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- // Copyright (c) 2022 Shivaram Lingamneni
- // released under the MIT license
-
- package utils
-
- import (
- "sync/atomic"
- "unsafe"
- )
-
- /*
- This can be used to implement the following pattern:
-
- 1. Prepare a config object (this can be arbitrarily expensive)
- 2. Take a pointer to the config object and use Set() to install it
- 3. Use Get() to access the config from any goroutine
- 4. To update the config, call Set() again with a new prepared config object
- 5. As long as any individual config object is not modified (by any goroutine)
- after it is installed with Set(), this is free of data races, and Get()
- is extremely cheap (on amd64 it compiles down to plain MOV instructions).
- */
-
- type ConfigStore[Config any] struct {
- ptr unsafe.Pointer
- }
-
- func (c *ConfigStore[Config]) Get() *Config {
- return (*Config)(atomic.LoadPointer(&c.ptr))
- }
-
- func (c *ConfigStore[Config]) Set(ptr *Config) {
- atomic.StorePointer(&c.ptr, unsafe.Pointer(ptr))
- }
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