maintain lenBytes as a running count

irc/client.go

 	target        string
 	responseLabel string // this is the value of the labeled-response tag sent with BATCH
 	message       utils.SplitMessage
+	lenBytes      int
 	tags          map[string]string
 }
 
 	s.fakelag.Unsuspend()
 
 	// heuristics to estimate how much data they used while fakelag was suspended
-	fakelagBill := (batch.message.LenBytes() / 512) + 1
+	fakelagBill := (batch.lenBytes / 512) + 1
 	fakelagBillLines := (batch.message.LenLines() * 60) / 512
 	if fakelagBill < fakelagBillLines {
 		fakelagBill = fakelagBillLines

irc/handlers.go

 		errorCode, errorMessage = "MULTILINE_INVALID", client.t("Cannot send a blank line with the multiline concat tag")
 		return
 	}
+	if !isConcat && len(rb.session.batch.message.Split) != 0 {
+		rb.session.batch.lenBytes++ // bill for the newline
+	}
 	rb.session.batch.message.Append(msg.Params[1], isConcat)
+	rb.session.batch.lenBytes += len(msg.Params[1])
 	config := server.Config()
-	if config.Limits.Multiline.MaxBytes < rb.session.batch.message.LenBytes() {
+	if config.Limits.Multiline.MaxBytes < rb.session.batch.lenBytes {
 		errorCode, errorMessage = "MULTILINE_MAX_BYTES", strconv.Itoa(config.Limits.Multiline.MaxBytes)
 	} else if config.Limits.Multiline.MaxLines != 0 && config.Limits.Multiline.MaxLines < rb.session.batch.message.LenLines() {
 		errorCode, errorMessage = "MULTILINE_MAX_LINES", strconv.Itoa(config.Limits.Multiline.MaxLines)

irc/utils/text.go

 	return len(sm.Split)
 }
 
-func (sm *SplitMessage) LenBytes() (result int) {
-	if sm.Split == nil {
-		return len(sm.Message)
-	}
-	for i := 0; i < len(sm.Split); i++ {
-		result += len(sm.Split[i].Message)
-		// bill for the joining newline if necessary
-		if i != 0 && !sm.Split[i].Concat {
-			result += 1
-		}
-	}
-	return
-}
-
 func (sm *SplitMessage) ValidMultiline() bool {
 	// must contain at least one nonblank line
 	for i := 0; i < len(sm.Split); i++ {