GenerateBranch is now optimized although it increased allocs

client.go

@@ -138,9 +138,11 @@ func ClientRequestAddVia(c *Client, r *sip.Request) error {
 		Params:          sip.NewParams(),
 		Next:            nil,
 	}
-	newvia.Params.Add("branch", sip.GenerateBranch())
+	// NOTE: Consider lenght of branch configurable
+	newvia.Params.Add("branch", sip.GenerateBranchN(16))
 
 	if via, exists := r.Via(); exists {
+		// newvia.Params.Add("branch", via.Params["branch"])
 		if via.Params.Has("rport") {
 			h, p, _ := net.SplitHostPort(r.Source())
 			via.Params.Add("rport", p)

example/dialog/main.go

@@ -120,18 +120,18 @@ func (h *Handler) route(req *sip.Request, tx sip.ServerTransaction) {
 			clTx.Cancel()
 
 		case err := <-clTx.Errors():
-			log.Error().Err(err).Str("caller", req.Method().String()).Msg("Client Transaction Error")
+			log.Error().Err(err).Str("caller", req.Method.String()).Msg("Client Transaction Error")
 			return
 
 		case err := <-tx.Errors():
-			log.Error().Err(err).Str("caller", req.Method().String()).Msg("Server transaction error")
+			log.Error().Err(err).Str("caller", req.Method.String()).Msg("Server transaction error")
 			return
 
 		case <-tx.Done():
-			log.Debug().Str("req", req.Method().String()).Msg("Transaction done")
+			log.Debug().Str("req", req.Method.String()).Msg("Transaction done")
 			return
 		case <-clTx.Done():
-			log.Debug().Str("req", req.Method().String()).Msg("Client Transaction done")
+			log.Debug().Str("req", req.Method.String()).Msg("Client Transaction done")
 			return
 		}
 	}

example/proxysip/docker-compose.yml

@@ -36,7 +36,7 @@ services:
 
   uac:
     image: ctaloi/sipp
-    command: -sn uac -r 1 -rp 1000 -i 10.5.0.30 10.5.0.10:5060
+    command: -sn uac -r 1000 -rp 1000 -i 10.5.0.30 10.5.0.10:5060
     # network_mode: "host"
     cpuset: "5"
     networks:

example/proxysip/main.go

@@ -159,10 +159,10 @@ func setupSipProxy(proxydst string, ip string) *sipgo.Server {
 				}
 
 				// Early terminate
-				if req.Method == sip.BYE {
-					// We will call client Terminate
-					return
-				}
+				// if req.Method == sip.BYE {
+				// 	// We will call client Terminate
+				// 	return
+				// }
 
 			case m := <-tx.Acks():
 				// Acks can not be send directly trough destination

sip/sip.go

@@ -22,10 +22,21 @@ const (
 
 // GenerateBranch returns random unique branch ID.
 func GenerateBranch() string {
-	return strings.Join([]string{
-		RFC3261BranchMagicCookie,
-		RandString(32),
-	}, ".")
+	return GenerateBranchN(16)
+}
+
+// GenerateBranchN returns random unique branch ID in format MagicCookie.<n chars>
+func GenerateBranchN(n int) string {
+	sb := &strings.Builder{}
+	generateBranchStringWrite(sb, n)
+	return sb.String()
+}
+
+func generateBranchStringWrite(sb *strings.Builder, n int) {
+	sb.Grow(len(RFC3261BranchMagicCookie) + 33)
+	sb.WriteString(RFC3261BranchMagicCookie)
+	sb.WriteString(".")
+	RandStringBytesMask(sb, 32)
 }
 
 // DefaultPort returns protocol default port by network.

sip/utils.go

@@ -10,7 +10,10 @@ import (
 )
 
 const (
-	letterBytes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	letterBytes   = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	letterIdxBits = 6                    // 6 bits to represent a letter index
+	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
+	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
 )
 
 func init() {
@@ -41,6 +44,27 @@ func RandString(n int) string {
 	return string(output)
 }
 
+var src = rand.NewSource(time.Now().UnixNano())
+
+// https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-go
+func RandStringBytesMask(sb *strings.Builder, n int) string {
+	sb.Grow(n)
+	// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
+	for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
+		if remain == 0 {
+			cache, remain = src.Int63(), letterIdxMax
+		}
+		if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
+			sb.WriteByte(letterBytes[idx])
+			i--
+		}
+		cache >>= letterIdxBits
+		remain--
+	}
+
+	return sb.String()
+}
+
 // ASCIIToLower is faster than go version. It avoids one more loop
 func ASCIIToLower(s string) string {
 	var b strings.Builder

transaction/layer.go

@@ -145,7 +145,7 @@ func (txl *Layer) Request(req *sip.Request) (*ClientTx, error) {
 	}
 
 	if _, exists := txl.clientTransactions.get(key); exists {
-		return nil, fmt.Errorf("transaction already exists")
+		return nil, fmt.Errorf("transaction %q already exists", key)
 	}
 
 	conn, err := txl.tpl.ClientRequestConnection(req)