Don't allocate tmp slice in txPipelineWriteMulti

Author: vmihailenco

cluster.go

@@ -1070,7 +1070,7 @@ func (c *ClusterClient) _processPipeline(ctx context.Context, cmds []Cmder) erro
 
 				err := node.Client.withConn(ctx, func(ctx context.Context, cn *pool.Conn) error {
 					err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
-						return writeCmd(wr, cmds...)
+						return writeCmds(wr, cmds)
 					})
 					if err != nil {
 						return err

command.go

@@ -41,16 +41,19 @@ func cmdsFirstErr(cmds []Cmder) error {
 	return nil
 }
 
-func writeCmd(wr *proto.Writer, cmds ...Cmder) error {
+func writeCmds(wr *proto.Writer, cmds []Cmder) error {
 	for _, cmd := range cmds {
-		err := wr.WriteArgs(cmd.Args())
-		if err != nil {
+		if err := writeCmd(wr, cmd); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
+func writeCmd(wr *proto.Writer, cmd Cmder) error {
+	return wr.WriteArgs(cmd.Args())
+}
+
 func cmdString(cmd Cmder, val interface{}) string {
 	ss := make([]string, 0, len(cmd.Args()))
 	for _, arg := range cmd.Args() {

redis.go

@@ -411,7 +411,7 @@ func (c *baseClient) pipelineProcessCmds(
 	ctx context.Context, cn *pool.Conn, cmds []Cmder,
 ) (bool, error) {
 	err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
-		return writeCmd(wr, cmds...)
+		return writeCmds(wr, cmds)
 	})
 	if err != nil {
 		return true, err
@@ -453,12 +453,22 @@ func (c *baseClient) txPipelineProcessCmds(
 	return false, err
 }
 
+var (
+	multi = NewStatusCmd("multi")
+	exec  = NewSliceCmd("exec")
+)
+
 func txPipelineWriteMulti(wr *proto.Writer, cmds []Cmder) error {
-	multiExec := make([]Cmder, 0, len(cmds)+2)
-	multiExec = append(multiExec, NewStatusCmd("MULTI"))
-	multiExec = append(multiExec, cmds...)
-	multiExec = append(multiExec, NewSliceCmd("EXEC"))
-	return writeCmd(wr, multiExec...)
+	if err := writeCmd(wr, multi); err != nil {
+		return err
+	}
+	if err := writeCmds(wr, cmds); err != nil {
+		return err
+	}
+	if err := writeCmd(wr, exec); err != nil {
+		return err
+	}
+	return nil
 }
 
 func txPipelineReadQueued(rd *proto.Reader, cmds []Cmder) error {