Improve perf of integer command arguments.

redis/conn.go

@@ -28,21 +28,27 @@ import (
 
 // conn is the low-level implementation of Conn
 type conn struct {
-	conn net.Conn
+
+	// Shared
+	mu      sync.Mutex
+	pending int
+	err     error
+	conn    net.Conn
 
 	// Read
 	readTimeout time.Duration
 	br          *bufio.Reader
-	scratch     []byte
 
 	// Write
 	writeTimeout time.Duration
 	bw           *bufio.Writer
 
-	// Shared
-	mu      sync.Mutex
-	pending int
-	err     error
+	// Scratch space for formatting argument length.
+	// '*' or '$', length, "\r\n"
+	lenScratch [1 + 19 + 2]byte
+
+	// Scratch space for formatting integers.
+	intScratch [20]byte
 }
 
 // Dial connects to the Redis server at the given network and address.
@@ -107,30 +113,34 @@ func (c *conn) Err() error {
 	return err
 }
 
-func (c *conn) writeN(prefix byte, n int) error {
-	c.scratch = append(c.scratch[0:0], prefix)
-	c.scratch = strconv.AppendInt(c.scratch, int64(n), 10)
-	c.scratch = append(c.scratch, "\r\n"...)
-	_, err := c.bw.Write(c.scratch)
+func (c *conn) writeLen(prefix byte, n int) error {
+	c.lenScratch[0] = prefix
+	s := strconv.AppendInt(c.lenScratch[:1], int64(n), 10)
+	s = append(s, "\r\n"...)
+	_, err := c.bw.Write(s)
 	return err
 }
 
 func (c *conn) writeString(s string) error {
-	c.writeN('$', len(s))
+	c.writeLen('$', len(s))
 	c.bw.WriteString(s)
 	_, err := c.bw.WriteString("\r\n")
 	return err
 }
 
 func (c *conn) writeBytes(p []byte) error {
-	c.writeN('$', len(p))
+	c.writeLen('$', len(p))
 	c.bw.Write(p)
 	_, err := c.bw.WriteString("\r\n")
 	return err
 }
 
+func (c *conn) writeInt64(n int64) error {
+	return c.writeBytes(strconv.AppendInt(c.intScratch[0:0], n, 10))
+}
+
 func (c *conn) writeCommand(cmd string, args []interface{}) (err error) {
-	c.writeN('*', 1+len(args))
+	c.writeLen('*', 1+len(args))
 	err = c.writeString(cmd)
 	for _, arg := range args {
 		if err != nil {
@@ -141,6 +151,10 @@ func (c *conn) writeCommand(cmd string, args []interface{}) (err error) {
 			err = c.writeString(arg)
 		case []byte:
 			err = c.writeBytes(arg)
+		case int:
+			err = c.writeInt64(int64(arg))
+		case int64:
+			err = c.writeInt64(arg)
 		case bool:
 			if arg {
 				err = c.writeString("1")

redis/conn_test.go

@@ -18,12 +18,14 @@ import (
 	"bufio"
 	"bytes"
 	"errors"
-	"github.com/garyburd/redigo/redis"
+	"math"
 	"net"
 	"reflect"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/garyburd/redigo/redis"
 )
 
 var writeTests = []struct {
@@ -38,10 +40,18 @@ var writeTests = []struct {
 		[]interface{}{"SET", "foo", "bar"},
 		"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nbar\r\n",
 	},
+	{
+		[]interface{}{"SET", "foo", byte(100)},
+		"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\n100\r\n",
+	},
 	{
 		[]interface{}{"SET", "foo", 100},
 		"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\n100\r\n",
 	},
+	{
+		[]interface{}{"SET", "foo", int64(math.MinInt64)},
+		"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$20\r\n-9223372036854775808\r\n",
+	},
 	{
 		[]interface{}{"SET", "", []byte("foo")},
 		"*3\r\n$3\r\nSET\r\n$0\r\n\r\n$3\r\nfoo\r\n",