ",weak=" + p.Weak
+	}
+	if p.Proto3 {
+		s += ",proto3"
+	}
+	if p.Oneof {
+		s += ",oneof"
+	}
+	if p.HasDefault {
+		s += ",def=" + p.Default
+	}
+	return s
+}
+
+// Parse populates p by parsing a string in the protobuf struct field tag style.
+func (p *Properties) Parse(tag string) {
+	// For example: "bytes,49,opt,name=foo,def=hello!"
+	for len(tag) > 0 {
+		i := strings.IndexByte(tag, ',')
+		if i < 0 {
+			i = len(tag)
+		}
+		switch s := tag[:i]; {
+		case strings.HasPrefix(s, "name="):
+			p.OrigName = s[len("name="):]
+		case strings.HasPrefix(s, "json="):
+			p.JSONName = s[len("json="):]
+		case strings.HasPrefix(s, "enum="):
+			p.Enum = s[len("enum="):]
+		case strings.HasPrefix(s, "weak="):
+			p.Weak = s[len("weak="):]
+		case strings.Trim(s, "0123456789") == "":
+			n, _ := strconv.ParseUint(s, 10, 32)
+			p.Tag = int(n)
+		case s == "opt":
+			p.Optional = true
+		case s == "req":
+			p.Required = true
+		case s == "rep":
+			p.Repeated = true
+		case s == "varint" || s == "zigzag32" || s == "zigzag64":
+			p.Wire = s
+			p.WireType = WireVarint
+		case s == "fixed32":
+			p.Wire = s
+			p.WireType = WireFixed32
+		case s == "fixed64":
+			p.Wire = s
+			p.WireType = WireFixed64
+		case s == "bytes":
+			p.Wire = s
+			p.WireType = WireBytes
+		case s == "group":
+			p.Wire = s
+			p.WireType = WireStartGroup
+		case s == "packed":
+			p.Packed = true
+		case s == "proto3":
+			p.Proto3 = true
+		case s == "oneof":
+			p.Oneof = true
+		case strings.HasPrefix(s, "def="):
+			// The default tag is special in that everything afterwards is the
+			// default regardless of the presence of commas.
+			p.HasDefault = true
+			p.Default, i = tag[len("def="):], len(tag)
+		}
+		tag = strings.TrimPrefix(tag[i:], ",")
+	}
+}
+
+// Init populates the properties from a protocol buffer struct tag.
+//
+// Deprecated: Do not use.
+func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
+	p.Name = name
+	p.OrigName = name
+	if tag == "" {
+		return
+	}
+	p.Parse(tag)
+
+	if typ != nil && typ.Kind() == reflect.Map {
+		p.MapKeyProp = new(Properties)
+		p.MapKeyProp.Init(nil, "Key", f.Tag.Get("protobuf_key"), nil)
+		p.MapValProp = new(Properties)
+		p.MapValProp.Init(nil, "Value", f.Tag.Get("protobuf_val"), nil)
+	}
+}
+
+var propertiesCache sync.Map // map[reflect.Type]*StructProperties
+
+// GetProperties returns the list of properties for the type represented by t,
+// which must be a generated protocol buffer message in the open-struct API,
+// where protobuf message fields are represented by exported Go struct fields.
+//
+// Deprecated: Use protobuf reflection instead.
+func GetProperties(t reflect.Type) *StructProperties {
+	if p, ok := propertiesCache.Load(t); ok {
+		return p.(*StructProperties)
+	}
+	p, _ := propertiesCache.LoadOrStore(t, newProperties(t))
+	return p.(*StructProperties)
+}
+
+func newProperties(t reflect.Type) *StructProperties {
+	if t.Kind() != reflect.Struct {
+		panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
+	}
+
+	var hasOneof bool
+	prop := new(StructProperties)
+
+	// Construct a list of properties for each field in the struct.
+	for i := 0; i < t.NumField(); i++ {
+		p := new(Properties)
+		f := t.Field(i)
+		tagField := f.Tag.Get("protobuf")
+		p.Init(f.Type, f.Name, tagField, &f)
+
+		tagOneof := f.Tag.Get("protobuf_oneof")
+		if tagOneof != "" {
+			hasOneof = true
+			p.OrigName = tagOneof
+		}
+
+		// Rename unrelated struct fields with the "XXX_" prefix since so much
+		// user code simply checks for this to exclude special fields.
+		if tagField == "" && tagOneof == "" && !strings.HasPrefix(p.Name, "XXX_") {
+			p.Name = "XXX_" + p.Name
+			p.OrigName = "XXX_" + p.OrigName
+		} else if p.Weak != "" {
+			p.Name = p.OrigName // avoid possible "XXX_" prefix on weak field
+		}
+
+		prop.Prop = append(prop.Prop, p)
+	}
+
+	// Construct a mapping of oneof field names to properties.
+	if hasOneof {
+		var oneofWrappers []interface{}
+		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofFuncs"); ok {
+			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[3].Interface().([]interface{})
+		}
+		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofWrappers"); ok {
+			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0].Interface().([]interface{})
+		}
+		if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(protoreflect.ProtoMessage); ok {
+			if m, ok := m.ProtoReflect().(interface{ ProtoMessageInfo() *protoimpl.MessageInfo }); ok {
+				oneofWrappers = m.ProtoMessageInfo().OneofWrappers
+			}
+		}
+
+		prop.OneofTypes = make(map[string]*OneofProperties)
+		for _, wrapper := range oneofWrappers {
+			p := &OneofProperties{
+				Type: reflect.ValueOf(wrapper).Type(), // *T
+				Prop: new(Properties),
+			}
+			f := p.Type.Elem().Field(0)
+			p.Prop.Name = f.Name
+			p.Prop.Parse(f.Tag.Get("protobuf"))
+
+			// Determine the struct field that contains this oneof.
+			// Each wrapper is assignable to exactly one parent field.
+			var foundOneof bool
+			for i := 0; i < t.NumField() && !foundOneof; i++ {
+				if p.Type.AssignableTo(t.Field(i).Type) {
+					p.Field = i
+					foundOneof = true
+				}
+			}
+			if !foundOneof {
+				panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
+			}
+			prop.OneofTypes[p.Prop.OrigName] = p
+		}
+	}
+
+	return prop
+}
+
+func (sp *StructProperties) Len() int           { return len(sp.Prop) }
+func (sp *StructProperties) Less(i, j int) bool { return false }
+func (sp *StructProperties) Swap(i, j int)      { return }

vendor/github.com/golang/protobuf/proto/proto.go

@@ -0,0 +1,167 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package proto provides functionality for handling protocol buffer messages.
+// In particular, it provides marshaling and unmarshaling between a protobuf
+// message and the binary wire format.
+//
+// See https://developers.google.com/protocol-buffers/docs/gotutorial for
+// more information.
+//
+// Deprecated: Use the "google.golang.org/protobuf/proto" package instead.
+package proto
+
+import (
+	protoV2 "google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/runtime/protoiface"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+const (
+	ProtoPackageIsVersion1 = true
+	ProtoPackageIsVersion2 = true
+	ProtoPackageIsVersion3 = true
+	ProtoPackageIsVersion4 = true
+)
+
+// GeneratedEnum is any enum type generated by protoc-gen-go
+// which is a named int32 kind.
+// This type exists for documentation purposes.
+type GeneratedEnum interface{}
+
+// GeneratedMessage is any message type generated by protoc-gen-go
+// which is a pointer to a named struct kind.
+// This type exists for documentation purposes.
+type GeneratedMessage interface{}
+
+// Message is a protocol buffer message.
+//
+// This is the v1 version of the message interface and is marginally better
+// than an empty interface as it lacks any method to programatically interact
+// with the contents of the message.
+//
+// A v2 message is declared in "google.golang.org/protobuf/proto".Message and
+// exposes protobuf reflection as a first-class feature of the interface.
+//
+// To convert a v1 message to a v2 message, use the MessageV2 function.
+// To convert a v2 message to a v1 message, use the MessageV1 function.
+type Message = protoiface.MessageV1
+
+// MessageV1 converts either a v1 or v2 message to a v1 message.
+// It returns nil if m is nil.
+func MessageV1(m GeneratedMessage) protoiface.MessageV1 {
+	return protoimpl.X.ProtoMessageV1Of(m)
+}
+
+// MessageV2 converts either a v1 or v2 message to a v2 message.
+// It returns nil if m is nil.
+func MessageV2(m GeneratedMessage) protoV2.Message {
+	return protoimpl.X.ProtoMessageV2Of(m)
+}
+
+// MessageReflect returns a reflective view for a message.
+// It returns nil if m is nil.
+func MessageReflect(m Message) protoreflect.Message {
+	return protoimpl.X.MessageOf(m)
+}
+
+// Marshaler is implemented by messages that can marshal themselves.
+// This interface is used by the following functions: Size, Marshal,
+// Buffer.Marshal, and Buffer.EncodeMessage.
+//
+// Deprecated: Do not implement.
+type Marshaler interface {
+	// Marshal formats the encoded bytes of the message.
+	// It should be deterministic and emit valid protobuf wire data.
+	// The caller takes ownership of the returned buffer.
+	Marshal() ([]byte, error)
+}
+
+// Unmarshaler is implemented by messages that can unmarshal themselves.
+// This interface is used by the following functions: Unmarshal, UnmarshalMerge,
+// Buffer.Unmarshal, Buffer.DecodeMessage, and Buffer.DecodeGroup.
+//
+// Deprecated: Do not implement.
+type Unmarshaler interface {
+	// Unmarshal parses the encoded bytes of the protobuf wire input.
+	// The provided buffer is only valid for during method call.
+	// It should not reset the receiver message.
+	Unmarshal([]byte) error
+}
+
+// Merger is implemented by messages that can merge themselves.
+// This interface is used by the following functions: Clone and Merge.
+//
+// Deprecated: Do not implement.
+type Merger interface {
+	// Merge merges the contents of src into the receiver message.
+	// It clones all data structures in src such that it aliases no mutable
+	// memory referenced by src.
+	Merge(src Message)
+}
+
+// RequiredNotSetError is an error type returned when
+// marshaling or unmarshaling a message with missing required fields.
+type RequiredNotSetError struct {
+	err error
+}
+
+func (e *RequiredNotSetError) Error() string {
+	if e.err != nil {
+		return e.err.Error()
+	}
+	return "proto: required field not set"
+}
+func (e *RequiredNotSetError) RequiredNotSet() bool {
+	return true
+}
+
+func checkRequiredNotSet(m protoV2.Message) error {
+	if err := protoV2.CheckInitialized(m); err != nil {
+		return &RequiredNotSetError{err: err}
+	}
+	return nil
+}
+
+// Clone returns a deep copy of src.
+func Clone(src Message) Message {
+	return MessageV1(protoV2.Clone(MessageV2(src)))
+}
+
+// Merge merges src into dst, which must be messages of the same type.
+//
+// Populated scalar fields in src are copied to dst, while populated
+// singular messages in src are merged into dst by recursively calling Merge.
+// The elements of every list field in src is appended to the corresponded
+// list fields in dst. The entries of every map field in src is copied into
+// the corresponding map field in dst, possibly replacing existing entries.
+// The unknown fields of src are appended to the unknown fields of dst.
+func Merge(dst, src Message) {
+	protoV2.Merge(MessageV2(dst), MessageV2(src))
+}
+
+// Equal reports whether two messages are equal.
+// If two messages marshal to the same bytes under deterministic serialization,
+// then Equal is guaranteed to report true.
+//
+// Two messages are equal if they are the same protobuf message type,
+// have the same set of populated known and extension field values,
+// and the same set of unknown fields values.
+//
+// Scalar values are compared with the equivalent of the == operator in Go,
+// except bytes values which are compared using bytes.Equal and
+// floating point values which specially treat NaNs as equal.
+// Message values are compared by recursively calling Equal.
+// Lists are equal if each element value is also equal.
+// Maps are equal if they have the same set of keys, where the pair of values
+// for each key is also equal.
+func Equal(x, y Message) bool {
+	return protoV2.Equal(MessageV2(x), MessageV2(y))
+}
+
+func isMessageSet(md protoreflect.MessageDescriptor) bool {
+	ms, ok := md.(interface{ IsMessageSet() bool })
+	return ok && ms.IsMessageSet()
+}

vendor/github.com/golang/protobuf/proto/registry.go

@@ -0,0 +1,317 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io/ioutil"
+	"reflect"
+	"strings"
+	"sync"
+
+	"google.golang.org/protobuf/reflect/protodesc"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+// filePath is the path to the proto source file.
+type filePath = string // e.g., "google/protobuf/descriptor.proto"
+
+// fileDescGZIP is the compressed contents of the encoded FileDescriptorProto.
+type fileDescGZIP = []byte
+
+var fileCache sync.Map // map[filePath]fileDescGZIP
+
+// RegisterFile is called from generated code to register the compressed
+// FileDescriptorProto with the file path for a proto source file.
+//
+// Deprecated: Use protoregistry.GlobalFiles.RegisterFile instead.
+func RegisterFile(s filePath, d fileDescGZIP) {
+	// Decompress the descriptor.
+	zr, err := gzip.NewReader(bytes.NewReader(d))
+	if err != nil {
+		panic(fmt.Sprintf("proto: invalid compressed file descriptor: %v", err))
+	}
+	b, err := ioutil.ReadAll(zr)
+	if err != nil {
+		panic(fmt.Sprintf("proto: invalid compressed file descriptor: %v", err))
+	}
+
+	// Construct a protoreflect.FileDescriptor from the raw descriptor.
+	// Note that DescBuilder.Build automatically registers the constructed
+	// file descriptor with the v2 registry.
+	protoimpl.DescBuilder{RawDescriptor: b}.Build()
+
+	// Locally cache the raw descriptor form for the file.
+	fileCache.Store(s, d)
+}
+
+// FileDescriptor returns the compressed FileDescriptorProto given the file path
+// for a proto source file. It returns nil if not found.
+//
+// Deprecated: Use protoregistry.GlobalFiles.FindFileByPath instead.
+func FileDescriptor(s filePath) fileDescGZIP {
+	if v, ok := fileCache.Load(s); ok {
+		return v.(fileDescGZIP)
+	}
+
+	// Find the descriptor in the v2 registry.
+	var b []byte
+	if fd, _ := protoregistry.GlobalFiles.FindFileByPath(s); fd != nil {
+		b, _ = Marshal(protodesc.ToFileDescriptorProto(fd))
+	}
+
+	// Locally cache the raw descriptor form for the file.
+	if len(b) > 0 {
+		v, _ := fileCache.LoadOrStore(s, protoimpl.X.CompressGZIP(b))
+		return v.(fileDescGZIP)
+	}
+	return nil
+}
+
+// enumName is the name of an enum. For historical reasons, the enum name is
+// neither the full Go name nor the full protobuf name of the enum.
+// The name is the dot-separated combination of just the proto package that the
+// enum is declared within followed by the Go type name of the generated enum.
+type enumName = string // e.g., "my.proto.package.GoMessage_GoEnum"
+
+// enumsByName maps enum values by name to their numeric counterpart.
+type enumsByName = map[string]int32
+
+// enumsByNumber maps enum values by number to their name counterpart.
+type enumsByNumber = map[int32]string
+
+var enumCache sync.Map     // map[enumName]enumsByName
+var numFilesCache sync.Map // map[protoreflect.FullName]int
+
+// RegisterEnum is called from the generated code to register the mapping of
+// enum value names to enum numbers for the enum identified by s.
+//
+// Deprecated: Use protoregistry.GlobalTypes.RegisterEnum instead.
+func RegisterEnum(s enumName, _ enumsByNumber, m enumsByName) {
+	if _, ok := enumCache.Load(s); ok {
+		panic("proto: duplicate enum registered: " + s)
+	}
+	enumCache.Store(s, m)
+
+	// This does not forward registration to the v2 registry since this API
+	// lacks sufficient information to construct a complete v2 enum descriptor.
+}
+
+// EnumValueMap returns the mapping from enum value names to enum numbers for
+// the enum of the given name. It returns nil if not found.
+//
+// Deprecated: Use protoregistry.GlobalTypes.FindEnumByName instead.
+func EnumValueMap(s enumName) enumsByName {
+	if v, ok := enumCache.Load(s); ok {
+		return v.(enumsByName)
+	}
+
+	// Check whether the cache is stale. If the number of files in the current
+	// package differs, then it means that some enums may have been recently
+	// registered upstream that we do not know about.
+	var protoPkg protoreflect.FullName
+	if i := strings.LastIndexByte(s, '.'); i >= 0 {
+		protoPkg = protoreflect.FullName(s[:i])
+	}
+	v, _ := numFilesCache.Load(protoPkg)
+	numFiles, _ := v.(int)
+	if protoregistry.GlobalFiles.NumFilesByPackage(protoPkg) == numFiles {
+		return nil // cache is up-to-date; was not found earlier
+	}
+
+	// Update the enum cache for all enums declared in the given proto package.
+	numFiles = 0
+	protoregistry.GlobalFiles.RangeFilesByPackage(protoPkg, func(fd protoreflect.FileDescriptor) bool {
+		walkEnums(fd, func(ed protoreflect.EnumDescriptor) {
+			name := protoimpl.X.LegacyEnumName(ed)
+			if _, ok := enumCache.Load(name); !ok {
+				m := make(enumsByName)
+				evs := ed.Values()
+				for i := evs.Len() - 1; i >= 0; i-- {
+					ev := evs.Get(i)
+					m[string(ev.Name())] = int32(ev.Number())
+				}
+				enumCache.LoadOrStore(name, m)
+			}
+		})
+		numFiles++
+		return true
+	})
+	numFilesCache.Store(protoPkg, numFiles)
+
+	// Check cache again for enum map.
+	if v, ok := enumCache.Load(s); ok {
+		return v.(enumsByName)
+	}
+	return nil
+}
+
+// walkEnums recursively walks all enums declared in d.
+func walkEnums(d interface {
+	Enums() protoreflect.EnumDescriptors
+	Messages() protoreflect.MessageDescriptors
+}, f func(protoreflect.EnumDescriptor)) {
+	eds := d.Enums()
+	for i := eds.Len() - 1; i >= 0; i-- {
+		f(eds.Get(i))
+	}
+	mds := d.Messages()
+	for i := mds.Len() - 1; i >= 0; i-- {
+		walkEnums(mds.Get(i), f)
+	}
+}
+
+// messageName is the full name of protobuf message.
+type messageName = string
+
+var messageTypeCache sync.Map // map[messageName]reflect.Type
+
+// RegisterType is called from generated code to register the message Go type
+// for a message of the given name.
+//
+// Deprecated: Use protoregistry.GlobalTypes.RegisterMessage instead.
+func RegisterType(m Message, s messageName) {
+	mt := protoimpl.X.LegacyMessageTypeOf(m, protoreflect.FullName(s))
+	if err := protoregistry.GlobalTypes.RegisterMessage(mt); err != nil {
+		panic(err)
+	}
+	messageTypeCache.Store(s, reflect.TypeOf(m))
+}
+
+// RegisterMapType is called from generated code to register the Go map type
+// for a protobuf message representing a map entry.
+//
+// Deprecated: Do not use.
+func RegisterMapType(m interface{}, s messageName) {
+	t := reflect.TypeOf(m)
+	if t.Kind() != reflect.Map {
+		panic(fmt.Sprintf("invalid map kind: %v", t))
+	}
+	if _, ok := messageTypeCache.Load(s); ok {
+		panic(fmt.Errorf("proto: duplicate proto message registered: %s", s))
+	}
+	messageTypeCache.Store(s, t)
+}
+
+// MessageType returns the message type for a named message.
+// It returns nil if not found.
+//
+// Deprecated: Use protoregistry.GlobalTypes.FindMessageByName instead.
+func MessageType(s messageName) reflect.Type {
+	if v, ok := messageTypeCache.Load(s); ok {
+		return v.(reflect.Type)
+	}
+
+	// Derive the message type from the v2 registry.
+	var t reflect.Type
+	if mt, _ := protoregistry.GlobalTypes.FindMessageByName(protoreflect.FullName(s)); mt != nil {
+		t = messageGoType(mt)
+	}
+
+	// If we could not get a concrete type, it is possible that it is a
+	// pseudo-message for a map entry.
+	if t == nil {
+		d, _ := protoregistry.GlobalFiles.FindDescriptorByName(protoreflect.FullName(s))
+		if md, _ := d.(protoreflect.MessageDescriptor); md != nil && md.IsMapEntry() {
+			kt := goTypeForField(md.Fields().ByNumber(1))
+			vt := goTypeForField(md.Fields().ByNumber(2))
+			t = reflect.MapOf(kt, vt)
+		}
+	}
+
+	// Locally cache the message type for the given name.
+	if t != nil {
+		v, _ := messageTypeCache.LoadOrStore(s, t)
+		return v.(reflect.Type)
+	}
+	return nil
+}
+
+func goTypeForField(fd protoreflect.FieldDescriptor) reflect.Type {
+	switch k := fd.Kind(); k {
+	case protoreflect.EnumKind:
+		if et, _ := protoregistry.GlobalTypes.FindEnumByName(fd.Enum().FullName()); et != nil {
+			return enumGoType(et)
+		}
+		return reflect.TypeOf(protoreflect.EnumNumber(0))
+	case protoreflect.MessageKind, protoreflect.GroupKind:
+		if mt, _ := protoregistry.GlobalTypes.FindMessageByName(fd.Message().FullName()); mt != nil {
+			return messageGoType(mt)
+		}
+		return reflect.TypeOf((*protoreflect.Message)(nil)).Elem()
+	default:
+		return reflect.TypeOf(fd.Default().Interface())
+	}
+}
+
+func enumGoType(et protoreflect.EnumType) reflect.Type {
+	return reflect.TypeOf(et.New(0))
+}
+
+func messageGoType(mt protoreflect.MessageType) reflect.Type {
+	return reflect.TypeOf(MessageV1(mt.Zero().Interface()))
+}
+
+// MessageName returns the full protobuf name for the given message type.
+//
+// Deprecated: Use protoreflect.MessageDescriptor.FullName instead.
+func MessageName(m Message) messageName {
+	if m == nil {
+		return ""
+	}
+	if m, ok := m.(interface{ XXX_MessageName() messageName }); ok {
+		return m.XXX_MessageName()
+	}
+	return messageName(protoimpl.X.MessageDescriptorOf(m).FullName())
+}
+
+// RegisterExtension is called from the generated code to register
+// the extension descriptor.
+//
+// Deprecated: Use protoregistry.GlobalTypes.RegisterExtension instead.
+func RegisterExtension(d *ExtensionDesc) {
+	if err := protoregistry.GlobalTypes.RegisterExtension(d); err != nil {
+		panic(err)
+	}
+}
+
+type extensionsByNumber = map[int32]*ExtensionDesc
+
+var extensionCache sync.Map // map[messageName]extensionsByNumber
+
+// RegisteredExtensions returns a map of the registered extensions for the
+// provided protobuf message, indexed by the extension field number.
+//
+// Deprecated: Use protoregistry.GlobalTypes.RangeExtensionsByMessage instead.
+func RegisteredExtensions(m Message) extensionsByNumber {
+	// Check whether the cache is stale. If the number of extensions for
+	// the given message differs, then it means that some extensions were
+	// recently registered upstream that we do not know about.
+	s := MessageName(m)
+	v, _ := extensionCache.Load(s)
+	xs, _ := v.(extensionsByNumber)
+	if protoregistry.GlobalTypes.NumExtensionsByMessage(protoreflect.FullName(s)) == len(xs) {
+		return xs // cache is up-to-date
+	}
+
+	// Cache is stale, re-compute the extensions map.
+	xs = make(extensionsByNumber)
+	protoregistry.GlobalTypes.RangeExtensionsByMessage(protoreflect.FullName(s), func(xt protoreflect.ExtensionType) bool {
+		if xd, ok := xt.(*ExtensionDesc); ok {
+			xs[int32(xt.TypeDescriptor().Number())] = xd
+		} else {
+			// TODO: This implies that the protoreflect.ExtensionType is a
+			// custom type not generated by protoc-gen-go. We could try and
+			// convert the type to an ExtensionDesc.
+		}
+		return true
+	})
+	extensionCache.Store(s, xs)
+	return xs
+}

vendor/github.com/golang/protobuf/proto/text_decode.go

@@ -0,0 +1,801 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+
+	"google.golang.org/protobuf/encoding/prototext"
+	protoV2 "google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+)
+
+const wrapTextUnmarshalV2 = false
+
+// ParseError is returned by UnmarshalText.
+type ParseError struct {
+	Message string
+
+	// Deprecated: Do not use.
+	Line, Offset int
+}
+
+func (e *ParseError) Error() string {
+	if wrapTextUnmarshalV2 {
+		return e.Message
+	}
+	if e.Line == 1 {
+		return fmt.Sprintf("line 1.%d: %v", e.Offset, e.Message)
+	}
+	return fmt.Sprintf("line %d: %v", e.Line, e.Message)
+}
+
+// UnmarshalText parses a proto text formatted string into m.
+func UnmarshalText(s string, m Message) error {
+	if u, ok := m.(encoding.TextUnmarshaler); ok {
+		return u.UnmarshalText([]byte(s))
+	}
+
+	m.Reset()
+	mi := MessageV2(m)
+
+	if wrapTextUnmarshalV2 {
+		err := prototext.UnmarshalOptions{
+			AllowPartial: true,
+		}.Unmarshal([]byte(s), mi)
+		if err != nil {
+			return &ParseError{Message: err.Error()}
+		}
+		return checkRequiredNotSet(mi)
+	} else {
+		if err := newTextParser(s).unmarshalMessage(mi.ProtoReflect(), ""); err != nil {
+			return err
+		}
+		return checkRequiredNotSet(mi)
+	}
+}
+
+type textParser struct {
+	s            string // remaining input
+	done         bool   // whether the parsing is finished (success or error)
+	backed       bool   // whether back() was called
+	offset, line int
+	cur          token
+}
+
+type token struct {
+	value    string
+	err      *ParseError
+	line     int    // line number
+	offset   int    // byte number from start of input, not start of line
+	unquoted string // the unquoted version of value, if it was a quoted string
+}
+
+func newTextParser(s string) *textParser {
+	p := new(textParser)
+	p.s = s
+	p.line = 1
+	p.cur.line = 1
+	return p
+}
+
+func (p *textParser) unmarshalMessage(m protoreflect.Message, terminator string) (err error) {
+	md := m.Descriptor()
+	fds := md.Fields()
+
+	// A struct is a sequence of "name: value", terminated by one of
+	// '>' or '}', or the end of the input.  A name may also be
+	// "[extension]" or "[type/url]".
+	//
+	// The whole struct can also be an expanded Any message, like:
+	// [type/url] < ... struct contents ... >
+	seen := make(map[protoreflect.FieldNumber]bool)
+	for {
+		tok := p.next()
+		if tok.err != nil {
+			return tok.err
+		}
+		if tok.value == terminator {
+			break
+		}
+		if tok.value == "[" {
+			if err := p.unmarshalExtensionOrAny(m, seen); err != nil {
+				return err
+			}
+			continue
+		}
+
+		// This is a normal, non-extension field.
+		name := protoreflect.Name(tok.value)
+		fd := fds.ByName(name)
+		switch {
+		case fd == nil:
+			gd := fds.ByName(protoreflect.Name(strings.ToLower(string(name))))
+			if gd != nil && gd.Kind() == protoreflect.GroupKind && gd.Message().Name() == name {
+				fd = gd
+			}
+		case fd.Kind() == protoreflect.GroupKind && fd.Message().Name() != name:
+			fd = nil
+		case fd.IsWeak() && fd.Message().IsPlaceholder():
+			fd = nil
+		}
+		if fd == nil {
+			typeName := string(md.FullName())
+			if m, ok := m.Interface().(Message); ok {
+				t := reflect.TypeOf(m)
+				if t.Kind() == reflect.Ptr {
+					typeName = t.Elem().String()
+				}
+			}
+			return p.errorf("unknown field name %q in %v", name, typeName)
+		}
+		if od := fd.ContainingOneof(); od != nil && m.WhichOneof(od) != nil {
+			return p.errorf("field '%s' would overwrite already parsed oneof '%s'", name, od.Name())
+		}
+		if fd.Cardinality() != protoreflect.Repeated && seen[fd.Number()] {
+			return p.errorf("non-repeated field %q was repeated", fd.Name())
+		}
+		seen[fd.Number()] = true
+
+		// Consume any colon.
+		if err := p.checkForColon(fd); err != nil {
+			return err
+		}
+
+		// Parse into the field.
+		v := m.Get(fd)
+		if !m.Has(fd) && (fd.IsList() || fd.IsMap() || fd.Message() != nil) {
+			v = m.Mutable(fd)
+		}
+		if v, err = p.unmarshalValue(v, fd); err != nil {
+			return err
+		}
+		m.Set(fd, v)
+
+		if err := p.consumeOptionalSeparator(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (p *textParser) unmarshalExtensionOrAny(m protoreflect.Message, seen map[protoreflect.FieldNumber]bool) error {
+	name, err := p.consumeExtensionOrAnyName()
+	if err != nil {
+		return err
+	}
+
+	// If it contains a slash, it's an Any type URL.
+	if slashIdx := strings.LastIndex(name, "/"); slashIdx >= 0 {
+		tok := p.next()
+		if tok.err != nil {
+			return tok.err
+		}
+		// consume an optional colon
+		if tok.value == ":" {
+			tok = p.next()
+			if tok.err != nil {
+				return tok.err
+			}
+		}
+
+		var terminator string
+		switch tok.value {
+		case "<":
+			terminator = ">"
+		case "{":
+			terminator = "}"
+		default:
+			return p.errorf("expected '{' or '<', found %q", tok.value)
+		}
+
+		mt, err := protoregistry.GlobalTypes.FindMessageByURL(name)
+		if err != nil {
+			return p.errorf("unrecognized message %q in google.protobuf.Any", name[slashIdx+len("/"):])
+		}
+		m2 := mt.New()
+		if err := p.unmarshalMessage(m2, terminator); err != nil {
+			return err
+		}
+		b, err := protoV2.Marshal(m2.Interface())
+		if err != nil {
+			return p.errorf("failed to marshal message of type %q: %v", name[slashIdx+len("/"):], err)
+		}
+
+		urlFD := m.Descriptor().Fields().ByName("type_url")
+		valFD := m.Descriptor().Fields().ByName("value")
+		if seen[urlFD.Number()] {
+			return p.errorf("Any message unpacked multiple times, or %q already set", urlFD.Name())
+		}
+		if seen[valFD.Number()] {
+			return p.errorf("Any message unpacked multiple times, or %q already set", valFD.Name())
+		}
+		m.Set(urlFD, protoreflect.ValueOfString(name))
+		m.Set(valFD, protoreflect.ValueOfBytes(b))
+		seen[urlFD.Number()] = true
+		seen[valFD.Number()] = true
+		return nil
+	}
+
+	xname := protoreflect.FullName(name)
+	xt, _ := protoregistry.GlobalTypes.FindExtensionByName(xname)
+	if xt == nil && isMessageSet(m.Descriptor()) {
+		xt, _ = protoregistry.GlobalTypes.FindExtensionByName(xname.Append("message_set_extension"))
+	}
+	if xt == nil {
+		return p.errorf("unrecognized extension %q", name)
+	}
+	fd := xt.TypeDescriptor()
+	if fd.ContainingMessage().FullName() != m.Descriptor().FullName() {
+		return p.errorf("extension field %q does not extend message %q", name, m.Descriptor().FullName())
+	}
+
+	if err := p.checkForColon(fd); err != nil {
+		return err
+	}
+
+	v := m.Get(fd)
+	if !m.Has(fd) && (fd.IsList() || fd.IsMap() || fd.Message() != nil) {
+		v = m.Mutable(fd)
+	}
+	v, err = p.unmarshalValue(v, fd)
+	if err != nil {
+		return err
+	}
+	m.Set(fd, v)
+	return p.consumeOptionalSeparator()
+}
+
+func (p *textParser) unmarshalValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
+	tok := p.next()
+	if tok.err != nil {
+		return v, tok.err
+	}
+	if tok.value == "" {
+		return v, p.errorf("unexpected EOF")
+	}
+
+	switch {
+	case fd.IsList():
+		lv := v.List()
+		var err error
+		if tok.value == "[" {
+			// Repeated field with list notation, like [1,2,3].
+			for {
+				vv := lv.NewElement()
+				vv, err = p.unmarshalSingularValue(vv, fd)
+				if err != nil {
+					return v, err
+				}
+				lv.Append(vv)
+
+				tok := p.next()
+				if tok.err != nil {
+					return v, tok.err
+				}
+				if tok.value == "]" {
+					break
+				}
+				if tok.value != "," {
+					return v, p.errorf("Expected ']' or ',' found %q", tok.value)
+				}
+			}
+			return v, nil
+		}
+
+		// One value of the repeated field.
+		p.back()
+		vv := lv.NewElement()
+		vv, err = p.unmarshalSingularValue(vv, fd)
+		if err != nil {
+			return v, err
+		}
+		lv.Append(vv)
+		return v, nil
+	case fd.IsMap():
+		// The map entry should be this sequence of tokens:
+		//	< key : KEY value : VALUE >
+		// However, implementations may omit key or value, and technically
+		// we should support them in any order.
+		var terminator string
+		switch tok.value {
+		case "<":
+			terminator = ">"
+		case "{":
+			terminator = "}"
+		default:
+			return v, p.errorf("expected '{' or '<', found %q", tok.value)
+		}
+
+		keyFD := fd.MapKey()
+		valFD := fd.MapValue()
+
+		mv := v.Map()
+		kv := keyFD.Default()
+		vv := mv.NewValue()
+		for {
+			tok := p.next()
+			if tok.err != nil {
+				return v, tok.err
+			}
+			if tok.value == terminator {
+				break
+			}
+			var err error
+			switch tok.value {
+			case "key":
+				if err := p.consumeToken(":"); err != nil {
+					return v, err
+				}
+				if kv, err = p.unmarshalSingularValue(kv, keyFD); err != nil {
+					return v, err
+				}
+				if err := p.consumeOptionalSeparator(); err != nil {
+					return v, err
+				}
+			case "value":
+				if err := p.checkForColon(valFD); err != nil {
+					return v, err
+				}
+				if vv, err = p.unmarshalSingularValue(vv, valFD); err != nil {
+					return v, err
+				}
+				if err := p.consumeOptionalSeparator(); err != nil {
+					return v, err
+				}
+			default:
+				p.back()
+				return v, p.errorf(`expected "key", "value", or %q, found %q`, terminator, tok.value)
+			}
+		}
+		mv.Set(kv.MapKey(), vv)
+		return v, nil
+	default:
+		p.back()
+		return p.unmarshalSingularValue(v, fd)
+	}
+}
+
+func (p *textParser) unmarshalSingularValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
+	tok := p.next()
+	if tok.err != nil {
+		return v, tok.err
+	}
+	if tok.value == "" {
+		return v, p.errorf("unexpected EOF")
+	}
+
+	switch fd.Kind() {
+	case protoreflect.BoolKind:
+		switch tok.value {
+		case "true", "1", "t", "True":
+			return protoreflect.ValueOfBool(true), nil
+		case "false", "0", "f", "False":
+			return protoreflect.ValueOfBool(false), nil
+		}
+	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
+		if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
+			return protoreflect.ValueOfInt32(int32(x)), nil
+		}
+
+		// The C++ parser accepts large positive hex numbers that uses
+		// two's complement arithmetic to represent negative numbers.
+		// This feature is here for backwards compatibility with C++.
+		if strings.HasPrefix(tok.value, "0x") {
+			if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
+				return protoreflect.ValueOfInt32(int32(-(int64(^x) + 1))), nil
+			}
+		}
+	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
+		if x, err := strconv.ParseInt(tok.value, 0, 64); err == nil {
+			return protoreflect.ValueOfInt64(int64(x)), nil
+		}
+
+		// The C++ parser accepts large positive hex numbers that uses
+		// two's complement arithmetic to represent negative numbers.
+		// This feature is here for backwards compatibility with C++.
+		if strings.HasPrefix(tok.value, "0x") {
+			if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
+				return protoreflect.ValueOfInt64(int64(-(int64(^x) + 1))), nil
+			}
+		}
+	case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
+		if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
+			return protoreflect.ValueOfUint32(uint32(x)), nil
+		}
+	case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
+		if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
+			return protoreflect.ValueOfUint64(uint64(x)), nil
+		}
+	case protoreflect.FloatKind:
+		// Ignore 'f' for compatibility with output generated by C++,
+		// but don't remove 'f' when the value is "-inf" or "inf".
+		v := tok.value
+		if strings.HasSuffix(v, "f") && v != "-inf" && v != "inf" {
+			v = v[:len(v)-len("f")]
+		}
+		if x, err := strconv.ParseFloat(v, 32); err == nil {
+			return protoreflect.ValueOfFloat32(float32(x)), nil
+		}
+	case protoreflect.DoubleKind:
+		// Ignore 'f' for compatibility with output generated by C++,
+		// but don't remove 'f' when the value is "-inf" or "inf".
+		v := tok.value
+		if strings.HasSuffix(v, "f") && v != "-inf" && v != "inf" {
+			v = v[:len(v)-len("f")]
+		}
+		if x, err := strconv.ParseFloat(v, 64); err == nil {
+			return protoreflect.ValueOfFloat64(float64(x)), nil
+		}
+	case protoreflect.StringKind:
+		if isQuote(tok.value[0]) {
+			return protoreflect.ValueOfString(tok.unquoted), nil
+		}
+	case protoreflect.BytesKind:
+		if isQuote(tok.value[0]) {
+			return protoreflect.ValueOfBytes([]byte(tok.unquoted)), nil
+		}
+	case protoreflect.EnumKind:
+		if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
+			return protoreflect.ValueOfEnum(protoreflect.EnumNumber(x)), nil
+		}
+		vd := fd.Enum().Values().ByName(protoreflect.Name(tok.value))
+		if vd != nil {
+			return protoreflect.ValueOfEnum(vd.Number()), nil
+		}
+	case protoreflect.MessageKind, protoreflect.GroupKind:
+		var terminator string
+		switch tok.value {
+		case "{":
+			terminator = "}"
+		case "<":
+			terminator = ">"
+		default:
+			return v, p.errorf("expected '{' or '<', found %q", tok.value)
+		}
+		err := p.unmarshalMessage(v.Message(), terminator)
+		return v, err
+	default:
+		panic(fmt.Sprintf("invalid kind %v", fd.Kind()))
+	}
+	return v, p.errorf("invalid %v: %v", fd.Kind(), tok.value)
+}
+
+// Consume a ':' from the input stream (if the next token is a colon),
+// returning an error if a colon is needed but not present.
+func (p *textParser) checkForColon(fd protoreflect.FieldDescriptor) *ParseError {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ":" {
+		if fd.Message() == nil {
+			return p.errorf("expected ':', found %q", tok.value)
+		}
+		p.back()
+	}
+	return nil
+}
+
+// consumeExtensionOrAnyName consumes an extension name or an Any type URL and
+// the following ']'. It returns the name or URL consumed.
+func (p *textParser) consumeExtensionOrAnyName() (string, error) {
+	tok := p.next()
+	if tok.err != nil {
+		return "", tok.err
+	}
+
+	// If extension name or type url is quoted, it's a single token.
+	if len(tok.value) > 2 && isQuote(tok.value[0]) && tok.value[len(tok.value)-1] == tok.value[0] {
+		name, err := unquoteC(tok.value[1:len(tok.value)-1], rune(tok.value[0]))
+		if err != nil {
+			return "", err
+		}
+		return name, p.consumeToken("]")
+	}
+
+	// Consume everything up to "]"
+	var parts []string
+	for tok.value != "]" {
+		parts = append(parts, tok.value)
+		tok = p.next()
+		if tok.err != nil {
+			return "", p.errorf("unrecognized type_url or extension name: %s", tok.err)
+		}
+		if p.done && tok.value != "]" {
+			return "", p.errorf("unclosed type_url or extension name")
+		}
+	}
+	return strings.Join(parts, ""), nil
+}
+
+// consumeOptionalSeparator consumes an optional semicolon or comma.
+// It is used in unmarshalMessage to provide backward compatibility.
+func (p *textParser) consumeOptionalSeparator() error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ";" && tok.value != "," {
+		p.back()
+	}
+	return nil
+}
+
+func (p *textParser) errorf(format string, a ...interface{}) *ParseError {
+	pe := &ParseError{fmt.Sprintf(format, a...), p.cur.line, p.cur.offset}
+	p.cur.err = pe
+	p.done = true
+	return pe
+}
+
+func (p *textParser) skipWhitespace() {
+	i := 0
+	for i < len(p.s) && (isWhitespace(p.s[i]) || p.s[i] == '#') {
+		if p.s[i] == '#' {
+			// comment; skip to end of line or input
+			for i < len(p.s) && p.s[i] != '\n' {
+				i++
+			}
+			if i == len(p.s) {
+				break
+			}
+		}
+		if p.s[i] == '\n' {
+			p.line++
+		}
+		i++
+	}
+	p.offset += i
+	p.s = p.s[i:len(p.s)]
+	if len(p.s) == 0 {
+		p.done = true
+	}
+}
+
+func (p *textParser) advance() {
+	// Skip whitespace
+	p.skipWhitespace()
+	if p.done {
+		return
+	}
+
+	// Start of non-whitespace
+	p.cur.err = nil
+	p.cur.offset, p.cur.line = p.offset, p.line
+	p.cur.unquoted = ""
+	switch p.s[0] {
+	case '<', '>', '{', '}', ':', '[', ']', ';', ',', '/':
+		// Single symbol
+		p.cur.value, p.s = p.s[0:1], p.s[1:len(p.s)]
+	case '"', '\'':
+		// Quoted string
+		i := 1
+		for i < len(p.s) && p.s[i] != p.s[0] && p.s[i] != '\n' {
+			if p.s[i] == '\\' && i+1 < len(p.s) {
+				// skip escaped char
+				i++
+			}
+			i++
+		}
+		if i >= len(p.s) || p.s[i] != p.s[0] {
+			p.errorf("unmatched quote")
+			return
+		}
+		unq, err := unquoteC(p.s[1:i], rune(p.s[0]))
+		if err != nil {
+			p.errorf("invalid quoted string %s: %v", p.s[0:i+1], err)
+			return
+		}
+		p.cur.value, p.s = p.s[0:i+1], p.s[i+1:len(p.s)]
+		p.cur.unquoted = unq
+	default:
+		i := 0
+		for i < len(p.s) && isIdentOrNumberChar(p.s[i]) {
+			i++
+		}
+		if i == 0 {
+			p.errorf("unexpected byte %#x", p.s[0])
+			return
+		}
+		p.cur.value, p.s = p.s[0:i], p.s[i:len(p.s)]
+	}
+	p.offset += len(p.cur.value)
+}
+
+// Back off the parser by one token. Can only be done between calls to next().
+// It makes the next advance() a no-op.
+func (p *textParser) back() { p.backed = true }
+
+// Advances the parser and returns the new current token.
+func (p *textParser) next() *token {
+	if p.backed || p.done {
+		p.backed = false
+		return &p.cur
+	}
+	p.advance()
+	if p.done {
+		p.cur.value = ""
+	} else if len(p.cur.value) > 0 && isQuote(p.cur.value[0]) {
+		// Look for multiple quoted strings separated by whitespace,
+		// and concatenate them.
+		cat := p.cur
+		for {
+			p.skipWhitespace()
+			if p.done || !isQuote(p.s[0]) {
+				break
+			}
+			p.advance()
+			if p.cur.err != nil {
+				return &p.cur
+			}
+			cat.value += " " + p.cur.value
+			cat.unquoted += p.cur.unquoted
+		}
+		p.done = false // parser may have seen EOF, but we want to return cat
+		p.cur = cat
+	}
+	return &p.cur
+}
+
+func (p *textParser) consumeToken(s string) error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != s {
+		p.back()
+		return p.errorf("expected %q, found %q", s, tok.value)
+	}
+	return nil
+}
+
+var errBadUTF8 = errors.New("proto: bad UTF-8")
+
+func unquoteC(s string, quote rune) (string, error) {
+	// This is based on C++'s tokenizer.cc.
+	// Despite its name, this is *not* parsing C syntax.
+	// For instance, "\0" is an invalid quoted string.
+
+	// Avoid allocation in trivial cases.
+	simple := true
+	for _, r := range s {
+		if r == '\\' || r == quote {
+			simple = false
+			break
+		}
+	}
+	if simple {
+		return s, nil
+	}
+
+	buf := make([]byte, 0, 3*len(s)/2)
+	for len(s) > 0 {
+		r, n := utf8.DecodeRuneInString(s)
+		if r == utf8.RuneError && n == 1 {
+			return "", errBadUTF8
+		}
+		s = s[n:]
+		if r != '\\' {
+			if r < utf8.RuneSelf {
+				buf = append(buf, byte(r))
+			} else {
+				buf = append(buf, string(r)...)
+			}
+			continue
+		}
+
+		ch, tail, err := unescape(s)
+		if err != nil {
+			return "", err
+		}
+		buf = append(buf, ch...)
+		s = tail
+	}
+	return string(buf), nil
+}
+
+func unescape(s string) (ch string, tail string, err error) {
+	r, n := utf8.DecodeRuneInString(s)
+	if r == utf8.RuneError && n == 1 {
+		return "", "", errBadUTF8
+	}
+	s = s[n:]
+	switch r {
+	case 'a':
+		return "\a", s, nil
+	case 'b':
+		return "\b", s, nil
+	case 'f':
+		return "\f", s, nil
+	case 'n':
+		return "\n", s, nil
+	case 'r':
+		return "\r", s, nil
+	case 't':
+		return "\t", s, nil
+	case 'v':
+		return "\v", s, nil
+	case '?':
+		return "?", s, nil // trigraph workaround
+	case '\'', '"', '\\':
+		return string(r), s, nil
+	case '0', '1', '2', '3', '4', '5', '6', '7':
+		if len(s) < 2 {
+			return "", "", fmt.Errorf(`\%c requires 2 following digits`, r)
+		}
+		ss := string(r) + s[:2]
+		s = s[2:]
+		i, err := strconv.ParseUint(ss, 8, 8)
+		if err != nil {
+			return "", "", fmt.Errorf(`\%s contains non-octal digits`, ss)
+		}
+		return string([]byte{byte(i)}), s, nil
+	case 'x', 'X', 'u', 'U':
+		var n int
+		switch r {
+		case 'x', 'X':
+			n = 2
+		case 'u':
+			n = 4
+		case 'U':
+			n = 8
+		}
+		if len(s) < n {
+			return "", "", fmt.Errorf(`\%c requires %d following digits`, r, n)
+		}
+		ss := s[:n]
+		s = s[n:]
+		i, err := strconv.ParseUint(ss, 16, 64)
+		if err != nil {
+			return "", "", fmt.Errorf(`\%c%s contains non-hexadecimal digits`, r, ss)
+		}
+		if r == 'x' || r == 'X' {
+			return string([]byte{byte(i)}), s, nil
+		}
+		if i > utf8.MaxRune {
+			return "", "", fmt.Errorf(`\%c%s is not a valid Unicode code point`, r, ss)
+		}
+		return string(rune(i)), s, nil
+	}
+	return "", "", fmt.Errorf(`unknown escape \%c`, r)
+}
+
+func isIdentOrNumberChar(c byte) bool {
+	switch {
+	case 'A' <= c && c <= 'Z', 'a' <= c && c <= 'z':
+		return true
+	case '0' <= c && c <= '9':
+		return true
+	}
+	switch c {
+	case '-', '+', '.', '_':
+		return true
+	}
+	return false
+}
+
+func isWhitespace(c byte) bool {
+	switch c {
+	case ' ', '\t', '\n', '\r':
+		return true
+	}
+	return false
+}
+
+func isQuote(c byte) bool {
+	switch c {
+	case '"', '\'':
+		return true
+	}
+	return false
+}

vendor/github.com/golang/protobuf/proto/text_encode.go

@@ -0,0 +1,560 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"bytes"
+	"encoding"
+	"fmt"
+	"io"
+	"math"
+	"sort"
+	"strings"
+
+	"google.golang.org/protobuf/encoding/prototext"
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+)
+
+const wrapTextMarshalV2 = false
+
+// TextMarshaler is a configurable text format marshaler.
+type TextMarshaler struct {
+	Compact   bool // use compact text format (one line)
+	ExpandAny bool // expand google.protobuf.Any messages of known types
+}
+
+// Marshal writes the proto text format of m to w.
+func (tm *TextMarshaler) Marshal(w io.Writer, m Message) error {
+	b, err := tm.marshal(m)
+	if len(b) > 0 {
+		if _, err := w.Write(b); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// Text returns a proto text formatted string of m.
+func (tm *TextMarshaler) Text(m Message) string {
+	b, _ := tm.marshal(m)
+	return string(b)
+}
+
+func (tm *TextMarshaler) marshal(m Message) ([]byte, error) {
+	mr := MessageReflect(m)
+	if mr == nil || !mr.IsValid() {
+		return []byte("<nil>"), nil
+	}
+
+	if wrapTextMarshalV2 {
+		if m, ok := m.(encoding.TextMarshaler); ok {
+			return m.MarshalText()
+		}
+
+		opts := prototext.MarshalOptions{
+			AllowPartial: true,
+			EmitUnknown:  true,
+		}
+		if !tm.Compact {
+			opts.Indent = "  "
+		}
+		if !tm.ExpandAny {
+			opts.Resolver = (*protoregistry.Types)(nil)
+		}
+		return opts.Marshal(mr.Interface())
+	} else {
+		w := &textWriter{
+			compact:   tm.Compact,
+			expandAny: tm.ExpandAny,
+			complete:  true,
+		}
+
+		if m, ok := m.(encoding.TextMarshaler); ok {
+			b, err := m.MarshalText()
+			if err != nil {
+				return nil, err
+			}
+			w.Write(b)
+			return w.buf, nil
+		}
+
+		err := w.writeMessage(mr)
+		return w.buf, err
+	}
+}
+
+var (
+	defaultTextMarshaler = TextMarshaler{}
+	compactTextMarshaler = TextMarshaler{Compact: true}
+)
+
+// MarshalText writes the proto text format of m to w.
+func MarshalText(w io.Writer, m Message) error { return defaultTextMarshaler.Marshal(w, m) }
+
+// MarshalTextString returns a proto text formatted string of m.
+func MarshalTextString(m Message) string { return defaultTextMarshaler.Text(m) }
+
+// CompactText writes the compact proto text format of m to w.
+func CompactText(w io.Writer, m Message) error { return compactTextMarshaler.Marshal(w, m) }
+
+// CompactTextString returns a compact proto text formatted string of m.
+func CompactTextString(m Message) string { return compactTextMarshaler.Text(m) }
+
+var (
+	newline         = []byte("\n")
+	endBraceNewline = []byte("}\n")
+	posInf          = []byte("inf")
+	negInf          = []byte("-inf")
+	nan             = []byte("nan")
+)
+
+// textWriter is an io.Writer that tracks its indentation level.
+type textWriter struct {
+	compact   bool // same as TextMarshaler.Compact
+	expandAny bool // same as TextMarshaler.ExpandAny
+	complete  bool // whether the current position is a complete line
+	indent    int  // indentation level; never negative
+	buf       []byte
+}
+
+func (w *textWriter) Write(p []byte) (n int, _ error) {
+	newlines := bytes.Count(p, newline)
+	if newlines == 0 {
+		if !w.compact && w.complete {
+			w.writeIndent()
+		}
+		w.buf = append(w.buf, p...)
+		w.complete = false
+		return len(p), nil
+	}
+
+	frags := bytes.SplitN(p, newline, newlines+1)
+	if w.compact {
+		for i, frag := range frags {
+			if i > 0 {
+				w.buf = append(w.buf, ' ')
+				n++
+			}
+			w.buf = append(w.buf, frag...)
+			n += len(frag)
+		}
+		return n, nil
+	}
+
+	for i, frag := range frags {
+		if w.complete {
+			w.writeIndent()
+		}
+		w.buf = append(w.buf, frag...)
+		n += len(frag)
+		if i+1 < len(frags) {
+			w.buf = append(w.buf, '\n')
+			n++
+		}
+	}
+	w.complete = len(frags[len(frags)-1]) == 0
+	return n, nil
+}
+
+func (w *textWriter) WriteByte(c byte) error {
+	if w.compact && c == '\n' {
+		c = ' '
+	}
+	if !w.compact && w.complete {
+		w.writeIndent()
+	}
+	w.buf = append(w.buf, c)
+	w.complete = c == '\n'
+	return nil
+}
+
+func (w *textWriter) writeName(fd protoreflect.FieldDescriptor) {
+	if !w.compact && w.complete {
+		w.writeIndent()
+	}
+	w.complete = false
+
+	if fd.Kind() != protoreflect.GroupKind {
+		w.buf = append(w.buf, fd.Name()...)
+		w.WriteByte(':')
+	} else {
+		// Use message type name for group field name.
+		w.buf = append(w.buf, fd.Message().Name()...)
+	}
+
+	if !w.compact {
+		w.WriteByte(' ')
+	}
+}
+
+func requiresQuotes(u string) bool {
+	// When type URL contains any characters except [0-9A-Za-z./\-]*, it must be quoted.
+	for _, ch := range u {
+		switch {
+		case ch == '.' || ch == '/' || ch == '_':
+			continue
+		case '0' <= ch && ch <= '9':
+			continue
+		case 'A' <= ch && ch <= 'Z':
+			continue
+		case 'a' <= ch && ch <= 'z':
+			continue
+		default:
+			return true
+		}
+	}
+	return false
+}
+
+// writeProto3Any writes an expanded google.protobuf.Any message.
+//
+// It returns (false, nil) if sv value can't be unmarshaled (e.g. because
+// required messages are not linked in).
+//
+// It returns (true, error) when sv was written in expanded format or an error
+// was encountered.
+func (w *textWriter) writeProto3Any(m protoreflect.Message) (bool, error) {
+	md := m.Descriptor()
+	fdURL := md.Fields().ByName("type_url")
+	fdVal := md.Fields().ByName("value")
+
+	url := m.Get(fdURL).String()
+	mt, err := protoregistry.GlobalTypes.FindMessageByURL(url)
+	if err != nil {
+		return false, nil
+	}
+
+	b := m.Get(fdVal).Bytes()
+	m2 := mt.New()
+	if err := proto.Unmarshal(b, m2.Interface()); err != nil {
+		return false, nil
+	}
+	w.Write([]byte("["))
+	if requiresQuotes(url) {
+		w.writeQuotedString(url)
+	} else {
+		w.Write([]byte(url))
+	}
+	if w.compact {
+		w.Write([]byte("]:<"))
+	} else {
+		w.Write([]byte("]: <\n"))
+		w.indent++
+	}
+	if err := w.writeMessage(m2); err != nil {
+		return true, err
+	}
+	if w.compact {
+		w.Write([]byte("> "))
+	} else {
+		w.indent--
+		w.Write([]byte(">\n"))
+	}
+	return true, nil
+}
+
+func (w *textWriter) writeMessage(m protoreflect.Message) error {
+	md := m.Descriptor()
+	if w.expandAny && md.FullName() == "google.protobuf.Any" {
+		if canExpand, err := w.writeProto3Any(m); canExpand {
+			return err
+		}
+	}
+
+	fds := md.Fields()
+	for i := 0; i < fds.Len(); {
+		fd := fds.Get(i)
+		if od := fd.ContainingOneof(); od != nil {
+			fd = m.WhichOneof(od)
+			i += od.Fields().Len()
+		} else {
+			i++
+		}
+		if fd == nil || !m.Has(fd) {
+			continue
+		}
+
+		switch {
+		case fd.IsList():
+			lv := m.Get(fd).List()
+			for j := 0; j < lv.Len(); j++ {
+				w.writeName(fd)
+				v := lv.Get(j)
+				if err := w.writeSingularValue(v, fd); err != nil {
+					return err
+				}
+				w.WriteByte('\n')
+			}
+		case fd.IsMap():
+			kfd := fd.MapKey()
+			vfd := fd.MapValue()
+			mv := m.Get(fd).Map()
+
+			type entry struct{ key, val protoreflect.Value }
+			var entries []entry
+			mv.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool {
+				entries = append(entries, entry{k.Value(), v})
+				return true
+			})
+			sort.Slice(entries, func(i, j int) bool {
+				switch kfd.Kind() {
+				case protoreflect.BoolKind:
+					return !entries[i].key.Bool() && entries[j].key.Bool()
+				case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind, protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
+					return entries[i].key.Int() < entries[j].key.Int()
+				case protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
+					return entries[i].key.Uint() < entries[j].key.Uint()
+				case protoreflect.StringKind:
+					return entries[i].key.String() < entries[j].key.String()
+				default:
+					panic("invalid kind")
+				}
+			})
+			for _, entry := range entries {
+				w.writeName(fd)
+				w.WriteByte('<')
+				if !w.compact {
+					w.WriteByte('\n')
+				}
+				w.indent++
+				w.writeName(kfd)
+				if err := w.writeSingularValue(entry.key, kfd); err != nil {
+					return err
+				}
+				w.WriteByte('\n')
+				w.writeName(vfd)
+				if err := w.writeSingularValue(entry.val, vfd); err != nil {
+					return err
+				}
+				w.WriteByte('\n')
+				w.indent--
+				w.WriteByte('>')
+				w.WriteByte('\n')
+			}
+		default:
+			w.writeName(fd)
+			if err := w.writeSingularValue(m.Get(fd), fd); err != nil {
+				return err
+			}
+			w.WriteByte('\n')
+		}
+	}
+
+	if b := m.GetUnknown(); len(b) > 0 {
+		w.writeUnknownFields(b)
+	}
+	return w.writeExtensions(m)
+}
+
+func (w *textWriter) writeSingularValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) error {
+	switch fd.Kind() {
+	case protoreflect.FloatKind, protoreflect.DoubleKind:
+		switch vf := v.Float(); {
+		case math.IsInf(vf, +1):
+			w.Write(posInf)
+		case math.IsInf(vf, -1):
+			w.Write(negInf)
+		case math.IsNaN(vf):
+			w.Write(nan)
+		default:
+			fmt.Fprint(w, v.Interface())
+		}
+	case protoreflect.StringKind:
+		// NOTE: This does not validate UTF-8 for historical reasons.
+		w.writeQuotedString(string(v.String()))
+	case protoreflect.BytesKind:
+		w.writeQuotedString(string(v.Bytes()))
+	case protoreflect.MessageKind, protoreflect.GroupKind:
+		var bra, ket byte = '<', '>'
+		if fd.Kind() == protoreflect.GroupKind {
+			bra, ket = '{', '}'
+		}
+		w.WriteByte(bra)
+		if !w.compact {
+			w.WriteByte('\n')
+		}
+		w.indent++
+		m := v.Message()
+		if m2, ok := m.Interface().(encoding.TextMarshaler); ok {
+			b, err := m2.MarshalText()
+			if err != nil {
+				return err
+			}
+			w.Write(b)
+		} else {
+			w.writeMessage(m)
+		}
+		w.indent--
+		w.WriteByte(ket)
+	case protoreflect.EnumKind:
+		if ev := fd.Enum().Values().ByNumber(v.Enum()); ev != nil {
+			fmt.Fprint(w, ev.Name())
+		} else {
+			fmt.Fprint(w, v.Enum())
+		}
+	default:
+		fmt.Fprint(w, v.Interface())
+	}
+	return nil
+}
+
+// writeQuotedString writes a quoted string in the protocol buffer text format.
+func (w *textWriter) writeQuotedString(s string) {
+	w.WriteByte('"')
+	for i := 0; i < len(s); i++ {
+		switch c := s[i]; c {
+		case '\n':
+			w.buf = append(w.buf, `\n`...)
+		case '\r':
+			w.buf = append(w.buf, `\r`...)
+		case '\t':
+			w.buf = append(w.buf, `\t`...)
+		case '"':
+			w.buf = append(w.buf, `\"`...)
+		case '\\':
+			w.buf = append(w.buf, `\\`...)
+		default:
+			if isPrint := c >= 0x20 && c < 0x7f; isPrint {
+				w.buf = append(w.buf, c)
+			} else {
+				w.buf = append(w.buf, fmt.Sprintf(`\%03o`, c)...)
+			}
+		}
+	}
+	w.WriteByte('"')
+}
+
+func (w *textWriter) writeUnknownFields(b []byte) {
+	if !w.compact {
+		fmt.Fprintf(w, "/* %d unknown bytes */\n", len(b))
+	}
+
+	for len(b) > 0 {
+		num, wtyp, n := protowire.ConsumeTag(b)
+		if n < 0 {
+			return
+		}
+		b = b[n:]
+
+		if wtyp == protowire.EndGroupType {
+			w.indent--
+			w.Write(endBraceNewline)
+			continue
+		}
+		fmt.Fprint(w, num)
+		if wtyp != protowire.StartGroupType {
+			w.WriteByte(':')
+		}
+		if !w.compact || wtyp == protowire.StartGroupType {
+			w.WriteByte(' ')
+		}
+		switch wtyp {
+		case protowire.VarintType:
+			v, n := protowire.ConsumeVarint(b)
+			if n < 0 {
+				return
+			}
+			b = b[n:]
+			fmt.Fprint(w, v)
+		case protowire.Fixed32Type:
+			v, n := protowire.ConsumeFixed32(b)
+			if n < 0 {
+				return
+			}
+			b = b[n:]
+			fmt.Fprint(w, v)
+		case protowire.Fixed64Type:
+			v, n := protowire.ConsumeFixed64(b)
+			if n < 0 {
+				return
+			}
+			b = b[n:]
+			fmt.Fprint(w, v)
+		case protowire.BytesType:
+			v, n := protowire.ConsumeBytes(b)
+			if n < 0 {
+				return
+			}
+			b = b[n:]
+			fmt.Fprintf(w, "%q", v)
+		case protowire.StartGroupType:
+			w.WriteByte('{')
+			w.indent++
+		default:
+			fmt.Fprintf(w, "/* unknown wire type %d */", wtyp)
+		}
+		w.WriteByte('\n')
+	}
+}
+
+// writeExtensions writes all the extensions in m.
+func (w *textWriter) writeExtensions(m protoreflect.Message) error {
+	md := m.Descriptor()
+	if md.ExtensionRanges().Len() == 0 {
+		return nil
+	}
+
+	type ext struct {
+		desc protoreflect.FieldDescriptor
+		val  protoreflect.Value
+	}
+	var exts []ext
+	m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		if fd.IsExtension() {
+			exts = append(exts, ext{fd, v})
+		}
+		return true
+	})
+	sort.Slice(exts, func(i, j int) bool {
+		return exts[i].desc.Number() < exts[j].desc.Number()
+	})
+
+	for _, ext := range exts {
+		// For message set, use the name of the message as the extension name.
+		name := string(ext.desc.FullName())
+		if isMessageSet(ext.desc.ContainingMessage()) {
+			name = strings.TrimSuffix(name, ".message_set_extension")
+		}
+
+		if !ext.desc.IsList() {
+			if err := w.writeSingularExtension(name, ext.val, ext.desc); err != nil {
+				return err
+			}
+		} else {
+			lv := ext.val.List()
+			for i := 0; i < lv.Len(); i++ {
+				if err := w.writeSingularExtension(name, lv.Get(i), ext.desc); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func (w *textWriter) writeSingularExtension(name string, v protoreflect.Value, fd protoreflect.FieldDescriptor) error {
+	fmt.Fprintf(w, "[%s]:", name)
+	if !w.compact {
+		w.WriteByte(' ')
+	}
+	if err := w.writeSingularValue(v, fd); err != nil {
+		return err
+	}
+	w.WriteByte('\n')
+	return nil
+}
+
+func (w *textWriter) writeIndent() {
+	if !w.complete {
+		return
+	}
+	for i := 0; i < w.indent*2; i++ {
+		w.buf = append(w.buf, ' ')
+	}
+	w.complete = false
+}

vendor/github.com/golang/protobuf/proto/wire.go

@@ -0,0 +1,78 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	protoV2 "google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/runtime/protoiface"
+)
+
+// Size returns the size in bytes of the wire-format encoding of m.
+func Size(m Message) int {
+	if m == nil {
+		return 0
+	}
+	mi := MessageV2(m)
+	return protoV2.Size(mi)
+}
+
+// Marshal returns the wire-format encoding of m.
+func Marshal(m Message) ([]byte, error) {
+	b, err := marshalAppend(nil, m, false)
+	if b == nil {
+		b = zeroBytes
+	}
+	return b, err
+}
+
+var zeroBytes = make([]byte, 0, 0)
+
+func marshalAppend(buf []byte, m Message, deterministic bool) ([]byte, error) {
+	if m == nil {
+		return nil, ErrNil
+	}
+	mi := MessageV2(m)
+	nbuf, err := protoV2.MarshalOptions{
+		Deterministic: deterministic,
+		AllowPartial:  true,
+	}.MarshalAppend(buf, mi)
+	if err != nil {
+		return buf, err
+	}
+	if len(buf) == len(nbuf) {
+		if !mi.ProtoReflect().IsValid() {
+			return buf, ErrNil
+		}
+	}
+	return nbuf, checkRequiredNotSet(mi)
+}
+
+// Unmarshal parses a wire-format message in b and places the decoded results in m.
+//
+// Unmarshal resets m before starting to unmarshal, so any existing data in m is always
+// removed. Use UnmarshalMerge to preserve and append to existing data.
+func Unmarshal(b []byte, m Message) error {
+	m.Reset()
+	return UnmarshalMerge(b, m)
+}
+
+// UnmarshalMerge parses a wire-format message in b and places the decoded results in m.
+func UnmarshalMerge(b []byte, m Message) error {
+	mi := MessageV2(m)
+	out, err := protoV2.UnmarshalOptions{
+		AllowPartial: true,
+		Merge:        true,
+	}.UnmarshalState(protoiface.UnmarshalInput{
+		Buf:     b,
+		Message: mi.ProtoReflect(),
+	})
+	if err != nil {
+		return err
+	}
+	if out.Flags&protoiface.UnmarshalInitialized > 0 {
+		return nil
+	}
+	return checkRequiredNotSet(mi)
+}

vendor/github.com/golang/protobuf/proto/wrappers.go

@@ -0,0 +1,34 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+// Bool stores v in a new bool value and returns a pointer to it.
+func Bool(v bool) *bool { return &v }
+
+// Int stores v in a new int32 value and returns a pointer to it.
+//
+// Deprecated: Use Int32 instead.
+func Int(v int) *int32 { return Int32(int32(v)) }
+
+// Int32 stores v in a new int32 value and returns a pointer to it.
+func Int32(v int32) *int32 { return &v }
+
+// Int64 stores v in a new int64 value and returns a pointer to it.
+func Int64(v int64) *int64 { return &v }
+
+// Uint32 stores v in a new uint32 value and returns a pointer to it.
+func Uint32(v uint32) *uint32 { return &v }
+
+// Uint64 stores v in a new uint64 value and returns a pointer to it.
+func Uint64(v uint64) *uint64 { return &v }
+
+// Float32 stores v in a new float32 value and returns a pointer to it.
+func Float32(v float32) *float32 { return &v }
+
+// Float64 stores v in a new float64 value and returns a pointer to it.
+func Float64(v float64) *float64 { return &v }
+
+// String stores v in a new string value and returns a pointer to it.
+func String(v string) *string { return &v }

vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE

@@ -0,0 +1 @@
+Copyright 2012 Matt T. Proud (matt.proud@gmail.com)

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore

@@ -0,0 +1 @@
+cover.dat

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile

@@ -0,0 +1,7 @@
+all:
+
+cover:
+	go test -cover -v -coverprofile=cover.dat ./...
+	go tool cover -func cover.dat
+
+.PHONY: cover

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go

@@ -0,0 +1,75 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+var errInvalidVarint = errors.New("invalid varint32 encountered")
+
+// ReadDelimited decodes a message from the provided length-delimited stream,
+// where the length is encoded as 32-bit varint prefix to the message body.
+// It returns the total number of bytes read and any applicable error.  This is
+// roughly equivalent to the companion Java API's
+// MessageLite#parseDelimitedFrom.  As per the reader contract, this function
+// calls r.Read repeatedly as required until exactly one message including its
+// prefix is read and decoded (or an error has occurred).  The function never
+// reads more bytes from the stream than required.  The function never returns
+// an error if a message has been read and decoded correctly, even if the end
+// of the stream has been reached in doing so.  In that case, any subsequent
+// calls return (0, io.EOF).
+func ReadDelimited(r io.Reader, m proto.Message) (n int, err error) {
+	// Per AbstractParser#parsePartialDelimitedFrom with
+	// CodedInputStream#readRawVarint32.
+	var headerBuf [binary.MaxVarintLen32]byte
+	var bytesRead, varIntBytes int
+	var messageLength uint64
+	for varIntBytes == 0 { // i.e. no varint has been decoded yet.
+		if bytesRead >= len(headerBuf) {
+			return bytesRead, errInvalidVarint
+		}
+		// We have to read byte by byte here to avoid reading more bytes
+		// than required. Each read byte is appended to what we have
+		// read before.
+		newBytesRead, err := r.Read(headerBuf[bytesRead : bytesRead+1])
+		if newBytesRead == 0 {
+			if err != nil {
+				return bytesRead, err
+			}
+			// A Reader should not return (0, nil), but if it does,
+			// it should be treated as no-op (according to the
+			// Reader contract). So let's go on...
+			continue
+		}
+		bytesRead += newBytesRead
+		// Now present everything read so far to the varint decoder and
+		// see if a varint can be decoded already.
+		messageLength, varIntBytes = proto.DecodeVarint(headerBuf[:bytesRead])
+	}
+
+	messageBuf := make([]byte, messageLength)
+	newBytesRead, err := io.ReadFull(r, messageBuf)
+	bytesRead += newBytesRead
+	if err != nil {
+		return bytesRead, err
+	}
+
+	return bytesRead, proto.Unmarshal(messageBuf, m)
+}

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pbutil provides record length-delimited Protocol Buffer streaming.
+package pbutil

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go

@@ -0,0 +1,46 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// WriteDelimited encodes and dumps a message to the provided writer prefixed
+// with a 32-bit varint indicating the length of the encoded message, producing
+// a length-delimited record stream, which can be used to chain together
+// encoded messages of the same type together in a file.  It returns the total
+// number of bytes written and any applicable error.  This is roughly
+// equivalent to the companion Java API's MessageLite#writeDelimitedTo.
+func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
+	buffer, err := proto.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+
+	var buf [binary.MaxVarintLen32]byte
+	encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
+
+	sync, err := w.Write(buf[:encodedLength])
+	if err != nil {
+		return sync, err
+	}
+
+	n, err = w.Write(buffer)
+	return n + sync, err
+}

vendor/github.com/prometheus/client_golang/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/prometheus/client_golang/NOTICE

@@ -0,0 +1,23 @@
+Prometheus instrumentation library for Go applications
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
+
+
+The following components are included in this product:
+
+perks - a fork of https://github.com/bmizerany/perks
+https://github.com/beorn7/perks
+Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
+See https://github.com/beorn7/perks/blob/master/README.md for license details.
+
+Go support for Protocol Buffers - Google's data interchange format
+http://github.com/golang/protobuf/
+Copyright 2010 The Go Authors
+See source code for license details.
+
+Support for streaming Protocol Buffer messages for the Go language (golang).
+https://github.com/matttproud/golang_protobuf_extensions
+Copyright 2013 Matt T. Proud
+Licensed under the Apache License, Version 2.0

vendor/github.com/prometheus/client_golang/prometheus/.gitignore

@@ -0,0 +1 @@
+command-line-arguments.test

vendor/github.com/prometheus/client_golang/prometheus/README.md

@@ -0,0 +1 @@
+See [![Go Reference](https://pkg.go.dev/badge/github.com/prometheus/client_golang/prometheus.svg)](https://pkg.go.dev/github.com/prometheus/client_golang/prometheus).

vendor/github.com/prometheus/client_golang/prometheus/build_info_collector.go

@@ -0,0 +1,38 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "runtime/debug"
+
+// NewBuildInfoCollector is the obsolete version of collectors.NewBuildInfoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewBuildInfoCollector instead.
+func NewBuildInfoCollector() Collector {
+	path, version, sum := "unknown", "unknown", "unknown"
+	if bi, ok := debug.ReadBuildInfo(); ok {
+		path = bi.Main.Path
+		version = bi.Main.Version
+		sum = bi.Main.Sum
+	}
+	c := &selfCollector{MustNewConstMetric(
+		NewDesc(
+			"go_build_info",
+			"Build information about the main Go module.",
+			nil, Labels{"path": path, "version": version, "checksum": sum},
+		),
+		GaugeValue, 1)}
+	c.init(c.self)
+	return c
+}

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -0,0 +1,128 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Collector is the interface implemented by anything that can be used by
+// Prometheus to collect metrics. A Collector has to be registered for
+// collection. See Registerer.Register.
+//
+// The stock metrics provided by this package (Gauge, Counter, Summary,
+// Histogram, Untyped) are also Collectors (which only ever collect one metric,
+// namely itself). An implementer of Collector may, however, collect multiple
+// metrics in a coordinated fashion and/or create metrics on the fly. Examples
+// for collectors already implemented in this library are the metric vectors
+// (i.e. collection of multiple instances of the same Metric but with different
+// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
+type Collector interface {
+	// Describe sends the super-set of all possible descriptors of metrics
+	// collected by this Collector to the provided channel and returns once
+	// the last descriptor has been sent. The sent descriptors fulfill the
+	// consistency and uniqueness requirements described in the Desc
+	// documentation.
+	//
+	// It is valid if one and the same Collector sends duplicate
+	// descriptors. Those duplicates are simply ignored. However, two
+	// different Collectors must not send duplicate descriptors.
+	//
+	// Sending no descriptor at all marks the Collector as “unchecked”,
+	// i.e. no checks will be performed at registration time, and the
+	// Collector may yield any Metric it sees fit in its Collect method.
+	//
+	// This method idempotently sends the same descriptors throughout the
+	// lifetime of the Collector. It may be called concurrently and
+	// therefore must be implemented in a concurrency safe way.
+	//
+	// If a Collector encounters an error while executing this method, it
+	// must send an invalid descriptor (created with NewInvalidDesc) to
+	// signal the error to the registry.
+	Describe(chan<- *Desc)
+	// Collect is called by the Prometheus registry when collecting
+	// metrics. The implementation sends each collected metric via the
+	// provided channel and returns once the last metric has been sent. The
+	// descriptor of each sent metric is one of those returned by Describe
+	// (unless the Collector is unchecked, see above). Returned metrics that
+	// share the same descriptor must differ in their variable label
+	// values.
+	//
+	// This method may be called concurrently and must therefore be
+	// implemented in a concurrency safe way. Blocking occurs at the expense
+	// of total performance of rendering all registered metrics. Ideally,
+	// Collector implementations support concurrent readers.
+	Collect(chan<- Metric)
+}
+
+// DescribeByCollect is a helper to implement the Describe method of a custom
+// Collector. It collects the metrics from the provided Collector and sends
+// their descriptors to the provided channel.
+//
+// If a Collector collects the same metrics throughout its lifetime, its
+// Describe method can simply be implemented as:
+//
+//	func (c customCollector) Describe(ch chan<- *Desc) {
+//		DescribeByCollect(c, ch)
+//	}
+//
+// However, this will not work if the metrics collected change dynamically over
+// the lifetime of the Collector in a way that their combined set of descriptors
+// changes as well. The shortcut implementation will then violate the contract
+// of the Describe method. If a Collector sometimes collects no metrics at all
+// (for example vectors like CounterVec, GaugeVec, etc., which only collect
+// metrics after a metric with a fully specified label set has been accessed),
+// it might even get registered as an unchecked Collector (cf. the Register
+// method of the Registerer interface). Hence, only use this shortcut
+// implementation of Describe if you are certain to fulfill the contract.
+//
+// The Collector example demonstrates a use of DescribeByCollect.
+func DescribeByCollect(c Collector, descs chan<- *Desc) {
+	metrics := make(chan Metric)
+	go func() {
+		c.Collect(metrics)
+		close(metrics)
+	}()
+	for m := range metrics {
+		descs <- m.Desc()
+	}
+}
+
+// selfCollector implements Collector for a single Metric so that the Metric
+// collects itself. Add it as an anonymous field to a struct that implements
+// Metric, and call init with the Metric itself as an argument.
+type selfCollector struct {
+	self Metric
+}
+
+// init provides the selfCollector with a reference to the metric it is supposed
+// to collect. It is usually called within the factory function to create a
+// metric. See example.
+func (c *selfCollector) init(self Metric) {
+	c.self = self
+}
+
+// Describe implements Collector.
+func (c *selfCollector) Describe(ch chan<- *Desc) {
+	ch <- c.self.Desc()
+}
+
+// Collect implements Collector.
+func (c *selfCollector) Collect(ch chan<- Metric) {
+	ch <- c.self
+}
+
+// collectorMetric is a metric that is also a collector.
+// Because of selfCollector, most (if not all) Metrics in
+// this package are also collectors.
+type collectorMetric interface {
+	Metric
+	Collector
+}

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -0,0 +1,358 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+// Counter is a Metric that represents a single numerical value that only ever
+// goes up. That implies that it cannot be used to count items whose number can
+// also go down, e.g. the number of currently running goroutines. Those
+// "counters" are represented by Gauges.
+//
+// A Counter is typically used to count requests served, tasks completed, errors
+// occurred, etc.
+//
+// To create Counter instances, use NewCounter.
+type Counter interface {
+	Metric
+	Collector
+
+	// Inc increments the counter by 1. Use Add to increment it by arbitrary
+	// non-negative values.
+	Inc()
+	// Add adds the given value to the counter. It panics if the value is <
+	// 0.
+	Add(float64)
+}
+
+// ExemplarAdder is implemented by Counters that offer the option of adding a
+// value to the Counter together with an exemplar. Its AddWithExemplar method
+// works like the Add method of the Counter interface but also replaces the
+// currently saved exemplar (if any) with a new one, created from the provided
+// value, the current time as timestamp, and the provided labels. Empty Labels
+// will lead to a valid (label-less) exemplar. But if Labels is nil, the current
+// exemplar is left in place. AddWithExemplar panics if the value is < 0, if any
+// of the provided labels are invalid, or if the provided labels contain more
+// than 128 runes in total.
+type ExemplarAdder interface {
+	AddWithExemplar(value float64, exemplar Labels)
+}
+
+// CounterOpts is an alias for Opts. See there for doc comments.
+type CounterOpts Opts
+
+// CounterVecOpts bundles the options to create a CounterVec metric.
+// It is mandatory to set CounterOpts, see there for mandatory fields. VariableLabels
+// is optional and can safely be left to its default value.
+type CounterVecOpts struct {
+	CounterOpts
+
+	// VariableLabels are used to partition the metric vector by the given set
+	// of labels. Each label value will be constrained with the optional Constraint
+	// function, if provided.
+	VariableLabels ConstrainableLabels
+}
+
+// NewCounter creates a new Counter based on the provided CounterOpts.
+//
+// The returned implementation also implements ExemplarAdder. It is safe to
+// perform the corresponding type assertion.
+//
+// The returned implementation tracks the counter value in two separate
+// variables, a float64 and a uint64. The latter is used to track calls of the
+// Inc method and calls of the Add method with a value that can be represented
+// as a uint64. This allows atomic increments of the counter with optimal
+// performance. (It is common to have an Inc call in very hot execution paths.)
+// Both internal tracking values are added up in the Write method. This has to
+// be taken into account when it comes to precision and overflow behavior.
+func NewCounter(opts CounterOpts) Counter {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	if opts.now == nil {
+		opts.now = time.Now
+	}
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs, now: opts.now}
+	result.init(result) // Init self-collection.
+	result.createdTs = timestamppb.New(opts.now())
+	return result
+}
+
+type counter struct {
+	// valBits contains the bits of the represented float64 value, while
+	// valInt stores values that are exact integers. Both have to go first
+	// in the struct to guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+	valInt  uint64
+
+	selfCollector
+	desc *Desc
+
+	createdTs  *timestamppb.Timestamp
+	labelPairs []*dto.LabelPair
+	exemplar   atomic.Value // Containing nil or a *dto.Exemplar.
+
+	// now is for testing purposes, by default it's time.Now.
+	now func() time.Time
+}
+
+func (c *counter) Desc() *Desc {
+	return c.desc
+}
+
+func (c *counter) Add(v float64) {
+	if v < 0 {
+		panic(errors.New("counter cannot decrease in value"))
+	}
+
+	ival := uint64(v)
+	if float64(ival) == v {
+		atomic.AddUint64(&c.valInt, ival)
+		return
+	}
+
+	for {
+		oldBits := atomic.LoadUint64(&c.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (c *counter) AddWithExemplar(v float64, e Labels) {
+	c.Add(v)
+	c.updateExemplar(v, e)
+}
+
+func (c *counter) Inc() {
+	atomic.AddUint64(&c.valInt, 1)
+}
+
+func (c *counter) get() float64 {
+	fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
+	ival := atomic.LoadUint64(&c.valInt)
+	return fval + float64(ival)
+}
+
+func (c *counter) Write(out *dto.Metric) error {
+	// Read the Exemplar first and the value second. This is to avoid a race condition
+	// where users see an exemplar for a not-yet-existing observation.
+	var exemplar *dto.Exemplar
+	if e := c.exemplar.Load(); e != nil {
+		exemplar = e.(*dto.Exemplar)
+	}
+	val := c.get()
+	return populateMetric(CounterValue, val, c.labelPairs, exemplar, out, c.createdTs)
+}
+
+func (c *counter) updateExemplar(v float64, l Labels) {
+	if l == nil {
+		return
+	}
+	e, err := newExemplar(v, c.now(), l)
+	if err != nil {
+		panic(err)
+	}
+	c.exemplar.Store(e)
+}
+
+// CounterVec is a Collector that bundles a set of Counters that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. number of HTTP requests, partitioned by response code and
+// method). Create instances with NewCounterVec.
+type CounterVec struct {
+	*MetricVec
+}
+
+// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
+// partitioned by the given label names.
+func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
+	return V2.NewCounterVec(CounterVecOpts{
+		CounterOpts:    opts,
+		VariableLabels: UnconstrainedLabels(labelNames),
+	})
+}
+
+// NewCounterVec creates a new CounterVec based on the provided CounterVecOpts.
+func (v2) NewCounterVec(opts CounterVecOpts) *CounterVec {
+	desc := V2.NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		opts.VariableLabels,
+		opts.ConstLabels,
+	)
+	if opts.now == nil {
+		opts.now = time.Now
+	}
+	return &CounterVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels.names) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, lvs))
+			}
+			result := &counter{desc: desc, labelPairs: MakeLabelPairs(desc, lvs), now: opts.now}
+			result.init(result) // Init self-collection.
+			result.createdTs = timestamppb.New(opts.now())
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Counter for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Counter is created.
+//
+// It is possible to call this method without using the returned Counter to only
+// create the new Counter but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Counter for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Counter from the CounterVec. In that case,
+// the Counter will still exist, but it will not be exported anymore, even if a
+// Counter with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Counter for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Counter is created. Implications of
+// creating a Counter without using it and keeping the Counter for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//
+//	myVec.WithLabelValues("404", "GET").Add(42)
+func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
+	c, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//
+//	myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *CounterVec) With(labels Labels) Counter {
+	c, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the CounterVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &CounterVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// CounterFunc is a Counter whose value is determined at collect time by calling a
+// provided function.
+//
+// To create CounterFunc instances, use NewCounterFunc.
+type CounterFunc interface {
+	Metric
+	Collector
+}
+
+// NewCounterFunc creates a new CounterFunc based on the provided
+// CounterOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a CounterFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe. The function should also honor
+// the contract for a Counter (values only go up, not down), but compliance will
+// not be checked.
+//
+// Check out the ExampleGaugeFunc examples for the similar GaugeFunc.
+func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), CounterValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -0,0 +1,207 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/cespare/xxhash/v2"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/model"
+	"google.golang.org/protobuf/proto"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
+)
+
+// Desc is the descriptor used by every Prometheus Metric. It is essentially
+// the immutable meta-data of a Metric. The normal Metric implementations
+// included in this package manage their Desc under the hood. Users only have to
+// deal with Desc if they use advanced features like the ExpvarCollector or
+// custom Collectors and Metrics.
+//
+// Descriptors registered with the same registry have to fulfill certain
+// consistency and uniqueness criteria if they share the same fully-qualified
+// name: They must have the same help string and the same label names (aka label
+// dimensions) in each, constLabels and variableLabels, but they must differ in
+// the values of the constLabels.
+//
+// Descriptors that share the same fully-qualified names and the same label
+// values of their constLabels are considered equal.
+//
+// Use NewDesc to create new Desc instances.
+type Desc struct {
+	// fqName has been built from Namespace, Subsystem, and Name.
+	fqName string
+	// help provides some helpful information about this metric.
+	help string
+	// constLabelPairs contains precalculated DTO label pairs based on
+	// the constant labels.
+	constLabelPairs []*dto.LabelPair
+	// variableLabels contains names of labels and normalization function for
+	// which the metric maintains variable values.
+	variableLabels *compiledLabels
+	// id is a hash of the values of the ConstLabels and fqName. This
+	// must be unique among all registered descriptors and can therefore be
+	// used as an identifier of the descriptor.
+	id uint64
+	// dimHash is a hash of the label names (preset and variable) and the
+	// Help string. Each Desc with the same fqName must have the same
+	// dimHash.
+	dimHash uint64
+	// err is an error that occurred during construction. It is reported on
+	// registration time.
+	err error
+}
+
+// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
+// and will be reported on registration time. variableLabels and constLabels can
+// be nil if no such labels should be set. fqName must not be empty.
+//
+// variableLabels only contain the label names. Their label values are variable
+// and therefore not part of the Desc. (They are managed within the Metric.)
+//
+// For constLabels, the label values are constant. Therefore, they are fully
+// specified in the Desc. See the Collector example for a usage pattern.
+func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
+	return V2.NewDesc(fqName, help, UnconstrainedLabels(variableLabels), constLabels)
+}
+
+// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
+// and will be reported on registration time. variableLabels and constLabels can
+// be nil if no such labels should be set. fqName must not be empty.
+//
+// variableLabels only contain the label names and normalization functions. Their
+// label values are variable and therefore not part of the Desc. (They are managed
+// within the Metric.)
+//
+// For constLabels, the label values are constant. Therefore, they are fully
+// specified in the Desc. See the Collector example for a usage pattern.
+func (v2) NewDesc(fqName, help string, variableLabels ConstrainableLabels, constLabels Labels) *Desc {
+	d := &Desc{
+		fqName:         fqName,
+		help:           help,
+		variableLabels: variableLabels.compile(),
+	}
+	if !model.IsValidMetricName(model.LabelValue(fqName)) {
+		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
+		return d
+	}
+	// labelValues contains the label values of const labels (in order of
+	// their sorted label names) plus the fqName (at position 0).
+	labelValues := make([]string, 1, len(constLabels)+1)
+	labelValues[0] = fqName
+	labelNames := make([]string, 0, len(constLabels)+len(d.variableLabels.names))
+	labelNameSet := map[string]struct{}{}
+	// First add only the const label names and sort them...
+	for labelName := range constLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
+			return d
+		}
+		labelNames = append(labelNames, labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	sort.Strings(labelNames)
+	// ... so that we can now add const label values in the order of their names.
+	for _, labelName := range labelNames {
+		labelValues = append(labelValues, constLabels[labelName])
+	}
+	// Validate the const label values. They can't have a wrong cardinality, so
+	// use in len(labelValues) as expectedNumberOfValues.
+	if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
+		d.err = err
+		return d
+	}
+	// Now add the variable label names, but prefix them with something that
+	// cannot be in a regular label name. That prevents matching the label
+	// dimension with a different mix between preset and variable labels.
+	for _, label := range d.variableLabels.names {
+		if !checkLabelName(label) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", label, fqName)
+			return d
+		}
+		labelNames = append(labelNames, "$"+label)
+		labelNameSet[label] = struct{}{}
+	}
+	if len(labelNames) != len(labelNameSet) {
+		d.err = fmt.Errorf("duplicate label names in constant and variable labels for metric %q", fqName)
+		return d
+	}
+
+	xxh := xxhash.New()
+	for _, val := range labelValues {
+		xxh.WriteString(val)
+		xxh.Write(separatorByteSlice)
+	}
+	d.id = xxh.Sum64()
+	// Sort labelNames so that order doesn't matter for the hash.
+	sort.Strings(labelNames)
+	// Now hash together (in this order) the help string and the sorted
+	// label names.
+	xxh.Reset()
+	xxh.WriteString(help)
+	xxh.Write(separatorByteSlice)
+	for _, labelName := range labelNames {
+		xxh.WriteString(labelName)
+		xxh.Write(separatorByteSlice)
+	}
+	d.dimHash = xxh.Sum64()
+
+	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
+	for n, v := range constLabels {
+		d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
+			Name:  proto.String(n),
+			Value: proto.String(v),
+		})
+	}
+	sort.Sort(internal.LabelPairSorter(d.constLabelPairs))
+	return d
+}
+
+// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
+// provided error set. If a collector returning such a descriptor is registered,
+// registration will fail with the provided error. NewInvalidDesc can be used by
+// a Collector to signal inability to describe itself.
+func NewInvalidDesc(err error) *Desc {
+	return &Desc{
+		err: err,
+	}
+}
+
+func (d *Desc) String() string {
+	lpStrings := make([]string, 0, len(d.constLabelPairs))
+	for _, lp := range d.constLabelPairs {
+		lpStrings = append(
+			lpStrings,
+			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
+		)
+	}
+	vlStrings := make([]string, 0, len(d.variableLabels.names))
+	for _, vl := range d.variableLabels.names {
+		if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
+			vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
+		} else {
+			vlStrings = append(vlStrings, vl)
+		}
+	}
+	return fmt.Sprintf(
+		"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: {%s}}",
+		d.fqName,
+		d.help,
+		strings.Join(lpStrings, ","),
+		strings.Join(vlStrings, ","),
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -0,0 +1,210 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package prometheus is the core instrumentation package. It provides metrics
+// primitives to instrument code for monitoring. It also offers a registry for
+// metrics. Sub-packages allow to expose the registered metrics via HTTP
+// (package promhttp) or push them to a Pushgateway (package push). There is
+// also a sub-package promauto, which provides metrics constructors with
+// automatic registration.
+//
+// All exported functions and methods are safe to be used concurrently unless
+// specified otherwise.
+//
+// # A Basic Example
+//
+// As a starting point, a very basic usage example:
+//
+//	package main
+//
+//	import (
+//		"log"
+//		"net/http"
+//
+//		"github.com/prometheus/client_golang/prometheus"
+//		"github.com/prometheus/client_golang/prometheus/promhttp"
+//	)
+//
+//	type metrics struct {
+//		cpuTemp  prometheus.Gauge
+//		hdFailures *prometheus.CounterVec
+//	}
+//
+//	func NewMetrics(reg prometheus.Registerer) *metrics {
+//		m := &metrics{
+//			cpuTemp: prometheus.NewGauge(prometheus.GaugeOpts{
+//				Name: "cpu_temperature_celsius",
+//				Help: "Current temperature of the CPU.",
+//			}),
+//			hdFailures: prometheus.NewCounterVec(
+//				prometheus.CounterOpts{
+//					Name: "hd_errors_total",
+//					Help: "Number of hard-disk errors.",
+//				},
+//				[]string{"device"},
+//			),
+//		}
+//		reg.MustRegister(m.cpuTemp)
+//		reg.MustRegister(m.hdFailures)
+//		return m
+//	}
+//
+//	func main() {
+//		// Create a non-global registry.
+//		reg := prometheus.NewRegistry()
+//
+//		// Create new metrics and register them using the custom registry.
+//		m := NewMetrics(reg)
+//		// Set values for the new created metrics.
+//		m.cpuTemp.Set(65.3)
+//		m.hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
+//
+//		// Expose metrics and custom registry via an HTTP server
+//		// using the HandleFor function. "/metrics" is the usual endpoint for that.
+//		http.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))
+//		log.Fatal(http.ListenAndServe(":8080", nil))
+//	}
+//
+// This is a complete program that exports two metrics, a Gauge and a Counter,
+// the latter with a label attached to turn it into a (one-dimensional) vector.
+// It register the metrics using a custom registry and exposes them via an HTTP server
+// on the /metrics endpoint.
+//
+// # Metrics
+//
+// The number of exported identifiers in this package might appear a bit
+// overwhelming. However, in addition to the basic plumbing shown in the example
+// above, you only need to understand the different metric types and their
+// vector versions for basic usage. Furthermore, if you are not concerned with
+// fine-grained control of when and how to register metrics with the registry,
+// have a look at the promauto package, which will effectively allow you to
+// ignore registration altogether in simple cases.
+//
+// Above, you have already touched the Counter and the Gauge. There are two more
+// advanced metric types: the Summary and Histogram. A more thorough description
+// of those four metric types can be found in the Prometheus docs:
+// https://prometheus.io/docs/concepts/metric_types/
+//
+// In addition to the fundamental metric types Gauge, Counter, Summary, and
+// Histogram, a very important part of the Prometheus data model is the
+// partitioning of samples along dimensions called labels, which results in
+// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
+// and HistogramVec.
+//
+// While only the fundamental metric types implement the Metric interface, both
+// the metrics and their vector versions implement the Collector interface. A
+// Collector manages the collection of a number of Metrics, but for convenience,
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary, and
+// Histogram are interfaces themselves while GaugeVec, CounterVec, SummaryVec,
+// and HistogramVec are not.
+//
+// To create instances of Metrics and their vector versions, you need a suitable
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, or HistogramOpts.
+//
+// # Custom Collectors and constant Metrics
+//
+// While you could create your own implementations of Metric, most likely you
+// will only ever implement the Collector interface on your own. At a first
+// glance, a custom Collector seems handy to bundle Metrics for common
+// registration (with the prime example of the different metric vectors above,
+// which bundle all the metrics of the same name but with different labels).
+//
+// There is a more involved use case, too: If you already have metrics
+// available, created outside of the Prometheus context, you don't need the
+// interface of the various Metric types. You essentially want to mirror the
+// existing numbers into Prometheus Metrics during collection. An own
+// implementation of the Collector interface is perfect for that. You can create
+// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
+// NewConstSummary (and their respective Must… versions). NewConstMetric is used
+// for all metric types with just a float64 as their value: Counter, Gauge, and
+// a special “type” called Untyped. Use the latter if you are not sure if the
+// mirrored metric is a Counter or a Gauge. Creation of the Metric instance
+// happens in the Collect method. The Describe method has to return separate
+// Desc instances, representative of the “throw-away” metrics to be created
+// later.  NewDesc comes in handy to create those Desc instances. Alternatively,
+// you could return no Desc at all, which will mark the Collector “unchecked”.
+// No checks are performed at registration time, but metric consistency will
+// still be ensured at scrape time, i.e. any inconsistencies will lead to scrape
+// errors. Thus, with unchecked Collectors, the responsibility to not collect
+// metrics that lead to inconsistencies in the total scrape result lies with the
+// implementer of the Collector. While this is not a desirable state, it is
+// sometimes necessary. The typical use case is a situation where the exact
+// metrics to be returned by a Collector cannot be predicted at registration
+// time, but the implementer has sufficient knowledge of the whole system to
+// guarantee metric consistency.
+//
+// The Collector example illustrates the use case. You can also look at the
+// source code of the processCollector (mirroring process metrics), the
+// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
+// metrics) as examples that are used in this package itself.
+//
+// If you just need to call a function to get a single float value to collect as
+// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
+// shortcuts.
+//
+// # Advanced Uses of the Registry
+//
+// While MustRegister is the by far most common way of registering a Collector,
+// sometimes you might want to handle the errors the registration might cause.
+// As suggested by the name, MustRegister panics if an error occurs. With the
+// Register function, the error is returned and can be handled.
+//
+// An error is returned if the registered Collector is incompatible or
+// inconsistent with already registered metrics. The registry aims for
+// consistency of the collected metrics according to the Prometheus data model.
+// Inconsistencies are ideally detected at registration time, not at collect
+// time. The former will usually be detected at start-up time of a program,
+// while the latter will only happen at scrape time, possibly not even on the
+// first scrape if the inconsistency only becomes relevant later. That is the
+// main reason why a Collector and a Metric have to describe themselves to the
+// registry.
+//
+// So far, everything we did operated on the so-called default registry, as it
+// can be found in the global DefaultRegisterer variable. With NewRegistry, you
+// can create a custom registry, or you can even implement the Registerer or
+// Gatherer interfaces yourself. The methods Register and Unregister work in the
+// same way on a custom registry as the global functions Register and Unregister
+// on the default registry.
+//
+// There are a number of uses for custom registries: You can use registries with
+// special properties, see NewPedanticRegistry. You can avoid global state, as
+// it is imposed by the DefaultRegisterer. You can use multiple registries at
+// the same time to expose different metrics in different ways.  You can use
+// separate registries for testing purposes.
+//
+// Also note that the DefaultRegisterer comes registered with a Collector for Go
+// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
+// NewProcessCollector). With a custom registry, you are in control and decide
+// yourself about the Collectors to register.
+//
+// # HTTP Exposition
+//
+// The Registry implements the Gatherer interface. The caller of the Gather
+// method can then expose the gathered metrics in some way. Usually, the metrics
+// are served via HTTP on the /metrics endpoint. That's happening in the example
+// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
+//
+// # Pushing to the Pushgateway
+//
+// Function for pushing to the Pushgateway can be found in the push sub-package.
+//
+// # Graphite Bridge
+//
+// Functions and examples to push metrics from a Gatherer to Graphite can be
+// found in the graphite sub-package.
+//
+// # Other Means of Exposition
+//
+// More ways of exposing metrics can easily be added by following the approaches
+// of the existing implementations.
+package prometheus

vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go

@@ -0,0 +1,86 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"encoding/json"
+	"expvar"
+)
+
+type expvarCollector struct {
+	exports map[string]*Desc
+}
+
+// NewExpvarCollector is the obsolete version of collectors.NewExpvarCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewExpvarCollector instead.
+func NewExpvarCollector(exports map[string]*Desc) Collector {
+	return &expvarCollector{
+		exports: exports,
+	}
+}
+
+// Describe implements Collector.
+func (e *expvarCollector) Describe(ch chan<- *Desc) {
+	for _, desc := range e.exports {
+		ch <- desc
+	}
+}
+
+// Collect implements Collector.
+func (e *expvarCollector) Collect(ch chan<- Metric) {
+	for name, desc := range e.exports {
+		var m Metric
+		expVar := expvar.Get(name)
+		if expVar == nil {
+			continue
+		}
+		var v interface{}
+		labels := make([]string, len(desc.variableLabels.names))
+		if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
+			ch <- NewInvalidMetric(desc, err)
+			continue
+		}
+		var processValue func(v interface{}, i int)
+		processValue = func(v interface{}, i int) {
+			if i >= len(labels) {
+				copiedLabels := append(make([]string, 0, len(labels)), labels...)
+				switch v := v.(type) {
+				case float64:
+					m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
+				case bool:
+					if v {
+						m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
+					} else {
+						m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
+					}
+				default:
+					return
+				}
+				ch <- m
+				return
+			}
+			vm, ok := v.(map[string]interface{})
+			if !ok {
+				return
+			}
+			for lv, val := range vm {
+				labels[i] = lv
+				processValue(val, i+1)
+			}
+		}
+		processValue(v, 0)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/fnv.go

@@ -0,0 +1,42 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -0,0 +1,311 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Gauge is a Metric that represents a single numerical value that can
+// arbitrarily go up and down.
+//
+// A Gauge is typically used for measured values like temperatures or current
+// memory usage, but also "counts" that can go up and down, like the number of
+// running goroutines.
+//
+// To create Gauge instances, use NewGauge.
+type Gauge interface {
+	Metric
+	Collector
+
+	// Set sets the Gauge to an arbitrary value.
+	Set(float64)
+	// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
+	// values.
+	Inc()
+	// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
+	// values.
+	Dec()
+	// Add adds the given value to the Gauge. (The value can be negative,
+	// resulting in a decrease of the Gauge.)
+	Add(float64)
+	// Sub subtracts the given value from the Gauge. (The value can be
+	// negative, resulting in an increase of the Gauge.)
+	Sub(float64)
+
+	// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
+	SetToCurrentTime()
+}
+
+// GaugeOpts is an alias for Opts. See there for doc comments.
+type GaugeOpts Opts
+
+// GaugeVecOpts bundles the options to create a GaugeVec metric.
+// It is mandatory to set GaugeOpts, see there for mandatory fields. VariableLabels
+// is optional and can safely be left to its default value.
+type GaugeVecOpts struct {
+	GaugeOpts
+
+	// VariableLabels are used to partition the metric vector by the given set
+	// of labels. Each label value will be constrained with the optional Constraint
+	// function, if provided.
+	VariableLabels ConstrainableLabels
+}
+
+// NewGauge creates a new Gauge based on the provided GaugeOpts.
+//
+// The returned implementation is optimized for a fast Set method. If you have a
+// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
+// the former. For example, the Inc method of the returned Gauge is slower than
+// the Inc method of a Counter returned by NewCounter. This matches the typical
+// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
+// the latter Inc-heavy.
+func NewGauge(opts GaugeOpts) Gauge {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type gauge struct {
+	// valBits contains the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	labelPairs []*dto.LabelPair
+}
+
+func (g *gauge) Desc() *Desc {
+	return g.desc
+}
+
+func (g *gauge) Set(val float64) {
+	atomic.StoreUint64(&g.valBits, math.Float64bits(val))
+}
+
+func (g *gauge) SetToCurrentTime() {
+	g.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
+func (g *gauge) Inc() {
+	g.Add(1)
+}
+
+func (g *gauge) Dec() {
+	g.Add(-1)
+}
+
+func (g *gauge) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&g.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (g *gauge) Sub(val float64) {
+	g.Add(val * -1)
+}
+
+func (g *gauge) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
+	return populateMetric(GaugeValue, val, g.labelPairs, nil, out, nil)
+}
+
+// GaugeVec is a Collector that bundles a set of Gauges that all share the same
+// Desc, but have different values for their variable labels. This is used if
+// you want to count the same thing partitioned by various dimensions
+// (e.g. number of operations queued, partitioned by user and operation
+// type). Create instances with NewGaugeVec.
+type GaugeVec struct {
+	*MetricVec
+}
+
+// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
+// partitioned by the given label names.
+func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
+	return V2.NewGaugeVec(GaugeVecOpts{
+		GaugeOpts:      opts,
+		VariableLabels: UnconstrainedLabels(labelNames),
+	})
+}
+
+// NewGaugeVec creates a new GaugeVec based on the provided GaugeVecOpts.
+func (v2) NewGaugeVec(opts GaugeVecOpts) *GaugeVec {
+	desc := V2.NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		opts.VariableLabels,
+		opts.ConstLabels,
+	)
+	return &GaugeVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels.names) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, lvs))
+			}
+			result := &gauge{desc: desc, labelPairs: MakeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Gauge for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Gauge is created.
+//
+// It is possible to call this method without using the returned Gauge to only
+// create the new Gauge but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Gauge for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
+// Gauge will still exist, but it will not be exported anymore, even if a
+// Gauge with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Gauge for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Gauge is created. Implications of
+// creating a Gauge without using it and keeping the Gauge for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//
+//	myVec.WithLabelValues("404", "GET").Add(42)
+func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	g, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//
+//	myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *GaugeVec) With(labels Labels) Gauge {
+	g, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the GaugeVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &GaugeVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// GaugeFunc is a Gauge whose value is determined at collect time by calling a
+// provided function.
+//
+// To create GaugeFunc instances, use NewGaugeFunc.
+type GaugeFunc interface {
+	Metric
+	Collector
+}
+
+// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
+// value reported is determined by calling the given function from within the
+// Write method. Take into account that metric collection may happen
+// concurrently. Therefore, it must be safe to call the provided function
+// concurrently.
+//
+// NewGaugeFunc is a good way to create an “info” style metric with a constant
+// value of 1. Example:
+// https://github.com/prometheus/common/blob/8558a5b7db3c84fa38b4766966059a7bd5bfa2ee/version/info.go#L36-L56
+func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), GaugeValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/get_pid.go

@@ -0,0 +1,26 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !js || wasm
+// +build !js wasm
+
+package prometheus
+
+import "os"
+
+func getPIDFn() func() (int, error) {
+	pid := os.Getpid()
+	return func() (int, error) {
+		return pid, nil
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/get_pid_gopherjs.go

@@ -0,0 +1,23 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build js && !wasm
+// +build js,!wasm
+
+package prometheus
+
+func getPIDFn() func() (int, error) {
+	return func() (int, error) {
+		return 1, nil
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -0,0 +1,281 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"runtime"
+	"runtime/debug"
+	"time"
+)
+
+// goRuntimeMemStats provides the metrics initially provided by runtime.ReadMemStats.
+// From Go 1.17 those similar (and better) statistics are provided by runtime/metrics, so
+// while eval closure works on runtime.MemStats, the struct from Go 1.17+ is
+// populated using runtime/metrics.
+func goRuntimeMemStats() memStatsMetrics {
+	return memStatsMetrics{
+		{
+			desc: NewDesc(
+				memstatNamespace("alloc_bytes"),
+				"Number of bytes allocated and still in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("alloc_bytes_total"),
+				"Total number of bytes allocated, even if freed.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("sys_bytes"),
+				"Number of bytes obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("lookups_total"),
+				"Total number of pointer lookups.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mallocs_total"),
+				"Total number of mallocs.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("frees_total"),
+				"Total number of frees.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_alloc_bytes"),
+				"Number of heap bytes allocated and still in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_sys_bytes"),
+				"Number of heap bytes obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_idle_bytes"),
+				"Number of heap bytes waiting to be used.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_inuse_bytes"),
+				"Number of heap bytes that are in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_released_bytes"),
+				"Number of heap bytes released to OS.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_objects"),
+				"Number of allocated objects.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("stack_inuse_bytes"),
+				"Number of bytes in use by the stack allocator.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("stack_sys_bytes"),
+				"Number of bytes obtained from system for stack allocator.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mspan_inuse_bytes"),
+				"Number of bytes in use by mspan structures.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mspan_sys_bytes"),
+				"Number of bytes used for mspan structures obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mcache_inuse_bytes"),
+				"Number of bytes in use by mcache structures.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mcache_sys_bytes"),
+				"Number of bytes used for mcache structures obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("buck_hash_sys_bytes"),
+				"Number of bytes used by the profiling bucket hash table.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("gc_sys_bytes"),
+				"Number of bytes used for garbage collection system metadata.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("other_sys_bytes"),
+				"Number of bytes used for other system allocations.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("next_gc_bytes"),
+				"Number of heap bytes when next garbage collection will take place.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+			valType: GaugeValue,
+		},
+	}
+}
+
+type baseGoCollector struct {
+	goroutinesDesc *Desc
+	threadsDesc    *Desc
+	gcDesc         *Desc
+	gcLastTimeDesc *Desc
+	goInfoDesc     *Desc
+}
+
+func newBaseGoCollector() baseGoCollector {
+	return baseGoCollector{
+		goroutinesDesc: NewDesc(
+			"go_goroutines",
+			"Number of goroutines that currently exist.",
+			nil, nil),
+		threadsDesc: NewDesc(
+			"go_threads",
+			"Number of OS threads created.",
+			nil, nil),
+		gcDesc: NewDesc(
+			"go_gc_duration_seconds",
+			"A summary of the pause duration of garbage collection cycles.",
+			nil, nil),
+		gcLastTimeDesc: NewDesc(
+			"go_memstats_last_gc_time_seconds",
+			"Number of seconds since 1970 of last garbage collection.",
+			nil, nil),
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *baseGoCollector) Describe(ch chan<- *Desc) {
+	ch <- c.goroutinesDesc
+	ch <- c.threadsDesc
+	ch <- c.gcDesc
+	ch <- c.gcLastTimeDesc
+	ch <- c.goInfoDesc
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *baseGoCollector) Collect(ch chan<- Metric) {
+	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+
+	n := getRuntimeNumThreads()
+	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, n)
+
+	var stats debug.GCStats
+	stats.PauseQuantiles = make([]time.Duration, 5)
+	debug.ReadGCStats(&stats)
+
+	quantiles := make(map[float64]float64)
+	for idx, pq := range stats.PauseQuantiles[1:] {
+		quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
+	}
+	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
+	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
+	ch <- MustNewConstMetric(c.gcLastTimeDesc, GaugeValue, float64(stats.LastGC.UnixNano())/1e9)
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+}
+
+func memstatNamespace(s string) string {
+	return "go_memstats_" + s
+}
+
+// memStatsMetrics provide description, evaluator, runtime/metrics name, and
+// value type for memstat metrics.
+type memStatsMetrics []struct {
+	desc    *Desc
+	eval    func(*runtime.MemStats) float64
+	valType ValueType
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector_go116.go

@@ -0,0 +1,122 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !go1.17
+// +build !go1.17
+
+package prometheus
+
+import (
+	"runtime"
+	"sync"
+	"time"
+)
+
+type goCollector struct {
+	base baseGoCollector
+
+	// ms... are memstats related.
+	msLast          *runtime.MemStats // Previously collected memstats.
+	msLastTimestamp time.Time
+	msMtx           sync.Mutex // Protects msLast and msLastTimestamp.
+	msMetrics       memStatsMetrics
+	msRead          func(*runtime.MemStats) // For mocking in tests.
+	msMaxWait       time.Duration           // Wait time for fresh memstats.
+	msMaxAge        time.Duration           // Maximum allowed age of old memstats.
+}
+
+// NewGoCollector is the obsolete version of collectors.NewGoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewGoCollector instead.
+func NewGoCollector() Collector {
+	msMetrics := goRuntimeMemStats()
+	msMetrics = append(msMetrics, struct {
+		desc    *Desc
+		eval    func(*runtime.MemStats) float64
+		valType ValueType
+	}{
+		// This metric is omitted in Go1.17+, see https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
+		desc: NewDesc(
+			memstatNamespace("gc_cpu_fraction"),
+			"The fraction of this program's available CPU time used by the GC since the program started.",
+			nil, nil,
+		),
+		eval:    func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
+		valType: GaugeValue,
+	})
+	return &goCollector{
+		base:      newBaseGoCollector(),
+		msLast:    &runtime.MemStats{},
+		msRead:    runtime.ReadMemStats,
+		msMaxWait: time.Second,
+		msMaxAge:  5 * time.Minute,
+		msMetrics: msMetrics,
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	c.base.Describe(ch)
+	for _, i := range c.msMetrics {
+		ch <- i.desc
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	var (
+		ms   = &runtime.MemStats{}
+		done = make(chan struct{})
+	)
+	// Start reading memstats first as it might take a while.
+	go func() {
+		c.msRead(ms)
+		c.msMtx.Lock()
+		c.msLast = ms
+		c.msLastTimestamp = time.Now()
+		c.msMtx.Unlock()
+		close(done)
+	}()
+
+	// Collect base non-memory metrics.
+	c.base.Collect(ch)
+
+	timer := time.NewTimer(c.msMaxWait)
+	select {
+	case <-done: // Our own ReadMemStats succeeded in time. Use it.
+		timer.Stop() // Important for high collection frequencies to not pile up timers.
+		c.msCollect(ch, ms)
+		return
+	case <-timer.C: // Time out, use last memstats if possible. Continue below.
+	}
+	c.msMtx.Lock()
+	if time.Since(c.msLastTimestamp) < c.msMaxAge {
+		// Last memstats are recent enough. Collect from them under the lock.
+		c.msCollect(ch, c.msLast)
+		c.msMtx.Unlock()
+		return
+	}
+	// If we are here, the last memstats are too old or don't exist. We have
+	// to wait until our own ReadMemStats finally completes. For that to
+	// happen, we have to release the lock.
+	c.msMtx.Unlock()
+	<-done
+	c.msCollect(ch, ms)
+}
+
+func (c *goCollector) msCollect(ch chan<- Metric, ms *runtime.MemStats) {
+	for _, i := range c.msMetrics {
+		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector_latest.go

@@ -0,0 +1,567 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.17
+// +build go1.17
+
+package prometheus
+
+import (
+	"math"
+	"runtime"
+	"runtime/metrics"
+	"strings"
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
+
+	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/proto"
+)
+
+const (
+	// constants for strings referenced more than once.
+	goGCHeapTinyAllocsObjects               = "/gc/heap/tiny/allocs:objects"
+	goGCHeapAllocsObjects                   = "/gc/heap/allocs:objects"
+	goGCHeapFreesObjects                    = "/gc/heap/frees:objects"
+	goGCHeapFreesBytes                      = "/gc/heap/frees:bytes"
+	goGCHeapAllocsBytes                     = "/gc/heap/allocs:bytes"
+	goGCHeapObjects                         = "/gc/heap/objects:objects"
+	goGCHeapGoalBytes                       = "/gc/heap/goal:bytes"
+	goMemoryClassesTotalBytes               = "/memory/classes/total:bytes"
+	goMemoryClassesHeapObjectsBytes         = "/memory/classes/heap/objects:bytes"
+	goMemoryClassesHeapUnusedBytes          = "/memory/classes/heap/unused:bytes"
+	goMemoryClassesHeapReleasedBytes        = "/memory/classes/heap/released:bytes"
+	goMemoryClassesHeapFreeBytes            = "/memory/classes/heap/free:bytes"
+	goMemoryClassesHeapStacksBytes          = "/memory/classes/heap/stacks:bytes"
+	goMemoryClassesOSStacksBytes            = "/memory/classes/os-stacks:bytes"
+	goMemoryClassesMetadataMSpanInuseBytes  = "/memory/classes/metadata/mspan/inuse:bytes"
+	goMemoryClassesMetadataMSPanFreeBytes   = "/memory/classes/metadata/mspan/free:bytes"
+	goMemoryClassesMetadataMCacheInuseBytes = "/memory/classes/metadata/mcache/inuse:bytes"
+	goMemoryClassesMetadataMCacheFreeBytes  = "/memory/classes/metadata/mcache/free:bytes"
+	goMemoryClassesProfilingBucketsBytes    = "/memory/classes/profiling/buckets:bytes"
+	goMemoryClassesMetadataOtherBytes       = "/memory/classes/metadata/other:bytes"
+	goMemoryClassesOtherBytes               = "/memory/classes/other:bytes"
+)
+
+// rmNamesForMemStatsMetrics represents runtime/metrics names required to populate goRuntimeMemStats from like logic.
+var rmNamesForMemStatsMetrics = []string{
+	goGCHeapTinyAllocsObjects,
+	goGCHeapAllocsObjects,
+	goGCHeapFreesObjects,
+	goGCHeapAllocsBytes,
+	goGCHeapObjects,
+	goGCHeapGoalBytes,
+	goMemoryClassesTotalBytes,
+	goMemoryClassesHeapObjectsBytes,
+	goMemoryClassesHeapUnusedBytes,
+	goMemoryClassesHeapReleasedBytes,
+	goMemoryClassesHeapFreeBytes,
+	goMemoryClassesHeapStacksBytes,
+	goMemoryClassesOSStacksBytes,
+	goMemoryClassesMetadataMSpanInuseBytes,
+	goMemoryClassesMetadataMSPanFreeBytes,
+	goMemoryClassesMetadataMCacheInuseBytes,
+	goMemoryClassesMetadataMCacheFreeBytes,
+	goMemoryClassesProfilingBucketsBytes,
+	goMemoryClassesMetadataOtherBytes,
+	goMemoryClassesOtherBytes,
+}
+
+func bestEffortLookupRM(lookup []string) []metrics.Description {
+	ret := make([]metrics.Description, 0, len(lookup))
+	for _, rm := range metrics.All() {
+		for _, m := range lookup {
+			if m == rm.Name {
+				ret = append(ret, rm)
+			}
+		}
+	}
+	return ret
+}
+
+type goCollector struct {
+	base baseGoCollector
+
+	// mu protects updates to all fields ensuring a consistent
+	// snapshot is always produced by Collect.
+	mu sync.Mutex
+
+	// Contains all samples that has to retrieved from runtime/metrics (not all of them will be exposed).
+	sampleBuf []metrics.Sample
+	// sampleMap allows lookup for MemStats metrics and runtime/metrics histograms for exact sums.
+	sampleMap map[string]*metrics.Sample
+
+	// rmExposedMetrics represents all runtime/metrics package metrics
+	// that were configured to be exposed.
+	rmExposedMetrics     []collectorMetric
+	rmExactSumMapForHist map[string]string
+
+	// With Go 1.17, the runtime/metrics package was introduced.
+	// From that point on, metric names produced by the runtime/metrics
+	// package could be generated from runtime/metrics names. However,
+	// these differ from the old names for the same values.
+	//
+	// This field exists to export the same values under the old names
+	// as well.
+	msMetrics        memStatsMetrics
+	msMetricsEnabled bool
+}
+
+type rmMetricDesc struct {
+	metrics.Description
+}
+
+func matchRuntimeMetricsRules(rules []internal.GoCollectorRule) []rmMetricDesc {
+	var descs []rmMetricDesc
+	for _, d := range metrics.All() {
+		var (
+			deny = true
+			desc rmMetricDesc
+		)
+
+		for _, r := range rules {
+			if !r.Matcher.MatchString(d.Name) {
+				continue
+			}
+			deny = r.Deny
+		}
+		if deny {
+			continue
+		}
+
+		desc.Description = d
+		descs = append(descs, desc)
+	}
+	return descs
+}
+
+func defaultGoCollectorOptions() internal.GoCollectorOptions {
+	return internal.GoCollectorOptions{
+		RuntimeMetricSumForHist: map[string]string{
+			"/gc/heap/allocs-by-size:bytes": goGCHeapAllocsBytes,
+			"/gc/heap/frees-by-size:bytes":  goGCHeapFreesBytes,
+		},
+		RuntimeMetricRules: []internal.GoCollectorRule{
+			//{Matcher: regexp.MustCompile("")},
+		},
+	}
+}
+
+// NewGoCollector is the obsolete version of collectors.NewGoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewGoCollector instead.
+func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
+	opt := defaultGoCollectorOptions()
+	for _, o := range opts {
+		o(&opt)
+	}
+
+	exposedDescriptions := matchRuntimeMetricsRules(opt.RuntimeMetricRules)
+
+	// Collect all histogram samples so that we can get their buckets.
+	// The API guarantees that the buckets are always fixed for the lifetime
+	// of the process.
+	var histograms []metrics.Sample
+	for _, d := range exposedDescriptions {
+		if d.Kind == metrics.KindFloat64Histogram {
+			histograms = append(histograms, metrics.Sample{Name: d.Name})
+		}
+	}
+
+	if len(histograms) > 0 {
+		metrics.Read(histograms)
+	}
+
+	bucketsMap := make(map[string][]float64)
+	for i := range histograms {
+		bucketsMap[histograms[i].Name] = histograms[i].Value.Float64Histogram().Buckets
+	}
+
+	// Generate a collector for each exposed runtime/metrics metric.
+	metricSet := make([]collectorMetric, 0, len(exposedDescriptions))
+	// SampleBuf is used for reading from runtime/metrics.
+	// We are assuming the largest case to have stable pointers for sampleMap purposes.
+	sampleBuf := make([]metrics.Sample, 0, len(exposedDescriptions)+len(opt.RuntimeMetricSumForHist)+len(rmNamesForMemStatsMetrics))
+	sampleMap := make(map[string]*metrics.Sample, len(exposedDescriptions))
+	for _, d := range exposedDescriptions {
+		namespace, subsystem, name, ok := internal.RuntimeMetricsToProm(&d.Description)
+		if !ok {
+			// Just ignore this metric; we can't do anything with it here.
+			// If a user decides to use the latest version of Go, we don't want
+			// to fail here. This condition is tested in TestExpectedRuntimeMetrics.
+			continue
+		}
+
+		sampleBuf = append(sampleBuf, metrics.Sample{Name: d.Name})
+		sampleMap[d.Name] = &sampleBuf[len(sampleBuf)-1]
+
+		var m collectorMetric
+		if d.Kind == metrics.KindFloat64Histogram {
+			_, hasSum := opt.RuntimeMetricSumForHist[d.Name]
+			unit := d.Name[strings.IndexRune(d.Name, ':')+1:]
+			m = newBatchHistogram(
+				NewDesc(
+					BuildFQName(namespace, subsystem, name),
+					d.Description.Description,
+					nil,
+					nil,
+				),
+				internal.RuntimeMetricsBucketsForUnit(bucketsMap[d.Name], unit),
+				hasSum,
+			)
+		} else if d.Cumulative {
+			m = NewCounter(CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      name,
+				Help:      d.Description.Description,
+			},
+			)
+		} else {
+			m = NewGauge(GaugeOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      name,
+				Help:      d.Description.Description,
+			})
+		}
+		metricSet = append(metricSet, m)
+	}
+
+	// Add exact sum metrics to sampleBuf if not added before.
+	for _, h := range histograms {
+		sumMetric, ok := opt.RuntimeMetricSumForHist[h.Name]
+		if !ok {
+			continue
+		}
+
+		if _, ok := sampleMap[sumMetric]; ok {
+			continue
+		}
+		sampleBuf = append(sampleBuf, metrics.Sample{Name: sumMetric})
+		sampleMap[sumMetric] = &sampleBuf[len(sampleBuf)-1]
+	}
+
+	var (
+		msMetrics      memStatsMetrics
+		msDescriptions []metrics.Description
+	)
+
+	if !opt.DisableMemStatsLikeMetrics {
+		msMetrics = goRuntimeMemStats()
+		msDescriptions = bestEffortLookupRM(rmNamesForMemStatsMetrics)
+
+		// Check if metric was not exposed before and if not, add to sampleBuf.
+		for _, mdDesc := range msDescriptions {
+			if _, ok := sampleMap[mdDesc.Name]; ok {
+				continue
+			}
+			sampleBuf = append(sampleBuf, metrics.Sample{Name: mdDesc.Name})
+			sampleMap[mdDesc.Name] = &sampleBuf[len(sampleBuf)-1]
+		}
+	}
+
+	return &goCollector{
+		base:                 newBaseGoCollector(),
+		sampleBuf:            sampleBuf,
+		sampleMap:            sampleMap,
+		rmExposedMetrics:     metricSet,
+		rmExactSumMapForHist: opt.RuntimeMetricSumForHist,
+		msMetrics:            msMetrics,
+		msMetricsEnabled:     !opt.DisableMemStatsLikeMetrics,
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	c.base.Describe(ch)
+	for _, i := range c.msMetrics {
+		ch <- i.desc
+	}
+	for _, m := range c.rmExposedMetrics {
+		ch <- m.Desc()
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	// Collect base non-memory metrics.
+	c.base.Collect(ch)
+
+	if len(c.sampleBuf) == 0 {
+		return
+	}
+
+	// Collect must be thread-safe, so prevent concurrent use of
+	// sampleBuf elements. Just read into sampleBuf but write all the data
+	// we get into our Metrics or MemStats.
+	//
+	// This lock also ensures that the Metrics we send out are all from
+	// the same updates, ensuring their mutual consistency insofar as
+	// is guaranteed by the runtime/metrics package.
+	//
+	// N.B. This locking is heavy-handed, but Collect is expected to be called
+	// relatively infrequently. Also the core operation here, metrics.Read,
+	// is fast (O(tens of microseconds)) so contention should certainly be
+	// low, though channel operations and any allocations may add to that.
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Populate runtime/metrics sample buffer.
+	metrics.Read(c.sampleBuf)
+
+	// Collect all our runtime/metrics user chose to expose from sampleBuf (if any).
+	for i, metric := range c.rmExposedMetrics {
+		// We created samples for exposed metrics first in order, so indexes match.
+		sample := c.sampleBuf[i]
+
+		// N.B. switch on concrete type because it's significantly more efficient
+		// than checking for the Counter and Gauge interface implementations. In
+		// this case, we control all the types here.
+		switch m := metric.(type) {
+		case *counter:
+			// Guard against decreases. This should never happen, but a failure
+			// to do so will result in a panic, which is a harsh consequence for
+			// a metrics collection bug.
+			v0, v1 := m.get(), unwrapScalarRMValue(sample.Value)
+			if v1 > v0 {
+				m.Add(unwrapScalarRMValue(sample.Value) - m.get())
+			}
+			m.Collect(ch)
+		case *gauge:
+			m.Set(unwrapScalarRMValue(sample.Value))
+			m.Collect(ch)
+		case *batchHistogram:
+			m.update(sample.Value.Float64Histogram(), c.exactSumFor(sample.Name))
+			m.Collect(ch)
+		default:
+			panic("unexpected metric type")
+		}
+	}
+
+	if c.msMetricsEnabled {
+		// ms is a dummy MemStats that we populate ourselves so that we can
+		// populate the old metrics from it if goMemStatsCollection is enabled.
+		var ms runtime.MemStats
+		memStatsFromRM(&ms, c.sampleMap)
+		for _, i := range c.msMetrics {
+			ch <- MustNewConstMetric(i.desc, i.valType, i.eval(&ms))
+		}
+	}
+}
+
+// unwrapScalarRMValue unwraps a runtime/metrics value that is assumed
+// to be scalar and returns the equivalent float64 value. Panics if the
+// value is not scalar.
+func unwrapScalarRMValue(v metrics.Value) float64 {
+	switch v.Kind() {
+	case metrics.KindUint64:
+		return float64(v.Uint64())
+	case metrics.KindFloat64:
+		return v.Float64()
+	case metrics.KindBad:
+		// Unsupported metric.
+		//
+		// This should never happen because we always populate our metric
+		// set from the runtime/metrics package.
+		panic("unexpected unsupported metric")
+	default:
+		// Unsupported metric kind.
+		//
+		// This should never happen because we check for this during initialization
+		// and flag and filter metrics whose kinds we don't understand.
+		panic("unexpected unsupported metric kind")
+	}
+}
+
+// exactSumFor takes a runtime/metrics metric name (that is assumed to
+// be of kind KindFloat64Histogram) and returns its exact sum and whether
+// its exact sum exists.
+//
+// The runtime/metrics API for histograms doesn't currently expose exact
+// sums, but some of the other metrics are in fact exact sums of histograms.
+func (c *goCollector) exactSumFor(rmName string) float64 {
+	sumName, ok := c.rmExactSumMapForHist[rmName]
+	if !ok {
+		return 0
+	}
+	s, ok := c.sampleMap[sumName]
+	if !ok {
+		return 0
+	}
+	return unwrapScalarRMValue(s.Value)
+}
+
+func memStatsFromRM(ms *runtime.MemStats, rm map[string]*metrics.Sample) {
+	lookupOrZero := func(name string) uint64 {
+		if s, ok := rm[name]; ok {
+			return s.Value.Uint64()
+		}
+		return 0
+	}
+
+	// Currently, MemStats adds tiny alloc count to both Mallocs AND Frees.
+	// The reason for this is because MemStats couldn't be extended at the time
+	// but there was a desire to have Mallocs at least be a little more representative,
+	// while having Mallocs - Frees still represent a live object count.
+	// Unfortunately, MemStats doesn't actually export a large allocation count,
+	// so it's impossible to pull this number out directly.
+	tinyAllocs := lookupOrZero(goGCHeapTinyAllocsObjects)
+	ms.Mallocs = lookupOrZero(goGCHeapAllocsObjects) + tinyAllocs
+	ms.Frees = lookupOrZero(goGCHeapFreesObjects) + tinyAllocs
+
+	ms.TotalAlloc = lookupOrZero(goGCHeapAllocsBytes)
+	ms.Sys = lookupOrZero(goMemoryClassesTotalBytes)
+	ms.Lookups = 0 // Already always zero.
+	ms.HeapAlloc = lookupOrZero(goMemoryClassesHeapObjectsBytes)
+	ms.Alloc = ms.HeapAlloc
+	ms.HeapInuse = ms.HeapAlloc + lookupOrZero(goMemoryClassesHeapUnusedBytes)
+	ms.HeapReleased = lookupOrZero(goMemoryClassesHeapReleasedBytes)
+	ms.HeapIdle = ms.HeapReleased + lookupOrZero(goMemoryClassesHeapFreeBytes)
+	ms.HeapSys = ms.HeapInuse + ms.HeapIdle
+	ms.HeapObjects = lookupOrZero(goGCHeapObjects)
+	ms.StackInuse = lookupOrZero(goMemoryClassesHeapStacksBytes)
+	ms.StackSys = ms.StackInuse + lookupOrZero(goMemoryClassesOSStacksBytes)
+	ms.MSpanInuse = lookupOrZero(goMemoryClassesMetadataMSpanInuseBytes)
+	ms.MSpanSys = ms.MSpanInuse + lookupOrZero(goMemoryClassesMetadataMSPanFreeBytes)
+	ms.MCacheInuse = lookupOrZero(goMemoryClassesMetadataMCacheInuseBytes)
+	ms.MCacheSys = ms.MCacheInuse + lookupOrZero(goMemoryClassesMetadataMCacheFreeBytes)
+	ms.BuckHashSys = lookupOrZero(goMemoryClassesProfilingBucketsBytes)
+	ms.GCSys = lookupOrZero(goMemoryClassesMetadataOtherBytes)
+	ms.OtherSys = lookupOrZero(goMemoryClassesOtherBytes)
+	ms.NextGC = lookupOrZero(goGCHeapGoalBytes)
+
+	// N.B. GCCPUFraction is intentionally omitted. This metric is not useful,
+	// and often misleading due to the fact that it's an average over the lifetime
+	// of the process.
+	// See https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
+	// for more details.
+	ms.GCCPUFraction = 0
+}
+
+// batchHistogram is a mutable histogram that is updated
+// in batches.
+type batchHistogram struct {
+	selfCollector
+
+	// Static fields updated only once.
+	desc   *Desc
+	hasSum bool
+
+	// Because this histogram operates in batches, it just uses a
+	// single mutex for everything. updates are always serialized
+	// but Write calls may operate concurrently with updates.
+	// Contention between these two sources should be rare.
+	mu      sync.Mutex
+	buckets []float64 // Inclusive lower bounds, like runtime/metrics.
+	counts  []uint64
+	sum     float64 // Used if hasSum is true.
+}
+
+// newBatchHistogram creates a new batch histogram value with the given
+// Desc, buckets, and whether or not it has an exact sum available.
+//
+// buckets must always be from the runtime/metrics package, following
+// the same conventions.
+func newBatchHistogram(desc *Desc, buckets []float64, hasSum bool) *batchHistogram {
+	// We need to remove -Inf values. runtime/metrics keeps them around.
+	// But -Inf bucket should not be allowed for prometheus histograms.
+	if buckets[0] == math.Inf(-1) {
+		buckets = buckets[1:]
+	}
+	h := &batchHistogram{
+		desc:    desc,
+		buckets: buckets,
+		// Because buckets follows runtime/metrics conventions, there's
+		// 1 more value in the buckets list than there are buckets represented,
+		// because in runtime/metrics, the bucket values represent *boundaries*,
+		// and non-Inf boundaries are inclusive lower bounds for that bucket.
+		counts: make([]uint64, len(buckets)-1),
+		hasSum: hasSum,
+	}
+	h.init(h)
+	return h
+}
+
+// update updates the batchHistogram from a runtime/metrics histogram.
+//
+// sum must be provided if the batchHistogram was created to have an exact sum.
+// h.buckets must be a strict subset of his.Buckets.
+func (h *batchHistogram) update(his *metrics.Float64Histogram, sum float64) {
+	counts, buckets := his.Counts, his.Buckets
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	// Clear buckets.
+	for i := range h.counts {
+		h.counts[i] = 0
+	}
+	// Copy and reduce buckets.
+	var j int
+	for i, count := range counts {
+		h.counts[j] += count
+		if buckets[i+1] == h.buckets[j+1] {
+			j++
+		}
+	}
+	if h.hasSum {
+		h.sum = sum
+	}
+}
+
+func (h *batchHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *batchHistogram) Write(out *dto.Metric) error {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	sum := float64(0)
+	if h.hasSum {
+		sum = h.sum
+	}
+	dtoBuckets := make([]*dto.Bucket, 0, len(h.counts))
+	totalCount := uint64(0)
+	for i, count := range h.counts {
+		totalCount += count
+		if !h.hasSum {
+			if count != 0 {
+				// N.B. This computed sum is an underestimate.
+				sum += h.buckets[i] * float64(count)
+			}
+		}
+
+		// Skip the +Inf bucket, but only for the bucket list.
+		// It must still count for sum and totalCount.
+		if math.IsInf(h.buckets[i+1], 1) {
+			break
+		}
+		// Float64Histogram's upper bound is exclusive, so make it inclusive
+		// by obtaining the next float64 value down, in order.
+		upperBound := math.Nextafter(h.buckets[i+1], h.buckets[i])
+		dtoBuckets = append(dtoBuckets, &dto.Bucket{
+			CumulativeCount: proto.Uint64(totalCount),
+			UpperBound:      proto.Float64(upperBound),
+		})
+	}
+	out.Histogram = &dto.Histogram{
+		Bucket:      dtoBuckets,
+		SampleCount: proto.Uint64(totalCount),
+		SampleSum:   proto.Float64(sum),
+	}
+	return nil
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/almost_equal.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2015 Björn Rabenstein
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// The code in this package is copy/paste to avoid a dependency. Hence this file
+// carries the copyright of the original repo.
+// https://github.com/beorn7/floats
+package internal
+
+import (
+	"math"
+)
+
+// minNormalFloat64 is the smallest positive normal value of type float64.
+var minNormalFloat64 = math.Float64frombits(0x0010000000000000)
+
+// AlmostEqualFloat64 returns true if a and b are equal within a relative error
+// of epsilon. See http://floating-point-gui.de/errors/comparison/ for the
+// details of the applied method.
+func AlmostEqualFloat64(a, b, epsilon float64) bool {
+	if a == b {
+		return true
+	}
+	absA := math.Abs(a)
+	absB := math.Abs(b)
+	diff := math.Abs(a - b)
+	if a == 0 || b == 0 || absA+absB < minNormalFloat64 {
+		return diff < epsilon*minNormalFloat64
+	}
+	return diff/math.Min(absA+absB, math.MaxFloat64) < epsilon
+}
+
+// AlmostEqualFloat64s is the slice form of AlmostEqualFloat64.
+func AlmostEqualFloat64s(a, b []float64, epsilon float64) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if !AlmostEqualFloat64(a[i], b[i], epsilon) {
+			return false
+		}
+	}
+	return true
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/difflib.go

@@ -0,0 +1,654 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// It provides tools to compare sequences of strings and generate textual diffs.
+//
+// Maintaining `GetUnifiedDiffString` here because original repository
+// (https://github.com/pmezard/go-difflib) is no longer maintained.
+package internal
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func calculateRatio(matches, length int) float64 {
+	if length > 0 {
+		return 2.0 * float64(matches) / float64(length)
+	}
+	return 1.0
+}
+
+type Match struct {
+	A    int
+	B    int
+	Size int
+}
+
+type OpCode struct {
+	Tag byte
+	I1  int
+	I2  int
+	J1  int
+	J2  int
+}
+
+// SequenceMatcher compares sequence of strings. The basic
+// algorithm predates, and is a little fancier than, an algorithm
+// published in the late 1980's by Ratcliff and Obershelp under the
+// hyperbolic name "gestalt pattern matching".  The basic idea is to find
+// the longest contiguous matching subsequence that contains no "junk"
+// elements (R-O doesn't address junk).  The same idea is then applied
+// recursively to the pieces of the sequences to the left and to the right
+// of the matching subsequence.  This does not yield minimal edit
+// sequences, but does tend to yield matches that "look right" to people.
+//
+// SequenceMatcher tries to compute a "human-friendly diff" between two
+// sequences.  Unlike e.g. UNIX(tm) diff, the fundamental notion is the
+// longest *contiguous* & junk-free matching subsequence.  That's what
+// catches peoples' eyes.  The Windows(tm) windiff has another interesting
+// notion, pairing up elements that appear uniquely in each sequence.
+// That, and the method here, appear to yield more intuitive difference
+// reports than does diff.  This method appears to be the least vulnerable
+// to synching up on blocks of "junk lines", though (like blank lines in
+// ordinary text files, or maybe "<P>" lines in HTML files).  That may be
+// because this is the only method of the 3 that has a *concept* of
+// "junk" <wink>.
+//
+// Timing:  Basic R-O is cubic time worst case and quadratic time expected
+// case.  SequenceMatcher is quadratic time for the worst case and has
+// expected-case behavior dependent in a complicated way on how many
+// elements the sequences have in common; best case time is linear.
+type SequenceMatcher struct {
+	a              []string
+	b              []string
+	b2j            map[string][]int
+	IsJunk         func(string) bool
+	autoJunk       bool
+	bJunk          map[string]struct{}
+	matchingBlocks []Match
+	fullBCount     map[string]int
+	bPopular       map[string]struct{}
+	opCodes        []OpCode
+}
+
+func NewMatcher(a, b []string) *SequenceMatcher {
+	m := SequenceMatcher{autoJunk: true}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+func NewMatcherWithJunk(a, b []string, autoJunk bool,
+	isJunk func(string) bool,
+) *SequenceMatcher {
+	m := SequenceMatcher{IsJunk: isJunk, autoJunk: autoJunk}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+// Set two sequences to be compared.
+func (m *SequenceMatcher) SetSeqs(a, b []string) {
+	m.SetSeq1(a)
+	m.SetSeq2(b)
+}
+
+// Set the first sequence to be compared. The second sequence to be compared is
+// not changed.
+//
+// SequenceMatcher computes and caches detailed information about the second
+// sequence, so if you want to compare one sequence S against many sequences,
+// use .SetSeq2(s) once and call .SetSeq1(x) repeatedly for each of the other
+// sequences.
+//
+// See also SetSeqs() and SetSeq2().
+func (m *SequenceMatcher) SetSeq1(a []string) {
+	if &a == &m.a {
+		return
+	}
+	m.a = a
+	m.matchingBlocks = nil
+	m.opCodes = nil
+}
+
+// Set the second sequence to be compared. The first sequence to be compared is
+// not changed.
+func (m *SequenceMatcher) SetSeq2(b []string) {
+	if &b == &m.b {
+		return
+	}
+	m.b = b
+	m.matchingBlocks = nil
+	m.opCodes = nil
+	m.fullBCount = nil
+	m.chainB()
+}
+
+func (m *SequenceMatcher) chainB() {
+	// Populate line -> index mapping
+	b2j := map[string][]int{}
+	for i, s := range m.b {
+		indices := b2j[s]
+		indices = append(indices, i)
+		b2j[s] = indices
+	}
+
+	// Purge junk elements
+	m.bJunk = map[string]struct{}{}
+	if m.IsJunk != nil {
+		junk := m.bJunk
+		for s := range b2j {
+			if m.IsJunk(s) {
+				junk[s] = struct{}{}
+			}
+		}
+		for s := range junk {
+			delete(b2j, s)
+		}
+	}
+
+	// Purge remaining popular elements
+	popular := map[string]struct{}{}
+	n := len(m.b)
+	if m.autoJunk && n >= 200 {
+		ntest := n/100 + 1
+		for s, indices := range b2j {
+			if len(indices) > ntest {
+				popular[s] = struct{}{}
+			}
+		}
+		for s := range popular {
+			delete(b2j, s)
+		}
+	}
+	m.bPopular = popular
+	m.b2j = b2j
+}
+
+func (m *SequenceMatcher) isBJunk(s string) bool {
+	_, ok := m.bJunk[s]
+	return ok
+}
+
+// Find longest matching block in a[alo:ahi] and b[blo:bhi].
+//
+// If IsJunk is not defined:
+//
+// Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
+//
+//	alo <= i <= i+k <= ahi
+//	blo <= j <= j+k <= bhi
+//
+// and for all (i',j',k') meeting those conditions,
+//
+//	k >= k'
+//	i <= i'
+//	and if i == i', j <= j'
+//
+// In other words, of all maximal matching blocks, return one that
+// starts earliest in a, and of all those maximal matching blocks that
+// start earliest in a, return the one that starts earliest in b.
+//
+// If IsJunk is defined, first the longest matching block is
+// determined as above, but with the additional restriction that no
+// junk element appears in the block.  Then that block is extended as
+// far as possible by matching (only) junk elements on both sides.  So
+// the resulting block never matches on junk except as identical junk
+// happens to be adjacent to an "interesting" match.
+//
+// If no blocks match, return (alo, blo, 0).
+func (m *SequenceMatcher) findLongestMatch(alo, ahi, blo, bhi int) Match {
+	// CAUTION:  stripping common prefix or suffix would be incorrect.
+	// E.g.,
+	//    ab
+	//    acab
+	// Longest matching block is "ab", but if common prefix is
+	// stripped, it's "a" (tied with "b").  UNIX(tm) diff does so
+	// strip, so ends up claiming that ab is changed to acab by
+	// inserting "ca" in the middle.  That's minimal but unintuitive:
+	// "it's obvious" that someone inserted "ac" at the front.
+	// Windiff ends up at the same place as diff, but by pairing up
+	// the unique 'b's and then matching the first two 'a's.
+	besti, bestj, bestsize := alo, blo, 0
+
+	// find longest junk-free match
+	// during an iteration of the loop, j2len[j] = length of longest
+	// junk-free match ending with a[i-1] and b[j]
+	j2len := map[int]int{}
+	for i := alo; i != ahi; i++ {
+		// look at all instances of a[i] in b; note that because
+		// b2j has no junk keys, the loop is skipped if a[i] is junk
+		newj2len := map[int]int{}
+		for _, j := range m.b2j[m.a[i]] {
+			// a[i] matches b[j]
+			if j < blo {
+				continue
+			}
+			if j >= bhi {
+				break
+			}
+			k := j2len[j-1] + 1
+			newj2len[j] = k
+			if k > bestsize {
+				besti, bestj, bestsize = i-k+1, j-k+1, k
+			}
+		}
+		j2len = newj2len
+	}
+
+	// Extend the best by non-junk elements on each end.  In particular,
+	// "popular" non-junk elements aren't in b2j, which greatly speeds
+	// the inner loop above, but also means "the best" match so far
+	// doesn't contain any junk *or* popular non-junk elements.
+	for besti > alo && bestj > blo && !m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		!m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize++
+	}
+
+	// Now that we have a wholly interesting match (albeit possibly
+	// empty!), we may as well suck up the matching junk on each
+	// side of it too.  Can't think of a good reason not to, and it
+	// saves post-processing the (possibly considerable) expense of
+	// figuring out what to do with it.  In the case of an empty
+	// interesting match, this is clearly the right thing to do,
+	// because no other kind of match is possible in the regions.
+	for besti > alo && bestj > blo && m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize++
+	}
+
+	return Match{A: besti, B: bestj, Size: bestsize}
+}
+
+// Return list of triples describing matching subsequences.
+//
+// Each triple is of the form (i, j, n), and means that
+// a[i:i+n] == b[j:j+n].  The triples are monotonically increasing in
+// i and in j. It's also guaranteed that if (i, j, n) and (i', j', n') are
+// adjacent triples in the list, and the second is not the last triple in the
+// list, then i+n != i' or j+n != j'. IOW, adjacent triples never describe
+// adjacent equal blocks.
+//
+// The last triple is a dummy, (len(a), len(b), 0), and is the only
+// triple with n==0.
+func (m *SequenceMatcher) GetMatchingBlocks() []Match {
+	if m.matchingBlocks != nil {
+		return m.matchingBlocks
+	}
+
+	var matchBlocks func(alo, ahi, blo, bhi int, matched []Match) []Match
+	matchBlocks = func(alo, ahi, blo, bhi int, matched []Match) []Match {
+		match := m.findLongestMatch(alo, ahi, blo, bhi)
+		i, j, k := match.A, match.B, match.Size
+		if match.Size > 0 {
+			if alo < i && blo < j {
+				matched = matchBlocks(alo, i, blo, j, matched)
+			}
+			matched = append(matched, match)
+			if i+k < ahi && j+k < bhi {
+				matched = matchBlocks(i+k, ahi, j+k, bhi, matched)
+			}
+		}
+		return matched
+	}
+	matched := matchBlocks(0, len(m.a), 0, len(m.b), nil)
+
+	// It's possible that we have adjacent equal blocks in the
+	// matching_blocks list now.
+	nonAdjacent := []Match{}
+	i1, j1, k1 := 0, 0, 0
+	for _, b := range matched {
+		// Is this block adjacent to i1, j1, k1?
+		i2, j2, k2 := b.A, b.B, b.Size
+		if i1+k1 == i2 && j1+k1 == j2 {
+			// Yes, so collapse them -- this just increases the length of
+			// the first block by the length of the second, and the first
+			// block so lengthened remains the block to compare against.
+			k1 += k2
+		} else {
+			// Not adjacent.  Remember the first block (k1==0 means it's
+			// the dummy we started with), and make the second block the
+			// new block to compare against.
+			if k1 > 0 {
+				nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+			}
+			i1, j1, k1 = i2, j2, k2
+		}
+	}
+	if k1 > 0 {
+		nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+	}
+
+	nonAdjacent = append(nonAdjacent, Match{len(m.a), len(m.b), 0})
+	m.matchingBlocks = nonAdjacent
+	return m.matchingBlocks
+}
+
+// Return list of 5-tuples describing how to turn a into b.
+//
+// Each tuple is of the form (tag, i1, i2, j1, j2).  The first tuple
+// has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
+// tuple preceding it, and likewise for j1 == the previous j2.
+//
+// The tags are characters, with these meanings:
+//
+// 'r' (replace):  a[i1:i2] should be replaced by b[j1:j2]
+//
+// 'd' (delete):   a[i1:i2] should be deleted, j1==j2 in this case.
+//
+// 'i' (insert):   b[j1:j2] should be inserted at a[i1:i1], i1==i2 in this case.
+//
+// 'e' (equal):    a[i1:i2] == b[j1:j2]
+func (m *SequenceMatcher) GetOpCodes() []OpCode {
+	if m.opCodes != nil {
+		return m.opCodes
+	}
+	i, j := 0, 0
+	matching := m.GetMatchingBlocks()
+	opCodes := make([]OpCode, 0, len(matching))
+	for _, m := range matching {
+		//  invariant:  we've pumped out correct diffs to change
+		//  a[:i] into b[:j], and the next matching block is
+		//  a[ai:ai+size] == b[bj:bj+size]. So we need to pump
+		//  out a diff to change a[i:ai] into b[j:bj], pump out
+		//  the matching block, and move (i,j) beyond the match
+		ai, bj, size := m.A, m.B, m.Size
+		tag := byte(0)
+		if i < ai && j < bj {
+			tag = 'r'
+		} else if i < ai {
+			tag = 'd'
+		} else if j < bj {
+			tag = 'i'
+		}
+		if tag > 0 {
+			opCodes = append(opCodes, OpCode{tag, i, ai, j, bj})
+		}
+		i, j = ai+size, bj+size
+		// the list of matching blocks is terminated by a
+		// sentinel with size 0
+		if size > 0 {
+			opCodes = append(opCodes, OpCode{'e', ai, i, bj, j})
+		}
+	}
+	m.opCodes = opCodes
+	return m.opCodes
+}
+
+// Isolate change clusters by eliminating ranges with no changes.
+//
+// Return a generator of groups with up to n lines of context.
+// Each group is in the same format as returned by GetOpCodes().
+func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
+	if n < 0 {
+		n = 3
+	}
+	codes := m.GetOpCodes()
+	if len(codes) == 0 {
+		codes = []OpCode{{'e', 0, 1, 0, 1}}
+	}
+	// Fixup leading and trailing groups if they show no changes.
+	if codes[0].Tag == 'e' {
+		c := codes[0]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+	}
+	if codes[len(codes)-1].Tag == 'e' {
+		c := codes[len(codes)-1]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+	}
+	nn := n + n
+	groups := [][]OpCode{}
+	group := []OpCode{}
+	for _, c := range codes {
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		// End the current group and start a new one whenever
+		// there is a large range with no changes.
+		if c.Tag == 'e' && i2-i1 > nn {
+			group = append(group, OpCode{
+				c.Tag, i1, min(i2, i1+n),
+				j1, min(j2, j1+n),
+			})
+			groups = append(groups, group)
+			group = []OpCode{}
+			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+		}
+		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
+	}
+	if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
+		groups = append(groups, group)
+	}
+	return groups
+}
+
+// Return a measure of the sequences' similarity (float in [0,1]).
+//
+// Where T is the total number of elements in both sequences, and
+// M is the number of matches, this is 2.0*M / T.
+// Note that this is 1 if the sequences are identical, and 0 if
+// they have nothing in common.
+//
+// .Ratio() is expensive to compute if you haven't already computed
+// .GetMatchingBlocks() or .GetOpCodes(), in which case you may
+// want to try .QuickRatio() or .RealQuickRation() first to get an
+// upper bound.
+func (m *SequenceMatcher) Ratio() float64 {
+	matches := 0
+	for _, m := range m.GetMatchingBlocks() {
+		matches += m.Size
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() relatively quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute.
+func (m *SequenceMatcher) QuickRatio() float64 {
+	// viewing a and b as multisets, set matches to the cardinality
+	// of their intersection; this counts the number of matches
+	// without regard to order, so is clearly an upper bound
+	if m.fullBCount == nil {
+		m.fullBCount = map[string]int{}
+		for _, s := range m.b {
+			m.fullBCount[s]++
+		}
+	}
+
+	// avail[x] is the number of times x appears in 'b' less the
+	// number of times we've seen it in 'a' so far ... kinda
+	avail := map[string]int{}
+	matches := 0
+	for _, s := range m.a {
+		n, ok := avail[s]
+		if !ok {
+			n = m.fullBCount[s]
+		}
+		avail[s] = n - 1
+		if n > 0 {
+			matches++
+		}
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() very quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute than either .Ratio() or .QuickRatio().
+func (m *SequenceMatcher) RealQuickRatio() float64 {
+	la, lb := len(m.a), len(m.b)
+	return calculateRatio(min(la, lb), la+lb)
+}
+
+// Convert range to the "ed" format
+func formatRangeUnified(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	if length == 0 {
+		beginning-- // empty ranges begin at line just before the range
+	}
+	return fmt.Sprintf("%d,%d", beginning, length)
+}
+
+// Unified diff parameters
+type UnifiedDiff struct {
+	A        []string // First sequence lines
+	FromFile string   // First file name
+	FromDate string   // First file time
+	B        []string // Second sequence lines
+	ToFile   string   // Second file name
+	ToDate   string   // Second file time
+	Eol      string   // Headers end of line, defaults to LF
+	Context  int      // Number of context lines
+}
+
+// Compare two sequences of lines; generate the delta as a unified diff.
+//
+// Unified diffs are a compact way of showing line changes and a few
+// lines of context.  The number of context lines is set by 'n' which
+// defaults to three.
+//
+// By default, the diff control lines (those with ---, +++, or @@) are
+// created with a trailing newline.  This is helpful so that inputs
+// created from file.readlines() result in diffs that are suitable for
+// file.writelines() since both the inputs and outputs have trailing
+// newlines.
+//
+// For inputs that do not have trailing newlines, set the lineterm
+// argument to "" so that the output will be uniformly newline free.
+//
+// The unidiff format normally has a header for filenames and modification
+// times.  Any or all of these may be specified using strings for
+// 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
+// The modification times are normally expressed in the ISO 8601 format.
+func WriteUnifiedDiff(writer io.Writer, diff UnifiedDiff) error {
+	buf := bufio.NewWriter(writer)
+	defer buf.Flush()
+	wf := func(format string, args ...interface{}) error {
+		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		return err
+	}
+	ws := func(s string) error {
+		_, err := buf.WriteString(s)
+		return err
+	}
+
+	if len(diff.Eol) == 0 {
+		diff.Eol = "\n"
+	}
+
+	started := false
+	m := NewMatcher(diff.A, diff.B)
+	for _, g := range m.GetGroupedOpCodes(diff.Context) {
+		if !started {
+			started = true
+			fromDate := ""
+			if len(diff.FromDate) > 0 {
+				fromDate = "\t" + diff.FromDate
+			}
+			toDate := ""
+			if len(diff.ToDate) > 0 {
+				toDate = "\t" + diff.ToDate
+			}
+			if diff.FromFile != "" || diff.ToFile != "" {
+				err := wf("--- %s%s%s", diff.FromFile, fromDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+				err = wf("+++ %s%s%s", diff.ToFile, toDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+			}
+		}
+		first, last := g[0], g[len(g)-1]
+		range1 := formatRangeUnified(first.I1, last.I2)
+		range2 := formatRangeUnified(first.J1, last.J2)
+		if err := wf("@@ -%s +%s @@%s", range1, range2, diff.Eol); err != nil {
+			return err
+		}
+		for _, c := range g {
+			i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+			if c.Tag == 'e' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws(" " + line); err != nil {
+						return err
+					}
+				}
+				continue
+			}
+			if c.Tag == 'r' || c.Tag == 'd' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws("-" + line); err != nil {
+						return err
+					}
+				}
+			}
+			if c.Tag == 'r' || c.Tag == 'i' {
+				for _, line := range diff.B[j1:j2] {
+					if err := ws("+" + line); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// Like WriteUnifiedDiff but returns the diff a string.
+func GetUnifiedDiffString(diff UnifiedDiff) (string, error) {
+	w := &bytes.Buffer{}
+	err := WriteUnifiedDiff(w, diff)
+	return w.String(), err
+}
+
+// Split a string on "\n" while preserving them. The output can be used
+// as input for UnifiedDiff and ContextDiff structures.
+func SplitLines(s string) []string {
+	lines := strings.SplitAfter(s, "\n")
+	lines[len(lines)-1] += "\n"
+	return lines
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/go_collector_options.go

@@ -0,0 +1,32 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import "regexp"
+
+type GoCollectorRule struct {
+	Matcher *regexp.Regexp
+	Deny    bool
+}
+
+// GoCollectorOptions should not be used be directly by anything, except `collectors` package.
+// Use it via collectors package instead. See issue
+// https://github.com/prometheus/client_golang/issues/1030.
+//
+// This is internal, so external users only can use it via `collector.WithGoCollector*` methods
+type GoCollectorOptions struct {
+	DisableMemStatsLikeMetrics bool
+	RuntimeMetricSumForHist    map[string]string
+	RuntimeMetricRules         []GoCollectorRule
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/go_runtime_metrics.go

@@ -0,0 +1,142 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.17
+// +build go1.17
+
+package internal
+
+import (
+	"math"
+	"path"
+	"runtime/metrics"
+	"strings"
+
+	"github.com/prometheus/common/model"
+)
+
+// RuntimeMetricsToProm produces a Prometheus metric name from a runtime/metrics
+// metric description and validates whether the metric is suitable for integration
+// with Prometheus.
+//
+// Returns false if a name could not be produced, or if Prometheus does not understand
+// the runtime/metrics Kind.
+//
+// Note that the main reason a name couldn't be produced is if the runtime/metrics
+// package exports a name with characters outside the valid Prometheus metric name
+// character set. This is theoretically possible, but should never happen in practice.
+// Still, don't rely on it.
+func RuntimeMetricsToProm(d *metrics.Description) (string, string, string, bool) {
+	namespace := "go"
+
+	comp := strings.SplitN(d.Name, ":", 2)
+	key := comp[0]
+	unit := comp[1]
+
+	// The last path element in the key is the name,
+	// the rest is the subsystem.
+	subsystem := path.Dir(key[1:] /* remove leading / */)
+	name := path.Base(key)
+
+	// subsystem is translated by replacing all / and - with _.
+	subsystem = strings.ReplaceAll(subsystem, "/", "_")
+	subsystem = strings.ReplaceAll(subsystem, "-", "_")
+
+	// unit is translated assuming that the unit contains no
+	// non-ASCII characters.
+	unit = strings.ReplaceAll(unit, "-", "_")
+	unit = strings.ReplaceAll(unit, "*", "_")
+	unit = strings.ReplaceAll(unit, "/", "_per_")
+
+	// name has - replaced with _ and is concatenated with the unit and
+	// other data.
+	name = strings.ReplaceAll(name, "-", "_")
+	name += "_" + unit
+	if d.Cumulative && d.Kind != metrics.KindFloat64Histogram {
+		name += "_total"
+	}
+
+	valid := model.IsValidMetricName(model.LabelValue(namespace + "_" + subsystem + "_" + name))
+	switch d.Kind {
+	case metrics.KindUint64:
+	case metrics.KindFloat64:
+	case metrics.KindFloat64Histogram:
+	default:
+		valid = false
+	}
+	return namespace, subsystem, name, valid
+}
+
+// RuntimeMetricsBucketsForUnit takes a set of buckets obtained for a runtime/metrics histogram
+// type (so, lower-bound inclusive) and a unit from a runtime/metrics name, and produces
+// a reduced set of buckets. This function always removes any -Inf bucket as it's represented
+// as the bottom-most upper-bound inclusive bucket in Prometheus.
+func RuntimeMetricsBucketsForUnit(buckets []float64, unit string) []float64 {
+	switch unit {
+	case "bytes":
+		// Re-bucket as powers of 2.
+		return reBucketExp(buckets, 2)
+	case "seconds":
+		// Re-bucket as powers of 10 and then merge all buckets greater
+		// than 1 second into the +Inf bucket.
+		b := reBucketExp(buckets, 10)
+		for i := range b {
+			if b[i] <= 1 {
+				continue
+			}
+			b[i] = math.Inf(1)
+			b = b[:i+1]
+			break
+		}
+		return b
+	}
+	return buckets
+}
+
+// reBucketExp takes a list of bucket boundaries (lower bound inclusive) and
+// downsamples the buckets to those a multiple of base apart. The end result
+// is a roughly exponential (in many cases, perfectly exponential) bucketing
+// scheme.
+func reBucketExp(buckets []float64, base float64) []float64 {
+	bucket := buckets[0]
+	var newBuckets []float64
+	// We may see a -Inf here, in which case, add it and skip it
+	// since we risk producing NaNs otherwise.
+	//
+	// We need to preserve -Inf values to maintain runtime/metrics
+	// conventions. We'll strip it out later.
+	if bucket == math.Inf(-1) {
+		newBuckets = append(newBuckets, bucket)
+		buckets = buckets[1:]
+		bucket = buckets[0]
+	}
+	// From now on, bucket should always have a non-Inf value because
+	// Infs are only ever at the ends of the bucket lists, so
+	// arithmetic operations on it are non-NaN.
+	for i := 1; i < len(buckets); i++ {
+		if bucket >= 0 && buckets[i] < bucket*base {
+			// The next bucket we want to include is at least bucket*base.
+			continue
+		} else if bucket < 0 && buckets[i] < bucket/base {
+			// In this case the bucket we're targeting is negative, and since
+			// we're ascending through buckets here, we need to divide to get
+			// closer to zero exponentially.
+			continue
+		}
+		// The +Inf bucket will always be the last one, and we'll always
+		// end up including it here because bucket
+		newBuckets = append(newBuckets, bucket)
+		bucket = buckets[i]
+	}
+	return append(newBuckets, bucket)
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/metric.go

@@ -0,0 +1,101 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"sort"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// LabelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers.
+type LabelPairSorter []*dto.LabelPair
+
+func (s LabelPairSorter) Len() int {
+	return len(s)
+}
+
+func (s LabelPairSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s LabelPairSorter) Less(i, j int) bool {
+	return s[i].GetName() < s[j].GetName()
+}
+
+// MetricSorter is a sortable slice of *dto.Metric.
+type MetricSorter []*dto.Metric
+
+func (s MetricSorter) Len() int {
+	return len(s)
+}
+
+func (s MetricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s MetricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// NormalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func NormalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(MetricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -0,0 +1,186 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/prometheus/common/model"
+)
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//
+//	myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// LabelConstraint normalizes label values.
+type LabelConstraint func(string) string
+
+// ConstrainedLabels represents a label name and its constrain function
+// to normalize label values. This type is commonly used when constructing
+// metric vector Collectors.
+type ConstrainedLabel struct {
+	Name       string
+	Constraint LabelConstraint
+}
+
+// ConstrainableLabels is an interface that allows creating of labels that can
+// be optionally constrained.
+//
+//	prometheus.V2().NewCounterVec(CounterVecOpts{
+//	  CounterOpts: {...}, // Usual CounterOpts fields
+//	  VariableLabels: []ConstrainedLabels{
+//	    {Name: "A"},
+//	    {Name: "B", Constraint: func(v string) string { ... }},
+//	  },
+//	})
+type ConstrainableLabels interface {
+	compile() *compiledLabels
+	labelNames() []string
+}
+
+// ConstrainedLabels represents a collection of label name -> constrain function
+// to normalize label values. This type is commonly used when constructing
+// metric vector Collectors.
+type ConstrainedLabels []ConstrainedLabel
+
+func (cls ConstrainedLabels) compile() *compiledLabels {
+	compiled := &compiledLabels{
+		names:            make([]string, len(cls)),
+		labelConstraints: map[string]LabelConstraint{},
+	}
+
+	for i, label := range cls {
+		compiled.names[i] = label.Name
+		if label.Constraint != nil {
+			compiled.labelConstraints[label.Name] = label.Constraint
+		}
+	}
+
+	return compiled
+}
+
+func (cls ConstrainedLabels) labelNames() []string {
+	names := make([]string, len(cls))
+	for i, label := range cls {
+		names[i] = label.Name
+	}
+	return names
+}
+
+// UnconstrainedLabels represents collection of label without any constraint on
+// their value. Thus, it is simply a collection of label names.
+//
+//	UnconstrainedLabels([]string{ "A", "B" })
+//
+// is equivalent to
+//
+//	ConstrainedLabels {
+//	  { Name: "A" },
+//	  { Name: "B" },
+//	}
+type UnconstrainedLabels []string
+
+func (uls UnconstrainedLabels) compile() *compiledLabels {
+	return &compiledLabels{
+		names: uls,
+	}
+}
+
+func (uls UnconstrainedLabels) labelNames() []string {
+	return uls
+}
+
+type compiledLabels struct {
+	names            []string
+	labelConstraints map[string]LabelConstraint
+}
+
+func (cls *compiledLabels) compile() *compiledLabels {
+	return cls
+}
+
+func (cls *compiledLabels) labelNames() []string {
+	return cls.names
+}
+
+func (cls *compiledLabels) constrain(labelName, value string) string {
+	if fn, ok := cls.labelConstraints[labelName]; ok && fn != nil {
+		return fn(value)
+	}
+	return value
+}
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
+	return fmt.Errorf(
+		"%w: %q has %d variable labels named %q but %d values %q were provided",
+		errInconsistentCardinality, fqName,
+		len(labels), labels,
+		len(labelValues), labelValues,
+	)
+}
+
+func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
+	if len(labels) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%w: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(labels), labels,
+		)
+	}
+
+	for name, val := range labels {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
+		}
+	}
+
+	return nil
+}
+
+func validateLabelValues(vals []string, expectedNumberOfValues int) error {
+	if len(vals) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%w: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(vals), vals,
+		)
+	}
+
+	for _, val := range vals {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label value %q is not valid UTF-8", val)
+		}
+	}
+
+	return nil
+}
+
+func checkLabelName(l string) bool {
+	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+}

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -0,0 +1,257 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"math"
+	"sort"
+	"strings"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/model"
+	"google.golang.org/protobuf/proto"
+)
+
+var separatorByteSlice = []byte{model.SeparatorByte} // For convenient use with xxhash.
+
+// A Metric models a single sample value with its meta data being exported to
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
+type Metric interface {
+	// Desc returns the descriptor for the Metric. This method idempotently
+	// returns the same descriptor throughout the lifetime of the
+	// Metric. The returned descriptor is immutable by contract. A Metric
+	// unable to describe itself must return an invalid descriptor (created
+	// with NewInvalidDesc).
+	Desc() *Desc
+	// Write encodes the Metric into a "Metric" Protocol Buffer data
+	// transmission object.
+	//
+	// Metric implementations must observe concurrency safety as reads of
+	// this metric may occur at any time, and any blocking occurs at the
+	// expense of total performance of rendering all registered
+	// metrics. Ideally, Metric implementations should support concurrent
+	// readers.
+	//
+	// While populating dto.Metric, it is the responsibility of the
+	// implementation to ensure validity of the Metric protobuf (like valid
+	// UTF-8 strings or syntactically valid metric and label names). It is
+	// recommended to sort labels lexicographically. Callers of Write should
+	// still make sure of sorting if they depend on it.
+	Write(*dto.Metric) error
+	// TODO(beorn7): The original rationale of passing in a pre-allocated
+	// dto.Metric protobuf to save allocations has disappeared. The
+	// signature of this method should be changed to "Write() (*dto.Metric,
+	// error)".
+}
+
+// Opts bundles the options for creating most Metric types. Each metric
+// implementation XXX has its own XXXOpts type, but in most cases, it is just
+// an alias of this type (which might change when the requirement arises.)
+//
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type Opts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Metric (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the metric must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this metric.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
+	ConstLabels Labels
+
+	// now is for testing purposes, by default it's time.Now.
+	now func() time.Time
+}
+
+// BuildFQName joins the given three name components by "_". Empty name
+// components are ignored. If the name parameter itself is empty, an empty
+// string is returned, no matter what. Metric implementations included in this
+// library use this function internally to generate the fully-qualified metric
+// name from the name component in their Opts. Users of the library will only
+// need this function if they implement their own Metric or instantiate a Desc
+// (with NewDesc) directly.
+func BuildFQName(namespace, subsystem, name string) string {
+	if name == "" {
+		return ""
+	}
+	switch {
+	case namespace != "" && subsystem != "":
+		return strings.Join([]string{namespace, subsystem, name}, "_")
+	case namespace != "":
+		return strings.Join([]string{namespace, name}, "_")
+	case subsystem != "":
+		return strings.Join([]string{subsystem, name}, "_")
+	}
+	return name
+}
+
+type invalidMetric struct {
+	desc *Desc
+	err  error
+}
+
+// NewInvalidMetric returns a metric whose Write method always returns the
+// provided error. It is useful if a Collector finds itself unable to collect
+// a metric and wishes to report an error to the registry.
+func NewInvalidMetric(desc *Desc, err error) Metric {
+	return &invalidMetric{desc, err}
+}
+
+func (m *invalidMetric) Desc() *Desc { return m.desc }
+
+func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
+
+type timestampedMetric struct {
+	Metric
+	t time.Time
+}
+
+func (m timestampedMetric) Write(pb *dto.Metric) error {
+	e := m.Metric.Write(pb)
+	pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
+	return e
+}
+
+// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
+// way that it has an explicit timestamp set to the provided Time. This is only
+// useful in rare cases as the timestamp of a Prometheus metric should usually
+// be set by the Prometheus server during scraping. Exceptions include mirroring
+// metrics with given timestamps from other metric
+// sources.
+//
+// NewMetricWithTimestamp works best with MustNewConstMetric,
+// MustNewConstHistogram, and MustNewConstSummary, see example.
+//
+// Currently, the exposition formats used by Prometheus are limited to
+// millisecond resolution. Thus, the provided time will be rounded down to the
+// next full millisecond value.
+func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
+	return timestampedMetric{Metric: m, t: t}
+}
+
+type withExemplarsMetric struct {
+	Metric
+
+	exemplars []*dto.Exemplar
+}
+
+func (m *withExemplarsMetric) Write(pb *dto.Metric) error {
+	if err := m.Metric.Write(pb); err != nil {
+		return err
+	}
+
+	switch {
+	case pb.Counter != nil:
+		pb.Counter.Exemplar = m.exemplars[len(m.exemplars)-1]
+	case pb.Histogram != nil:
+		for _, e := range m.exemplars {
+			// pb.Histogram.Bucket are sorted by UpperBound.
+			i := sort.Search(len(pb.Histogram.Bucket), func(i int) bool {
+				return pb.Histogram.Bucket[i].GetUpperBound() >= e.GetValue()
+			})
+			if i < len(pb.Histogram.Bucket) {
+				pb.Histogram.Bucket[i].Exemplar = e
+			} else {
+				// The +Inf bucket should be explicitly added if there is an exemplar for it, similar to non-const histogram logic in https://github.com/prometheus/client_golang/blob/main/prometheus/histogram.go#L357-L365.
+				b := &dto.Bucket{
+					CumulativeCount: proto.Uint64(pb.Histogram.GetSampleCount()),
+					UpperBound:      proto.Float64(math.Inf(1)),
+					Exemplar:        e,
+				}
+				pb.Histogram.Bucket = append(pb.Histogram.Bucket, b)
+			}
+		}
+	default:
+		// TODO(bwplotka): Implement Gauge?
+		return errors.New("cannot inject exemplar into Gauge, Summary or Untyped")
+	}
+
+	return nil
+}
+
+// Exemplar is easier to use, user-facing representation of *dto.Exemplar.
+type Exemplar struct {
+	Value  float64
+	Labels Labels
+	// Optional.
+	// Default value (time.Time{}) indicates its empty, which should be
+	// understood as time.Now() time at the moment of creation of metric.
+	Timestamp time.Time
+}
+
+// NewMetricWithExemplars returns a new Metric wrapping the provided Metric with given
+// exemplars. Exemplars are validated.
+//
+// Only last applicable exemplar is injected from the list.
+// For example for Counter it means last exemplar is injected.
+// For Histogram, it means last applicable exemplar for each bucket is injected.
+//
+// NewMetricWithExemplars works best with MustNewConstMetric and
+// MustNewConstHistogram, see example.
+func NewMetricWithExemplars(m Metric, exemplars ...Exemplar) (Metric, error) {
+	if len(exemplars) == 0 {
+		return nil, errors.New("no exemplar was passed for NewMetricWithExemplars")
+	}
+
+	var (
+		now = time.Now()
+		exs = make([]*dto.Exemplar, len(exemplars))
+		err error
+	)
+	for i, e := range exemplars {
+		ts := e.Timestamp
+		if ts == (time.Time{}) {
+			ts = now
+		}
+		exs[i], err = newExemplar(e.Value, ts, e.Labels)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &withExemplarsMetric{Metric: m, exemplars: exs}, nil
+}
+
+// MustNewMetricWithExemplars is a version of NewMetricWithExemplars that panics where
+// NewMetricWithExemplars would have returned an error.
+func MustNewMetricWithExemplars(m Metric, exemplars ...Exemplar) Metric {
+	ret, err := NewMetricWithExemplars(m, exemplars...)
+	if err != nil {
+		panic(err)
+	}
+	return ret
+}

vendor/github.com/prometheus/client_golang/prometheus/num_threads.go

@@ -0,0 +1,25 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !js || wasm
+// +build !js wasm
+
+package prometheus
+
+import "runtime"
+
+// getRuntimeNumThreads returns the number of open OS threads.
+func getRuntimeNumThreads() float64 {
+	n, _ := runtime.ThreadCreateProfile(nil)
+	return float64(n)
+}

vendor/github.com/prometheus/client_golang/prometheus/num_threads_gopherjs.go

@@ -0,0 +1,22 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build js && !wasm
+// +build js,!wasm
+
+package prometheus
+
+// getRuntimeNumThreads returns the number of open OS threads.
+func getRuntimeNumThreads() float64 {
+	return 1
+}

vendor/github.com/prometheus/client_golang/prometheus/observer.go

@@ -0,0 +1,64 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
+type ObserverVec interface {
+	GetMetricWith(Labels) (Observer, error)
+	GetMetricWithLabelValues(lvs ...string) (Observer, error)
+	With(Labels) Observer
+	WithLabelValues(...string) Observer
+	CurryWith(Labels) (ObserverVec, error)
+	MustCurryWith(Labels) ObserverVec
+
+	Collector
+}
+
+// ExemplarObserver is implemented by Observers that offer the option of
+// observing a value together with an exemplar. Its ObserveWithExemplar method
+// works like the Observe method of an Observer but also replaces the currently
+// saved exemplar (if any) with a new one, created from the provided value, the
+// current time as timestamp, and the provided Labels. Empty Labels will lead to
+// a valid (label-less) exemplar. But if Labels is nil, the current exemplar is
+// left in place. ObserveWithExemplar panics if any of the provided labels are
+// invalid or if the provided labels contain more than 128 runes in total.
+type ExemplarObserver interface {
+	ObserveWithExemplar(value float64, exemplar Labels)
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -0,0 +1,164 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type processCollector struct {
+	collectFn       func(chan<- Metric)
+	pidFn           func() (int, error)
+	reportErrors    bool
+	cpuTotal        *Desc
+	openFDs, maxFDs *Desc
+	vsize, maxVsize *Desc
+	rss             *Desc
+	startTime       *Desc
+}
+
+// ProcessCollectorOpts defines the behavior of a process metrics collector
+// created with NewProcessCollector.
+type ProcessCollectorOpts struct {
+	// PidFn returns the PID of the process the collector collects metrics
+	// for. It is called upon each collection. By default, the PID of the
+	// current process is used, as determined on construction time by
+	// calling os.Getpid().
+	PidFn func() (int, error)
+	// If non-empty, each of the collected metrics is prefixed by the
+	// provided string and an underscore ("_").
+	Namespace string
+	// If true, any error encountered during collection is reported as an
+	// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
+	// and the collected metrics will be incomplete. (Possibly, no metrics
+	// will be collected at all.) While that's usually not desired, it is
+	// appropriate for the common "mix-in" of process metrics, where process
+	// metrics are nice to have, but failing to collect them should not
+	// disrupt the collection of the remaining metrics.
+	ReportErrors bool
+}
+
+// NewProcessCollector is the obsolete version of collectors.NewProcessCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewProcessCollector instead.
+func NewProcessCollector(opts ProcessCollectorOpts) Collector {
+	ns := ""
+	if len(opts.Namespace) > 0 {
+		ns = opts.Namespace + "_"
+	}
+
+	c := &processCollector{
+		reportErrors: opts.ReportErrors,
+		cpuTotal: NewDesc(
+			ns+"process_cpu_seconds_total",
+			"Total user and system CPU time spent in seconds.",
+			nil, nil,
+		),
+		openFDs: NewDesc(
+			ns+"process_open_fds",
+			"Number of open file descriptors.",
+			nil, nil,
+		),
+		maxFDs: NewDesc(
+			ns+"process_max_fds",
+			"Maximum number of open file descriptors.",
+			nil, nil,
+		),
+		vsize: NewDesc(
+			ns+"process_virtual_memory_bytes",
+			"Virtual memory size in bytes.",
+			nil, nil,
+		),
+		maxVsize: NewDesc(
+			ns+"process_virtual_memory_max_bytes",
+			"Maximum amount of virtual memory available in bytes.",
+			nil, nil,
+		),
+		rss: NewDesc(
+			ns+"process_resident_memory_bytes",
+			"Resident memory size in bytes.",
+			nil, nil,
+		),
+		startTime: NewDesc(
+			ns+"process_start_time_seconds",
+			"Start time of the process since unix epoch in seconds.",
+			nil, nil,
+		),
+	}
+
+	if opts.PidFn == nil {
+		c.pidFn = getPIDFn()
+	} else {
+		c.pidFn = opts.PidFn
+	}
+
+	// Set up process metric collection if supported by the runtime.
+	if canCollectProcess() {
+		c.collectFn = c.processCollect
+	} else {
+		c.collectFn = func(ch chan<- Metric) {
+			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+		}
+	}
+
+	return c
+}
+
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.maxVsize
+	ch <- c.rss
+	ch <- c.startTime
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *processCollector) Collect(ch chan<- Metric) {
+	c.collectFn(ch)
+}
+
+func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
+	if !c.reportErrors {
+		return
+	}
+	if desc == nil {
+		desc = NewInvalidDesc(err)
+	}
+	ch <- NewInvalidMetric(desc, err)
+}
+
+// NewPidFileFn returns a function that retrieves a pid from the specified file.
+// It is meant to be used for the PidFn field in ProcessCollectorOpts.
+func NewPidFileFn(pidFilePath string) func() (int, error) {
+	return func() (int, error) {
+		content, err := os.ReadFile(pidFilePath)
+		if err != nil {
+			return 0, fmt.Errorf("can't read pid file %q: %w", pidFilePath, err)
+		}
+		pid, err := strconv.Atoi(strings.TrimSpace(string(content)))
+		if err != nil {
+			return 0, fmt.Errorf("can't parse pid file %q: %w", pidFilePath, err)
+		}
+
+		return pid, nil
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_js.go

@@ -0,0 +1,26 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build js
+// +build js
+
+package prometheus
+
+func canCollectProcess() bool {
+	return false
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	// noop on this platform
+	return
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_other.go

@@ -0,0 +1,66 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows && !js
+// +build !windows,!js
+
+package prometheus
+
+import (
+	"github.com/prometheus/procfs"
+)
+
+func canCollectProcess() bool {
+	_, err := procfs.NewDefaultFS()
+	return err == nil
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	if stat, err := p.Stat(); err == nil {
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
+		if startTime, err := stat.StartTime(); err == nil {
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
+		} else {
+			c.reportError(ch, c.startTime, err)
+		}
+	} else {
+		c.reportError(ch, nil, err)
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err == nil {
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
+	} else {
+		c.reportError(ch, c.openFDs, err)
+	}
+
+	if limits, err := p.Limits(); err == nil {
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
+	} else {
+		c.reportError(ch, nil, err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_windows.go

@@ -0,0 +1,116 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func canCollectProcess() bool {
+	return true
+}
+
+var (
+	modpsapi    = syscall.NewLazyDLL("psapi.dll")
+	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
+
+	procGetProcessMemoryInfo  = modpsapi.NewProc("GetProcessMemoryInfo")
+	procGetProcessHandleCount = modkernel32.NewProc("GetProcessHandleCount")
+)
+
+type processMemoryCounters struct {
+	// System interface description
+	// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-process_memory_counters_ex
+
+	// Refer to the Golang internal implementation
+	// https://golang.org/src/internal/syscall/windows/psapi_windows.go
+	_                          uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+	PrivateUsage               uintptr
+}
+
+func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {
+	mem := processMemoryCounters{}
+	r1, _, err := procGetProcessMemoryInfo.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&mem)),
+		uintptr(unsafe.Sizeof(mem)),
+	)
+	if r1 != 1 {
+		return mem, err
+	} else {
+		return mem, nil
+	}
+}
+
+func getProcessHandleCount(handle windows.Handle) (uint32, error) {
+	var count uint32
+	r1, _, err := procGetProcessHandleCount.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&count)),
+	)
+	if r1 != 1 {
+		return 0, err
+	} else {
+		return count, nil
+	}
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	h, err := windows.GetCurrentProcess()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	var startTime, exitTime, kernelTime, userTime windows.Filetime
+	err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.startTime, GaugeValue, float64(startTime.Nanoseconds()/1e9))
+	ch <- MustNewConstMetric(c.cpuTotal, CounterValue, fileTimeToSeconds(kernelTime)+fileTimeToSeconds(userTime))
+
+	mem, err := getProcessMemoryInfo(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(mem.PrivateUsage))
+	ch <- MustNewConstMetric(c.rss, GaugeValue, float64(mem.WorkingSetSize))
+
+	handles, err := getProcessHandleCount(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(handles))
+	ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
+}
+
+func fileTimeToSeconds(ft windows.Filetime) float64 {
+	return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -0,0 +1,374 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+const (
+	closeNotifier = 1 << iota
+	flusher
+	hijacker
+	readerFrom
+	pusher
+)
+
+type delegator interface {
+	http.ResponseWriter
+
+	Status() int
+	Written() int64
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	status             int
+	written            int64
+	wroteHeader        bool
+	observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+	return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	if r.observeWriteHeader != nil && !r.wroteHeader {
+		// Only call observeWriteHeader for the 1st time. It's a bug if
+		// WriteHeader is called more than once, but we want to protect
+		// against it here. Note that we still delegate the WriteHeader
+		// to the original ResponseWriter to not mask the bug from it.
+		r.observeWriteHeader(code)
+	}
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type (
+	closeNotifierDelegator struct{ *responseWriterDelegator }
+	flusherDelegator       struct{ *responseWriterDelegator }
+	hijackerDelegator      struct{ *responseWriterDelegator }
+	readerFromDelegator    struct{ *responseWriterDelegator }
+	pusherDelegator        struct{ *responseWriterDelegator }
+)
+
+func (d closeNotifierDelegator) CloseNotify() <-chan bool {
+	//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
+	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (d flusherDelegator) Flush() {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	d.ResponseWriter.(http.Flusher).Flush()
+}
+
+func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return d.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+	d.written += n
+	return n, err
+}
+
+func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
+	return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+	// TODO(beorn7): Code generation would help here.
+	pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+		return d
+	}
+	pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+		return closeNotifierDelegator{d}
+	}
+	pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+		return flusherDelegator{d}
+	}
+	pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+		return struct {
+			*responseWriterDelegator
+			http.Flusher
+			http.CloseNotifier
+		}{d, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+		return hijackerDelegator{d}
+	}
+	pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+		}{d, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+		return readerFromDelegator{d}
+	}
+	pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+		}{d, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+		return pusherDelegator{d}
+	}
+	pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+		}{d, pusherDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+		}{d, pusherDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 23
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+		}{d, pusherDelegator{d}, readerFromDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+	if _, ok := w.(http.Pusher); ok {
+		id += pusher
+	}
+
+	return pickDelegator[id](d)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -0,0 +1,408 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package promhttp provides tooling around HTTP servers and clients.
+//
+// First, the package allows the creation of http.Handler instances to expose
+// Prometheus metrics via HTTP. promhttp.Handler acts on the
+// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
+// custom registry or anything that implements the Gatherer interface. It also
+// allows the creation of handlers that act differently on errors or allow to
+// log errors.
+//
+// Second, the package provides tooling to instrument instances of http.Handler
+// via middleware. Middleware wrappers follow the naming scheme
+// InstrumentHandlerX, where X describes the intended use of the middleware.
+// See each function's doc comment for specific details.
+//
+// Finally, the package allows for an http.RoundTripper to be instrumented via
+// middleware. Middleware wrappers follow the naming scheme
+// InstrumentRoundTripperX, where X describes the intended use of the
+// middleware. See each function's doc comment for specific details.
+package promhttp
+
+import (
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	contentTypeHeader      = "Content-Type"
+	contentEncodingHeader  = "Content-Encoding"
+	acceptEncodingHeader   = "Accept-Encoding"
+	processStartTimeHeader = "Process-Start-Time-Unix"
+)
+
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
+}
+
+// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
+// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
+// no error logging, and it applies compression if requested by the client.
+//
+// The returned http.Handler is already instrumented using the
+// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
+// create multiple http.Handlers by separate calls of the Handler function, the
+// metrics used for instrumentation will be shared between them, providing
+// global scrape counts.
+//
+// This function is meant to cover the bulk of basic use cases. If you are doing
+// anything that requires more customization (including using a non-default
+// Gatherer, different instrumentation, and non-default HandlerOpts), use the
+// HandlerFor function. See there for details.
+func Handler() http.Handler {
+	return InstrumentMetricHandler(
+		prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
+	)
+}
+
+// HandlerFor returns an uninstrumented http.Handler for the provided
+// Gatherer. The behavior of the Handler is defined by the provided
+// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
+// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
+// instrumentation. Use the InstrumentMetricHandler function to apply the same
+// kind of instrumentation as it is used by the Handler function.
+func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
+	return HandlerForTransactional(prometheus.ToTransactionalGatherer(reg), opts)
+}
+
+// HandlerForTransactional is like HandlerFor, but it uses transactional gather, which
+// can safely change in-place returned *dto.MetricFamily before call to `Gather` and after
+// call to `done` of that `Gather`.
+func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerOpts) http.Handler {
+	var (
+		inFlightSem chan struct{}
+		errCnt      = prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "promhttp_metric_handler_errors_total",
+				Help: "Total number of internal errors encountered by the promhttp metric handler.",
+			},
+			[]string{"cause"},
+		)
+	)
+
+	if opts.MaxRequestsInFlight > 0 {
+		inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
+	}
+	if opts.Registry != nil {
+		// Initialize all possibilities that can occur below.
+		errCnt.WithLabelValues("gathering")
+		errCnt.WithLabelValues("encoding")
+		if err := opts.Registry.Register(errCnt); err != nil {
+			are := &prometheus.AlreadyRegisteredError{}
+			if errors.As(err, are) {
+				errCnt = are.ExistingCollector.(*prometheus.CounterVec)
+			} else {
+				panic(err)
+			}
+		}
+	}
+
+	h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+		if !opts.ProcessStartTime.IsZero() {
+			rsp.Header().Set(processStartTimeHeader, strconv.FormatInt(opts.ProcessStartTime.Unix(), 10))
+		}
+		if inFlightSem != nil {
+			select {
+			case inFlightSem <- struct{}{}: // All good, carry on.
+				defer func() { <-inFlightSem }()
+			default:
+				http.Error(rsp, fmt.Sprintf(
+					"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
+				), http.StatusServiceUnavailable)
+				return
+			}
+		}
+		mfs, done, err := reg.Gather()
+		defer done()
+		if err != nil {
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error gathering metrics:", err)
+			}
+			errCnt.WithLabelValues("gathering").Inc()
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case ContinueOnError:
+				if len(mfs) == 0 {
+					// Still report the error if no metrics have been gathered.
+					httpError(rsp, err)
+					return
+				}
+			case HTTPErrorOnError:
+				httpError(rsp, err)
+				return
+			}
+		}
+
+		var contentType expfmt.Format
+		if opts.EnableOpenMetrics {
+			contentType = expfmt.NegotiateIncludingOpenMetrics(req.Header)
+		} else {
+			contentType = expfmt.Negotiate(req.Header)
+		}
+		header := rsp.Header()
+		header.Set(contentTypeHeader, string(contentType))
+
+		w := io.Writer(rsp)
+		if !opts.DisableCompression && gzipAccepted(req.Header) {
+			header.Set(contentEncodingHeader, "gzip")
+			gz := gzipPool.Get().(*gzip.Writer)
+			defer gzipPool.Put(gz)
+
+			gz.Reset(w)
+			defer gz.Close()
+
+			w = gz
+		}
+
+		enc := expfmt.NewEncoder(w, contentType)
+
+		// handleError handles the error according to opts.ErrorHandling
+		// and returns true if we have to abort after the handling.
+		handleError := func(err error) bool {
+			if err == nil {
+				return false
+			}
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error encoding and sending metric family:", err)
+			}
+			errCnt.WithLabelValues("encoding").Inc()
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case HTTPErrorOnError:
+				// We cannot really send an HTTP error at this
+				// point because we most likely have written
+				// something to rsp already. But at least we can
+				// stop sending.
+				return true
+			}
+			// Do nothing in all other cases, including ContinueOnError.
+			return false
+		}
+
+		for _, mf := range mfs {
+			if handleError(enc.Encode(mf)) {
+				return
+			}
+		}
+		if closer, ok := enc.(expfmt.Closer); ok {
+			// This in particular takes care of the final "# EOF\n" line for OpenMetrics.
+			if handleError(closer.Close()) {
+				return
+			}
+		}
+	})
+
+	if opts.Timeout <= 0 {
+		return h
+	}
+	return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
+		"Exceeded configured timeout of %v.\n",
+		opts.Timeout,
+	))
+}
+
+// InstrumentMetricHandler is usually used with an http.Handler returned by the
+// HandlerFor function. It instruments the provided http.Handler with two
+// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
+// scrapes partitioned by HTTP status code, and a gauge
+// "promhttp_metric_handler_requests_in_flight" to track the number of
+// simultaneous scrapes. This function idempotently registers collectors for
+// both metrics with the provided Registerer. It panics if the registration
+// fails. The provided metrics are useful to see how many scrapes hit the
+// monitored target (which could be from different Prometheus servers or other
+// scrapers), and how often they overlap (which would result in more than one
+// scrape in flight at the same time). Note that the scrapes-in-flight gauge
+// will contain the scrape by which it is exposed, while the scrape counter will
+// only get incremented after the scrape is complete (as only then the status
+// code is known). For tracking scrape durations, use the
+// "scrape_duration_seconds" gauge created by the Prometheus server upon each
+// scrape.
+func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
+	cnt := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "promhttp_metric_handler_requests_total",
+			Help: "Total number of scrapes by HTTP status code.",
+		},
+		[]string{"code"},
+	)
+	// Initialize the most likely HTTP status codes.
+	cnt.WithLabelValues("200")
+	cnt.WithLabelValues("500")
+	cnt.WithLabelValues("503")
+	if err := reg.Register(cnt); err != nil {
+		are := &prometheus.AlreadyRegisteredError{}
+		if errors.As(err, are) {
+			cnt = are.ExistingCollector.(*prometheus.CounterVec)
+		} else {
+			panic(err)
+		}
+	}
+
+	gge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "promhttp_metric_handler_requests_in_flight",
+		Help: "Current number of scrapes being served.",
+	})
+	if err := reg.Register(gge); err != nil {
+		are := &prometheus.AlreadyRegisteredError{}
+		if errors.As(err, are) {
+			gge = are.ExistingCollector.(prometheus.Gauge)
+		} else {
+			panic(err)
+		}
+	}
+
+	return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
+}
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+	// Serve an HTTP status code 500 upon the first error
+	// encountered. Report the error message in the body. Note that HTTP
+	// errors cannot be served anymore once the beginning of a regular
+	// payload has been sent. Thus, in the (unlikely) case that encoding the
+	// payload into the negotiated wire format fails, serving the response
+	// will simply be aborted. Set an ErrorLog in HandlerOpts to detect
+	// those errors.
+	HTTPErrorOnError HandlerErrorHandling = iota
+	// Ignore errors and try to serve as many metrics as possible.  However,
+	// if no metrics can be served, serve an HTTP status code 500 and the
+	// last error message in the body. Only use this in deliberate "best
+	// effort" metrics collection scenarios. In this case, it is highly
+	// recommended to provide other means of detecting errors: By setting an
+	// ErrorLog in HandlerOpts, the errors are logged. By providing a
+	// Registry in HandlerOpts, the exposed metrics include an error counter
+	// "promhttp_metric_handler_errors_total", which can be used for
+	// alerts.
+	ContinueOnError
+	// Panic upon the first error encountered (useful for "crash only" apps).
+	PanicOnError
+)
+
+// Logger is the minimal interface HandlerOpts needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+	Println(v ...interface{})
+}
+
+// HandlerOpts specifies options how to serve metrics via an http.Handler. The
+// zero value of HandlerOpts is a reasonable default.
+type HandlerOpts struct {
+	// ErrorLog specifies an optional Logger for errors collecting and
+	// serving metrics. If nil, errors are not logged at all. Note that the
+	// type of a reported error is often prometheus.MultiError, which
+	// formats into a multi-line error string. If you want to avoid the
+	// latter, create a Logger implementation that detects a
+	// prometheus.MultiError and formats the contained errors into one line.
+	ErrorLog Logger
+	// ErrorHandling defines how errors are handled. Note that errors are
+	// logged regardless of the configured ErrorHandling provided ErrorLog
+	// is not nil.
+	ErrorHandling HandlerErrorHandling
+	// If Registry is not nil, it is used to register a metric
+	// "promhttp_metric_handler_errors_total", partitioned by "cause". A
+	// failed registration causes a panic. Note that this error counter is
+	// different from the instrumentation you get from the various
+	// InstrumentHandler... helpers. It counts errors that don't necessarily
+	// result in a non-2xx HTTP status code. There are two typical cases:
+	// (1) Encoding errors that only happen after streaming of the HTTP body
+	// has already started (and the status code 200 has been sent). This
+	// should only happen with custom collectors. (2) Collection errors with
+	// no effect on the HTTP status code because ErrorHandling is set to
+	// ContinueOnError.
+	Registry prometheus.Registerer
+	// If DisableCompression is true, the handler will never compress the
+	// response, even if requested by the client.
+	DisableCompression bool
+	// The number of concurrent HTTP requests is limited to
+	// MaxRequestsInFlight. Additional requests are responded to with 503
+	// Service Unavailable and a suitable message in the body. If
+	// MaxRequestsInFlight is 0 or negative, no limit is applied.
+	MaxRequestsInFlight int
+	// If handling a request takes longer than Timeout, it is responded to
+	// with 503 ServiceUnavailable and a suitable Message. No timeout is
+	// applied if Timeout is 0 or negative. Note that with the current
+	// implementation, reaching the timeout simply ends the HTTP requests as
+	// described above (and even that only if sending of the body hasn't
+	// started yet), while the bulk work of gathering all the metrics keeps
+	// running in the background (with the eventual result to be thrown
+	// away). Until the implementation is improved, it is recommended to
+	// implement a separate timeout in potentially slow Collectors.
+	Timeout time.Duration
+	// If true, the experimental OpenMetrics encoding is added to the
+	// possible options during content negotiation. Note that Prometheus
+	// 2.5.0+ will negotiate OpenMetrics as first priority. OpenMetrics is
+	// the only way to transmit exemplars. However, the move to OpenMetrics
+	// is not completely transparent. Most notably, the values of "quantile"
+	// labels of Summaries and "le" labels of Histograms are formatted with
+	// a trailing ".0" if they would otherwise look like integer numbers
+	// (which changes the identity of the resulting series on the Prometheus
+	// server).
+	EnableOpenMetrics bool
+	// ProcessStartTime allows setting process start timevalue that will be exposed
+	// with "Process-Start-Time-Unix" response header along with the metrics
+	// payload. This allow callers to have efficient transformations to cumulative
+	// counters (e.g. OpenTelemetry) or generally _created timestamp estimation per
+	// scrape target.
+	// NOTE: This feature is experimental and not covered by OpenMetrics or Prometheus
+	// exposition format.
+	ProcessStartTime time.Time
+}
+
+// gzipAccepted returns whether the client will accept gzip-encoded content.
+func gzipAccepted(header http.Header) bool {
+	a := header.Get(acceptEncodingHeader)
+	parts := strings.Split(a, ",")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return true
+		}
+	}
+	return false
+}
+
+// httpError removes any content-encoding header and then calls http.Error with
+// the provided error and http.StatusInternalServerError. Error contents is
+// supposed to be uncompressed plain text. Same as with a plain http.Error, this
+// must not be called if the header or any payload has already been sent.
+func httpError(rsp http.ResponseWriter, err error) {
+	rsp.Header().Del(contentEncodingHeader)
+	http.Error(
+		rsp,
+		"An error has occurred while serving metrics:\n\n"+err.Error(),
+		http.StatusInternalServerError,
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go

@@ -0,0 +1,249 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"crypto/tls"
+	"net/http"
+	"net/http/httptrace"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// The RoundTripperFunc type is an adapter to allow the use of ordinary
+// functions as RoundTrippers. If f is a function with the appropriate
+// signature, RountTripperFunc(f) is a RoundTripper that calls f.
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+// RoundTrip implements the RoundTripper interface.
+func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return rt(r)
+}
+
+// InstrumentRoundTripperInFlight is a middleware that wraps the provided
+// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.RoundTripper.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
+	return func(r *http.Request) (*http.Response, error) {
+		gauge.Inc()
+		defer gauge.Dec()
+		return next.RoundTrip(r)
+	}
+}
+
+// InstrumentRoundTripperCounter is a middleware that wraps the provided
+// http.RoundTripper to observe the request result with the provided CounterVec.
+// The CounterVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. For the "method" label a predefined default label value set
+// is used to filter given values. Values besides predefined values will count
+// as `unknown` method.`WithExtraMethods` can be used to add more
+// methods to the set. Partitioning of the CounterVec happens by HTTP status code
+// and/or HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
+// is not incremented.
+//
+// Use with WithExemplarFromContext to instrument the exemplars on the counter of requests.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper, opts ...Option) RoundTripperFunc {
+	rtOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(rtOpts)
+	}
+
+	// Curry the counter with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(counter.MustCurryWith(rtOpts.emptyDynamicLabels()))
+
+	return func(r *http.Request) (*http.Response, error) {
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			l := labels(code, method, r.Method, resp.StatusCode, rtOpts.extraMethods...)
+			for label, resolve := range rtOpts.extraLabelsFromCtx {
+				l[label] = resolve(resp.Request.Context())
+			}
+			addWithExemplar(counter.With(l), 1, rtOpts.getExemplarFn(r.Context()))
+		}
+		return resp, err
+	}
+}
+
+// InstrumentRoundTripperDuration is a middleware that wraps the provided
+// http.RoundTripper to observe the request duration with the provided
+// ObserverVec.  The ObserverVec must have zero, one, or two non-const
+// non-curried labels. For those, the only allowed label names are "code" and
+// "method". The function panics otherwise. For the "method" label a predefined
+// default label value set is used to filter given values. Values besides
+// predefined values will count as `unknown` method. `WithExtraMethods`
+// can be used to add more methods to the set. The Observe method of the Observer
+// in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, no values are
+// reported.
+//
+// Use with WithExemplarFromContext to instrument the exemplars on the duration histograms.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper, opts ...Option) RoundTripperFunc {
+	rtOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(rtOpts)
+	}
+
+	// Curry the observer with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(obs.MustCurryWith(rtOpts.emptyDynamicLabels()))
+
+	return func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			l := labels(code, method, r.Method, resp.StatusCode, rtOpts.extraMethods...)
+			for label, resolve := range rtOpts.extraLabelsFromCtx {
+				l[label] = resolve(resp.Request.Context())
+			}
+			observeWithExemplar(obs.With(l), time.Since(start).Seconds(), rtOpts.getExemplarFn(r.Context()))
+		}
+		return resp, err
+	}
+}
+
+// InstrumentTrace is used to offer flexibility in instrumenting the available
+// httptrace.ClientTrace hook functions. Each function is passed a float64
+// representing the time in seconds since the start of the http request. A user
+// may choose to use separately buckets Histograms, or implement custom
+// instance labels on a per function basis.
+type InstrumentTrace struct {
+	GotConn              func(float64)
+	PutIdleConn          func(float64)
+	GotFirstResponseByte func(float64)
+	Got100Continue       func(float64)
+	DNSStart             func(float64)
+	DNSDone              func(float64)
+	ConnectStart         func(float64)
+	ConnectDone          func(float64)
+	TLSHandshakeStart    func(float64)
+	TLSHandshakeDone     func(float64)
+	WroteHeaders         func(float64)
+	Wait100Continue      func(float64)
+	WroteRequest         func(float64)
+}
+
+// InstrumentRoundTripperTrace is a middleware that wraps the provided
+// RoundTripper and reports times to hook functions provided in the
+// InstrumentTrace struct. Hook functions that are not present in the provided
+// InstrumentTrace struct are ignored. Times reported to the hook functions are
+// time since the start of the request. Only with Go1.9+, those times are
+// guaranteed to never be negative. (Earlier Go versions are not using a
+// monotonic clock.) Note that partitioning of Histograms is expensive and
+// should be used judiciously.
+//
+// For hook functions that receive an error as an argument, no observations are
+// made in the event of a non-nil error value.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
+	return func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+
+		trace := &httptrace.ClientTrace{
+			GotConn: func(_ httptrace.GotConnInfo) {
+				if it.GotConn != nil {
+					it.GotConn(time.Since(start).Seconds())
+				}
+			},
+			PutIdleConn: func(err error) {
+				if err != nil {
+					return
+				}
+				if it.PutIdleConn != nil {
+					it.PutIdleConn(time.Since(start).Seconds())
+				}
+			},
+			DNSStart: func(_ httptrace.DNSStartInfo) {
+				if it.DNSStart != nil {
+					it.DNSStart(time.Since(start).Seconds())
+				}
+			},
+			DNSDone: func(_ httptrace.DNSDoneInfo) {
+				if it.DNSDone != nil {
+					it.DNSDone(time.Since(start).Seconds())
+				}
+			},
+			ConnectStart: func(_, _ string) {
+				if it.ConnectStart != nil {
+					it.ConnectStart(time.Since(start).Seconds())
+				}
+			},
+			ConnectDone: func(_, _ string, err error) {
+				if err != nil {
+					return
+				}
+				if it.ConnectDone != nil {
+					it.ConnectDone(time.Since(start).Seconds())
+				}
+			},
+			GotFirstResponseByte: func() {
+				if it.GotFirstResponseByte != nil {
+					it.GotFirstResponseByte(time.Since(start).Seconds())
+				}
+			},
+			Got100Continue: func() {
+				if it.Got100Continue != nil {
+					it.Got100Continue(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeStart: func() {
+				if it.TLSHandshakeStart != nil {
+					it.TLSHandshakeStart(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
+				if err != nil {
+					return
+				}
+				if it.TLSHandshakeDone != nil {
+					it.TLSHandshakeDone(time.Since(start).Seconds())
+				}
+			},
+			WroteHeaders: func() {
+				if it.WroteHeaders != nil {
+					it.WroteHeaders(time.Since(start).Seconds())
+				}
+			},
+			Wait100Continue: func() {
+				if it.Wait100Continue != nil {
+					it.Wait100Continue(time.Since(start).Seconds())
+				}
+			},
+			WroteRequest: func(_ httptrace.WroteRequestInfo) {
+				if it.WroteRequest != nil {
+					it.WroteRequest(time.Since(start).Seconds())
+				}
+			},
+		}
+		r = r.WithContext(httptrace.WithClientTrace(r.Context(), trace))
+
+		return next.RoundTrip(r)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go

@@ -0,0 +1,576 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// magicString is used for the hacky label test in checkLabels. Remove once fixed.
+const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
+
+// observeWithExemplar is a wrapper for [prometheus.ExemplarAdder.ExemplarObserver],
+// which falls back to [prometheus.Observer.Observe] if no labels are provided.
+func observeWithExemplar(obs prometheus.Observer, val float64, labels map[string]string) {
+	if labels == nil {
+		obs.Observe(val)
+		return
+	}
+	obs.(prometheus.ExemplarObserver).ObserveWithExemplar(val, labels)
+}
+
+// addWithExemplar is a wrapper for [prometheus.ExemplarAdder.AddWithExemplar],
+// which falls back to [prometheus.Counter.Add] if no labels are provided.
+func addWithExemplar(obs prometheus.Counter, val float64, labels map[string]string) {
+	if labels == nil {
+		obs.Add(val)
+		return
+	}
+	obs.(prometheus.ExemplarAdder).AddWithExemplar(val, labels)
+}
+
+// InstrumentHandlerInFlight is a middleware that wraps the provided
+// http.Handler. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.Handler.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		g.Inc()
+		defer g.Dec()
+		next.ServeHTTP(w, r)
+	})
+}
+
+// InstrumentHandlerDuration is a middleware that wraps the provided
+// http.Handler to observe the request duration with the provided ObserverVec.
+// The ObserverVec must have valid metric and label names and must have zero,
+// one, or two non-const non-curried labels. For those, the only allowed label
+// names are "code" and "method". The function panics otherwise. For the "method"
+// label a predefined default label value set is used to filter given values.
+// Values besides predefined values will count as `unknown` method.
+// `WithExtraMethods` can be used to add more methods to the set. The Observe
+// method of the Observer in the ObserverVec is called with the request duration
+// in seconds. Partitioning happens by HTTP status code and/or HTTP method if
+// the respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
+	hOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(hOpts)
+	}
+
+	// Curry the observer with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
+
+	if code {
+		return func(w http.ResponseWriter, r *http.Request) {
+			now := time.Now()
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+
+			l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
+			for label, resolve := range hOpts.extraLabelsFromCtx {
+				l[label] = resolve(r.Context())
+			}
+			observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
+		}
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		next.ServeHTTP(w, r)
+		l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
+		for label, resolve := range hOpts.extraLabelsFromCtx {
+			l[label] = resolve(r.Context())
+		}
+		observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
+	}
+}
+
+// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
+// to observe the request result with the provided CounterVec. The CounterVec
+// must have valid metric and label names and must have zero, one, or two
+// non-const non-curried labels. For those, the only allowed label names are
+// "code" and "method". The function panics otherwise. For the "method"
+// label a predefined default label value set is used to filter given values.
+// Values besides predefined values will count as `unknown` method.
+// `WithExtraMethods` can be used to add more methods to the set. Partitioning of the
+// CounterVec happens by HTTP status code and/or HTTP method if the respective
+// instance label names are present in the CounterVec. For unpartitioned
+// counting, use a CounterVec with zero labels.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, the Counter is not incremented.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler, opts ...Option) http.HandlerFunc {
+	hOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(hOpts)
+	}
+
+	// Curry the counter with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(counter.MustCurryWith(hOpts.emptyDynamicLabels()))
+
+	if code {
+		return func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+
+			l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
+			for label, resolve := range hOpts.extraLabelsFromCtx {
+				l[label] = resolve(r.Context())
+			}
+			addWithExemplar(counter.With(l), 1, hOpts.getExemplarFn(r.Context()))
+		}
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+
+		l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
+		for label, resolve := range hOpts.extraLabelsFromCtx {
+			l[label] = resolve(r.Context())
+		}
+		addWithExemplar(counter.With(l), 1, hOpts.getExemplarFn(r.Context()))
+	}
+}
+
+// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
+// http.Handler to observe with the provided ObserverVec the request duration
+// until the response headers are written. The ObserverVec must have valid
+// metric and label names and must have zero, one, or two non-const non-curried
+// labels. For those, the only allowed label names are "code" and "method". The
+// function panics otherwise. For the "method" label a predefined default label
+// value set is used to filter given values. Values besides predefined values
+// will count as `unknown` method.`WithExtraMethods` can be used to add more
+// methods to the set. The Observe method of the Observer in the
+// ObserverVec is called with the request duration in seconds. Partitioning
+// happens by HTTP status code and/or HTTP method if the respective instance
+// label names are present in the ObserverVec. For unpartitioned observations,
+// use an ObserverVec with zero labels. Note that partitioning of Histograms is
+// expensive and should be used judiciously.
+//
+// If the wrapped Handler panics before calling WriteHeader, no value is
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
+	hOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(hOpts)
+	}
+
+	// Curry the observer with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		d := newDelegator(w, func(status int) {
+			l := labels(code, method, r.Method, status, hOpts.extraMethods...)
+			for label, resolve := range hOpts.extraLabelsFromCtx {
+				l[label] = resolve(r.Context())
+			}
+			observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
+		})
+		next.ServeHTTP(d, r)
+	}
+}
+
+// InstrumentHandlerRequestSize is a middleware that wraps the provided
+// http.Handler to observe the request size with the provided ObserverVec. The
+// ObserverVec must have valid metric and label names and must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. For the "method"
+// label a predefined default label value set is used to filter given values.
+// Values besides predefined values will count as `unknown` method.
+// `WithExtraMethods` can be used to add more methods to the set. The Observe
+// method of the Observer in the ObserverVec is called with the request size in
+// bytes. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
+	hOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(hOpts)
+	}
+
+	// Curry the observer with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
+
+	if code {
+		return func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+			size := computeApproximateRequestSize(r)
+
+			l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
+			for label, resolve := range hOpts.extraLabelsFromCtx {
+				l[label] = resolve(r.Context())
+			}
+			observeWithExemplar(obs.With(l), float64(size), hOpts.getExemplarFn(r.Context()))
+		}
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+		size := computeApproximateRequestSize(r)
+
+		l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
+		for label, resolve := range hOpts.extraLabelsFromCtx {
+			l[label] = resolve(r.Context())
+		}
+		observeWithExemplar(obs.With(l), float64(size), hOpts.getExemplarFn(r.Context()))
+	}
+}
+
+// InstrumentHandlerResponseSize is a middleware that wraps the provided
+// http.Handler to observe the response size with the provided ObserverVec. The
+// ObserverVec must have valid metric and label names and must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. For the "method"
+// label a predefined default label value set is used to filter given values.
+// Values besides predefined values will count as `unknown` method.
+// `WithExtraMethods` can be used to add more methods to the set. The Observe
+// method of the Observer in the ObserverVec is called with the response size in
+// bytes. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.Handler {
+	hOpts := defaultOptions()
+	for _, o := range opts {
+		o.apply(hOpts)
+	}
+
+	// Curry the observer with dynamic labels before checking the remaining labels.
+	code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		d := newDelegator(w, nil)
+		next.ServeHTTP(d, r)
+
+		l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
+		for label, resolve := range hOpts.extraLabelsFromCtx {
+			l[label] = resolve(r.Context())
+		}
+		observeWithExemplar(obs.With(l), float64(d.Written()), hOpts.getExemplarFn(r.Context()))
+	})
+}
+
+// checkLabels returns whether the provided Collector has a non-const,
+// non-curried label named "code" and/or "method". It panics if the provided
+// Collector does not have a Desc or has more than one Desc or its Desc is
+// invalid. It also panics if the Collector has any non-const, non-curried
+// labels that are not named "code" or "method".
+func checkLabels(c prometheus.Collector) (code, method bool) {
+	// TODO(beorn7): Remove this hacky way to check for instance labels
+	// once Descriptors can have their dimensionality queried.
+	var (
+		desc *prometheus.Desc
+		m    prometheus.Metric
+		pm   dto.Metric
+		lvs  []string
+	)
+
+	// Get the Desc from the Collector.
+	descc := make(chan *prometheus.Desc, 1)
+	c.Describe(descc)
+
+	select {
+	case desc = <-descc:
+	default:
+		panic("no description provided by collector")
+	}
+	select {
+	case <-descc:
+		panic("more than one description provided by collector")
+	default:
+	}
+
+	close(descc)
+
+	// Make sure the Collector has a valid Desc by registering it with a
+	// temporary registry.
+	prometheus.NewRegistry().MustRegister(c)
+
+	// Create a ConstMetric with the Desc. Since we don't know how many
+	// variable labels there are, try for as long as it needs.
+	for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
+		m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
+	}
+
+	// Write out the metric into a proto message and look at the labels.
+	// If the value is not the magicString, it is a constLabel, which doesn't interest us.
+	// If the label is curried, it doesn't interest us.
+	// In all other cases, only "code" or "method" is allowed.
+	if err := m.Write(&pm); err != nil {
+		panic("error checking metric for labels")
+	}
+	for _, label := range pm.Label {
+		name, value := label.GetName(), label.GetValue()
+		if value != magicString || isLabelCurried(c, name) {
+			continue
+		}
+		switch name {
+		case "code":
+			code = true
+		case "method":
+			method = true
+		default:
+			panic("metric partitioned with non-supported labels")
+		}
+	}
+	return
+}
+
+func isLabelCurried(c prometheus.Collector, label string) bool {
+	// This is even hackier than the label test above.
+	// We essentially try to curry again and see if it works.
+	// But for that, we need to type-convert to the two
+	// types we use here, ObserverVec or *CounterVec.
+	switch v := c.(type) {
+	case *prometheus.CounterVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	case prometheus.ObserverVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	default:
+		panic("unsupported metric vec type")
+	}
+	return true
+}
+
+func labels(code, method bool, reqMethod string, status int, extraMethods ...string) prometheus.Labels {
+	labels := prometheus.Labels{}
+
+	if !(code || method) {
+		return labels
+	}
+
+	if code {
+		labels["code"] = sanitizeCode(status)
+	}
+	if method {
+		labels["method"] = sanitizeMethod(reqMethod, extraMethods...)
+	}
+
+	return labels
+}
+
+func computeApproximateRequestSize(r *http.Request) int {
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	s += len(r.Method)
+	s += len(r.Proto)
+	for name, values := range r.Header {
+		s += len(name)
+		for _, value := range values {
+			s += len(value)
+		}
+	}
+	s += len(r.Host)
+
+	// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+	if r.ContentLength != -1 {
+		s += int(r.ContentLength)
+	}
+	return s
+}
+
+// If the wrapped http.Handler has a known method, it will be sanitized and returned.
+// Otherwise, "unknown" will be returned. The known method list can be extended
+// as needed by using extraMethods parameter.
+func sanitizeMethod(m string, extraMethods ...string) string {
+	// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods for
+	// the methods chosen as default.
+	switch m {
+	case "GET", "get":
+		return "get"
+	case "PUT", "put":
+		return "put"
+	case "HEAD", "head":
+		return "head"
+	case "POST", "post":
+		return "post"
+	case "DELETE", "delete":
+		return "delete"
+	case "CONNECT", "connect":
+		return "connect"
+	case "OPTIONS", "options":
+		return "options"
+	case "NOTIFY", "notify":
+		return "notify"
+	case "TRACE", "trace":
+		return "trace"
+	case "PATCH", "patch":
+		return "patch"
+	default:
+		for _, method := range extraMethods {
+			if strings.EqualFold(m, method) {
+				return strings.ToLower(m)
+			}
+		}
+		return "unknown"
+	}
+}
+
+// If the wrapped http.Handler has not set a status code, i.e. the value is
+// currently 0, sanitizeCode will return 200, for consistency with behavior in
+// the stdlib.
+func sanitizeCode(s int) string {
+	// See for accepted codes https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
+	switch s {
+	case 100:
+		return "100"
+	case 101:
+		return "101"
+
+	case 200, 0:
+		return "200"
+	case 201:
+		return "201"
+	case 202:
+		return "202"
+	case 203:
+		return "203"
+	case 204:
+		return "204"
+	case 205:
+		return "205"
+	case 206:
+		return "206"
+
+	case 300:
+		return "300"
+	case 301:
+		return "301"
+	case 302:
+		return "302"
+	case 304:
+		return "304"
+	case 305:
+		return "305"
+	case 307:
+		return "307"
+
+	case 400:
+		return "400"
+	case 401:
+		return "401"
+	case 402:
+		return "402"
+	case 403:
+		return "403"
+	case 404:
+		return "404"
+	case 405:
+		return "405"
+	case 406:
+		return "406"
+	case 407:
+		return "407"
+	case 408:
+		return "408"
+	case 409:
+		return "409"
+	case 410:
+		return "410"
+	case 411:
+		return "411"
+	case 412:
+		return "412"
+	case 413:
+		return "413"
+	case 414:
+		return "414"
+	case 415:
+		return "415"
+	case 416:
+		return "416"
+	case 417:
+		return "417"
+	case 418:
+		return "418"
+
+	case 500:
+		return "500"
+	case 501:
+		return "501"
+	case 502:
+		return "502"
+	case 503:
+		return "503"
+	case 504:
+		return "504"
+	case 505:
+		return "505"
+
+	case 428:
+		return "428"
+	case 429:
+		return "429"
+	case 431:
+		return "431"
+	case 511:
+		return "511"
+
+	default:
+		if s >= 100 && s <= 599 {
+			return strconv.Itoa(s)
+		}
+		return "unknown"
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/option.go

@@ -0,0 +1,84 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"context"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// Option are used to configure both handler (middleware) or round tripper.
+type Option interface {
+	apply(*options)
+}
+
+// LabelValueFromCtx are used to compute the label value from request context.
+// Context can be filled with values from request through middleware.
+type LabelValueFromCtx func(ctx context.Context) string
+
+// options store options for both a handler or round tripper.
+type options struct {
+	extraMethods       []string
+	getExemplarFn      func(requestCtx context.Context) prometheus.Labels
+	extraLabelsFromCtx map[string]LabelValueFromCtx
+}
+
+func defaultOptions() *options {
+	return &options{
+		getExemplarFn:      func(ctx context.Context) prometheus.Labels { return nil },
+		extraLabelsFromCtx: map[string]LabelValueFromCtx{},
+	}
+}
+
+func (o *options) emptyDynamicLabels() prometheus.Labels {
+	labels := prometheus.Labels{}
+
+	for label := range o.extraLabelsFromCtx {
+		labels[label] = ""
+	}
+
+	return labels
+}
+
+type optionApplyFunc func(*options)
+
+func (o optionApplyFunc) apply(opt *options) { o(opt) }
+
+// WithExtraMethods adds additional HTTP methods to the list of allowed methods.
+// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods for the default list.
+//
+// See the example for ExampleInstrumentHandlerWithExtraMethods for example usage.
+func WithExtraMethods(methods ...string) Option {
+	return optionApplyFunc(func(o *options) {
+		o.extraMethods = methods
+	})
+}
+
+// WithExemplarFromContext allows to inject function that will get exemplar from context that will be put to counter and histogram metrics.
+// If the function returns nil labels or the metric does not support exemplars, no exemplar will be added (noop), but
+// metric will continue to observe/increment.
+func WithExemplarFromContext(getExemplarFn func(requestCtx context.Context) prometheus.Labels) Option {
+	return optionApplyFunc(func(o *options) {
+		o.getExemplarFn = getExemplarFn
+	})
+}
+
+// WithLabelFromCtx registers a label for dynamic resolution with access to context.
+// See the example for ExampleInstrumentHandlerWithLabelResolver for example usage
+func WithLabelFromCtx(name string, valueFn LabelValueFromCtx) Option {
+	return optionApplyFunc(func(o *options) {
+		o.extraLabelsFromCtx[name] = valueFn
+	})
+}

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -0,0 +1,785 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"math"
+	"runtime"
+	"sort"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/beorn7/perks/quantile"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+// quantileLabel is used for the label that defines the quantile in a
+// summary.
+const quantileLabel = "quantile"
+
+// A Summary captures individual observations from an event or sample stream and
+// summarizes them in a manner similar to traditional summary statistics: 1. sum
+// of observations, 2. observation count, 3. rank estimations.
+//
+// A typical use-case is the observation of request latencies. By default, a
+// Summary provides the median, the 90th and the 99th percentile of the latency
+// as rank estimations. However, the default behavior will change in the
+// upcoming v1.0.0 of the library. There will be no rank estimations at all by
+// default. For a sane transition, it is recommended to set the desired rank
+// estimations explicitly.
+//
+// Note that the rank estimations cannot be aggregated in a meaningful way with
+// the Prometheus query language (i.e. you cannot average or add them). If you
+// need aggregatable quantiles (e.g. you want the 99th percentile latency of all
+// queries served across all instances of a service), consider the Histogram
+// metric type. See the Prometheus documentation for more details.
+//
+// To create Summary instances, use NewSummary.
+type Summary interface {
+	Metric
+	Collector
+
+	// Observe adds a single observation to the summary. Observations are
+	// usually positive or zero. Negative observations are accepted but
+	// prevent current versions of Prometheus from properly detecting
+	// counter resets in the sum of observations. See
+	// https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
+	// for details.
+	Observe(float64)
+}
+
+var errQuantileLabelNotAllowed = fmt.Errorf(
+	"%q is not allowed as label name in summaries", quantileLabel,
+)
+
+// Default values for SummaryOpts.
+const (
+	// DefMaxAge is the default duration for which observations stay
+	// relevant.
+	DefMaxAge time.Duration = 10 * time.Minute
+	// DefAgeBuckets is the default number of buckets used to calculate the
+	// age of observations.
+	DefAgeBuckets = 5
+	// DefBufCap is the standard buffer size for collecting Summary observations.
+	DefBufCap = 500
+)
+
+// SummaryOpts bundles the options for creating a Summary metric. It is
+// mandatory to set Name to a non-empty string. While all other fields are
+// optional and can safely be left at their zero value, it is recommended to set
+// a help string and to explicitly set the Objectives field to the desired value
+// as the default value will change in the upcoming v1.0.0 of the library.
+type SummaryOpts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Summary (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the Summary must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this Summary.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// Due to the way a Summary is represented in the Prometheus text format
+	// and how it is handled by the Prometheus server internally, “quantile”
+	// is an illegal label name. Construction of a Summary or SummaryVec
+	// will panic if this label name is used in ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
+	ConstLabels Labels
+
+	// Objectives defines the quantile rank estimates with their respective
+	// absolute error. If Objectives[q] = e, then the value reported for q
+	// will be the φ-quantile value for some φ between q-e and q+e.  The
+	// default value is an empty map, resulting in a summary without
+	// quantiles.
+	Objectives map[float64]float64
+
+	// MaxAge defines the duration for which an observation stays relevant
+	// for the summary. Only applies to pre-calculated quantiles, does not
+	// apply to _sum and _count. Must be positive. The default value is
+	// DefMaxAge.
+	MaxAge time.Duration
+
+	// AgeBuckets is the number of buckets used to exclude observations that
+	// are older than MaxAge from the summary. A higher number has a
+	// resource penalty, so only increase it if the higher resolution is
+	// really required. For very high observation rates, you might want to
+	// reduce the number of age buckets. With only one age bucket, you will
+	// effectively see a complete reset of the summary each time MaxAge has
+	// passed. The default value is DefAgeBuckets.
+	AgeBuckets uint32
+
+	// BufCap defines the default sample stream buffer size.  The default
+	// value of DefBufCap should suffice for most uses. If there is a need
+	// to increase the value, a multiple of 500 is recommended (because that
+	// is the internal buffer size of the underlying package
+	// "github.com/bmizerany/perks/quantile").
+	BufCap uint32
+
+	// now is for testing purposes, by default it's time.Now.
+	now func() time.Time
+}
+
+// SummaryVecOpts bundles the options to create a SummaryVec metric.
+// It is mandatory to set SummaryOpts, see there for mandatory fields. VariableLabels
+// is optional and can safely be left to its default value.
+type SummaryVecOpts struct {
+	SummaryOpts
+
+	// VariableLabels are used to partition the metric vector by the given set
+	// of labels. Each label value will be constrained with the optional Constraint
+	// function, if provided.
+	VariableLabels ConstrainableLabels
+}
+
+// Problem with the sliding-window decay algorithm... The Merge method of
+// perk/quantile is actually not working as advertised - and it might be
+// unfixable, as the underlying algorithm is apparently not capable of merging
+// summaries in the first place. To avoid using Merge, we are currently adding
+// observations to _each_ age bucket, i.e. the effort to add a sample is
+// essentially multiplied by the number of age buckets. When rotating age
+// buckets, we empty the previous head stream. On scrape time, we simply take
+// the quantiles from the head stream (no merging required). Result: More effort
+// on observation time, less effort on scrape time, which is exactly the
+// opposite of what we try to accomplish, but at least the results are correct.
+//
+// The quite elegant previous contraption to merge the age buckets efficiently
+// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0)
+// can't be used anymore.
+
+// NewSummary creates a new Summary based on the provided SummaryOpts.
+func NewSummary(opts SummaryOpts) Summary {
+	return newSummary(
+		NewDesc(
+			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+			opts.Help,
+			nil,
+			opts.ConstLabels,
+		),
+		opts,
+	)
+}
+
+func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
+	if len(desc.variableLabels.names) != len(labelValues) {
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, labelValues))
+	}
+
+	for _, n := range desc.variableLabels.names {
+		if n == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
+	for _, lp := range desc.constLabelPairs {
+		if lp.GetName() == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
+
+	if opts.Objectives == nil {
+		opts.Objectives = map[float64]float64{}
+	}
+
+	if opts.MaxAge < 0 {
+		panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge))
+	}
+	if opts.MaxAge == 0 {
+		opts.MaxAge = DefMaxAge
+	}
+
+	if opts.AgeBuckets == 0 {
+		opts.AgeBuckets = DefAgeBuckets
+	}
+
+	if opts.BufCap == 0 {
+		opts.BufCap = DefBufCap
+	}
+
+	if opts.now == nil {
+		opts.now = time.Now
+	}
+	if len(opts.Objectives) == 0 {
+		// Use the lock-free implementation of a Summary without objectives.
+		s := &noObjectivesSummary{
+			desc:       desc,
+			labelPairs: MakeLabelPairs(desc, labelValues),
+			counts:     [2]*summaryCounts{{}, {}},
+		}
+		s.init(s) // Init self-collection.
+		s.createdTs = timestamppb.New(opts.now())
+		return s
+	}
+
+	s := &summary{
+		desc: desc,
+
+		objectives:       opts.Objectives,
+		sortedObjectives: make([]float64, 0, len(opts.Objectives)),
+
+		labelPairs: MakeLabelPairs(desc, labelValues),
+
+		hotBuf:         make([]float64, 0, opts.BufCap),
+		coldBuf:        make([]float64, 0, opts.BufCap),
+		streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets),
+	}
+	s.headStreamExpTime = opts.now().Add(s.streamDuration)
+	s.hotBufExpTime = s.headStreamExpTime
+
+	for i := uint32(0); i < opts.AgeBuckets; i++ {
+		s.streams = append(s.streams, s.newStream())
+	}
+	s.headStream = s.streams[0]
+
+	for qu := range s.objectives {
+		s.sortedObjectives = append(s.sortedObjectives, qu)
+	}
+	sort.Float64s(s.sortedObjectives)
+
+	s.init(s) // Init self-collection.
+	s.createdTs = timestamppb.New(opts.now())
+	return s
+}
+
+type summary struct {
+	selfCollector
+
+	bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
+	mtx    sync.Mutex // Protects every other moving part.
+	// Lock bufMtx before mtx if both are needed.
+
+	desc *Desc
+
+	objectives       map[float64]float64
+	sortedObjectives []float64
+
+	labelPairs []*dto.LabelPair
+
+	sum float64
+	cnt uint64
+
+	hotBuf, coldBuf []float64
+
+	streams                          []*quantile.Stream
+	streamDuration                   time.Duration
+	headStream                       *quantile.Stream
+	headStreamIdx                    int
+	headStreamExpTime, hotBufExpTime time.Time
+
+	createdTs *timestamppb.Timestamp
+}
+
+func (s *summary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *summary) Observe(v float64) {
+	s.bufMtx.Lock()
+	defer s.bufMtx.Unlock()
+
+	now := time.Now()
+	if now.After(s.hotBufExpTime) {
+		s.asyncFlush(now)
+	}
+	s.hotBuf = append(s.hotBuf, v)
+	if len(s.hotBuf) == cap(s.hotBuf) {
+		s.asyncFlush(now)
+	}
+}
+
+func (s *summary) Write(out *dto.Metric) error {
+	sum := &dto.Summary{
+		CreatedTimestamp: s.createdTs,
+	}
+	qs := make([]*dto.Quantile, 0, len(s.objectives))
+
+	s.bufMtx.Lock()
+	s.mtx.Lock()
+	// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
+	s.swapBufs(time.Now())
+	s.bufMtx.Unlock()
+
+	s.flushColdBuf()
+	sum.SampleCount = proto.Uint64(s.cnt)
+	sum.SampleSum = proto.Float64(s.sum)
+
+	for _, rank := range s.sortedObjectives {
+		var q float64
+		if s.headStream.Count() == 0 {
+			q = math.NaN()
+		} else {
+			q = s.headStream.Query(rank)
+		}
+		qs = append(qs, &dto.Quantile{
+			Quantile: proto.Float64(rank),
+			Value:    proto.Float64(q),
+		})
+	}
+
+	s.mtx.Unlock()
+
+	if len(qs) > 0 {
+		sort.Sort(quantSort(qs))
+	}
+	sum.Quantile = qs
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+	return nil
+}
+
+func (s *summary) newStream() *quantile.Stream {
+	return quantile.NewTargeted(s.objectives)
+}
+
+// asyncFlush needs bufMtx locked.
+func (s *summary) asyncFlush(now time.Time) {
+	s.mtx.Lock()
+	s.swapBufs(now)
+
+	// Unblock the original goroutine that was responsible for the mutation
+	// that triggered the compaction.  But hold onto the global non-buffer
+	// state mutex until the operation finishes.
+	go func() {
+		s.flushColdBuf()
+		s.mtx.Unlock()
+	}()
+}
+
+// rotateStreams needs mtx AND bufMtx locked.
+func (s *summary) maybeRotateStreams() {
+	for !s.hotBufExpTime.Equal(s.headStreamExpTime) {
+		s.headStream.Reset()
+		s.headStreamIdx++
+		if s.headStreamIdx >= len(s.streams) {
+			s.headStreamIdx = 0
+		}
+		s.headStream = s.streams[s.headStreamIdx]
+		s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration)
+	}
+}
+
+// flushColdBuf needs mtx locked.
+func (s *summary) flushColdBuf() {
+	for _, v := range s.coldBuf {
+		for _, stream := range s.streams {
+			stream.Insert(v)
+		}
+		s.cnt++
+		s.sum += v
+	}
+	s.coldBuf = s.coldBuf[0:0]
+	s.maybeRotateStreams()
+}
+
+// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty.
+func (s *summary) swapBufs(now time.Time) {
+	if len(s.coldBuf) != 0 {
+		panic("coldBuf is not empty")
+	}
+	s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf
+	// hotBuf is now empty and gets new expiration set.
+	for now.After(s.hotBufExpTime) {
+		s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration)
+	}
+}
+
+type summaryCounts struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+}
+
+type noObjectivesSummary struct {
+	// countAndHotIdx enables lock-free writes with use of atomic updates.
+	// The most significant bit is the hot index [0 or 1] of the count field
+	// below. Observe calls update the hot one. All remaining bits count the
+	// number of Observe calls. Observe starts by incrementing this counter,
+	// and finish by incrementing the count field in the respective
+	// summaryCounts, as a marker for completion.
+	//
+	// Calls of the Write method (which are non-mutating reads from the
+	// perspective of the summary) swap the hot–cold under the writeMtx
+	// lock. A cooldown is awaited (while locked) by comparing the number of
+	// observations with the initiation count. Once they match, then the
+	// last observation on the now cool one has completed. All cool fields must
+	// be merged into the new hot before releasing writeMtx.
+
+	// Fields with atomic access first! See alignment constraint:
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
+
+	selfCollector
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
+
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*summaryCounts
+
+	labelPairs []*dto.LabelPair
+
+	createdTs *timestamppb.Timestamp
+}
+
+func (s *noObjectivesSummary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *noObjectivesSummary) Observe(v float64) {
+	// We increment h.countAndHotIdx so that the counter in the lower
+	// 63 bits gets incremented. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&s.countAndHotIdx, 1)
+	hotCounts := s.counts[n>>63]
+
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+func (s *noObjectivesSummary) Write(out *dto.Metric) error {
+	// For simplicity, we protect this whole method by a mutex. It is not in
+	// the hot path, i.e. Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it, if possible at
+	// all.
+	s.writeMtx.Lock()
+	defer s.writeMtx.Unlock()
+
+	// Adding 1<<63 switches the hot index (from 0 to 1 or from 1 to 0)
+	// without touching the count bits. See the struct comments for a full
+	// description of the algorithm.
+	n := atomic.AddUint64(&s.countAndHotIdx, 1<<63)
+	// count is contained unchanged in the lower 63 bits.
+	count := n & ((1 << 63) - 1)
+	// The most significant bit tells us which counts is hot. The complement
+	// is thus the cold one.
+	hotCounts := s.counts[n>>63]
+	coldCounts := s.counts[(^n)>>63]
+
+	// Await cooldown.
+	for count != atomic.LoadUint64(&coldCounts.count) {
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	sum := &dto.Summary{
+		SampleCount:      proto.Uint64(count),
+		SampleSum:        proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits))),
+		CreatedTimestamp: s.createdTs,
+	}
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + sum.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	return nil
+}
+
+type quantSort []*dto.Quantile
+
+func (s quantSort) Len() int {
+	return len(s)
+}
+
+func (s quantSort) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s quantSort) Less(i, j int) bool {
+	return s[i].GetQuantile() < s[j].GetQuantile()
+}
+
+// SummaryVec is a Collector that bundles a set of Summaries that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. HTTP request latencies, partitioned by status code and method). Create
+// instances with NewSummaryVec.
+type SummaryVec struct {
+	*MetricVec
+}
+
+// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
+// partitioned by the given label names.
+//
+// Due to the way a Summary is represented in the Prometheus text format and how
+// it is handled by the Prometheus server internally, “quantile” is an illegal
+// label name. NewSummaryVec will panic if this label name is used.
+func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
+	return V2.NewSummaryVec(SummaryVecOpts{
+		SummaryOpts:    opts,
+		VariableLabels: UnconstrainedLabels(labelNames),
+	})
+}
+
+// NewSummaryVec creates a new SummaryVec based on the provided SummaryVecOpts.
+func (v2) NewSummaryVec(opts SummaryVecOpts) *SummaryVec {
+	for _, ln := range opts.VariableLabels.labelNames() {
+		if ln == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
+	desc := V2.NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		opts.VariableLabels,
+		opts.ConstLabels,
+	)
+	return &SummaryVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			return newSummary(desc, opts.SummaryOpts, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Summary for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Summary is created.
+//
+// It is possible to call this method without using the returned Summary to only
+// create the new Summary but leave it at its starting value, a Summary without
+// any observations.
+//
+// Keeping the Summary for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Summary from the SummaryVec. In that case,
+// the Summary will still exist, but it will not be exported anymore, even if a
+// Summary with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Summary for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Summary is created. Implications of
+// creating a Summary without using it and keeping the Summary for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//
+//	myVec.WithLabelValues("404", "GET").Observe(42.21)
+func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
+	s, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//
+//	myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *SummaryVec) With(labels Labels) Observer {
+	s, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the SummaryVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &SummaryVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+type constSummary struct {
+	desc       *Desc
+	count      uint64
+	sum        float64
+	quantiles  map[float64]float64
+	labelPairs []*dto.LabelPair
+	createdTs  *timestamppb.Timestamp
+}
+
+func (s *constSummary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *constSummary) Write(out *dto.Metric) error {
+	sum := &dto.Summary{
+		CreatedTimestamp: s.createdTs,
+	}
+	qs := make([]*dto.Quantile, 0, len(s.quantiles))
+
+	sum.SampleCount = proto.Uint64(s.count)
+	sum.SampleSum = proto.Float64(s.sum)
+
+	for rank, q := range s.quantiles {
+		qs = append(qs, &dto.Quantile{
+			Quantile: proto.Float64(rank),
+			Value:    proto.Float64(q),
+		})
+	}
+
+	if len(qs) > 0 {
+		sort.Sort(quantSort(qs))
+	}
+	sum.Quantile = qs
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+
+	return nil
+}
+
+// NewConstSummary returns a metric representing a Prometheus summary with fixed
+// values for the count, sum, and quantiles. As those parameters cannot be
+// changed, the returned value does not implement the Summary interface (but
+// only the Metric interface). Users of this package will not have much use for
+// it in regular operations. However, when implementing custom Collectors, it is
+// useful as a throw-away metric that is generated on the fly to send it to
+// Prometheus in the Collect method.
+//
+// quantiles maps ranks to quantile values. For example, a median latency of
+// 0.23s and a 99th percentile latency of 0.56s would be expressed as:
+//
+//	map[float64]float64{0.5: 0.23, 0.99: 0.56}
+//
+// NewConstSummary returns an error if the length of labelValues is not
+// consistent with the variable labels in Desc or if Desc is invalid.
+func NewConstSummary(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	return &constSummary{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		quantiles:  quantiles,
+		labelPairs: MakeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstSummary is a version of NewConstSummary that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstSummary(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}

vendor/github.com/prometheus/client_golang/prometheus/timer.go

@@ -0,0 +1,81 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "time"
+
+// Timer is a helper type to time functions. Use NewTimer to create new
+// instances.
+type Timer struct {
+	begin    time.Time
+	observer Observer
+}
+
+// NewTimer creates a new Timer. The provided Observer is used to observe a
+// duration in seconds. If the Observer implements ExemplarObserver, passing exemplar
+// later on will be also supported.
+// Timer is usually used to time a function call in the
+// following way:
+//
+//	func TimeMe() {
+//	    timer := NewTimer(myHistogram)
+//	    defer timer.ObserveDuration()
+//	    // Do actual work.
+//	}
+//
+// or
+//
+//	func TimeMeWithExemplar() {
+//		    timer := NewTimer(myHistogram)
+//		    defer timer.ObserveDurationWithExemplar(exemplar)
+//		    // Do actual work.
+//		}
+func NewTimer(o Observer) *Timer {
+	return &Timer{
+		begin:    time.Now(),
+		observer: o,
+	}
+}
+
+// ObserveDuration records the duration passed since the Timer was created with
+// NewTimer. It calls the Observe method of the Observer provided during
+// construction with the duration in seconds as an argument. The observed
+// duration is also returned. ObserveDuration is usually called with a defer
+// statement.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func (t *Timer) ObserveDuration() time.Duration {
+	d := time.Since(t.begin)
+	if t.observer != nil {
+		t.observer.Observe(d.Seconds())
+	}
+	return d
+}
+
+// ObserveDurationWithExemplar is like ObserveDuration, but it will also
+// observe exemplar with the duration unless exemplar is nil or provided Observer can't
+// be casted to ExemplarObserver.
+func (t *Timer) ObserveDurationWithExemplar(exemplar Labels) time.Duration {
+	d := time.Since(t.begin)
+	eo, ok := t.observer.(ExemplarObserver)
+	if ok && exemplar != nil {
+		eo.ObserveWithExemplar(d.Seconds(), exemplar)
+		return d
+	}
+	if t.observer != nil {
+		t.observer.Observe(d.Seconds())
+	}
+	return d
+}

vendor/github.com/prometheus/client_golang/prometheus/untyped.go

@@ -0,0 +1,42 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// UntypedOpts is an alias for Opts. See there for doc comments.
+type UntypedOpts Opts
+
+// UntypedFunc works like GaugeFunc but the collected metric is of type
+// "Untyped". UntypedFunc is useful to mirror an external metric of unknown
+// type.
+//
+// To create UntypedFunc instances, use NewUntypedFunc.
+type UntypedFunc interface {
+	Metric
+	Collector
+}
+
+// NewUntypedFunc creates a new UntypedFunc based on the provided
+// UntypedOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where an UntypedFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe.
+func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), UntypedValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/value.go

@@ -0,0 +1,274 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"time"
+	"unicode/utf8"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
+
+	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+// ValueType is an enumeration of metric types that represent a simple value.
+type ValueType int
+
+// Possible values for the ValueType enum. Use UntypedValue to mark a metric
+// with an unknown type.
+const (
+	_ ValueType = iota
+	CounterValue
+	GaugeValue
+	UntypedValue
+)
+
+var (
+	CounterMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_COUNTER; return &d }()
+	GaugeMetricTypePtr   = func() *dto.MetricType { d := dto.MetricType_GAUGE; return &d }()
+	UntypedMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_UNTYPED; return &d }()
+)
+
+func (v ValueType) ToDTO() *dto.MetricType {
+	switch v {
+	case CounterValue:
+		return CounterMetricTypePtr
+	case GaugeValue:
+		return GaugeMetricTypePtr
+	default:
+		return UntypedMetricTypePtr
+	}
+}
+
+// valueFunc is a generic metric for simple values retrieved on collect time
+// from a function. It implements Metric and Collector. Its effective type is
+// determined by ValueType. This is a low-level building block used by the
+// library to back the implementations of CounterFunc, GaugeFunc, and
+// UntypedFunc.
+type valueFunc struct {
+	selfCollector
+
+	desc       *Desc
+	valType    ValueType
+	function   func() float64
+	labelPairs []*dto.LabelPair
+}
+
+// newValueFunc returns a newly allocated valueFunc with the given Desc and
+// ValueType. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a valueFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe.
+func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
+	result := &valueFunc{
+		desc:       desc,
+		valType:    valueType,
+		function:   function,
+		labelPairs: MakeLabelPairs(desc, nil),
+	}
+	result.init(result)
+	return result
+}
+
+func (v *valueFunc) Desc() *Desc {
+	return v.desc
+}
+
+func (v *valueFunc) Write(out *dto.Metric) error {
+	return populateMetric(v.valType, v.function(), v.labelPairs, nil, out, nil)
+}
+
+// NewConstMetric returns a metric with one fixed value that cannot be
+// changed. Users of this package will not have much use for it in regular
+// operations. However, when implementing custom Collectors, it is useful as a
+// throw-away metric that is generated on the fly to send it to Prometheus in
+// the Collect method. NewConstMetric returns an error if the length of
+// labelValues is not consistent with the variable labels in Desc or if Desc is
+// invalid.
+func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+
+	metric := &dto.Metric{}
+	if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, nil); err != nil {
+		return nil, err
+	}
+
+	return &constMetric{
+		desc:   desc,
+		metric: metric,
+	}, nil
+}
+
+// MustNewConstMetric is a version of NewConstMetric that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
+	m, err := NewConstMetric(desc, valueType, value, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+// NewConstMetricWithCreatedTimestamp does the same thing as NewConstMetric, but generates Counters
+// with created timestamp set and returns an error for other metric types.
+func NewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	switch valueType {
+	case CounterValue:
+		break
+	default:
+		return nil, errors.New("created timestamps are only supported for counters")
+	}
+
+	metric := &dto.Metric{}
+	if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, timestamppb.New(ct)); err != nil {
+		return nil, err
+	}
+
+	return &constMetric{
+		desc:   desc,
+		metric: metric,
+	}, nil
+}
+
+// MustNewConstMetricWithCreatedTimestamp is a version of NewConstMetricWithCreatedTimestamp that panics where
+// NewConstMetricWithCreatedTimestamp would have returned an error.
+func MustNewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) Metric {
+	m, err := NewConstMetricWithCreatedTimestamp(desc, valueType, value, ct, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+type constMetric struct {
+	desc   *Desc
+	metric *dto.Metric
+}
+
+func (m *constMetric) Desc() *Desc {
+	return m.desc
+}
+
+func (m *constMetric) Write(out *dto.Metric) error {
+	out.Label = m.metric.Label
+	out.Counter = m.metric.Counter
+	out.Gauge = m.metric.Gauge
+	out.Untyped = m.metric.Untyped
+	return nil
+}
+
+func populateMetric(
+	t ValueType,
+	v float64,
+	labelPairs []*dto.LabelPair,
+	e *dto.Exemplar,
+	m *dto.Metric,
+	ct *timestamppb.Timestamp,
+) error {
+	m.Label = labelPairs
+	switch t {
+	case CounterValue:
+		m.Counter = &dto.Counter{Value: proto.Float64(v), Exemplar: e, CreatedTimestamp: ct}
+	case GaugeValue:
+		m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
+	case UntypedValue:
+		m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
+	default:
+		return fmt.Errorf("encountered unknown type %v", t)
+	}
+	return nil
+}
+
+// MakeLabelPairs is a helper function to create protobuf LabelPairs from the
+// variable and constant labels in the provided Desc. The values for the
+// variable labels are defined by the labelValues slice, which must be in the
+// same order as the corresponding variable labels in the Desc.
+//
+// This function is only needed for custom Metric implementations. See MetricVec
+// example.
+func MakeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
+	totalLen := len(desc.variableLabels.names) + len(desc.constLabelPairs)
+	if totalLen == 0 {
+		// Super fast path.
+		return nil
+	}
+	if len(desc.variableLabels.names) == 0 {
+		// Moderately fast path.
+		return desc.constLabelPairs
+	}
+	labelPairs := make([]*dto.LabelPair, 0, totalLen)
+	for i, l := range desc.variableLabels.names {
+		labelPairs = append(labelPairs, &dto.LabelPair{
+			Name:  proto.String(l),
+			Value: proto.String(labelValues[i]),
+		})
+	}
+	labelPairs = append(labelPairs, desc.constLabelPairs...)
+	sort.Sort(internal.LabelPairSorter(labelPairs))
+	return labelPairs
+}
+
+// ExemplarMaxRunes is the max total number of runes allowed in exemplar labels.
+const ExemplarMaxRunes = 128
+
+// newExemplar creates a new dto.Exemplar from the provided values. An error is
+// returned if any of the label names or values are invalid or if the total
+// number of runes in the label names and values exceeds ExemplarMaxRunes.
+func newExemplar(value float64, ts time.Time, l Labels) (*dto.Exemplar, error) {
+	e := &dto.Exemplar{}
+	e.Value = proto.Float64(value)
+	tsProto := timestamppb.New(ts)
+	if err := tsProto.CheckValid(); err != nil {
+		return nil, err
+	}
+	e.Timestamp = tsProto
+	labelPairs := make([]*dto.LabelPair, 0, len(l))
+	var runes int
+	for name, value := range l {
+		if !checkLabelName(name) {
+			return nil, fmt.Errorf("exemplar label name %q is invalid", name)
+		}
+		runes += utf8.RuneCountInString(name)
+		if !utf8.ValidString(value) {
+			return nil, fmt.Errorf("exemplar label value %q is not valid UTF-8", value)
+		}
+		runes += utf8.RuneCountInString(value)
+		labelPairs = append(labelPairs, &dto.LabelPair{
+			Name:  proto.String(name),
+			Value: proto.String(value),
+		})
+	}
+	if runes > ExemplarMaxRunes {
+		return nil, fmt.Errorf("exemplar labels have %d runes, exceeding the limit of %d", runes, ExemplarMaxRunes)
+	}
+	e.Label = labelPairs
+	return e, nil
+}

vendor/github.com/prometheus/client_golang/prometheus/vec.go

@@ -0,0 +1,709 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/prometheus/common/model"
+)
+
+// MetricVec is a Collector to bundle metrics of the same name that differ in
+// their label values. MetricVec is not used directly but as a building block
+// for implementations of vectors of a given metric type, like GaugeVec,
+// CounterVec, SummaryVec, and HistogramVec. It is exported so that it can be
+// used for custom Metric implementations.
+//
+// To create a FooVec for custom Metric Foo, embed a pointer to MetricVec in
+// FooVec and initialize it with NewMetricVec. Implement wrappers for
+// GetMetricWithLabelValues and GetMetricWith that return (Foo, error) rather
+// than (Metric, error). Similarly, create a wrapper for CurryWith that returns
+// (*FooVec, error) rather than (*MetricVec, error). It is recommended to also
+// add the convenience methods WithLabelValues, With, and MustCurryWith, which
+// panic instead of returning errors. See also the MetricVec example.
+type MetricVec struct {
+	*metricMap
+
+	curry []curriedLabelValue
+
+	// hashAdd and hashAddByte can be replaced for testing collision handling.
+	hashAdd     func(h uint64, s string) uint64
+	hashAddByte func(h uint64, b byte) uint64
+}
+
+// NewMetricVec returns an initialized metricVec.
+func NewMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
+	return &MetricVec{
+		metricMap: &metricMap{
+			metrics:   map[uint64][]metricWithLabelValues{},
+			desc:      desc,
+			newMetric: newMetric,
+		},
+		hashAdd:     hashAdd,
+		hashAddByte: hashAddByte,
+	}
+}
+
+// DeleteLabelValues removes the metric where the variable labels are the same
+// as those passed in as labels (same order as the VariableLabels in Desc). It
+// returns true if a metric was deleted.
+//
+// It is not an error if the number of label values is not the same as the
+// number of VariableLabels in Desc. However, such inconsistent label count can
+// never match an actual metric, so the method will always return false in that
+// case.
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider Delete(Labels) as an
+// alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the CounterVec example.
+func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
+	lvs = constrainLabelValues(m.desc, lvs, m.curry)
+
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
+}
+
+// Delete deletes the metric where the variable labels are the same as those
+// passed in as labels. It returns true if a metric was deleted.
+//
+// It is not an error if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc. However, such inconsistent Labels
+// can never match an actual metric, so the method will always return false in
+// that case.
+//
+// This method is used for the same purpose as DeleteLabelValues(...string). See
+// there for pros and cons of the two methods.
+func (m *MetricVec) Delete(labels Labels) bool {
+	labels, closer := constrainLabels(m.desc, labels)
+	defer closer()
+
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
+}
+
+// DeletePartialMatch deletes all metrics where the variable labels contain all of those
+// passed in as labels. The order of the labels does not matter.
+// It returns the number of metrics deleted.
+//
+// Note that curried labels will never be matched if deleting from the curried vector.
+// To match curried labels with DeletePartialMatch, it must be called on the base vector.
+func (m *MetricVec) DeletePartialMatch(labels Labels) int {
+	labels, closer := constrainLabels(m.desc, labels)
+	defer closer()
+
+	return m.metricMap.deleteByLabels(labels, m.curry)
+}
+
+// Without explicit forwarding of Describe, Collect, Reset, those methods won't
+// show up in GoDoc.
+
+// Describe implements Collector.
+func (m *MetricVec) Describe(ch chan<- *Desc) { m.metricMap.Describe(ch) }
+
+// Collect implements Collector.
+func (m *MetricVec) Collect(ch chan<- Metric) { m.metricMap.Collect(ch) }
+
+// Reset deletes all metrics in this vector.
+func (m *MetricVec) Reset() { m.metricMap.Reset() }
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the MetricVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+//
+// Note that CurryWith is usually not called directly but through a wrapper
+// around MetricVec, implementing a vector for a specific Metric
+// implementation, for example GaugeVec.
+func (m *MetricVec) CurryWith(labels Labels) (*MetricVec, error) {
+	var (
+		newCurry []curriedLabelValue
+		oldCurry = m.curry
+		iCurry   int
+	)
+	for i, labelName := range m.desc.variableLabels.names {
+		val, ok := labels[labelName]
+		if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
+			if ok {
+				return nil, fmt.Errorf("label name %q is already curried", labelName)
+			}
+			newCurry = append(newCurry, oldCurry[iCurry])
+			iCurry++
+		} else {
+			if !ok {
+				continue // Label stays uncurried.
+			}
+			newCurry = append(newCurry, curriedLabelValue{
+				i,
+				m.desc.variableLabels.constrain(labelName, val),
+			})
+		}
+	}
+	if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
+		return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
+	}
+
+	return &MetricVec{
+		metricMap:   m.metricMap,
+		curry:       newCurry,
+		hashAdd:     m.hashAdd,
+		hashAddByte: m.hashAddByte,
+	}, nil
+}
+
+// GetMetricWithLabelValues returns the Metric for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Metric is created (by
+// calling the newMetric function provided during construction of the
+// MetricVec).
+//
+// It is possible to call this method without using the returned Metric to only
+// create the new Metric but leave it in its initial state.
+//
+// Keeping the Metric for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Metric from the MetricVec. In that case, the
+// Metric will still exist, but it will not be exported anymore, even if a
+// Metric with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+//
+// Note that GetMetricWithLabelValues is usually not called directly but through
+// a wrapper around MetricVec, implementing a vector for a specific Metric
+// implementation, for example GaugeVec.
+func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
+	lvs = constrainLabelValues(m.desc, lvs, m.curry)
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
+}
+
+// GetMetricWith returns the Metric for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Metric is created. Implications of
+// creating a Metric without using it and keeping the Metric for later use
+// are the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+//
+// Note that GetMetricWith is usually not called directly but through a wrapper
+// around MetricVec, implementing a vector for a specific Metric implementation,
+// for example GaugeVec.
+func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
+	labels, closer := constrainLabels(m.desc, labels)
+	defer closer()
+
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
+}
+
+func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
+	if err := validateLabelValues(vals, len(m.desc.variableLabels.names)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h             = hashNew()
+		curry         = m.curry
+		iVals, iCurry int
+	)
+	for i := 0; i < len(m.desc.variableLabels.names); i++ {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			h = m.hashAdd(h, vals[iVals])
+			iVals++
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
+	if err := validateValuesInLabels(labels, len(m.desc.variableLabels.names)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h      = hashNew()
+		curry  = m.curry
+		iCurry int
+	)
+	for i, labelName := range m.desc.variableLabels.names {
+		val, ok := labels[labelName]
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if ok {
+				return 0, fmt.Errorf("label name %q is already curried", labelName)
+			}
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			if !ok {
+				return 0, fmt.Errorf("label name %q missing in label map", labelName)
+			}
+			h = m.hashAdd(h, val)
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+// metricWithLabelValues provides the metric and its label values for
+// disambiguation on hash collision.
+type metricWithLabelValues struct {
+	values []string
+	metric Metric
+}
+
+// curriedLabelValue sets the curried value for a label at the given index.
+type curriedLabelValue struct {
+	index int
+	value string
+}
+
+// metricMap is a helper for metricVec and shared between differently curried
+// metricVecs.
+type metricMap struct {
+	mtx       sync.RWMutex // Protects metrics.
+	metrics   map[uint64][]metricWithLabelValues
+	desc      *Desc
+	newMetric func(labelValues ...string) Metric
+}
+
+// Describe implements Collector. It will send exactly one Desc to the provided
+// channel.
+func (m *metricMap) Describe(ch chan<- *Desc) {
+	ch <- m.desc
+}
+
+// Collect implements Collector.
+func (m *metricMap) Collect(ch chan<- Metric) {
+	m.mtx.RLock()
+	defer m.mtx.RUnlock()
+
+	for _, metrics := range m.metrics {
+		for _, metric := range metrics {
+			ch <- metric.metric
+		}
+	}
+}
+
+// Reset deletes all metrics in this vector.
+func (m *metricMap) Reset() {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	for h := range m.metrics {
+		delete(m.metrics, h)
+	}
+}
+
+// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
+// there are multiple matches in the bucket, use lvs to select a metric and
+// remove only that metric.
+func (m *metricMap) deleteByHashWithLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	metrics, ok := m.metrics[h]
+	if !ok {
+		return false
+	}
+
+	i := findMetricWithLabelValues(metrics, lvs, curry)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		old := metrics
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
+		old[len(old)-1] = metricWithLabelValues{}
+	} else {
+		delete(m.metrics, h)
+	}
+	return true
+}
+
+// deleteByHashWithLabels removes the metric from the hash bucket h. If there
+// are multiple matches in the bucket, use lvs to select a metric and remove
+// only that metric.
+func (m *metricMap) deleteByHashWithLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	metrics, ok := m.metrics[h]
+	if !ok {
+		return false
+	}
+	i := findMetricWithLabels(m.desc, metrics, labels, curry)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		old := metrics
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
+		old[len(old)-1] = metricWithLabelValues{}
+	} else {
+		delete(m.metrics, h)
+	}
+	return true
+}
+
+// deleteByLabels deletes a metric if the given labels are present in the metric.
+func (m *metricMap) deleteByLabels(labels Labels, curry []curriedLabelValue) int {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	var numDeleted int
+
+	for h, metrics := range m.metrics {
+		i := findMetricWithPartialLabels(m.desc, metrics, labels, curry)
+		if i >= len(metrics) {
+			// Didn't find matching labels in this metric slice.
+			continue
+		}
+		delete(m.metrics, h)
+		numDeleted++
+	}
+
+	return numDeleted
+}
+
+// findMetricWithPartialLabel returns the index of the matching metric or
+// len(metrics) if not found.
+func findMetricWithPartialLabels(
+	desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
+) int {
+	for i, metric := range metrics {
+		if matchPartialLabels(desc, metric.values, labels, curry) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+// indexOf searches the given slice of strings for the target string and returns
+// the index or len(items) as well as a boolean whether the search succeeded.
+func indexOf(target string, items []string) (int, bool) {
+	for i, l := range items {
+		if l == target {
+			return i, true
+		}
+	}
+	return len(items), false
+}
+
+// valueMatchesVariableOrCurriedValue determines if a value was previously curried,
+// and returns whether it matches either the "base" value or the curried value accordingly.
+// It also indicates whether the match is against a curried or uncurried value.
+func valueMatchesVariableOrCurriedValue(targetValue string, index int, values []string, curry []curriedLabelValue) (bool, bool) {
+	for _, curriedValue := range curry {
+		if curriedValue.index == index {
+			// This label was curried. See if the curried value matches our target.
+			return curriedValue.value == targetValue, true
+		}
+	}
+	// This label was not curried. See if the current value matches our target label.
+	return values[index] == targetValue, false
+}
+
+// matchPartialLabels searches the current metric and returns whether all of the target label:value pairs are present.
+func matchPartialLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
+	for l, v := range labels {
+		// Check if the target label exists in our metrics and get the index.
+		varLabelIndex, validLabel := indexOf(l, desc.variableLabels.names)
+		if validLabel {
+			// Check the value of that label against the target value.
+			// We don't consider curried values in partial matches.
+			matches, curried := valueMatchesVariableOrCurriedValue(v, varLabelIndex, values, curry)
+			if matches && !curried {
+				continue
+			}
+		}
+		return false
+	}
+	return true
+}
+
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *metricMap) getOrCreateMetricWithLabelValues(
+	hash uint64, lvs []string, curry []curriedLabelValue,
+) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
+	if !ok {
+		inlinedLVs := inlineLabelValues(lvs, curry)
+		metric = m.newMetric(inlinedLVs...)
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
+	}
+	return metric
+}
+
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *metricMap) getOrCreateMetricWithLabels(
+	hash uint64, labels Labels, curry []curriedLabelValue,
+) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
+	if !ok {
+		lvs := extractLabelValues(m.desc, labels, curry)
+		metric = m.newMetric(lvs...)
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
+	}
+	return metric
+}
+
+// getMetricWithHashAndLabelValues gets a metric while handling possible
+// collisions in the hash space. Must be called while holding the read mutex.
+func (m *metricMap) getMetricWithHashAndLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
+	if ok {
+		if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// getMetricWithHashAndLabels gets a metric while handling possible collisions in
+// the hash space. Must be called while holding read mutex.
+func (m *metricMap) getMetricWithHashAndLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
+	if ok {
+		if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// findMetricWithLabelValues returns the index of the matching metric or
+// len(metrics) if not found.
+func findMetricWithLabelValues(
+	metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
+) int {
+	for i, metric := range metrics {
+		if matchLabelValues(metric.values, lvs, curry) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+// findMetricWithLabels returns the index of the matching metric or len(metrics)
+// if not found.
+func findMetricWithLabels(
+	desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
+) int {
+	for i, metric := range metrics {
+		if matchLabels(desc, metric.values, labels, curry) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+func matchLabelValues(values, lvs []string, curry []curriedLabelValue) bool {
+	if len(values) != len(lvs)+len(curry) {
+		return false
+	}
+	var iLVs, iCurry int
+	for i, v := range values {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if v != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
+		if v != lvs[iLVs] {
+			return false
+		}
+		iLVs++
+	}
+	return true
+}
+
+func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
+	if len(values) != len(labels)+len(curry) {
+		return false
+	}
+	iCurry := 0
+	for i, k := range desc.variableLabels.names {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if values[i] != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
+		if values[i] != labels[k] {
+			return false
+		}
+	}
+	return true
+}
+
+func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(labels)+len(curry))
+	iCurry := 0
+	for i, k := range desc.variableLabels.names {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
+		labelValues[i] = labels[k]
+	}
+	return labelValues
+}
+
+func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(lvs)+len(curry))
+	var iCurry, iLVs int
+	for i := range labelValues {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
+		labelValues[i] = lvs[iLVs]
+		iLVs++
+	}
+	return labelValues
+}
+
+var labelsPool = &sync.Pool{
+	New: func() interface{} {
+		return make(Labels)
+	},
+}
+
+func constrainLabels(desc *Desc, labels Labels) (Labels, func()) {
+	if len(desc.variableLabels.labelConstraints) == 0 {
+		// Fast path when there's no constraints
+		return labels, func() {}
+	}
+
+	constrainedLabels := labelsPool.Get().(Labels)
+	for l, v := range labels {
+		constrainedLabels[l] = desc.variableLabels.constrain(l, v)
+	}
+
+	return constrainedLabels, func() {
+		for k := range constrainedLabels {
+			delete(constrainedLabels, k)
+		}
+		labelsPool.Put(constrainedLabels)
+	}
+}
+
+func constrainLabelValues(desc *Desc, lvs []string, curry []curriedLabelValue) []string {
+	if len(desc.variableLabels.labelConstraints) == 0 {
+		// Fast path when there's no constraints
+		return lvs
+	}
+
+	constrainedValues := make([]string, len(lvs))
+	var iCurry, iLVs int
+	for i := 0; i < len(lvs)+len(curry); i++ {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			iCurry++
+			continue
+		}
+
+		if i < len(desc.variableLabels.names) {
+			constrainedValues[iLVs] = desc.variableLabels.constrain(
+				desc.variableLabels.names[i],
+				lvs[iLVs],
+			)
+		} else {
+			constrainedValues[iLVs] = lvs[iLVs]
+		}
+		iLVs++
+	}
+	return constrainedValues
+}

vendor/github.com/prometheus/client_golang/prometheus/vnext.go

@@ -0,0 +1,23 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+type v2 struct{}
+
+// V2 is a struct that can be referenced to access experimental API that might
+// be present in v2 of client golang someday. It offers extended functionality
+// of v1 with slightly changed API. It is acceptable to use some pieces from v1
+// and e.g `prometheus.NewGauge` and some from v2 e.g. `prometheus.V2.NewDesc`
+// in the same codebase.
+var V2 = v2{}

vendor/github.com/prometheus/client_golang/prometheus/wrap.go

@@ -0,0 +1,214 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
+
+	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/proto"
+)
+
+// WrapRegistererWith returns a Registerer wrapping the provided
+// Registerer. Collectors registered with the returned Registerer will be
+// registered with the wrapped Registerer in a modified way. The modified
+// Collector adds the provided Labels to all Metrics it collects (as
+// ConstLabels). The Metrics collected by the unmodified Collector must not
+// duplicate any of those labels. Wrapping a nil value is valid, resulting
+// in a no-op Registerer.
+//
+// WrapRegistererWith provides a way to add fixed labels to a subset of
+// Collectors. It should not be used to add fixed labels to all metrics
+// exposed. See also
+// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
+//
+// Conflicts between Collectors registered through the original Registerer with
+// Collectors registered through the wrapping Registerer will still be
+// detected. Any AlreadyRegisteredError returned by the Register method of
+// either Registerer will contain the ExistingCollector in the form it was
+// provided to the respective registry.
+//
+// The Collector example demonstrates a use of WrapRegistererWith.
+func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
+	return &wrappingRegisterer{
+		wrappedRegisterer: reg,
+		labels:            labels,
+	}
+}
+
+// WrapRegistererWithPrefix returns a Registerer wrapping the provided
+// Registerer. Collectors registered with the returned Registerer will be
+// registered with the wrapped Registerer in a modified way. The modified
+// Collector adds the provided prefix to the name of all Metrics it collects.
+// Wrapping a nil value is valid, resulting in a no-op Registerer.
+//
+// WrapRegistererWithPrefix is useful to have one place to prefix all metrics of
+// a sub-system. To make this work, register metrics of the sub-system with the
+// wrapping Registerer returned by WrapRegistererWithPrefix. It is rarely useful
+// to use the same prefix for all metrics exposed. In particular, do not prefix
+// metric names that are standardized across applications, as that would break
+// horizontal monitoring, for example the metrics provided by the Go collector
+// (see NewGoCollector) and the process collector (see NewProcessCollector). (In
+// fact, those metrics are already prefixed with “go_” or “process_”,
+// respectively.)
+//
+// Conflicts between Collectors registered through the original Registerer with
+// Collectors registered through the wrapping Registerer will still be
+// detected. Any AlreadyRegisteredError returned by the Register method of
+// either Registerer will contain the ExistingCollector in the form it was
+// provided to the respective registry.
+func WrapRegistererWithPrefix(prefix string, reg Registerer) Registerer {
+	return &wrappingRegisterer{
+		wrappedRegisterer: reg,
+		prefix:            prefix,
+	}
+}
+
+type wrappingRegisterer struct {
+	wrappedRegisterer Registerer
+	prefix            string
+	labels            Labels
+}
+
+func (r *wrappingRegisterer) Register(c Collector) error {
+	if r.wrappedRegisterer == nil {
+		return nil
+	}
+	return r.wrappedRegisterer.Register(&wrappingCollector{
+		wrappedCollector: c,
+		prefix:           r.prefix,
+		labels:           r.labels,
+	})
+}
+
+func (r *wrappingRegisterer) MustRegister(cs ...Collector) {
+	if r.wrappedRegisterer == nil {
+		return
+	}
+	for _, c := range cs {
+		if err := r.Register(c); err != nil {
+			panic(err)
+		}
+	}
+}
+
+func (r *wrappingRegisterer) Unregister(c Collector) bool {
+	if r.wrappedRegisterer == nil {
+		return false
+	}
+	return r.wrappedRegisterer.Unregister(&wrappingCollector{
+		wrappedCollector: c,
+		prefix:           r.prefix,
+		labels:           r.labels,
+	})
+}
+
+type wrappingCollector struct {
+	wrappedCollector Collector
+	prefix           string
+	labels           Labels
+}
+
+func (c *wrappingCollector) Collect(ch chan<- Metric) {
+	wrappedCh := make(chan Metric)
+	go func() {
+		c.wrappedCollector.Collect(wrappedCh)
+		close(wrappedCh)
+	}()
+	for m := range wrappedCh {
+		ch <- &wrappingMetric{
+			wrappedMetric: m,
+			prefix:        c.prefix,
+			labels:        c.labels,
+		}
+	}
+}
+
+func (c *wrappingCollector) Describe(ch chan<- *Desc) {
+	wrappedCh := make(chan *Desc)
+	go func() {
+		c.wrappedCollector.Describe(wrappedCh)
+		close(wrappedCh)
+	}()
+	for desc := range wrappedCh {
+		ch <- wrapDesc(desc, c.prefix, c.labels)
+	}
+}
+
+func (c *wrappingCollector) unwrapRecursively() Collector {
+	switch wc := c.wrappedCollector.(type) {
+	case *wrappingCollector:
+		return wc.unwrapRecursively()
+	default:
+		return wc
+	}
+}
+
+type wrappingMetric struct {
+	wrappedMetric Metric
+	prefix        string
+	labels        Labels
+}
+
+func (m *wrappingMetric) Desc() *Desc {
+	return wrapDesc(m.wrappedMetric.Desc(), m.prefix, m.labels)
+}
+
+func (m *wrappingMetric) Write(out *dto.Metric) error {
+	if err := m.wrappedMetric.Write(out); err != nil {
+		return err
+	}
+	if len(m.labels) == 0 {
+		// No wrapping labels.
+		return nil
+	}
+	for ln, lv := range m.labels {
+		out.Label = append(out.Label, &dto.LabelPair{
+			Name:  proto.String(ln),
+			Value: proto.String(lv),
+		})
+	}
+	sort.Sort(internal.LabelPairSorter(out.Label))
+	return nil
+}
+
+func wrapDesc(desc *Desc, prefix string, labels Labels) *Desc {
+	constLabels := Labels{}
+	for _, lp := range desc.constLabelPairs {
+		constLabels[*lp.Name] = *lp.Value
+	}
+	for ln, lv := range labels {
+		if _, alreadyUsed := constLabels[ln]; alreadyUsed {
+			return &Desc{
+				fqName:          desc.fqName,
+				help:            desc.help,
+				variableLabels:  desc.variableLabels,
+				constLabelPairs: desc.constLabelPairs,
+				err:             fmt.Errorf("attempted wrapping with already existing label name %q", ln),
+			}
+		}
+		constLabels[ln] = lv
+	}
+	// NewDesc will do remaining validations.
+	newDesc := V2.NewDesc(prefix+desc.fqName, desc.help, desc.variableLabels, constLabels)
+	// Propagate errors if there was any. This will override any errer
+	// created by NewDesc above, i.e. earlier errors get precedence.
+	if desc.err != nil {
+		newDesc.err = desc.err
+	}
+	return newDesc
+}

vendor/github.com/prometheus/client_model/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/prometheus/client_model/NOTICE

@@ -0,0 +1,5 @@
+Data model artifacts for Prometheus.
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).

vendor/github.com/prometheus/common/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/prometheus/common/NOTICE

@@ -0,0 +1,5 @@
+Common libraries shared by Prometheus Go components.
+Copyright 2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -0,0 +1,428 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"mime"
+	"net/http"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
+	"github.com/prometheus/common/model"
+)
+
+// Decoder types decode an input stream into metric families.
+type Decoder interface {
+	Decode(*dto.MetricFamily) error
+}
+
+// DecodeOptions contains options used by the Decoder and in sample extraction.
+type DecodeOptions struct {
+	// Timestamp is added to each value from the stream that has no explicit timestamp set.
+	Timestamp model.Time
+}
+
+// ResponseFormat extracts the correct format from a HTTP response header.
+// If no matching format can be found FormatUnknown is returned.
+func ResponseFormat(h http.Header) Format {
+	ct := h.Get(hdrContentType)
+
+	mediatype, params, err := mime.ParseMediaType(ct)
+	if err != nil {
+		return FmtUnknown
+	}
+
+	const textType = "text/plain"
+
+	switch mediatype {
+	case ProtoType:
+		if p, ok := params["proto"]; ok && p != ProtoProtocol {
+			return FmtUnknown
+		}
+		if e, ok := params["encoding"]; ok && e != "delimited" {
+			return FmtUnknown
+		}
+		return FmtProtoDelim
+
+	case textType:
+		if v, ok := params["version"]; ok && v != TextVersion {
+			return FmtUnknown
+		}
+		return FmtText
+	}
+
+	return FmtUnknown
+}
+
+// NewDecoder returns a new decoder based on the given input format.
+// If the input format does not imply otherwise, a text format decoder is returned.
+func NewDecoder(r io.Reader, format Format) Decoder {
+	switch format {
+	case FmtProtoDelim:
+		return &protoDecoder{r: r}
+	}
+	return &textDecoder{r: r}
+}
+
+// protoDecoder implements the Decoder interface for protocol buffers.
+type protoDecoder struct {
+	r io.Reader
+}
+
+// Decode implements the Decoder interface.
+func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
+	_, err := pbutil.ReadDelimited(d.r, v)
+	if err != nil {
+		return err
+	}
+	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
+		return fmt.Errorf("invalid metric name %q", v.GetName())
+	}
+	for _, m := range v.GetMetric() {
+		if m == nil {
+			continue
+		}
+		for _, l := range m.GetLabel() {
+			if l == nil {
+				continue
+			}
+			if !model.LabelValue(l.GetValue()).IsValid() {
+				return fmt.Errorf("invalid label value %q", l.GetValue())
+			}
+			if !model.LabelName(l.GetName()).IsValid() {
+				return fmt.Errorf("invalid label name %q", l.GetName())
+			}
+		}
+	}
+	return nil
+}
+
+// textDecoder implements the Decoder interface for the text protocol.
+type textDecoder struct {
+	r    io.Reader
+	fams map[string]*dto.MetricFamily
+	err  error
+}
+
+// Decode implements the Decoder interface.
+func (d *textDecoder) Decode(v *dto.MetricFamily) error {
+	if d.err == nil {
+		// Read all metrics in one shot.
+		var p TextParser
+		d.fams, d.err = p.TextToMetricFamilies(d.r)
+		// If we don't get an error, store io.EOF for the end.
+		if d.err == nil {
+			d.err = io.EOF
+		}
+	}
+	// Pick off one MetricFamily per Decode until there's nothing left.
+	for key, fam := range d.fams {
+		v.Name = fam.Name
+		v.Help = fam.Help
+		v.Type = fam.Type
+		v.Metric = fam.Metric
+		delete(d.fams, key)
+		return nil
+	}
+	return d.err
+}
+
+// SampleDecoder wraps a Decoder to extract samples from the metric families
+// decoded by the wrapped Decoder.
+type SampleDecoder struct {
+	Dec  Decoder
+	Opts *DecodeOptions
+
+	f dto.MetricFamily
+}
+
+// Decode calls the Decode method of the wrapped Decoder and then extracts the
+// samples from the decoded MetricFamily into the provided model.Vector.
+func (sd *SampleDecoder) Decode(s *model.Vector) error {
+	err := sd.Dec.Decode(&sd.f)
+	if err != nil {
+		return err
+	}
+	*s, err = extractSamples(&sd.f, sd.Opts)
+	return err
+}
+
+// ExtractSamples builds a slice of samples from the provided metric
+// families. If an error occurs during sample extraction, it continues to
+// extract from the remaining metric families. The returned error is the last
+// error that has occurred.
+func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) (model.Vector, error) {
+	var (
+		all     model.Vector
+		lastErr error
+	)
+	for _, f := range fams {
+		some, err := extractSamples(f, o)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		all = append(all, some...)
+	}
+	return all, lastErr
+}
+
+func extractSamples(f *dto.MetricFamily, o *DecodeOptions) (model.Vector, error) {
+	switch f.GetType() {
+	case dto.MetricType_COUNTER:
+		return extractCounter(o, f), nil
+	case dto.MetricType_GAUGE:
+		return extractGauge(o, f), nil
+	case dto.MetricType_SUMMARY:
+		return extractSummary(o, f), nil
+	case dto.MetricType_UNTYPED:
+		return extractUntyped(o, f), nil
+	case dto.MetricType_HISTOGRAM:
+		return extractHistogram(o, f), nil
+	}
+	return nil, fmt.Errorf("expfmt.extractSamples: unknown metric family type %v", f.GetType())
+}
+
+func extractCounter(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Counter == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Counter.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractGauge(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Gauge == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Gauge.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractUntyped(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Untyped == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Untyped.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractSummary(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Summary == nil {
+			continue
+		}
+
+		timestamp := o.Timestamp
+		if m.TimestampMs != nil {
+			timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		}
+
+		for _, q := range m.Summary.Quantile {
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			// BUG(matt): Update other names to "quantile".
+			lset[model.LabelName(model.QuantileLabel)] = model.LabelValue(fmt.Sprint(q.GetQuantile()))
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     model.SampleValue(q.GetValue()),
+				Timestamp: timestamp,
+			})
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_sum")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Summary.GetSampleSum()),
+			Timestamp: timestamp,
+		})
+
+		lset = make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_count")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Summary.GetSampleCount()),
+			Timestamp: timestamp,
+		})
+	}
+
+	return samples
+}
+
+func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Histogram == nil {
+			continue
+		}
+
+		timestamp := o.Timestamp
+		if m.TimestampMs != nil {
+			timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		}
+
+		infSeen := false
+
+		for _, q := range m.Histogram.Bucket {
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			lset[model.LabelName(model.BucketLabel)] = model.LabelValue(fmt.Sprint(q.GetUpperBound()))
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_bucket")
+
+			if math.IsInf(q.GetUpperBound(), +1) {
+				infSeen = true
+			}
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     model.SampleValue(q.GetCumulativeCount()),
+				Timestamp: timestamp,
+			})
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_sum")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Histogram.GetSampleSum()),
+			Timestamp: timestamp,
+		})
+
+		lset = make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_count")
+
+		count := &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Histogram.GetSampleCount()),
+			Timestamp: timestamp,
+		}
+		samples = append(samples, count)
+
+		if !infSeen {
+			// Append an infinity bucket sample.
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			lset[model.LabelName(model.BucketLabel)] = model.LabelValue("+Inf")
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_bucket")
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     count.Value,
+				Timestamp: timestamp,
+			})
+		}
+	}
+
+	return samples
+}

vendor/github.com/prometheus/common/expfmt/encode.go

@@ -0,0 +1,165 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
+	"github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg"
+	"google.golang.org/protobuf/encoding/prototext"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Encoder types encode metric families into an underlying wire protocol.
+type Encoder interface {
+	Encode(*dto.MetricFamily) error
+}
+
+// Closer is implemented by Encoders that need to be closed to finalize
+// encoding. (For example, OpenMetrics needs a final `# EOF` line.)
+//
+// Note that all Encoder implementations returned from this package implement
+// Closer, too, even if the Close call is a no-op. This happens in preparation
+// for adding a Close method to the Encoder interface directly in a (mildly
+// breaking) release in the future.
+type Closer interface {
+	Close() error
+}
+
+type encoderCloser struct {
+	encode func(*dto.MetricFamily) error
+	close  func() error
+}
+
+func (ec encoderCloser) Encode(v *dto.MetricFamily) error {
+	return ec.encode(v)
+}
+
+func (ec encoderCloser) Close() error {
+	return ec.close()
+}
+
+// Negotiate returns the Content-Type based on the given Accept header. If no
+// appropriate accepted type is found, FmtText is returned (which is the
+// Prometheus text format). This function will never negotiate FmtOpenMetrics,
+// as the support is still experimental. To include the option to negotiate
+// FmtOpenMetrics, use NegotiateOpenMetrics.
+func Negotiate(h http.Header) Format {
+	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
+		ver := ac.Params["version"]
+		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
+			switch ac.Params["encoding"] {
+			case "delimited":
+				return FmtProtoDelim
+			case "text":
+				return FmtProtoText
+			case "compact-text":
+				return FmtProtoCompact
+			}
+		}
+		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
+			return FmtText
+		}
+	}
+	return FmtText
+}
+
+// NegotiateIncludingOpenMetrics works like Negotiate but includes
+// FmtOpenMetrics as an option for the result. Note that this function is
+// temporary and will disappear once FmtOpenMetrics is fully supported and as
+// such may be negotiated by the normal Negotiate function.
+func NegotiateIncludingOpenMetrics(h http.Header) Format {
+	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
+		ver := ac.Params["version"]
+		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
+			switch ac.Params["encoding"] {
+			case "delimited":
+				return FmtProtoDelim
+			case "text":
+				return FmtProtoText
+			case "compact-text":
+				return FmtProtoCompact
+			}
+		}
+		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
+			return FmtText
+		}
+		if ac.Type+"/"+ac.SubType == OpenMetricsType && (ver == OpenMetricsVersion_0_0_1 || ver == OpenMetricsVersion_1_0_0 || ver == "") {
+			if ver == OpenMetricsVersion_1_0_0 {
+				return FmtOpenMetrics_1_0_0
+			}
+			return FmtOpenMetrics_0_0_1
+		}
+	}
+	return FmtText
+}
+
+// NewEncoder returns a new encoder based on content type negotiation. All
+// Encoder implementations returned by NewEncoder also implement Closer, and
+// callers should always call the Close method. It is currently only required
+// for FmtOpenMetrics, but a future (breaking) release will add the Close method
+// to the Encoder interface directly. The current version of the Encoder
+// interface is kept for backwards compatibility.
+func NewEncoder(w io.Writer, format Format) Encoder {
+	switch format {
+	case FmtProtoDelim:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := pbutil.WriteDelimited(w, v)
+				return err
+			},
+			close: func() error { return nil },
+		}
+	case FmtProtoCompact:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := fmt.Fprintln(w, v.String())
+				return err
+			},
+			close: func() error { return nil },
+		}
+	case FmtProtoText:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := fmt.Fprintln(w, prototext.Format(v))
+				return err
+			},
+			close: func() error { return nil },
+		}
+	case FmtText:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := MetricFamilyToText(w, v)
+				return err
+			},
+			close: func() error { return nil },
+		}
+	case FmtOpenMetrics_0_0_1, FmtOpenMetrics_1_0_0:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := MetricFamilyToOpenMetrics(w, v)
+				return err
+			},
+			close: func() error {
+				_, err := FinalizeOpenMetrics(w)
+				return err
+			},
+		}
+	}
+	panic(fmt.Errorf("expfmt.NewEncoder: unknown format %q", format))
+}

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -0,0 +1,43 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package expfmt contains tools for reading and writing Prometheus metrics.
+package expfmt
+
+// Format specifies the HTTP content type of the different wire protocols.
+type Format string
+
+// Constants to assemble the Content-Type values for the different wire protocols.
+const (
+	TextVersion              = "0.0.4"
+	ProtoType                = `application/vnd.google.protobuf`
+	ProtoProtocol            = `io.prometheus.client.MetricFamily`
+	ProtoFmt                 = ProtoType + "; proto=" + ProtoProtocol + ";"
+	OpenMetricsType          = `application/openmetrics-text`
+	OpenMetricsVersion_0_0_1 = "0.0.1"
+	OpenMetricsVersion_1_0_0 = "1.0.0"
+
+	// The Content-Type values for the different wire protocols.
+	FmtUnknown           Format = `<unknown>`
+	FmtText              Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
+	FmtProtoDelim        Format = ProtoFmt + ` encoding=delimited`
+	FmtProtoText         Format = ProtoFmt + ` encoding=text`
+	FmtProtoCompact      Format = ProtoFmt + ` encoding=compact-text`
+	FmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8`
+	FmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8`
+)
+
+const (
+	hdrContentType = "Content-Type"
+	hdrAccept      = "Accept"
+)

vendor/github.com/prometheus/common/expfmt/fuzz.go

@@ -0,0 +1,37 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Build only when actually fuzzing
+//go:build gofuzz
+// +build gofuzz
+
+package expfmt
+
+import "bytes"
+
+// Fuzz text metric parser with with github.com/dvyukov/go-fuzz:
+//
+//	go-fuzz-build github.com/prometheus/common/expfmt
+//	go-fuzz -bin expfmt-fuzz.zip -workdir fuzz
+//
+// Further input samples should go in the folder fuzz/corpus.
+func Fuzz(in []byte) int {
+	parser := TextParser{}
+	_, err := parser.TextToMetricFamilies(bytes.NewReader(in))
+
+	if err != nil {
+		return 0
+	}
+
+	return 1
+}

vendor/github.com/prometheus/common/expfmt/openmetrics_create.go

@@ -0,0 +1,527 @@
+// Copyright 2020 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// MetricFamilyToOpenMetrics converts a MetricFamily proto message into the
+// OpenMetrics text format and writes the resulting lines to 'out'. It returns
+// the number of bytes written and any error encountered. The output will have
+// the same order as the input, no further sorting is performed. Furthermore,
+// this function assumes the input is already sanitized and does not perform any
+// sanity checks. If the input contains duplicate metrics or invalid metric or
+// label names, the conversion will result in invalid text format output.
+//
+// This function fulfills the type 'expfmt.encoder'.
+//
+// Note that OpenMetrics requires a final `# EOF` line. Since this function acts
+// on individual metric families, it is the responsibility of the caller to
+// append this line to 'out' once all metric families have been written.
+// Conveniently, this can be done by calling FinalizeOpenMetrics.
+//
+// The output should be fully OpenMetrics compliant. However, there are a few
+// missing features and peculiarities to avoid complications when switching from
+// Prometheus to OpenMetrics or vice versa:
+//
+//   - Counters are expected to have the `_total` suffix in their metric name. In
+//     the output, the suffix will be truncated from the `# TYPE` and `# HELP`
+//     line. A counter with a missing `_total` suffix is not an error. However,
+//     its type will be set to `unknown` in that case to avoid invalid OpenMetrics
+//     output.
+//
+//   - No support for the following (optional) features: `# UNIT` line, `_created`
+//     line, info type, stateset type, gaugehistogram type.
+//
+//   - The size of exemplar labels is not checked (i.e. it's possible to create
+//     exemplars that are larger than allowed by the OpenMetrics specification).
+//
+//   - The value of Counters is not checked. (OpenMetrics doesn't allow counters
+//     with a `NaN` value.)
+func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int, err error) {
+	name := in.GetName()
+	if name == "" {
+		return 0, fmt.Errorf("MetricFamily has no name: %s", in)
+	}
+
+	// Try the interface upgrade. If it doesn't work, we'll use a
+	// bufio.Writer from the sync.Pool.
+	w, ok := out.(enhancedWriter)
+	if !ok {
+		b := bufPool.Get().(*bufio.Writer)
+		b.Reset(out)
+		w = b
+		defer func() {
+			bErr := b.Flush()
+			if err == nil {
+				err = bErr
+			}
+			bufPool.Put(b)
+		}()
+	}
+
+	var (
+		n          int
+		metricType = in.GetType()
+		shortName  = name
+	)
+	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(shortName, "_total") {
+		shortName = name[:len(name)-6]
+	}
+
+	// Comments, first HELP, then TYPE.
+	if in.Help != nil {
+		n, err = w.WriteString("# HELP ")
+		written += n
+		if err != nil {
+			return
+		}
+		n, err = w.WriteString(shortName)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return
+		}
+		n, err = writeEscapedString(w, *in.Help, true)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte('\n')
+		written++
+		if err != nil {
+			return
+		}
+	}
+	n, err = w.WriteString("# TYPE ")
+	written += n
+	if err != nil {
+		return
+	}
+	n, err = w.WriteString(shortName)
+	written += n
+	if err != nil {
+		return
+	}
+	switch metricType {
+	case dto.MetricType_COUNTER:
+		if strings.HasSuffix(name, "_total") {
+			n, err = w.WriteString(" counter\n")
+		} else {
+			n, err = w.WriteString(" unknown\n")
+		}
+	case dto.MetricType_GAUGE:
+		n, err = w.WriteString(" gauge\n")
+	case dto.MetricType_SUMMARY:
+		n, err = w.WriteString(" summary\n")
+	case dto.MetricType_UNTYPED:
+		n, err = w.WriteString(" unknown\n")
+	case dto.MetricType_HISTOGRAM:
+		n, err = w.WriteString(" histogram\n")
+	default:
+		return written, fmt.Errorf("unknown metric type %s", metricType.String())
+	}
+	written += n
+	if err != nil {
+		return
+	}
+
+	// Finally the samples, one line for each.
+	for _, metric := range in.Metric {
+		switch metricType {
+		case dto.MetricType_COUNTER:
+			if metric.Counter == nil {
+				return written, fmt.Errorf(
+					"expected counter in metric %s %s", name, metric,
+				)
+			}
+			// Note that we have ensured above that either the name
+			// ends on `_total` or that the rendered type is
+			// `unknown`. Therefore, no `_total` must be added here.
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Counter.GetValue(), 0, false,
+				metric.Counter.Exemplar,
+			)
+		case dto.MetricType_GAUGE:
+			if metric.Gauge == nil {
+				return written, fmt.Errorf(
+					"expected gauge in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Gauge.GetValue(), 0, false,
+				nil,
+			)
+		case dto.MetricType_UNTYPED:
+			if metric.Untyped == nil {
+				return written, fmt.Errorf(
+					"expected untyped in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Untyped.GetValue(), 0, false,
+				nil,
+			)
+		case dto.MetricType_SUMMARY:
+			if metric.Summary == nil {
+				return written, fmt.Errorf(
+					"expected summary in metric %s %s", name, metric,
+				)
+			}
+			for _, q := range metric.Summary.Quantile {
+				n, err = writeOpenMetricsSample(
+					w, name, "", metric,
+					model.QuantileLabel, q.GetQuantile(),
+					q.GetValue(), 0, false,
+					nil,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Summary.GetSampleSum(), 0, false,
+				nil,
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_count", metric, "", 0,
+				0, metric.Summary.GetSampleCount(), true,
+				nil,
+			)
+		case dto.MetricType_HISTOGRAM:
+			if metric.Histogram == nil {
+				return written, fmt.Errorf(
+					"expected histogram in metric %s %s", name, metric,
+				)
+			}
+			infSeen := false
+			for _, b := range metric.Histogram.Bucket {
+				n, err = writeOpenMetricsSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, b.GetUpperBound(),
+					0, b.GetCumulativeCount(), true,
+					b.Exemplar,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+				if math.IsInf(b.GetUpperBound(), +1) {
+					infSeen = true
+				}
+			}
+			if !infSeen {
+				n, err = writeOpenMetricsSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, math.Inf(+1),
+					0, metric.Histogram.GetSampleCount(), true,
+					nil,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Histogram.GetSampleSum(), 0, false,
+				nil,
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_count", metric, "", 0,
+				0, metric.Histogram.GetSampleCount(), true,
+				nil,
+			)
+		default:
+			return written, fmt.Errorf(
+				"unexpected type in metric %s %s", name, metric,
+			)
+		}
+		written += n
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// FinalizeOpenMetrics writes the final `# EOF\n` line required by OpenMetrics.
+func FinalizeOpenMetrics(w io.Writer) (written int, err error) {
+	return w.Write([]byte("# EOF\n"))
+}
+
+// writeOpenMetricsSample writes a single sample in OpenMetrics text format to
+// w, given the metric name, the metric proto message itself, optionally an
+// additional label name with a float64 value (use empty string as label name if
+// not required), the value (optionally as float64 or uint64, determined by
+// useIntValue), and optionally an exemplar (use nil if not required). The
+// function returns the number of bytes written and any error encountered.
+func writeOpenMetricsSample(
+	w enhancedWriter,
+	name, suffix string,
+	metric *dto.Metric,
+	additionalLabelName string, additionalLabelValue float64,
+	floatValue float64, intValue uint64, useIntValue bool,
+	exemplar *dto.Exemplar,
+) (int, error) {
+	var written int
+	n, err := w.WriteString(name)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if suffix != "" {
+		n, err = w.WriteString(suffix)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	n, err = writeOpenMetricsLabelPairs(
+		w, metric.Label, additionalLabelName, additionalLabelValue,
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	if useIntValue {
+		n, err = writeUint(w, intValue)
+	} else {
+		n, err = writeOpenMetricsFloat(w, floatValue)
+	}
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if metric.TimestampMs != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		// TODO(beorn7): Format this directly without converting to a float first.
+		n, err = writeOpenMetricsFloat(w, float64(*metric.TimestampMs)/1000)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	if exemplar != nil {
+		n, err = writeExemplar(w, exemplar)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	err = w.WriteByte('\n')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeOpenMetricsLabelPairs works like writeOpenMetrics but formats the float
+// in OpenMetrics style.
+func writeOpenMetricsLabelPairs(
+	w enhancedWriter,
+	in []*dto.LabelPair,
+	additionalLabelName string, additionalLabelValue float64,
+) (int, error) {
+	if len(in) == 0 && additionalLabelName == "" {
+		return 0, nil
+	}
+	var (
+		written   int
+		separator byte = '{'
+	)
+	for _, lp := range in {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(lp.GetName())
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeEscapedString(w, lp.GetValue(), true)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+		separator = ','
+	}
+	if additionalLabelName != "" {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(additionalLabelName)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeOpenMetricsFloat(w, additionalLabelValue)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+	}
+	err := w.WriteByte('}')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeExemplar writes the provided exemplar in OpenMetrics format to w. The
+// function returns the number of bytes written and any error encountered.
+func writeExemplar(w enhancedWriter, e *dto.Exemplar) (int, error) {
+	written := 0
+	n, err := w.WriteString(" # ")
+	written += n
+	if err != nil {
+		return written, err
+	}
+	n, err = writeOpenMetricsLabelPairs(w, e.Label, "", 0)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	n, err = writeOpenMetricsFloat(w, e.GetValue())
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if e.Timestamp != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		err = (*e).Timestamp.CheckValid()
+		if err != nil {
+			return written, err
+		}
+		ts := (*e).Timestamp.AsTime()
+		// TODO(beorn7): Format this directly from components of ts to
+		// avoid overflow/underflow and precision issues of the float
+		// conversion.
+		n, err = writeOpenMetricsFloat(w, float64(ts.UnixNano())/1e9)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	return written, nil
+}
+
+// writeOpenMetricsFloat works like writeFloat but appends ".0" if the resulting
+// number would otherwise contain neither a "." nor an "e".
+func writeOpenMetricsFloat(w enhancedWriter, f float64) (int, error) {
+	switch {
+	case f == 1:
+		return w.WriteString("1.0")
+	case f == 0:
+		return w.WriteString("0.0")
+	case f == -1:
+		return w.WriteString("-1.0")
+	case math.IsNaN(f):
+		return w.WriteString("NaN")
+	case math.IsInf(f, +1):
+		return w.WriteString("+Inf")
+	case math.IsInf(f, -1):
+		return w.WriteString("-Inf")
+	default:
+		bp := numBufPool.Get().(*[]byte)
+		*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
+		if !bytes.ContainsAny(*bp, "e.") {
+			*bp = append(*bp, '.', '0')
+		}
+		written, err := w.Write(*bp)
+		numBufPool.Put(bp)
+		return written, err
+	}
+}
+
+// writeUint is like writeInt just for uint64.
+func writeUint(w enhancedWriter, u uint64) (int, error) {
+	bp := numBufPool.Get().(*[]byte)
+	*bp = strconv.AppendUint((*bp)[:0], u, 10)
+	written, err := w.Write(*bp)
+	numBufPool.Put(bp)
+	return written, err
+}

vendor/github.com/prometheus/common/expfmt/text_create.go

@@ -0,0 +1,464 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// enhancedWriter has all the enhanced write functions needed here. bufio.Writer
+// implements it.
+type enhancedWriter interface {
+	io.Writer
+	WriteRune(r rune) (n int, err error)
+	WriteString(s string) (n int, err error)
+	WriteByte(c byte) error
+}
+
+const (
+	initialNumBufSize = 24
+)
+
+var (
+	bufPool = sync.Pool{
+		New: func() interface{} {
+			return bufio.NewWriter(io.Discard)
+		},
+	}
+	numBufPool = sync.Pool{
+		New: func() interface{} {
+			b := make([]byte, 0, initialNumBufSize)
+			return &b
+		},
+	}
+)
+
+// MetricFamilyToText converts a MetricFamily proto message into text format and
+// writes the resulting lines to 'out'. It returns the number of bytes written
+// and any error encountered. The output will have the same order as the input,
+// no further sorting is performed. Furthermore, this function assumes the input
+// is already sanitized and does not perform any sanity checks. If the input
+// contains duplicate metrics or invalid metric or label names, the conversion
+// will result in invalid text format output.
+//
+// This method fulfills the type 'prometheus.encoder'.
+func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (written int, err error) {
+	// Fail-fast checks.
+	if len(in.Metric) == 0 {
+		return 0, fmt.Errorf("MetricFamily has no metrics: %s", in)
+	}
+	name := in.GetName()
+	if name == "" {
+		return 0, fmt.Errorf("MetricFamily has no name: %s", in)
+	}
+
+	// Try the interface upgrade. If it doesn't work, we'll use a
+	// bufio.Writer from the sync.Pool.
+	w, ok := out.(enhancedWriter)
+	if !ok {
+		b := bufPool.Get().(*bufio.Writer)
+		b.Reset(out)
+		w = b
+		defer func() {
+			bErr := b.Flush()
+			if err == nil {
+				err = bErr
+			}
+			bufPool.Put(b)
+		}()
+	}
+
+	var n int
+
+	// Comments, first HELP, then TYPE.
+	if in.Help != nil {
+		n, err = w.WriteString("# HELP ")
+		written += n
+		if err != nil {
+			return
+		}
+		n, err = w.WriteString(name)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return
+		}
+		n, err = writeEscapedString(w, *in.Help, false)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte('\n')
+		written++
+		if err != nil {
+			return
+		}
+	}
+	n, err = w.WriteString("# TYPE ")
+	written += n
+	if err != nil {
+		return
+	}
+	n, err = w.WriteString(name)
+	written += n
+	if err != nil {
+		return
+	}
+	metricType := in.GetType()
+	switch metricType {
+	case dto.MetricType_COUNTER:
+		n, err = w.WriteString(" counter\n")
+	case dto.MetricType_GAUGE:
+		n, err = w.WriteString(" gauge\n")
+	case dto.MetricType_SUMMARY:
+		n, err = w.WriteString(" summary\n")
+	case dto.MetricType_UNTYPED:
+		n, err = w.WriteString(" untyped\n")
+	case dto.MetricType_HISTOGRAM:
+		n, err = w.WriteString(" histogram\n")
+	default:
+		return written, fmt.Errorf("unknown metric type %s", metricType.String())
+	}
+	written += n
+	if err != nil {
+		return
+	}
+
+	// Finally the samples, one line for each.
+	for _, metric := range in.Metric {
+		switch metricType {
+		case dto.MetricType_COUNTER:
+			if metric.Counter == nil {
+				return written, fmt.Errorf(
+					"expected counter in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				w, name, "", metric, "", 0,
+				metric.Counter.GetValue(),
+			)
+		case dto.MetricType_GAUGE:
+			if metric.Gauge == nil {
+				return written, fmt.Errorf(
+					"expected gauge in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				w, name, "", metric, "", 0,
+				metric.Gauge.GetValue(),
+			)
+		case dto.MetricType_UNTYPED:
+			if metric.Untyped == nil {
+				return written, fmt.Errorf(
+					"expected untyped in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				w, name, "", metric, "", 0,
+				metric.Untyped.GetValue(),
+			)
+		case dto.MetricType_SUMMARY:
+			if metric.Summary == nil {
+				return written, fmt.Errorf(
+					"expected summary in metric %s %s", name, metric,
+				)
+			}
+			for _, q := range metric.Summary.Quantile {
+				n, err = writeSample(
+					w, name, "", metric,
+					model.QuantileLabel, q.GetQuantile(),
+					q.GetValue(),
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Summary.GetSampleSum(),
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeSample(
+				w, name, "_count", metric, "", 0,
+				float64(metric.Summary.GetSampleCount()),
+			)
+		case dto.MetricType_HISTOGRAM:
+			if metric.Histogram == nil {
+				return written, fmt.Errorf(
+					"expected histogram in metric %s %s", name, metric,
+				)
+			}
+			infSeen := false
+			for _, b := range metric.Histogram.Bucket {
+				n, err = writeSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, b.GetUpperBound(),
+					float64(b.GetCumulativeCount()),
+				)
+				written += n
+				if err != nil {
+					return
+				}
+				if math.IsInf(b.GetUpperBound(), +1) {
+					infSeen = true
+				}
+			}
+			if !infSeen {
+				n, err = writeSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, math.Inf(+1),
+					float64(metric.Histogram.GetSampleCount()),
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Histogram.GetSampleSum(),
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeSample(
+				w, name, "_count", metric, "", 0,
+				float64(metric.Histogram.GetSampleCount()),
+			)
+		default:
+			return written, fmt.Errorf(
+				"unexpected type in metric %s %s", name, metric,
+			)
+		}
+		written += n
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// writeSample writes a single sample in text format to w, given the metric
+// name, the metric proto message itself, optionally an additional label name
+// with a float64 value (use empty string as label name if not required), and
+// the value. The function returns the number of bytes written and any error
+// encountered.
+func writeSample(
+	w enhancedWriter,
+	name, suffix string,
+	metric *dto.Metric,
+	additionalLabelName string, additionalLabelValue float64,
+	value float64,
+) (int, error) {
+	var written int
+	n, err := w.WriteString(name)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if suffix != "" {
+		n, err = w.WriteString(suffix)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	n, err = writeLabelPairs(
+		w, metric.Label, additionalLabelName, additionalLabelValue,
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	n, err = writeFloat(w, value)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if metric.TimestampMs != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err = writeInt(w, *metric.TimestampMs)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	err = w.WriteByte('\n')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeLabelPairs converts a slice of LabelPair proto messages plus the
+// explicitly given additional label pair into text formatted as required by the
+// text format and writes it to 'w'. An empty slice in combination with an empty
+// string 'additionalLabelName' results in nothing being written. Otherwise, the
+// label pairs are written, escaped as required by the text format, and enclosed
+// in '{...}'. The function returns the number of bytes written and any error
+// encountered.
+func writeLabelPairs(
+	w enhancedWriter,
+	in []*dto.LabelPair,
+	additionalLabelName string, additionalLabelValue float64,
+) (int, error) {
+	if len(in) == 0 && additionalLabelName == "" {
+		return 0, nil
+	}
+	var (
+		written   int
+		separator byte = '{'
+	)
+	for _, lp := range in {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(lp.GetName())
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeEscapedString(w, lp.GetValue(), true)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+		separator = ','
+	}
+	if additionalLabelName != "" {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(additionalLabelName)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeFloat(w, additionalLabelValue)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+	}
+	err := w.WriteByte('}')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeEscapedString replaces '\' by '\\', new line character by '\n', and - if
+// includeDoubleQuote is true - '"' by '\"'.
+var (
+	escaper       = strings.NewReplacer("\\", `\\`, "\n", `\n`)
+	quotedEscaper = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`)
+)
+
+func writeEscapedString(w enhancedWriter, v string, includeDoubleQuote bool) (int, error) {
+	if includeDoubleQuote {
+		return quotedEscaper.WriteString(w, v)
+	}
+	return escaper.WriteString(w, v)
+}
+
+// writeFloat is equivalent to fmt.Fprint with a float64 argument but hardcodes
+// a few common cases for increased efficiency. For non-hardcoded cases, it uses
+// strconv.AppendFloat to avoid allocations, similar to writeInt.
+func writeFloat(w enhancedWriter, f float64) (int, error) {
+	switch {
+	case f == 1:
+		return 1, w.WriteByte('1')
+	case f == 0:
+		return 1, w.WriteByte('0')
+	case f == -1:
+		return w.WriteString("-1")
+	case math.IsNaN(f):
+		return w.WriteString("NaN")
+	case math.IsInf(f, +1):
+		return w.WriteString("+Inf")
+	case math.IsInf(f, -1):
+		return w.WriteString("-Inf")
+	default:
+		bp := numBufPool.Get().(*[]byte)
+		*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
+		written, err := w.Write(*bp)
+		numBufPool.Put(bp)
+		return written, err
+	}
+}
+
+// writeInt is equivalent to fmt.Fprint with an int64 argument but uses
+// strconv.AppendInt with a byte slice taken from a sync.Pool to avoid
+// allocations.
+func writeInt(w enhancedWriter, i int64) (int, error) {
+	bp := numBufPool.Get().(*[]byte)
+	*bp = strconv.AppendInt((*bp)[:0], i, 10)
+	written, err := w.Write(*bp)
+	numBufPool.Put(bp)
+	return written, err
+}

vendor/github.com/prometheus/common/expfmt/text_parse.go

@@ -0,0 +1,779 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/common/model"
+	"google.golang.org/protobuf/proto"
+)
+
+// A stateFn is a function that represents a state in a state machine. By
+// executing it, the state is progressed to the next state. The stateFn returns
+// another stateFn, which represents the new state. The end state is represented
+// by nil.
+type stateFn func() stateFn
+
+// ParseError signals errors while parsing the simple and flat text-based
+// exchange format.
+type ParseError struct {
+	Line int
+	Msg  string
+}
+
+// Error implements the error interface.
+func (e ParseError) Error() string {
+	return fmt.Sprintf("text format parsing error in line %d: %s", e.Line, e.Msg)
+}
+
+// TextParser is used to parse the simple and flat text-based exchange format. Its
+// zero value is ready to use.
+type TextParser struct {
+	metricFamiliesByName map[string]*dto.MetricFamily
+	buf                  *bufio.Reader // Where the parsed input is read through.
+	err                  error         // Most recent error.
+	lineCount            int           // Tracks the line count for error messages.
+	currentByte          byte          // The most recent byte read.
+	currentToken         bytes.Buffer  // Re-used each time a token has to be gathered from multiple bytes.
+	currentMF            *dto.MetricFamily
+	currentMetric        *dto.Metric
+	currentLabelPair     *dto.LabelPair
+
+	// The remaining member variables are only used for summaries/histograms.
+	currentLabels map[string]string // All labels including '__name__' but excluding 'quantile'/'le'
+	// Summary specific.
+	summaries       map[uint64]*dto.Metric // Key is created with LabelsToSignature.
+	currentQuantile float64
+	// Histogram specific.
+	histograms    map[uint64]*dto.Metric // Key is created with LabelsToSignature.
+	currentBucket float64
+	// These tell us if the currently processed line ends on '_count' or
+	// '_sum' respectively and belong to a summary/histogram, representing the sample
+	// count and sum of that summary/histogram.
+	currentIsSummaryCount, currentIsSummarySum     bool
+	currentIsHistogramCount, currentIsHistogramSum bool
+}
+
+// TextToMetricFamilies reads 'in' as the simple and flat text-based exchange
+// format and creates MetricFamily proto messages. It returns the MetricFamily
+// proto messages in a map where the metric names are the keys, along with any
+// error encountered.
+//
+// If the input contains duplicate metrics (i.e. lines with the same metric name
+// and exactly the same label set), the resulting MetricFamily will contain
+// duplicate Metric proto messages. Similar is true for duplicate label
+// names. Checks for duplicates have to be performed separately, if required.
+// Also note that neither the metrics within each MetricFamily are sorted nor
+// the label pairs within each Metric. Sorting is not required for the most
+// frequent use of this method, which is sample ingestion in the Prometheus
+// server. However, for presentation purposes, you might want to sort the
+// metrics, and in some cases, you must sort the labels, e.g. for consumption by
+// the metric family injection hook of the Prometheus registry.
+//
+// Summaries and histograms are rather special beasts. You would probably not
+// use them in the simple text format anyway. This method can deal with
+// summaries and histograms if they are presented in exactly the way the
+// text.Create function creates them.
+//
+// This method must not be called concurrently. If you want to parse different
+// input concurrently, instantiate a separate Parser for each goroutine.
+func (p *TextParser) TextToMetricFamilies(in io.Reader) (map[string]*dto.MetricFamily, error) {
+	p.reset(in)
+	for nextState := p.startOfLine; nextState != nil; nextState = nextState() {
+		// Magic happens here...
+	}
+	// Get rid of empty metric families.
+	for k, mf := range p.metricFamiliesByName {
+		if len(mf.GetMetric()) == 0 {
+			delete(p.metricFamiliesByName, k)
+		}
+	}
+	// If p.err is io.EOF now, we have run into a premature end of the input
+	// stream. Turn this error into something nicer and more
+	// meaningful. (io.EOF is often used as a signal for the legitimate end
+	// of an input stream.)
+	if p.err == io.EOF {
+		p.parseError("unexpected end of input stream")
+	}
+	return p.metricFamiliesByName, p.err
+}
+
+func (p *TextParser) reset(in io.Reader) {
+	p.metricFamiliesByName = map[string]*dto.MetricFamily{}
+	if p.buf == nil {
+		p.buf = bufio.NewReader(in)
+	} else {
+		p.buf.Reset(in)
+	}
+	p.err = nil
+	p.lineCount = 0
+	if p.summaries == nil || len(p.summaries) > 0 {
+		p.summaries = map[uint64]*dto.Metric{}
+	}
+	if p.histograms == nil || len(p.histograms) > 0 {
+		p.histograms = map[uint64]*dto.Metric{}
+	}
+	p.currentQuantile = math.NaN()
+	p.currentBucket = math.NaN()
+}
+
+// startOfLine represents the state where the next byte read from p.buf is the
+// start of a line (or whitespace leading up to it).
+func (p *TextParser) startOfLine() stateFn {
+	p.lineCount++
+	if p.skipBlankTab(); p.err != nil {
+		// This is the only place that we expect to see io.EOF,
+		// which is not an error but the signal that we are done.
+		// Any other error that happens to align with the start of
+		// a line is still an error.
+		if p.err == io.EOF {
+			p.err = nil
+		}
+		return nil
+	}
+	switch p.currentByte {
+	case '#':
+		return p.startComment
+	case '\n':
+		return p.startOfLine // Empty line, start the next one.
+	}
+	return p.readingMetricName
+}
+
+// startComment represents the state where the next byte read from p.buf is the
+// start of a comment (or whitespace leading up to it).
+func (p *TextParser) startComment() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	// If we have hit the end of line already, there is nothing left
+	// to do. This is not considered a syntax error.
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	keyword := p.currentToken.String()
+	if keyword != "HELP" && keyword != "TYPE" {
+		// Generic comment, ignore by fast forwarding to end of line.
+		for p.currentByte != '\n' {
+			if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
+				return nil // Unexpected end of input.
+			}
+		}
+		return p.startOfLine
+	}
+	// There is something. Next has to be a metric name.
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.readTokenAsMetricName(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		// At the end of the line already.
+		// Again, this is not considered a syntax error.
+		return p.startOfLine
+	}
+	if !isBlankOrTab(p.currentByte) {
+		p.parseError("invalid metric name in comment")
+		return nil
+	}
+	p.setOrCreateCurrentMF()
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		// At the end of the line already.
+		// Again, this is not considered a syntax error.
+		return p.startOfLine
+	}
+	switch keyword {
+	case "HELP":
+		return p.readingHelp
+	case "TYPE":
+		return p.readingType
+	}
+	panic(fmt.Sprintf("code error: unexpected keyword %q", keyword))
+}
+
+// readingMetricName represents the state where the last byte read (now in
+// p.currentByte) is the first byte of a metric name.
+func (p *TextParser) readingMetricName() stateFn {
+	if p.readTokenAsMetricName(); p.err != nil {
+		return nil
+	}
+	if p.currentToken.Len() == 0 {
+		p.parseError("invalid metric name")
+		return nil
+	}
+	p.setOrCreateCurrentMF()
+	// Now is the time to fix the type if it hasn't happened yet.
+	if p.currentMF.Type == nil {
+		p.currentMF.Type = dto.MetricType_UNTYPED.Enum()
+	}
+	p.currentMetric = &dto.Metric{}
+	// Do not append the newly created currentMetric to
+	// currentMF.Metric right now. First wait if this is a summary,
+	// and the metric exists already, which we can only know after
+	// having read all the labels.
+	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	return p.readingLabels
+}
+
+// readingLabels represents the state where the last byte read (now in
+// p.currentByte) is either the first byte of the label set (i.e. a '{'), or the
+// first byte of the value (otherwise).
+func (p *TextParser) readingLabels() stateFn {
+	// Summaries/histograms are special. We have to reset the
+	// currentLabels map, currentQuantile and currentBucket before starting to
+	// read labels.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY || p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		p.currentLabels = map[string]string{}
+		p.currentLabels[string(model.MetricNameLabel)] = p.currentMF.GetName()
+		p.currentQuantile = math.NaN()
+		p.currentBucket = math.NaN()
+	}
+	if p.currentByte != '{' {
+		return p.readingValue
+	}
+	return p.startLabelName
+}
+
+// startLabelName represents the state where the next byte read from p.buf is
+// the start of a label name (or whitespace leading up to it).
+func (p *TextParser) startLabelName() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '}' {
+		if p.skipBlankTab(); p.err != nil {
+			return nil // Unexpected end of input.
+		}
+		return p.readingValue
+	}
+	if p.readTokenAsLabelName(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentToken.Len() == 0 {
+		p.parseError(fmt.Sprintf("invalid label name for metric %q", p.currentMF.GetName()))
+		return nil
+	}
+	p.currentLabelPair = &dto.LabelPair{Name: proto.String(p.currentToken.String())}
+	if p.currentLabelPair.GetName() == string(model.MetricNameLabel) {
+		p.parseError(fmt.Sprintf("label name %q is reserved", model.MetricNameLabel))
+		return nil
+	}
+	// Special summary/histogram treatment. Don't add 'quantile' and 'le'
+	// labels to 'real' labels.
+	if !(p.currentMF.GetType() == dto.MetricType_SUMMARY && p.currentLabelPair.GetName() == model.QuantileLabel) &&
+		!(p.currentMF.GetType() == dto.MetricType_HISTOGRAM && p.currentLabelPair.GetName() == model.BucketLabel) {
+		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPair)
+	}
+	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte != '=' {
+		p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
+		return nil
+	}
+	// Check for duplicate label names.
+	labels := make(map[string]struct{})
+	for _, l := range p.currentMetric.Label {
+		lName := l.GetName()
+		if _, exists := labels[lName]; !exists {
+			labels[lName] = struct{}{}
+		} else {
+			p.parseError(fmt.Sprintf("duplicate label names for metric %q", p.currentMF.GetName()))
+			return nil
+		}
+	}
+	return p.startLabelValue
+}
+
+// startLabelValue represents the state where the next byte read from p.buf is
+// the start of a (quoted) label value (or whitespace leading up to it).
+func (p *TextParser) startLabelValue() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte != '"' {
+		p.parseError(fmt.Sprintf("expected '\"' at start of label value, found %q", p.currentByte))
+		return nil
+	}
+	if p.readTokenAsLabelValue(); p.err != nil {
+		return nil
+	}
+	if !model.LabelValue(p.currentToken.String()).IsValid() {
+		p.parseError(fmt.Sprintf("invalid label value %q", p.currentToken.String()))
+		return nil
+	}
+	p.currentLabelPair.Value = proto.String(p.currentToken.String())
+	// Special treatment of summaries:
+	// - Quantile labels are special, will result in dto.Quantile later.
+	// - Other labels have to be added to currentLabels for signature calculation.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+		if p.currentLabelPair.GetName() == model.QuantileLabel {
+			if p.currentQuantile, p.err = parseFloat(p.currentLabelPair.GetValue()); p.err != nil {
+				// Create a more helpful error message.
+				p.parseError(fmt.Sprintf("expected float as value for 'quantile' label, got %q", p.currentLabelPair.GetValue()))
+				return nil
+			}
+		} else {
+			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
+		}
+	}
+	// Similar special treatment of histograms.
+	if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		if p.currentLabelPair.GetName() == model.BucketLabel {
+			if p.currentBucket, p.err = parseFloat(p.currentLabelPair.GetValue()); p.err != nil {
+				// Create a more helpful error message.
+				p.parseError(fmt.Sprintf("expected float as value for 'le' label, got %q", p.currentLabelPair.GetValue()))
+				return nil
+			}
+		} else {
+			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
+		}
+	}
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	switch p.currentByte {
+	case ',':
+		return p.startLabelName
+
+	case '}':
+		if p.skipBlankTab(); p.err != nil {
+			return nil // Unexpected end of input.
+		}
+		return p.readingValue
+	default:
+		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.GetValue()))
+		return nil
+	}
+}
+
+// readingValue represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the sample value (i.e. a float).
+func (p *TextParser) readingValue() stateFn {
+	// When we are here, we have read all the labels, so for the
+	// special case of a summary/histogram, we can finally find out
+	// if the metric already exists.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+		signature := model.LabelsToSignature(p.currentLabels)
+		if summary := p.summaries[signature]; summary != nil {
+			p.currentMetric = summary
+		} else {
+			p.summaries[signature] = p.currentMetric
+			p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+		}
+	} else if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		signature := model.LabelsToSignature(p.currentLabels)
+		if histogram := p.histograms[signature]; histogram != nil {
+			p.currentMetric = histogram
+		} else {
+			p.histograms[signature] = p.currentMetric
+			p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+		}
+	} else {
+		p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	value, err := parseFloat(p.currentToken.String())
+	if err != nil {
+		// Create a more helpful error message.
+		p.parseError(fmt.Sprintf("expected float as value, got %q", p.currentToken.String()))
+		return nil
+	}
+	switch p.currentMF.GetType() {
+	case dto.MetricType_COUNTER:
+		p.currentMetric.Counter = &dto.Counter{Value: proto.Float64(value)}
+	case dto.MetricType_GAUGE:
+		p.currentMetric.Gauge = &dto.Gauge{Value: proto.Float64(value)}
+	case dto.MetricType_UNTYPED:
+		p.currentMetric.Untyped = &dto.Untyped{Value: proto.Float64(value)}
+	case dto.MetricType_SUMMARY:
+		// *sigh*
+		if p.currentMetric.Summary == nil {
+			p.currentMetric.Summary = &dto.Summary{}
+		}
+		switch {
+		case p.currentIsSummaryCount:
+			p.currentMetric.Summary.SampleCount = proto.Uint64(uint64(value))
+		case p.currentIsSummarySum:
+			p.currentMetric.Summary.SampleSum = proto.Float64(value)
+		case !math.IsNaN(p.currentQuantile):
+			p.currentMetric.Summary.Quantile = append(
+				p.currentMetric.Summary.Quantile,
+				&dto.Quantile{
+					Quantile: proto.Float64(p.currentQuantile),
+					Value:    proto.Float64(value),
+				},
+			)
+		}
+	case dto.MetricType_HISTOGRAM:
+		// *sigh*
+		if p.currentMetric.Histogram == nil {
+			p.currentMetric.Histogram = &dto.Histogram{}
+		}
+		switch {
+		case p.currentIsHistogramCount:
+			p.currentMetric.Histogram.SampleCount = proto.Uint64(uint64(value))
+		case p.currentIsHistogramSum:
+			p.currentMetric.Histogram.SampleSum = proto.Float64(value)
+		case !math.IsNaN(p.currentBucket):
+			p.currentMetric.Histogram.Bucket = append(
+				p.currentMetric.Histogram.Bucket,
+				&dto.Bucket{
+					UpperBound:      proto.Float64(p.currentBucket),
+					CumulativeCount: proto.Uint64(uint64(value)),
+				},
+			)
+		}
+	default:
+		p.err = fmt.Errorf("unexpected type for metric name %q", p.currentMF.GetName())
+	}
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	return p.startTimestamp
+}
+
+// startTimestamp represents the state where the next byte read from p.buf is
+// the start of the timestamp (or whitespace leading up to it).
+func (p *TextParser) startTimestamp() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	timestamp, err := strconv.ParseInt(p.currentToken.String(), 10, 64)
+	if err != nil {
+		// Create a more helpful error message.
+		p.parseError(fmt.Sprintf("expected integer as timestamp, got %q", p.currentToken.String()))
+		return nil
+	}
+	p.currentMetric.TimestampMs = proto.Int64(timestamp)
+	if p.readTokenUntilNewline(false); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentToken.Len() > 0 {
+		p.parseError(fmt.Sprintf("spurious string after timestamp: %q", p.currentToken.String()))
+		return nil
+	}
+	return p.startOfLine
+}
+
+// readingHelp represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the docstring after 'HELP'.
+func (p *TextParser) readingHelp() stateFn {
+	if p.currentMF.Help != nil {
+		p.parseError(fmt.Sprintf("second HELP line for metric name %q", p.currentMF.GetName()))
+		return nil
+	}
+	// Rest of line is the docstring.
+	if p.readTokenUntilNewline(true); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	p.currentMF.Help = proto.String(p.currentToken.String())
+	return p.startOfLine
+}
+
+// readingType represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the type hint after 'HELP'.
+func (p *TextParser) readingType() stateFn {
+	if p.currentMF.Type != nil {
+		p.parseError(fmt.Sprintf("second TYPE line for metric name %q, or TYPE reported after samples", p.currentMF.GetName()))
+		return nil
+	}
+	// Rest of line is the type.
+	if p.readTokenUntilNewline(false); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	metricType, ok := dto.MetricType_value[strings.ToUpper(p.currentToken.String())]
+	if !ok {
+		p.parseError(fmt.Sprintf("unknown metric type %q", p.currentToken.String()))
+		return nil
+	}
+	p.currentMF.Type = dto.MetricType(metricType).Enum()
+	return p.startOfLine
+}
+
+// parseError sets p.err to a ParseError at the current line with the given
+// message.
+func (p *TextParser) parseError(msg string) {
+	p.err = ParseError{
+		Line: p.lineCount,
+		Msg:  msg,
+	}
+}
+
+// skipBlankTab reads (and discards) bytes from p.buf until it encounters a byte
+// that is neither ' ' nor '\t'. That byte is left in p.currentByte.
+func (p *TextParser) skipBlankTab() {
+	for {
+		if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil || !isBlankOrTab(p.currentByte) {
+			return
+		}
+	}
+}
+
+// skipBlankTabIfCurrentBlankTab works exactly as skipBlankTab but doesn't do
+// anything if p.currentByte is neither ' ' nor '\t'.
+func (p *TextParser) skipBlankTabIfCurrentBlankTab() {
+	if isBlankOrTab(p.currentByte) {
+		p.skipBlankTab()
+	}
+}
+
+// readTokenUntilWhitespace copies bytes from p.buf into p.currentToken.  The
+// first byte considered is the byte already read (now in p.currentByte).  The
+// first whitespace byte encountered is still copied into p.currentByte, but not
+// into p.currentToken.
+func (p *TextParser) readTokenUntilWhitespace() {
+	p.currentToken.Reset()
+	for p.err == nil && !isBlankOrTab(p.currentByte) && p.currentByte != '\n' {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+	}
+}
+
+// readTokenUntilNewline copies bytes from p.buf into p.currentToken.  The first
+// byte considered is the byte already read (now in p.currentByte).  The first
+// newline byte encountered is still copied into p.currentByte, but not into
+// p.currentToken. If recognizeEscapeSequence is true, two escape sequences are
+// recognized: '\\' translates into '\', and '\n' into a line-feed character.
+// All other escape sequences are invalid and cause an error.
+func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
+	p.currentToken.Reset()
+	escaped := false
+	for p.err == nil {
+		if recognizeEscapeSequence && escaped {
+			switch p.currentByte {
+			case '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+		} else {
+			switch p.currentByte {
+			case '\n':
+				return
+			case '\\':
+				escaped = true
+			default:
+				p.currentToken.WriteByte(p.currentByte)
+			}
+		}
+		p.currentByte, p.err = p.buf.ReadByte()
+	}
+}
+
+// readTokenAsMetricName copies a metric name from p.buf into p.currentToken.
+// The first byte considered is the byte already read (now in p.currentByte).
+// The first byte not part of a metric name is still copied into p.currentByte,
+// but not into p.currentToken.
+func (p *TextParser) readTokenAsMetricName() {
+	p.currentToken.Reset()
+	if !isValidMetricNameStart(p.currentByte) {
+		return
+	}
+	for {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+		if p.err != nil || !isValidMetricNameContinuation(p.currentByte) {
+			return
+		}
+	}
+}
+
+// readTokenAsLabelName copies a label name from p.buf into p.currentToken.
+// The first byte considered is the byte already read (now in p.currentByte).
+// The first byte not part of a label name is still copied into p.currentByte,
+// but not into p.currentToken.
+func (p *TextParser) readTokenAsLabelName() {
+	p.currentToken.Reset()
+	if !isValidLabelNameStart(p.currentByte) {
+		return
+	}
+	for {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+		if p.err != nil || !isValidLabelNameContinuation(p.currentByte) {
+			return
+		}
+	}
+}
+
+// readTokenAsLabelValue copies a label value from p.buf into p.currentToken.
+// In contrast to the other 'readTokenAs...' functions, which start with the
+// last read byte in p.currentByte, this method ignores p.currentByte and starts
+// with reading a new byte from p.buf. The first byte not part of a label value
+// is still copied into p.currentByte, but not into p.currentToken.
+func (p *TextParser) readTokenAsLabelValue() {
+	p.currentToken.Reset()
+	escaped := false
+	for {
+		if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
+			return
+		}
+		if escaped {
+			switch p.currentByte {
+			case '"', '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+			continue
+		}
+		switch p.currentByte {
+		case '"':
+			return
+		case '\n':
+			p.parseError(fmt.Sprintf("label value %q contains unescaped new-line", p.currentToken.String()))
+			return
+		case '\\':
+			escaped = true
+		default:
+			p.currentToken.WriteByte(p.currentByte)
+		}
+	}
+}
+
+func (p *TextParser) setOrCreateCurrentMF() {
+	p.currentIsSummaryCount = false
+	p.currentIsSummarySum = false
+	p.currentIsHistogramCount = false
+	p.currentIsHistogramSum = false
+	name := p.currentToken.String()
+	if p.currentMF = p.metricFamiliesByName[name]; p.currentMF != nil {
+		return
+	}
+	// Try out if this is a _sum or _count for a summary/histogram.
+	summaryName := summaryMetricName(name)
+	if p.currentMF = p.metricFamiliesByName[summaryName]; p.currentMF != nil {
+		if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+			if isCount(name) {
+				p.currentIsSummaryCount = true
+			}
+			if isSum(name) {
+				p.currentIsSummarySum = true
+			}
+			return
+		}
+	}
+	histogramName := histogramMetricName(name)
+	if p.currentMF = p.metricFamiliesByName[histogramName]; p.currentMF != nil {
+		if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+			if isCount(name) {
+				p.currentIsHistogramCount = true
+			}
+			if isSum(name) {
+				p.currentIsHistogramSum = true
+			}
+			return
+		}
+	}
+	p.currentMF = &dto.MetricFamily{Name: proto.String(name)}
+	p.metricFamiliesByName[name] = p.currentMF
+}
+
+func isValidLabelNameStart(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_'
+}
+
+func isValidLabelNameContinuation(b byte) bool {
+	return isValidLabelNameStart(b) || (b >= '0' && b <= '9')
+}
+
+func isValidMetricNameStart(b byte) bool {
+	return isValidLabelNameStart(b) || b == ':'
+}
+
+func isValidMetricNameContinuation(b byte) bool {
+	return isValidLabelNameContinuation(b) || b == ':'
+}
+
+func isBlankOrTab(b byte) bool {
+	return b == ' ' || b == '\t'
+}
+
+func isCount(name string) bool {
+	return len(name) > 6 && name[len(name)-6:] == "_count"
+}
+
+func isSum(name string) bool {
+	return len(name) > 4 && name[len(name)-4:] == "_sum"
+}
+
+func isBucket(name string) bool {
+	return len(name) > 7 && name[len(name)-7:] == "_bucket"
+}
+
+func summaryMetricName(name string) string {
+	switch {
+	case isCount(name):
+		return name[:len(name)-6]
+	case isSum(name):
+		return name[:len(name)-4]
+	default:
+		return name
+	}
+}
+
+func histogramMetricName(name string) string {
+	switch {
+	case isCount(name):
+		return name[:len(name)-6]
+	case isSum(name):
+		return name[:len(name)-4]
+	case isBucket(name):
+		return name[:len(name)-7]
+	default:
+		return name
+	}
+}
+
+func parseFloat(s string) (float64, error) {
+	if strings.ContainsAny(s, "pP_") {
+		return 0, fmt.Errorf("unsupported character in float")
+	}
+	return strconv.ParseFloat(s, 64)
+}

vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt

@@ -0,0 +1,67 @@
+PACKAGE
+
+package goautoneg
+import "bitbucket.org/ww/goautoneg"
+
+HTTP Content-Type Autonegotiation.
+
+The functions in this package implement the behaviour specified in
+http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
+
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    Neither the name of the Open Knowledge Foundation Ltd. nor the
+    names of its contributors may be used to endorse or promote
+    products derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+FUNCTIONS
+
+func Negotiate(header string, alternatives []string) (content_type string)
+Negotiate the most appropriate content_type given the accept header
+and a list of alternatives.
+
+func ParseAccept(header string) (accept []Accept)
+Parse an Accept Header string returning a sorted list
+of clauses
+
+
+TYPES
+
+type Accept struct {
+    Type, SubType string
+    Q             float32
+    Params        map[string]string
+}
+Structure to represent a clause in an HTTP Accept Header
+
+
+SUBDIRECTORIES
+
+	.hg