First commit

README.markdown

@@ -0,0 +1,44 @@
+Redigo
+======
+
+Redigo is a [Go](http://golang.org/) client for the [Redis](http://redis.io/) database.
+
+Features
+-------
+
+* A [Print-like](http://godoc.org/github.com/garyburd/redigo/redis#hdr-Executing_Commands) API with support for all Redis commands.
+* [Pipelining](http://godoc.org/github.com/garyburd/redigo/redis#hdr-Pipelining), including pipelined transactions.
+* [Publish/Subscribe](http://godoc.org/github.com/garyburd/redigo/redis#hdr-Publish_and_Subscribe).
+* [Connection pooling](http://godoc.org/github.com/garyburd/redigo/redis#Pool).
+* [Script helper type](http://godoc.org/github.com/garyburd/redigo/redis#Script) with optimistic use of EVALSHA.
+* [Helper functions](http://godoc.org/github.com/garyburd/redigo/redis#hdr-Reply_Helpers) for working with command replies.
+
+Documentation
+-------------
+
+- [API Reference](http://godoc.org/github.com/garyburd/redigo/redis)
+- [FAQ](https://github.com/garyburd/redigo/wiki/FAQ)
+
+Installation
+------------
+
+Install Redigo using the "go get" command:
+
+    go get github.com/garyburd/redigo/redis
+
+The Go distribution is Redigo's only dependency.
+
+Contributing
+------------
+
+Contributions are welcome. 
+
+Before writing code, send mail to gary@beagledreams.com to discuss what you
+plan to do. This gives me a chance to validate the design, avoid duplication of
+effort and ensure that the changes fit the goals of the project. Do not start
+the discussion with a pull request. 
+
+License
+-------
+
+Redigo is available under the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0.html).

go.mod

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+module git.bit5.ru/backend/redigo
+
+go 1.13

internal/commandinfo.go

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+// Copyright 2014 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package internal // import "github.com/garyburd/redigo/internal"
+
+import (
+	"strings"
+)
+
+const (
+	WatchState = 1 << iota
+	MultiState
+	SubscribeState
+	MonitorState
+)
+
+type CommandInfo struct {
+	Set, Clear int
+}
+
+var commandInfos = map[string]CommandInfo{
+	"WATCH":      {Set: WatchState},
+	"UNWATCH":    {Clear: WatchState},
+	"MULTI":      {Set: MultiState},
+	"EXEC":       {Clear: WatchState | MultiState},
+	"DISCARD":    {Clear: WatchState | MultiState},
+	"PSUBSCRIBE": {Set: SubscribeState},
+	"SUBSCRIBE":  {Set: SubscribeState},
+	"MONITOR":    {Set: MonitorState},
+}
+
+func LookupCommandInfo(commandName string) CommandInfo {
+	return commandInfos[strings.ToUpper(commandName)]
+}

internal/redistest/testdb.go

@@ -0,0 +1,65 @@
+// Copyright 2014 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// Package redistest contains utilities for writing Redigo tests.
+package redistest
+
+import (
+	"errors"
+	"time"
+
+	"github.com/garyburd/redigo/redis"
+)
+
+type testConn struct {
+	redis.Conn
+}
+
+func (t testConn) Close() error {
+	_, err := t.Conn.Do("SELECT", "9")
+	if err != nil {
+		return nil
+	}
+	_, err = t.Conn.Do("FLUSHDB")
+	if err != nil {
+		return err
+	}
+	return t.Conn.Close()
+}
+
+// Dial dials the local Redis server and selects database 9. To prevent
+// stomping on real data, DialTestDB fails if database 9 contains data. The
+// returned connection flushes database 9 on close.
+func Dial() (redis.Conn, error) {
+	c, err := redis.DialTimeout("tcp", ":6379", 0, 1*time.Second, 1*time.Second)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = c.Do("SELECT", "9")
+	if err != nil {
+		return nil, err
+	}
+
+	n, err := redis.Int(c.Do("DBSIZE"))
+	if err != nil {
+		return nil, err
+	}
+
+	if n != 0 {
+		return nil, errors.New("database #9 is not empty, test can not continue")
+	}
+
+	return testConn{c}, nil
+}

redis/conn.go

@@ -0,0 +1,455 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strconv"
+	"sync"
+	"time"
+)
+
+// conn is the low-level implementation of Conn
+type conn struct {
+
+	// Shared
+	mu      sync.Mutex
+	pending int
+	err     error
+	conn    net.Conn
+
+	// Read
+	readTimeout time.Duration
+	br          *bufio.Reader
+
+	// Write
+	writeTimeout time.Duration
+	bw           *bufio.Writer
+
+	// Scratch space for formatting argument length.
+	// '*' or '$', length, "\r\n"
+	lenScratch [32]byte
+
+	// Scratch space for formatting integers and floats.
+	numScratch [40]byte
+}
+
+// Dial connects to the Redis server at the given network and address.
+func Dial(network, address string) (Conn, error) {
+	dialer := xDialer{}
+	return dialer.Dial(network, address)
+}
+
+// DialTimeout acts like Dial but takes timeouts for establishing the
+// connection to the server, writing a command and reading a reply.
+func DialTimeout(network, address string, connectTimeout, readTimeout, writeTimeout time.Duration) (Conn, error) {
+	netDialer := net.Dialer{Timeout: connectTimeout}
+	dialer := xDialer{
+		NetDial:      netDialer.Dial,
+		ReadTimeout:  readTimeout,
+		WriteTimeout: writeTimeout,
+	}
+	return dialer.Dial(network, address)
+}
+
+// A Dialer specifies options for connecting to a Redis server.
+type xDialer struct {
+	// NetDial specifies the dial function for creating TCP connections. If
+	// NetDial is nil, then net.Dial is used.
+	NetDial func(network, addr string) (net.Conn, error)
+
+	// ReadTimeout specifies the timeout for reading a single command
+	// reply. If ReadTimeout is zero, then no timeout is used.
+	ReadTimeout time.Duration
+
+	// WriteTimeout specifies the timeout for writing a single command.  If
+	// WriteTimeout is zero, then no timeout is used.
+	WriteTimeout time.Duration
+}
+
+// Dial connects to the Redis server at address on the named network.
+func (d *xDialer) Dial(network, address string) (Conn, error) {
+	dial := d.NetDial
+	if dial == nil {
+		dial = net.Dial
+	}
+	netConn, err := dial(network, address)
+	if err != nil {
+		return nil, err
+	}
+	return &conn{
+		conn:         netConn,
+		bw:           bufio.NewWriter(netConn),
+		br:           bufio.NewReader(netConn),
+		readTimeout:  d.ReadTimeout,
+		writeTimeout: d.WriteTimeout,
+	}, nil
+}
+
+// NewConn returns a new Redigo connection for the given net connection.
+func NewConn(netConn net.Conn, readTimeout, writeTimeout time.Duration) Conn {
+	return &conn{
+		conn:         netConn,
+		bw:           bufio.NewWriter(netConn),
+		br:           bufio.NewReader(netConn),
+		readTimeout:  readTimeout,
+		writeTimeout: writeTimeout,
+	}
+}
+
+func (c *conn) Close() error {
+	c.mu.Lock()
+	err := c.err
+	if c.err == nil {
+		c.err = errors.New("redigo: closed")
+		err = c.conn.Close()
+	}
+	c.mu.Unlock()
+	return err
+}
+
+func (c *conn) fatal(err error) error {
+	c.mu.Lock()
+	if c.err == nil {
+		c.err = err
+		// Close connection to force errors on subsequent calls and to unblock
+		// other reader or writer.
+		c.conn.Close()
+	}
+	c.mu.Unlock()
+	return err
+}
+
+func (c *conn) Err() error {
+	c.mu.Lock()
+	err := c.err
+	c.mu.Unlock()
+	return err
+}
+
+func (c *conn) writeLen(prefix byte, n int) error {
+	c.lenScratch[len(c.lenScratch)-1] = '\n'
+	c.lenScratch[len(c.lenScratch)-2] = '\r'
+	i := len(c.lenScratch) - 3
+	for {
+		c.lenScratch[i] = byte('0' + n%10)
+		i -= 1
+		n = n / 10
+		if n == 0 {
+			break
+		}
+	}
+	c.lenScratch[i] = prefix
+	_, err := c.bw.Write(c.lenScratch[i:])
+	return err
+}
+
+func (c *conn) writeString(s string) error {
+	c.writeLen('$', len(s))
+	c.bw.WriteString(s)
+	_, err := c.bw.WriteString("\r\n")
+	return err
+}
+
+func (c *conn) writeBytes(p []byte) error {
+	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.numScratch[:0], n, 10))
+}
+
+func (c *conn) writeFloat64(n float64) error {
+	return c.writeBytes(strconv.AppendFloat(c.numScratch[:0], n, 'g', -1, 64))
+}
+
+func (c *conn) writeCommand(cmd string, args []interface{}) (err error) {
+	c.writeLen('*', 1+len(args))
+	err = c.writeString(cmd)
+	for _, arg := range args {
+		if err != nil {
+			break
+		}
+		switch arg := arg.(type) {
+		case string:
+			err = c.writeString(arg)
+		case []byte:
+			err = c.writeBytes(arg)
+		case int:
+			err = c.writeInt64(int64(arg))
+		case int64:
+			err = c.writeInt64(arg)
+		case float64:
+			err = c.writeFloat64(arg)
+		case bool:
+			if arg {
+				err = c.writeString("1")
+			} else {
+				err = c.writeString("0")
+			}
+		case nil:
+			err = c.writeString("")
+		default:
+			var buf bytes.Buffer
+			fmt.Fprint(&buf, arg)
+			err = c.writeBytes(buf.Bytes())
+		}
+	}
+	return err
+}
+
+type protocolError string
+
+func (pe protocolError) Error() string {
+	return fmt.Sprintf("redigo: %s (possible server error or unsupported concurrent read by application)", string(pe))
+}
+
+func (c *conn) readLine() ([]byte, error) {
+	p, err := c.br.ReadSlice('\n')
+	if err == bufio.ErrBufferFull {
+		return nil, protocolError("long response line")
+	}
+	if err != nil {
+		return nil, err
+	}
+	i := len(p) - 2
+	if i < 0 || p[i] != '\r' {
+		return nil, protocolError("bad response line terminator")
+	}
+	return p[:i], nil
+}
+
+// parseLen parses bulk string and array lengths.
+func parseLen(p []byte) (int, error) {
+	if len(p) == 0 {
+		return -1, protocolError("malformed length")
+	}
+
+	if p[0] == '-' && len(p) == 2 && p[1] == '1' {
+		// handle $-1 and $-1 null replies.
+		return -1, nil
+	}
+
+	var n int
+	for _, b := range p {
+		n *= 10
+		if b < '0' || b > '9' {
+			return -1, protocolError("illegal bytes in length")
+		}
+		n += int(b - '0')
+	}
+
+	return n, nil
+}
+
+// parseInt parses an integer reply.
+func parseInt(p []byte) (interface{}, error) {
+	if len(p) == 0 {
+		return 0, protocolError("malformed integer")
+	}
+
+	var negate bool
+	if p[0] == '-' {
+		negate = true
+		p = p[1:]
+		if len(p) == 0 {
+			return 0, protocolError("malformed integer")
+		}
+	}
+
+	var n int64
+	for _, b := range p {
+		n *= 10
+		if b < '0' || b > '9' {
+			return 0, protocolError("illegal bytes in length")
+		}
+		n += int64(b - '0')
+	}
+
+	if negate {
+		n = -n
+	}
+	return n, nil
+}
+
+var (
+	okReply   interface{} = "OK"
+	pongReply interface{} = "PONG"
+)
+
+func (c *conn) readReply() (interface{}, error) {
+	line, err := c.readLine()
+	if err != nil {
+		return nil, err
+	}
+	if len(line) == 0 {
+		return nil, protocolError("short response line")
+	}
+	switch line[0] {
+	case '+':
+		switch {
+		case len(line) == 3 && line[1] == 'O' && line[2] == 'K':
+			// Avoid allocation for frequent "+OK" response.
+			return okReply, nil
+		case len(line) == 5 && line[1] == 'P' && line[2] == 'O' && line[3] == 'N' && line[4] == 'G':
+			// Avoid allocation in PING command benchmarks :)
+			return pongReply, nil
+		default:
+			return string(line[1:]), nil
+		}
+	case '-':
+		return Error(string(line[1:])), nil
+	case ':':
+		return parseInt(line[1:])
+	case '$':
+		n, err := parseLen(line[1:])
+		if n < 0 || err != nil {
+			return nil, err
+		}
+		p := make([]byte, n)
+		_, err = io.ReadFull(c.br, p)
+		if err != nil {
+			return nil, err
+		}
+		if line, err := c.readLine(); err != nil {
+			return nil, err
+		} else if len(line) != 0 {
+			return nil, protocolError("bad bulk string format")
+		}
+		return p, nil
+	case '*':
+		n, err := parseLen(line[1:])
+		if n < 0 || err != nil {
+			return nil, err
+		}
+		r := make([]interface{}, n)
+		for i := range r {
+			r[i], err = c.readReply()
+			if err != nil {
+				return nil, err
+			}
+		}
+		return r, nil
+	}
+	return nil, protocolError("unexpected response line")
+}
+
+func (c *conn) Send(cmd string, args ...interface{}) error {
+	c.mu.Lock()
+	c.pending += 1
+	c.mu.Unlock()
+	if c.writeTimeout != 0 {
+		c.conn.SetWriteDeadline(time.Now().Add(c.writeTimeout))
+	}
+	if err := c.writeCommand(cmd, args); err != nil {
+		return c.fatal(err)
+	}
+	return nil
+}
+
+func (c *conn) Flush() error {
+	if c.writeTimeout != 0 {
+		c.conn.SetWriteDeadline(time.Now().Add(c.writeTimeout))
+	}
+	if err := c.bw.Flush(); err != nil {
+		return c.fatal(err)
+	}
+	return nil
+}
+
+func (c *conn) Receive() (reply interface{}, err error) {
+	if c.readTimeout != 0 {
+		c.conn.SetReadDeadline(time.Now().Add(c.readTimeout))
+	}
+	if reply, err = c.readReply(); err != nil {
+		return nil, c.fatal(err)
+	}
+	// When using pub/sub, the number of receives can be greater than the
+	// number of sends. To enable normal use of the connection after
+	// unsubscribing from all channels, we do not decrement pending to a
+	// negative value.
+	//
+	// The pending field is decremented after the reply is read to handle the
+	// case where Receive is called before Send.
+	c.mu.Lock()
+	if c.pending > 0 {
+		c.pending -= 1
+	}
+	c.mu.Unlock()
+	if err, ok := reply.(Error); ok {
+		return nil, err
+	}
+	return
+}
+
+func (c *conn) Do(cmd string, args ...interface{}) (interface{}, error) {
+	c.mu.Lock()
+	pending := c.pending
+	c.pending = 0
+	c.mu.Unlock()
+
+	if cmd == "" && pending == 0 {
+		return nil, nil
+	}
+
+	if c.writeTimeout != 0 {
+		c.conn.SetWriteDeadline(time.Now().Add(c.writeTimeout))
+	}
+
+	if cmd != "" {
+		c.writeCommand(cmd, args)
+	}
+
+	if err := c.bw.Flush(); err != nil {
+		return nil, c.fatal(err)
+	}
+
+	if c.readTimeout != 0 {
+		c.conn.SetReadDeadline(time.Now().Add(c.readTimeout))
+	}
+
+	if cmd == "" {
+		reply := make([]interface{}, pending)
+		for i := range reply {
+			r, e := c.readReply()
+			if e != nil {
+				return nil, c.fatal(e)
+			}
+			reply[i] = r
+		}
+		return reply, nil
+	}
+
+	var err error
+	var reply interface{}
+	for i := 0; i <= pending; i++ {
+		var e error
+		if reply, e = c.readReply(); e != nil {
+			return nil, c.fatal(e)
+		}
+		if e, ok := reply.(Error); ok && err == nil {
+			err = e
+		}
+	}
+	return reply, err
+}

redis/conn_test.go

@@ -0,0 +1,542 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"bufio"
+	"bytes"
+	"math"
+	"net"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+)
+
+var writeTests = []struct {
+	args     []interface{}
+	expected string
+}{
+	{
+		[]interface{}{"SET", "key", "value"},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$5\r\nvalue\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", "value"},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$5\r\nvalue\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", byte(100)},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$3\r\n100\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", 100},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$3\r\n100\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", int64(math.MinInt64)},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$20\r\n-9223372036854775808\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", float64(1349673917.939762)},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$21\r\n1.349673917939762e+09\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", ""},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$0\r\n\r\n",
+	},
+	{
+		[]interface{}{"SET", "key", nil},
+		"*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$0\r\n\r\n",
+	},
+	{
+		[]interface{}{"ECHO", true, false},
+		"*3\r\n$4\r\nECHO\r\n$1\r\n1\r\n$1\r\n0\r\n",
+	},
+}
+
+func TestWrite(t *testing.T) {
+	for _, tt := range writeTests {
+		var buf bytes.Buffer
+		rw := bufio.ReadWriter{Writer: bufio.NewWriter(&buf)}
+		c := redis.NewConnBufio(rw)
+		err := c.Send(tt.args[0].(string), tt.args[1:]...)
+		if err != nil {
+			t.Errorf("Send(%v) returned error %v", tt.args, err)
+			continue
+		}
+		rw.Flush()
+		actual := buf.String()
+		if actual != tt.expected {
+			t.Errorf("Send(%v) = %q, want %q", tt.args, actual, tt.expected)
+		}
+	}
+}
+
+var errorSentinel = &struct{}{}
+
+var readTests = []struct {
+	reply    string
+	expected interface{}
+}{
+	{
+		"+OK\r\n",
+		"OK",
+	},
+	{
+		"+PONG\r\n",
+		"PONG",
+	},
+	{
+		"@OK\r\n",
+		errorSentinel,
+	},
+	{
+		"$6\r\nfoobar\r\n",
+		[]byte("foobar"),
+	},
+	{
+		"$-1\r\n",
+		nil,
+	},
+	{
+		":1\r\n",
+		int64(1),
+	},
+	{
+		":-2\r\n",
+		int64(-2),
+	},
+	{
+		"*0\r\n",
+		[]interface{}{},
+	},
+	{
+		"*-1\r\n",
+		nil,
+	},
+	{
+		"*4\r\n$3\r\nfoo\r\n$3\r\nbar\r\n$5\r\nHello\r\n$5\r\nWorld\r\n",
+		[]interface{}{[]byte("foo"), []byte("bar"), []byte("Hello"), []byte("World")},
+	},
+	{
+		"*3\r\n$3\r\nfoo\r\n$-1\r\n$3\r\nbar\r\n",
+		[]interface{}{[]byte("foo"), nil, []byte("bar")},
+	},
+
+	{
+		// "x" is not a valid length
+		"$x\r\nfoobar\r\n",
+		errorSentinel,
+	},
+	{
+		// -2 is not a valid length
+		"$-2\r\n",
+		errorSentinel,
+	},
+	{
+		// "x"  is not a valid integer
+		":x\r\n",
+		errorSentinel,
+	},
+	{
+		// missing \r\n following value
+		"$6\r\nfoobar",
+		errorSentinel,
+	},
+	{
+		// short value
+		"$6\r\nxx",
+		errorSentinel,
+	},
+	{
+		// long value
+		"$6\r\nfoobarx\r\n",
+		errorSentinel,
+	},
+}
+
+func TestRead(t *testing.T) {
+	for _, tt := range readTests {
+		rw := bufio.ReadWriter{
+			Reader: bufio.NewReader(strings.NewReader(tt.reply)),
+			Writer: bufio.NewWriter(nil), // writer need to support Flush
+		}
+		c := redis.NewConnBufio(rw)
+		actual, err := c.Receive()
+		if tt.expected == errorSentinel {
+			if err == nil {
+				t.Errorf("Receive(%q) did not return expected error", tt.reply)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("Receive(%q) returned error %v", tt.reply, err)
+				continue
+			}
+			if !reflect.DeepEqual(actual, tt.expected) {
+				t.Errorf("Receive(%q) = %v, want %v", tt.reply, actual, tt.expected)
+			}
+		}
+	}
+}
+
+var testCommands = []struct {
+	args     []interface{}
+	expected interface{}
+}{
+	{
+		[]interface{}{"PING"},
+		"PONG",
+	},
+	{
+		[]interface{}{"SET", "foo", "bar"},
+		"OK",
+	},
+	{
+		[]interface{}{"GET", "foo"},
+		[]byte("bar"),
+	},
+	{
+		[]interface{}{"GET", "nokey"},
+		nil,
+	},
+	{
+		[]interface{}{"MGET", "nokey", "foo"},
+		[]interface{}{nil, []byte("bar")},
+	},
+	{
+		[]interface{}{"INCR", "mycounter"},
+		int64(1),
+	},
+	{
+		[]interface{}{"LPUSH", "mylist", "foo"},
+		int64(1),
+	},
+	{
+		[]interface{}{"LPUSH", "mylist", "bar"},
+		int64(2),
+	},
+	{
+		[]interface{}{"LRANGE", "mylist", 0, -1},
+		[]interface{}{[]byte("bar"), []byte("foo")},
+	},
+	{
+		[]interface{}{"MULTI"},
+		"OK",
+	},
+	{
+		[]interface{}{"LRANGE", "mylist", 0, -1},
+		"QUEUED",
+	},
+	{
+		[]interface{}{"PING"},
+		"QUEUED",
+	},
+	{
+		[]interface{}{"EXEC"},
+		[]interface{}{
+			[]interface{}{[]byte("bar"), []byte("foo")},
+			"PONG",
+		},
+	},
+}
+
+func TestDoCommands(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	for _, cmd := range testCommands {
+		actual, err := c.Do(cmd.args[0].(string), cmd.args[1:]...)
+		if err != nil {
+			t.Errorf("Do(%v) returned error %v", cmd.args, err)
+			continue
+		}
+		if !reflect.DeepEqual(actual, cmd.expected) {
+			t.Errorf("Do(%v) = %v, want %v", cmd.args, actual, cmd.expected)
+		}
+	}
+}
+
+func TestPipelineCommands(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	for _, cmd := range testCommands {
+		if err := c.Send(cmd.args[0].(string), cmd.args[1:]...); err != nil {
+			t.Fatalf("Send(%v) returned error %v", cmd.args, err)
+		}
+	}
+	if err := c.Flush(); err != nil {
+		t.Errorf("Flush() returned error %v", err)
+	}
+	for _, cmd := range testCommands {
+		actual, err := c.Receive()
+		if err != nil {
+			t.Fatalf("Receive(%v) returned error %v", cmd.args, err)
+		}
+		if !reflect.DeepEqual(actual, cmd.expected) {
+			t.Errorf("Receive(%v) = %v, want %v", cmd.args, actual, cmd.expected)
+		}
+	}
+}
+
+func TestBlankCommmand(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	for _, cmd := range testCommands {
+		if err := c.Send(cmd.args[0].(string), cmd.args[1:]...); err != nil {
+			t.Fatalf("Send(%v) returned error %v", cmd.args, err)
+		}
+	}
+	reply, err := redis.Values(c.Do(""))
+	if err != nil {
+		t.Fatalf("Do() returned error %v", err)
+	}
+	if len(reply) != len(testCommands) {
+		t.Fatalf("len(reply)=%d, want %d", len(reply), len(testCommands))
+	}
+	for i, cmd := range testCommands {
+		actual := reply[i]
+		if !reflect.DeepEqual(actual, cmd.expected) {
+			t.Errorf("Receive(%v) = %v, want %v", cmd.args, actual, cmd.expected)
+		}
+	}
+}
+
+func TestRecvBeforeSend(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+	done := make(chan struct{})
+	go func() {
+		c.Receive()
+		close(done)
+	}()
+	time.Sleep(time.Millisecond)
+	c.Send("PING")
+	c.Flush()
+	<-done
+	_, err = c.Do("")
+	if err != nil {
+		t.Fatalf("error=%v", err)
+	}
+}
+
+func TestError(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	c.Do("SET", "key", "val")
+	_, err = c.Do("HSET", "key", "fld", "val")
+	if err == nil {
+		t.Errorf("Expected err for HSET on string key.")
+	}
+	if c.Err() != nil {
+		t.Errorf("Conn has Err()=%v, expect nil", c.Err())
+	}
+	_, err = c.Do("SET", "key", "val")
+	if err != nil {
+		t.Errorf("Do(SET, key, val) returned error %v, expected nil.", err)
+	}
+}
+
+func TestReadDeadline(t *testing.T) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("net.Listen returned %v", err)
+	}
+	defer l.Close()
+
+	go func() {
+		for {
+			c, err := l.Accept()
+			if err != nil {
+				return
+			}
+			go func() {
+				time.Sleep(time.Second)
+				c.Write([]byte("+OK\r\n"))
+				c.Close()
+			}()
+		}
+	}()
+
+	c1, err := redis.DialTimeout(l.Addr().Network(), l.Addr().String(), 0, time.Millisecond, 0)
+	if err != nil {
+		t.Fatalf("redis.Dial returned %v", err)
+	}
+	defer c1.Close()
+
+	_, err = c1.Do("PING")
+	if err == nil {
+		t.Fatalf("c1.Do() returned nil, expect error")
+	}
+	if c1.Err() == nil {
+		t.Fatalf("c1.Err() = nil, expect error")
+	}
+
+	c2, err := redis.DialTimeout(l.Addr().Network(), l.Addr().String(), 0, time.Millisecond, 0)
+	if err != nil {
+		t.Fatalf("redis.Dial returned %v", err)
+	}
+	defer c2.Close()
+
+	c2.Send("PING")
+	c2.Flush()
+	_, err = c2.Receive()
+	if err == nil {
+		t.Fatalf("c2.Receive() returned nil, expect error")
+	}
+	if c2.Err() == nil {
+		t.Fatalf("c2.Err() = nil, expect error")
+	}
+}
+
+// Connect to local instance of Redis running on the default port.
+func ExampleDial(x int) {
+	c, err := redis.Dial("tcp", ":6379")
+	if err != nil {
+		// handle error
+	}
+	defer c.Close()
+}
+
+// TextExecError tests handling of errors in a transaction. See
+// http://redis.io/topics/transactions for information on how Redis handles
+// errors in a transaction.
+func TestExecError(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	// Execute commands that fail before EXEC is called.
+
+	c.Do("ZADD", "k0", 0, 0)
+	c.Send("MULTI")
+	c.Send("NOTACOMMAND", "k0", 0, 0)
+	c.Send("ZINCRBY", "k0", 0, 0)
+	v, err := c.Do("EXEC")
+	if err == nil {
+		t.Fatalf("EXEC returned values %v, expected error", v)
+	}
+
+	// Execute commands that fail after EXEC is called. The first command
+	// returns an error.
+
+	c.Do("ZADD", "k1", 0, 0)
+	c.Send("MULTI")
+	c.Send("HSET", "k1", 0, 0)
+	c.Send("ZINCRBY", "k1", 0, 0)
+	v, err = c.Do("EXEC")
+	if err != nil {
+		t.Fatalf("EXEC returned error %v", err)
+	}
+
+	vs, err := redis.Values(v, nil)
+	if err != nil {
+		t.Fatalf("Values(v) returned error %v", err)
+	}
+
+	if len(vs) != 2 {
+		t.Fatalf("len(vs) == %d, want 2", len(vs))
+	}
+
+	if _, ok := vs[0].(error); !ok {
+		t.Fatalf("first result is type %T, expected error", vs[0])
+	}
+
+	if _, ok := vs[1].([]byte); !ok {
+		t.Fatalf("second result is type %T, expected []byte", vs[2])
+	}
+
+	// Execute commands that fail after EXEC is called. The second command
+	// returns an error.
+
+	c.Do("ZADD", "k2", 0, 0)
+	c.Send("MULTI")
+	c.Send("ZINCRBY", "k2", 0, 0)
+	c.Send("HSET", "k2", 0, 0)
+	v, err = c.Do("EXEC")
+	if err != nil {
+		t.Fatalf("EXEC returned error %v", err)
+	}
+
+	vs, err = redis.Values(v, nil)
+	if err != nil {
+		t.Fatalf("Values(v) returned error %v", err)
+	}
+
+	if len(vs) != 2 {
+		t.Fatalf("len(vs) == %d, want 2", len(vs))
+	}
+
+	if _, ok := vs[0].([]byte); !ok {
+		t.Fatalf("first result is type %T, expected []byte", vs[0])
+	}
+
+	if _, ok := vs[1].(error); !ok {
+		t.Fatalf("second result is type %T, expected error", vs[2])
+	}
+}
+
+func BenchmarkDoEmpty(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer c.Close()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		if _, err := c.Do(""); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkDoPing(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer c.Close()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		if _, err := c.Do("PING"); err != nil {
+			b.Fatal(err)
+		}
+	}
+}

redis/doc.go

@@ -0,0 +1,169 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// Package redis is a client for the Redis database.
+//
+// The Redigo FAQ (https://github.com/garyburd/redigo/wiki/FAQ) contains more
+// documentation about this package.
+//
+// Connections
+//
+// The Conn interface is the primary interface for working with Redis.
+// Applications create connections by calling the Dial, DialWithTimeout or
+// NewConn functions. In the future, functions will be added for creating
+// sharded and other types of connections.
+//
+// The application must call the connection Close method when the application
+// is done with the connection.
+//
+// Executing Commands
+//
+// The Conn interface has a generic method for executing Redis commands:
+//
+//  Do(commandName string, args ...interface{}) (reply interface{}, err error)
+//
+// The Redis command reference (http://redis.io/commands) lists the available
+// commands. An example of using the Redis APPEND command is:
+//
+//  n, err := conn.Do("APPEND", "key", "value")
+//
+// The Do method converts command arguments to binary strings for transmission
+// to the server as follows:
+//
+//  Go Type                 Conversion
+//  []byte                  Sent as is
+//  string                  Sent as is
+//  int, int64              strconv.FormatInt(v)
+//  float64                 strconv.FormatFloat(v, 'g', -1, 64)
+//  bool                    true -> "1", false -> "0"
+//  nil                     ""
+//  all other types         fmt.Print(v)
+//
+// Redis command reply types are represented using the following Go types:
+//
+//  Redis type              Go type
+//  error                   redis.Error
+//  integer                 int64
+//  simple string           string
+//  bulk string             []byte or nil if value not present.
+//  array                   []interface{} or nil if value not present.
+//
+// Use type assertions or the reply helper functions to convert from
+// interface{} to the specific Go type for the command result.
+//
+// Pipelining
+//
+// Connections support pipelining using the Send, Flush and Receive methods.
+//
+//  Send(commandName string, args ...interface{}) error
+//  Flush() error
+//  Receive() (reply interface{}, err error)
+//
+// Send writes the command to the connection's output buffer. Flush flushes the
+// connection's output buffer to the server. Receive reads a single reply from
+// the server. The following example shows a simple pipeline.
+//
+//  c.Send("SET", "foo", "bar")
+//  c.Send("GET", "foo")
+//  c.Flush()
+//  c.Receive() // reply from SET
+//  v, err = c.Receive() // reply from GET
+//
+// The Do method combines the functionality of the Send, Flush and Receive
+// methods. The Do method starts by writing the command and flushing the output
+// buffer. Next, the Do method receives all pending replies including the reply
+// for the command just sent by Do. If any of the received replies is an error,
+// then Do returns the error. If there are no errors, then Do returns the last
+// reply. If the command argument to the Do method is "", then the Do method
+// will flush the output buffer and receive pending replies without sending a
+// command.
+//
+// Use the Send and Do methods to implement pipelined transactions.
+//
+//  c.Send("MULTI")
+//  c.Send("INCR", "foo")
+//  c.Send("INCR", "bar")
+//  r, err := c.Do("EXEC")
+//  fmt.Println(r) // prints [1, 1]
+//
+// Concurrency
+//
+// Connections do not support concurrent calls to the write methods (Send,
+// Flush) or concurrent calls to the read method (Receive). Connections do
+// allow a concurrent reader and writer.
+//
+// Because the Do method combines the functionality of Send, Flush and Receive,
+// the Do method cannot be called concurrently with the other methods.
+//
+// For full concurrent access to Redis, use the thread-safe Pool to get and
+// release connections from within a goroutine.
+//
+// Publish and Subscribe
+//
+// Use the Send, Flush and Receive methods to implement Pub/Sub subscribers.
+//
+//  c.Send("SUBSCRIBE", "example")
+//  c.Flush()
+//  for {
+//      reply, err := c.Receive()
+//      if err != nil {
+//          return err
+//      }
+//      // process pushed message
+//  }
+//
+// The PubSubConn type wraps a Conn with convenience methods for implementing
+// subscribers. The Subscribe, PSubscribe, Unsubscribe and PUnsubscribe methods
+// send and flush a subscription management command. The receive method
+// converts a pushed message to convenient types for use in a type switch.
+//
+//  psc := redis.PubSubConn{c}
+//  psc.Subscribe("example")
+//  for {
+//      switch v := psc.Receive().(type) {
+//      case redis.Message:
+//          fmt.Printf("%s: message: %s\n", v.Channel, v.Data)
+//      case redis.Subscription:
+//          fmt.Printf("%s: %s %d\n", v.Channel, v.Kind, v.Count)
+//      case error:
+//          return v
+//      }
+//  }
+//
+// Reply Helpers
+//
+// The Bool, Int, Bytes, String, Strings and Values functions convert a reply
+// to a value of a specific type. To allow convenient wrapping of calls to the
+// connection Do and Receive methods, the functions take a second argument of
+// type error.  If the error is non-nil, then the helper function returns the
+// error. If the error is nil, the function converts the reply to the specified
+// type:
+//
+//  exists, err := redis.Bool(c.Do("EXISTS", "foo"))
+//  if err != nil {
+//      // handle error return from c.Do or type conversion error.
+//  }
+//
+// The Scan function converts elements of a array reply to Go types:
+//
+//  var value1 int
+//  var value2 string
+//  reply, err := redis.Values(c.Do("MGET", "key1", "key2"))
+//  if err != nil {
+//      // handle error
+//  }
+//   if _, err := redis.Scan(reply, &value1, &value2); err != nil {
+//      // handle error
+//  }
+package redis // import "github.com/garyburd/redigo/redis"

redis/log.go

@@ -0,0 +1,117 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+)
+
+// NewLoggingConn returns a logging wrapper around a connection.
+func NewLoggingConn(conn Conn, logger *log.Logger, prefix string) Conn {
+	if prefix != "" {
+		prefix = prefix + "."
+	}
+	return &loggingConn{conn, logger, prefix}
+}
+
+type loggingConn struct {
+	Conn
+	logger *log.Logger
+	prefix string
+}
+
+func (c *loggingConn) Close() error {
+	err := c.Conn.Close()
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "%sClose() -> (%v)", c.prefix, err)
+	c.logger.Output(2, buf.String())
+	return err
+}
+
+func (c *loggingConn) printValue(buf *bytes.Buffer, v interface{}) {
+	const chop = 32
+	switch v := v.(type) {
+	case []byte:
+		if len(v) > chop {
+			fmt.Fprintf(buf, "%q...", v[:chop])
+		} else {
+			fmt.Fprintf(buf, "%q", v)
+		}
+	case string:
+		if len(v) > chop {
+			fmt.Fprintf(buf, "%q...", v[:chop])
+		} else {
+			fmt.Fprintf(buf, "%q", v)
+		}
+	case []interface{}:
+		if len(v) == 0 {
+			buf.WriteString("[]")
+		} else {
+			sep := "["
+			fin := "]"
+			if len(v) > chop {
+				v = v[:chop]
+				fin = "...]"
+			}
+			for _, vv := range v {
+				buf.WriteString(sep)
+				c.printValue(buf, vv)
+				sep = ", "
+			}
+			buf.WriteString(fin)
+		}
+	default:
+		fmt.Fprint(buf, v)
+	}
+}
+
+func (c *loggingConn) print(method, commandName string, args []interface{}, reply interface{}, err error) {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "%s%s(", c.prefix, method)
+	if method != "Receive" {
+		buf.WriteString(commandName)
+		for _, arg := range args {
+			buf.WriteString(", ")
+			c.printValue(&buf, arg)
+		}
+	}
+	buf.WriteString(") -> (")
+	if method != "Send" {
+		c.printValue(&buf, reply)
+		buf.WriteString(", ")
+	}
+	fmt.Fprintf(&buf, "%v)", err)
+	c.logger.Output(3, buf.String())
+}
+
+func (c *loggingConn) Do(commandName string, args ...interface{}) (interface{}, error) {
+	reply, err := c.Conn.Do(commandName, args...)
+	c.print("Do", commandName, args, reply, err)
+	return reply, err
+}
+
+func (c *loggingConn) Send(commandName string, args ...interface{}) error {
+	err := c.Conn.Send(commandName, args...)
+	c.print("Send", commandName, args, nil, err)
+	return err
+}
+
+func (c *loggingConn) Receive() (interface{}, error) {
+	reply, err := c.Conn.Receive()
+	c.print("Receive", "", nil, reply, err)
+	return reply, err
+}

redis/pool.go

@@ -0,0 +1,397 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"bytes"
+	"container/list"
+	"crypto/rand"
+	"crypto/sha1"
+	"errors"
+	"io"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/garyburd/redigo/internal"
+)
+
+var nowFunc = time.Now // for testing
+
+// ErrPoolExhausted is returned from a pool connection method (Do, Send,
+// Receive, Flush, Err) when the maximum number of database connections in the
+// pool has been reached.
+var ErrPoolExhausted = errors.New("redigo: connection pool exhausted")
+
+var (
+	errPoolClosed = errors.New("redigo: connection pool closed")
+	errConnClosed = errors.New("redigo: connection closed")
+)
+
+// Pool maintains a pool of connections. The application calls the Get method
+// to get a connection from the pool and the connection's Close method to
+// return the connection's resources to the pool.
+//
+// The following example shows how to use a pool in a web application. The
+// application creates a pool at application startup and makes it available to
+// request handlers using a global variable.
+//
+//  func newPool(server, password string) *redis.Pool {
+//      return &redis.Pool{
+//          MaxIdle: 3,
+//          IdleTimeout: 240 * time.Second,
+//          Dial: func () (redis.Conn, error) {
+//              c, err := redis.Dial("tcp", server)
+//              if err != nil {
+//                  return nil, err
+//              }
+//              if _, err := c.Do("AUTH", password); err != nil {
+//                  c.Close()
+//                  return nil, err
+//              }
+//              return c, err
+//          },
+//          TestOnBorrow: func(c redis.Conn, t time.Time) error {
+//              _, err := c.Do("PING")
+//              return err
+//          },
+//      }
+//  }
+//
+//  var (
+//      pool *redis.Pool
+//      redisServer = flag.String("redisServer", ":6379", "")
+//      redisPassword = flag.String("redisPassword", "", "")
+//  )
+//
+//  func main() {
+//      flag.Parse()
+//      pool = newPool(*redisServer, *redisPassword)
+//      ...
+//  }
+//
+// A request handler gets a connection from the pool and closes the connection
+// when the handler is done:
+//
+//  func serveHome(w http.ResponseWriter, r *http.Request) {
+//      conn := pool.Get()
+//      defer conn.Close()
+//      ....
+//  }
+//
+type Pool struct {
+
+	// Dial is an application supplied function for creating and configuring a
+	// connection
+	Dial func() (Conn, error)
+
+	// TestOnBorrow is an optional application supplied function for checking
+	// the health of an idle connection before the connection is used again by
+	// the application. Argument t is the time that the connection was returned
+	// to the pool. If the function returns an error, then the connection is
+	// closed.
+	TestOnBorrow func(c Conn, t time.Time) error
+
+	// Maximum number of idle connections in the pool.
+	MaxIdle int
+
+	// Maximum number of connections allocated by the pool at a given time.
+	// When zero, there is no limit on the number of connections in the pool.
+	MaxActive int
+
+	// Close connections after remaining idle for this duration. If the value
+	// is zero, then idle connections are not closed. Applications should set
+	// the timeout to a value less than the server's timeout.
+	IdleTimeout time.Duration
+
+	// If Wait is true and the pool is at the MaxIdle limit, then Get() waits
+	// for a connection to be returned to the pool before returning.
+	Wait bool
+
+	// mu protects fields defined below.
+	mu     sync.Mutex
+	cond   *sync.Cond
+	closed bool
+	active int
+
+	// Stack of idleConn with most recently used at the front.
+	idle list.List
+}
+
+type idleConn struct {
+	c Conn
+	t time.Time
+}
+
+// NewPool creates a new pool. This function is deprecated. Applications should
+// initialize the Pool fields directly as shown in example.
+func NewPool(newFn func() (Conn, error), maxIdle int) *Pool {
+	return &Pool{Dial: newFn, MaxIdle: maxIdle}
+}
+
+// Get gets a connection. The application must close the returned connection.
+// This method always returns a valid connection so that applications can defer
+// error handling to the first use of the connection. If there is an error
+// getting an underlying connection, then the connection Err, Do, Send, Flush
+// and Receive methods return that error.
+func (p *Pool) Get() Conn {
+	c, err := p.get()
+	if err != nil {
+		return errorConnection{err}
+	}
+	return &pooledConnection{p: p, c: c}
+}
+
+// ActiveCount returns the number of active connections in the pool.
+func (p *Pool) ActiveCount() int {
+	p.mu.Lock()
+	active := p.active
+	p.mu.Unlock()
+	return active
+}
+
+// IdleCount returns the number of idle connections in the pool.
+func (p *Pool) IdleCount() int {
+	p.mu.Lock()
+	idle := p.idle.Len()
+	p.mu.Unlock()
+	return idle
+}
+
+// Close releases the resources used by the pool.
+func (p *Pool) Close() error {
+	p.mu.Lock()
+	idle := p.idle
+	p.idle.Init()
+	p.closed = true
+	p.active -= idle.Len()
+	if p.cond != nil {
+		p.cond.Broadcast()
+	}
+	p.mu.Unlock()
+	for e := idle.Front(); e != nil; e = e.Next() {
+		e.Value.(idleConn).c.Close()
+	}
+	return nil
+}
+
+// release decrements the active count and signals waiters. The caller must
+// hold p.mu during the call.
+func (p *Pool) release() {
+	p.active -= 1
+	if p.cond != nil {
+		p.cond.Signal()
+	}
+}
+
+// get prunes stale connections and returns a connection from the idle list or
+// creates a new connection.
+func (p *Pool) get() (Conn, error) {
+	p.mu.Lock()
+
+	// Prune stale connections.
+
+	if timeout := p.IdleTimeout; timeout > 0 {
+		for i, n := 0, p.idle.Len(); i < n; i++ {
+			e := p.idle.Back()
+			if e == nil {
+				break
+			}
+			ic := e.Value.(idleConn)
+			if ic.t.Add(timeout).After(nowFunc()) {
+				break
+			}
+			p.idle.Remove(e)
+			p.release()
+			p.mu.Unlock()
+			ic.c.Close()
+			p.mu.Lock()
+		}
+	}
+
+	for {
+
+		// Get idle connection.
+
+		for i, n := 0, p.idle.Len(); i < n; i++ {
+			e := p.idle.Front()
+			if e == nil {
+				break
+			}
+			ic := e.Value.(idleConn)
+			p.idle.Remove(e)
+			test := p.TestOnBorrow
+			p.mu.Unlock()
+			if test == nil || test(ic.c, ic.t) == nil {
+				return ic.c, nil
+			}
+			ic.c.Close()
+			p.mu.Lock()
+			p.release()
+		}
+
+		// Check for pool closed before dialing a new connection.
+
+		if p.closed {
+			p.mu.Unlock()
+			return nil, errors.New("redigo: get on closed pool")
+		}
+
+		// Dial new connection if under limit.
+
+		if p.MaxActive == 0 || p.active < p.MaxActive {
+			dial := p.Dial
+			p.active += 1
+			p.mu.Unlock()
+			c, err := dial()
+			if err != nil {
+				p.mu.Lock()
+				p.release()
+				p.mu.Unlock()
+				c = nil
+			}
+			return c, err
+		}
+
+		if !p.Wait {
+			p.mu.Unlock()
+			return nil, ErrPoolExhausted
+		}
+
+		if p.cond == nil {
+			p.cond = sync.NewCond(&p.mu)
+		}
+		p.cond.Wait()
+	}
+}
+
+func (p *Pool) put(c Conn, forceClose bool) error {
+	err := c.Err()
+	p.mu.Lock()
+	if !p.closed && err == nil && !forceClose {
+		p.idle.PushFront(idleConn{t: nowFunc(), c: c})
+		if p.idle.Len() > p.MaxIdle {
+			c = p.idle.Remove(p.idle.Back()).(idleConn).c
+		} else {
+			c = nil
+		}
+	}
+
+	if c == nil {
+		if p.cond != nil {
+			p.cond.Signal()
+		}
+		p.mu.Unlock()
+		return nil
+	}
+
+	p.release()
+	p.mu.Unlock()
+	return c.Close()
+}
+
+type pooledConnection struct {
+	p     *Pool
+	c     Conn
+	state int
+}
+
+var (
+	sentinel     []byte
+	sentinelOnce sync.Once
+)
+
+func initSentinel() {
+	p := make([]byte, 64)
+	if _, err := rand.Read(p); err == nil {
+		sentinel = p
+	} else {
+		h := sha1.New()
+		io.WriteString(h, "Oops, rand failed. Use time instead.")
+		io.WriteString(h, strconv.FormatInt(time.Now().UnixNano(), 10))
+		sentinel = h.Sum(nil)
+	}
+}
+
+func (pc *pooledConnection) Close() error {
+	c := pc.c
+	if _, ok := c.(errorConnection); ok {
+		return nil
+	}
+	pc.c = errorConnection{errConnClosed}
+
+	if pc.state&internal.MultiState != 0 {
+		c.Send("DISCARD")
+		pc.state &^= (internal.MultiState | internal.WatchState)
+	} else if pc.state&internal.WatchState != 0 {
+		c.Send("UNWATCH")
+		pc.state &^= internal.WatchState
+	}
+	if pc.state&internal.SubscribeState != 0 {
+		c.Send("UNSUBSCRIBE")
+		c.Send("PUNSUBSCRIBE")
+		// To detect the end of the message stream, ask the server to echo
+		// a sentinel value and read until we see that value.
+		sentinelOnce.Do(initSentinel)
+		c.Send("ECHO", sentinel)
+		c.Flush()
+		for {
+			p, err := c.Receive()
+			if err != nil {
+				break
+			}
+			if p, ok := p.([]byte); ok && bytes.Equal(p, sentinel) {
+				pc.state &^= internal.SubscribeState
+				break
+			}
+		}
+	}
+	c.Do("")
+	pc.p.put(c, pc.state != 0)
+	return nil
+}
+
+func (pc *pooledConnection) Err() error {
+	return pc.c.Err()
+}
+
+func (pc *pooledConnection) Do(commandName string, args ...interface{}) (reply interface{}, err error) {
+	ci := internal.LookupCommandInfo(commandName)
+	pc.state = (pc.state | ci.Set) &^ ci.Clear
+	return pc.c.Do(commandName, args...)
+}
+
+func (pc *pooledConnection) Send(commandName string, args ...interface{}) error {
+	ci := internal.LookupCommandInfo(commandName)
+	pc.state = (pc.state | ci.Set) &^ ci.Clear
+	return pc.c.Send(commandName, args...)
+}
+
+func (pc *pooledConnection) Flush() error {
+	return pc.c.Flush()
+}
+
+func (pc *pooledConnection) Receive() (reply interface{}, err error) {
+	return pc.c.Receive()
+}
+
+type errorConnection struct{ err error }
+
+func (ec errorConnection) Do(string, ...interface{}) (interface{}, error) { return nil, ec.err }
+func (ec errorConnection) Send(string, ...interface{}) error              { return ec.err }
+func (ec errorConnection) Err() error                                     { return ec.err }
+func (ec errorConnection) Close() error                                   { return ec.err }
+func (ec errorConnection) Flush() error                                   { return ec.err }
+func (ec errorConnection) Receive() (interface{}, error)                  { return nil, ec.err }

redis/pool_test.go

@@ -0,0 +1,674 @@
+// Copyright 2011 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"errors"
+	"io"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+)
+
+type poolTestConn struct {
+	d   *poolDialer
+	err error
+	redis.Conn
+}
+
+func (c *poolTestConn) Close() error { c.d.open -= 1; return nil }
+func (c *poolTestConn) Err() error   { return c.err }
+
+func (c *poolTestConn) Do(commandName string, args ...interface{}) (reply interface{}, err error) {
+	if commandName == "ERR" {
+		c.err = args[0].(error)
+		commandName = "PING"
+	}
+	if commandName != "" {
+		c.d.commands = append(c.d.commands, commandName)
+	}
+	return c.Conn.Do(commandName, args...)
+}
+
+func (c *poolTestConn) Send(commandName string, args ...interface{}) error {
+	c.d.commands = append(c.d.commands, commandName)
+	return c.Conn.Send(commandName, args...)
+}
+
+type poolDialer struct {
+	t        *testing.T
+	dialed   int
+	open     int
+	commands []string
+	dialErr  error
+}
+
+func (d *poolDialer) dial() (redis.Conn, error) {
+	d.dialed += 1
+	if d.dialErr != nil {
+		return nil, d.dialErr
+	}
+	c, err := redistest.Dial()
+	if err != nil {
+		return nil, err
+	}
+	d.open += 1
+	return &poolTestConn{d: d, Conn: c}, nil
+}
+
+func (d *poolDialer) check(message string, p *redis.Pool, dialed, open int) {
+	if d.dialed != dialed {
+		d.t.Errorf("%s: dialed=%d, want %d", message, d.dialed, dialed)
+	}
+	if d.open != open {
+		d.t.Errorf("%s: open=%d, want %d", message, d.open, open)
+	}
+	if active := p.ActiveCount(); active != open {
+		d.t.Errorf("%s: active=%d, want %d", message, active, open)
+	}
+}
+
+func TestPoolReuse(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle: 2,
+		Dial:    d.dial,
+	}
+
+	for i := 0; i < 10; i++ {
+		c1 := p.Get()
+		c1.Do("PING")
+		c2 := p.Get()
+		c2.Do("PING")
+		c1.Close()
+		c2.Close()
+	}
+
+	d.check("before close", p, 2, 2)
+	p.Close()
+	d.check("after close", p, 2, 0)
+}
+
+func TestPoolMaxIdle(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle: 2,
+		Dial:    d.dial,
+	}
+	for i := 0; i < 10; i++ {
+		c1 := p.Get()
+		c1.Do("PING")
+		c2 := p.Get()
+		c2.Do("PING")
+		c3 := p.Get()
+		c3.Do("PING")
+		c1.Close()
+		c2.Close()
+		c3.Close()
+	}
+	d.check("before close", p, 12, 2)
+	p.Close()
+	d.check("after close", p, 12, 0)
+}
+
+func TestPoolError(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle: 2,
+		Dial:    d.dial,
+	}
+
+	c := p.Get()
+	c.Do("ERR", io.EOF)
+	if c.Err() == nil {
+		t.Errorf("expected c.Err() != nil")
+	}
+	c.Close()
+
+	c = p.Get()
+	c.Do("ERR", io.EOF)
+	c.Close()
+
+	d.check(".", p, 2, 0)
+}
+
+func TestPoolClose(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle: 2,
+		Dial:    d.dial,
+	}
+
+	c1 := p.Get()
+	c1.Do("PING")
+	c2 := p.Get()
+	c2.Do("PING")
+	c3 := p.Get()
+	c3.Do("PING")
+
+	c1.Close()
+	if _, err := c1.Do("PING"); err == nil {
+		t.Errorf("expected error after connection closed")
+	}
+
+	c2.Close()
+	c2.Close()
+
+	p.Close()
+
+	d.check("after pool close", p, 3, 1)
+
+	if _, err := c1.Do("PING"); err == nil {
+		t.Errorf("expected error after connection and pool closed")
+	}
+
+	c3.Close()
+
+	d.check("after conn close", p, 3, 0)
+
+	c1 = p.Get()
+	if _, err := c1.Do("PING"); err == nil {
+		t.Errorf("expected error after pool closed")
+	}
+}
+
+func TestPoolTimeout(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:     2,
+		IdleTimeout: 300 * time.Second,
+		Dial:        d.dial,
+	}
+
+	now := time.Now()
+	redis.SetNowFunc(func() time.Time { return now })
+	defer redis.SetNowFunc(time.Now)
+
+	c := p.Get()
+	c.Do("PING")
+	c.Close()
+
+	d.check("1", p, 1, 1)
+
+	now = now.Add(p.IdleTimeout)
+
+	c = p.Get()
+	c.Do("PING")
+	c.Close()
+
+	d.check("2", p, 2, 1)
+
+	p.Close()
+}
+
+func TestPoolConcurrenSendReceive(t *testing.T) {
+	p := &redis.Pool{
+		Dial: redistest.Dial,
+	}
+	c := p.Get()
+	done := make(chan error, 1)
+	go func() {
+		_, err := c.Receive()
+		done <- err
+	}()
+	c.Send("PING")
+	c.Flush()
+	err := <-done
+	if err != nil {
+		t.Fatalf("Receive() returned error %v", err)
+	}
+	_, err = c.Do("")
+	if err != nil {
+		t.Fatalf("Do() returned error %v", err)
+	}
+	c.Close()
+	p.Close()
+}
+
+func TestPoolBorrowCheck(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:      2,
+		Dial:         d.dial,
+		TestOnBorrow: func(redis.Conn, time.Time) error { return redis.Error("BLAH") },
+	}
+
+	for i := 0; i < 10; i++ {
+		c := p.Get()
+		c.Do("PING")
+		c.Close()
+	}
+	d.check("1", p, 10, 1)
+	p.Close()
+}
+
+func TestPoolMaxActive(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   2,
+		MaxActive: 2,
+		Dial:      d.dial,
+	}
+	c1 := p.Get()
+	c1.Do("PING")
+	c2 := p.Get()
+	c2.Do("PING")
+
+	d.check("1", p, 2, 2)
+
+	c3 := p.Get()
+	if _, err := c3.Do("PING"); err != redis.ErrPoolExhausted {
+		t.Errorf("expected pool exhausted")
+	}
+
+	c3.Close()
+	d.check("2", p, 2, 2)
+	c2.Close()
+	d.check("3", p, 2, 2)
+
+	c3 = p.Get()
+	if _, err := c3.Do("PING"); err != nil {
+		t.Errorf("expected good channel, err=%v", err)
+	}
+	c3.Close()
+
+	d.check("4", p, 2, 2)
+	p.Close()
+}
+
+func TestPoolMonitorCleanup(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   2,
+		MaxActive: 2,
+		Dial:      d.dial,
+	}
+	c := p.Get()
+	c.Send("MONITOR")
+	c.Close()
+
+	d.check("", p, 1, 0)
+	p.Close()
+}
+
+func TestPoolPubSubCleanup(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   2,
+		MaxActive: 2,
+		Dial:      d.dial,
+	}
+
+	c := p.Get()
+	c.Send("SUBSCRIBE", "x")
+	c.Close()
+
+	want := []string{"SUBSCRIBE", "UNSUBSCRIBE", "PUNSUBSCRIBE", "ECHO"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	c = p.Get()
+	c.Send("PSUBSCRIBE", "x*")
+	c.Close()
+
+	want = []string{"PSUBSCRIBE", "UNSUBSCRIBE", "PUNSUBSCRIBE", "ECHO"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	p.Close()
+}
+
+func TestPoolTransactionCleanup(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   2,
+		MaxActive: 2,
+		Dial:      d.dial,
+	}
+
+	c := p.Get()
+	c.Do("WATCH", "key")
+	c.Do("PING")
+	c.Close()
+
+	want := []string{"WATCH", "PING", "UNWATCH"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	c = p.Get()
+	c.Do("WATCH", "key")
+	c.Do("UNWATCH")
+	c.Do("PING")
+	c.Close()
+
+	want = []string{"WATCH", "UNWATCH", "PING"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	c = p.Get()
+	c.Do("WATCH", "key")
+	c.Do("MULTI")
+	c.Do("PING")
+	c.Close()
+
+	want = []string{"WATCH", "MULTI", "PING", "DISCARD"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	c = p.Get()
+	c.Do("WATCH", "key")
+	c.Do("MULTI")
+	c.Do("DISCARD")
+	c.Do("PING")
+	c.Close()
+
+	want = []string{"WATCH", "MULTI", "DISCARD", "PING"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	c = p.Get()
+	c.Do("WATCH", "key")
+	c.Do("MULTI")
+	c.Do("EXEC")
+	c.Do("PING")
+	c.Close()
+
+	want = []string{"WATCH", "MULTI", "EXEC", "PING"}
+	if !reflect.DeepEqual(d.commands, want) {
+		t.Errorf("got commands %v, want %v", d.commands, want)
+	}
+	d.commands = nil
+
+	p.Close()
+}
+
+func startGoroutines(p *redis.Pool, cmd string, args ...interface{}) chan error {
+	errs := make(chan error, 10)
+	for i := 0; i < cap(errs); i++ {
+		go func() {
+			c := p.Get()
+			_, err := c.Do(cmd, args...)
+			errs <- err
+			c.Close()
+		}()
+	}
+
+	// Wait for goroutines to block.
+	time.Sleep(time.Second / 4)
+
+	return errs
+}
+
+func TestWaitPool(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   1,
+		MaxActive: 1,
+		Dial:      d.dial,
+		Wait:      true,
+	}
+	defer p.Close()
+	c := p.Get()
+	errs := startGoroutines(p, "PING")
+	d.check("before close", p, 1, 1)
+	c.Close()
+	timeout := time.After(2 * time.Second)
+	for i := 0; i < cap(errs); i++ {
+		select {
+		case err := <-errs:
+			if err != nil {
+				t.Fatal(err)
+			}
+		case <-timeout:
+			t.Fatalf("timeout waiting for blocked goroutine %d", i)
+		}
+	}
+	d.check("done", p, 1, 1)
+}
+
+func TestWaitPoolClose(t *testing.T) {
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   1,
+		MaxActive: 1,
+		Dial:      d.dial,
+		Wait:      true,
+	}
+	c := p.Get()
+	if _, err := c.Do("PING"); err != nil {
+		t.Fatal(err)
+	}
+	errs := startGoroutines(p, "PING")
+	d.check("before close", p, 1, 1)
+	p.Close()
+	timeout := time.After(2 * time.Second)
+	for i := 0; i < cap(errs); i++ {
+		select {
+		case err := <-errs:
+			switch err {
+			case nil:
+				t.Fatal("blocked goroutine did not get error")
+			case redis.ErrPoolExhausted:
+				t.Fatal("blocked goroutine got pool exhausted error")
+			}
+		case <-timeout:
+			t.Fatal("timeout waiting for blocked goroutine")
+		}
+	}
+	c.Close()
+	d.check("done", p, 1, 0)
+}
+
+func TestWaitPoolCommandError(t *testing.T) {
+	testErr := errors.New("test")
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   1,
+		MaxActive: 1,
+		Dial:      d.dial,
+		Wait:      true,
+	}
+	defer p.Close()
+	c := p.Get()
+	errs := startGoroutines(p, "ERR", testErr)
+	d.check("before close", p, 1, 1)
+	c.Close()
+	timeout := time.After(2 * time.Second)
+	for i := 0; i < cap(errs); i++ {
+		select {
+		case err := <-errs:
+			if err != nil {
+				t.Fatal(err)
+			}
+		case <-timeout:
+			t.Fatalf("timeout waiting for blocked goroutine %d", i)
+		}
+	}
+	d.check("done", p, cap(errs), 0)
+}
+
+func TestWaitPoolDialError(t *testing.T) {
+	testErr := errors.New("test")
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   1,
+		MaxActive: 1,
+		Dial:      d.dial,
+		Wait:      true,
+	}
+	defer p.Close()
+	c := p.Get()
+	errs := startGoroutines(p, "ERR", testErr)
+	d.check("before close", p, 1, 1)
+
+	d.dialErr = errors.New("dial")
+	c.Close()
+
+	nilCount := 0
+	errCount := 0
+	timeout := time.After(2 * time.Second)
+	for i := 0; i < cap(errs); i++ {
+		select {
+		case err := <-errs:
+			switch err {
+			case nil:
+				nilCount++
+			case d.dialErr:
+				errCount++
+			default:
+				t.Fatalf("expected dial error or nil, got %v", err)
+			}
+		case <-timeout:
+			t.Fatalf("timeout waiting for blocked goroutine %d", i)
+		}
+	}
+	if nilCount != 1 {
+		t.Errorf("expected one nil error, got %d", nilCount)
+	}
+	if errCount != cap(errs)-1 {
+		t.Errorf("expected %d dial erors, got %d", cap(errs)-1, errCount)
+	}
+	d.check("done", p, cap(errs), 0)
+}
+
+// Borrowing requires us to iterate over the idle connections, unlock the pool,
+// and perform a blocking operation to check the connection still works. If
+// TestOnBorrow fails, we must reacquire the lock and continue iteration. This
+// test ensures that iteration will work correctly if multiple threads are
+// iterating simultaneously.
+func TestLocking_TestOnBorrowFails_PoolDoesntCrash(t *testing.T) {
+	count := 100
+
+	// First we'll Create a pool where the pilfering of idle connections fails.
+	d := poolDialer{t: t}
+	p := &redis.Pool{
+		MaxIdle:   count,
+		MaxActive: count,
+		Dial:      d.dial,
+		TestOnBorrow: func(c redis.Conn, t time.Time) error {
+			return errors.New("No way back into the real world.")
+		},
+	}
+	defer p.Close()
+
+	// Fill the pool with idle connections.
+	b1 := sync.WaitGroup{}
+	b1.Add(count)
+	b2 := sync.WaitGroup{}
+	b2.Add(count)
+	for i := 0; i < count; i++ {
+		go func() {
+			c := p.Get()
+			if c.Err() != nil {
+				t.Errorf("pool get failed: %v", c.Err())
+			}
+			b1.Done()
+			b1.Wait()
+			c.Close()
+			b2.Done()
+		}()
+	}
+	b2.Wait()
+	if d.dialed != count {
+		t.Errorf("Expected %d dials, got %d", count, d.dialed)
+	}
+
+	// Spawn a bunch of goroutines to thrash the pool.
+	b2.Add(count)
+	for i := 0; i < count; i++ {
+		go func() {
+			c := p.Get()
+			if c.Err() != nil {
+				t.Errorf("pool get failed: %v", c.Err())
+			}
+			c.Close()
+			b2.Done()
+		}()
+	}
+	b2.Wait()
+	if d.dialed != count*2 {
+		t.Errorf("Expected %d dials, got %d", count*2, d.dialed)
+	}
+}
+
+func BenchmarkPoolGet(b *testing.B) {
+	b.StopTimer()
+	p := redis.Pool{Dial: redistest.Dial, MaxIdle: 2}
+	c := p.Get()
+	if err := c.Err(); err != nil {
+		b.Fatal(err)
+	}
+	c.Close()
+	defer p.Close()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		c = p.Get()
+		c.Close()
+	}
+}
+
+func BenchmarkPoolGetErr(b *testing.B) {
+	b.StopTimer()
+	p := redis.Pool{Dial: redistest.Dial, MaxIdle: 2}
+	c := p.Get()
+	if err := c.Err(); err != nil {
+		b.Fatal(err)
+	}
+	c.Close()
+	defer p.Close()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		c = p.Get()
+		if err := c.Err(); err != nil {
+			b.Fatal(err)
+		}
+		c.Close()
+	}
+}
+
+func BenchmarkPoolGetPing(b *testing.B) {
+	b.StopTimer()
+	p := redis.Pool{Dial: redistest.Dial, MaxIdle: 2}
+	c := p.Get()
+	if err := c.Err(); err != nil {
+		b.Fatal(err)
+	}
+	c.Close()
+	defer p.Close()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		c = p.Get()
+		if _, err := c.Do("PING"); err != nil {
+			b.Fatal(err)
+		}
+		c.Close()
+	}
+}

redis/pubsub.go

@@ -0,0 +1,129 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"errors"
+)
+
+// Subscription represents a subscribe or unsubscribe notification.
+type Subscription struct {
+
+	// Kind is "subscribe", "unsubscribe", "psubscribe" or "punsubscribe"
+	Kind string
+
+	// The channel that was changed.
+	Channel string
+
+	// The current number of subscriptions for connection.
+	Count int
+}
+
+// Message represents a message notification.
+type Message struct {
+
+	// The originating channel.
+	Channel string
+
+	// The message data.
+	Data []byte
+}
+
+// PMessage represents a pmessage notification.
+type PMessage struct {
+
+	// The matched pattern.
+	Pattern string
+
+	// The originating channel.
+	Channel string
+
+	// The message data.
+	Data []byte
+}
+
+// PubSubConn wraps a Conn with convenience methods for subscribers.
+type PubSubConn struct {
+	Conn Conn
+}
+
+// Close closes the connection.
+func (c PubSubConn) Close() error {
+	return c.Conn.Close()
+}
+
+// Subscribe subscribes the connection to the specified channels.
+func (c PubSubConn) Subscribe(channel ...interface{}) error {
+	c.Conn.Send("SUBSCRIBE", channel...)
+	return c.Conn.Flush()
+}
+
+// PSubscribe subscribes the connection to the given patterns.
+func (c PubSubConn) PSubscribe(channel ...interface{}) error {
+	c.Conn.Send("PSUBSCRIBE", channel...)
+	return c.Conn.Flush()
+}
+
+// Unsubscribe unsubscribes the connection from the given channels, or from all
+// of them if none is given.
+func (c PubSubConn) Unsubscribe(channel ...interface{}) error {
+	c.Conn.Send("UNSUBSCRIBE", channel...)
+	return c.Conn.Flush()
+}
+
+// PUnsubscribe unsubscribes the connection from the given patterns, or from all
+// of them if none is given.
+func (c PubSubConn) PUnsubscribe(channel ...interface{}) error {
+	c.Conn.Send("PUNSUBSCRIBE", channel...)
+	return c.Conn.Flush()
+}
+
+// Receive returns a pushed message as a Subscription, Message, PMessage or
+// error. The return value is intended to be used directly in a type switch as
+// illustrated in the PubSubConn example.
+func (c PubSubConn) Receive() interface{} {
+	reply, err := Values(c.Conn.Receive())
+	if err != nil {
+		return err
+	}
+
+	var kind string
+	reply, err = Scan(reply, &kind)
+	if err != nil {
+		return err
+	}
+
+	switch kind {
+	case "message":
+		var m Message
+		if _, err := Scan(reply, &m.Channel, &m.Data); err != nil {
+			return err
+		}
+		return m
+	case "pmessage":
+		var pm PMessage
+		if _, err := Scan(reply, &pm.Pattern, &pm.Channel, &pm.Data); err != nil {
+			return err
+		}
+		return pm
+	case "subscribe", "psubscribe", "unsubscribe", "punsubscribe":
+		s := Subscription{Kind: kind}
+		if _, err := Scan(reply, &s.Channel, &s.Count); err != nil {
+			return err
+		}
+		return s
+	}
+	return errors.New("redigo: unknown pubsub notification")
+}

redis/pubsub_test.go

@@ -0,0 +1,143 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"fmt"
+	"net"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+)
+
+func publish(channel, value interface{}) {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+	c.Do("PUBLISH", channel, value)
+}
+
+// Applications can receive pushed messages from one goroutine and manage subscriptions from another goroutine.
+func ExamplePubSubConn() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	psc := redis.PubSubConn{Conn: c}
+
+	// This goroutine receives and prints pushed notifications from the server.
+	// The goroutine exits when the connection is unsubscribed from all
+	// channels or there is an error.
+	go func() {
+		defer wg.Done()
+		for {
+			switch n := psc.Receive().(type) {
+			case redis.Message:
+				fmt.Printf("Message: %s %s\n", n.Channel, n.Data)
+			case redis.PMessage:
+				fmt.Printf("PMessage: %s %s %s\n", n.Pattern, n.Channel, n.Data)
+			case redis.Subscription:
+				fmt.Printf("Subscription: %s %s %d\n", n.Kind, n.Channel, n.Count)
+				if n.Count == 0 {
+					return
+				}
+			case error:
+				fmt.Printf("error: %v\n", n)
+				return
+			}
+		}
+	}()
+
+	// This goroutine manages subscriptions for the connection.
+	go func() {
+		defer wg.Done()
+
+		psc.Subscribe("example")
+		psc.PSubscribe("p*")
+
+		// The following function calls publish a message using another
+		// connection to the Redis server.
+		publish("example", "hello")
+		publish("example", "world")
+		publish("pexample", "foo")
+		publish("pexample", "bar")
+
+		// Unsubscribe from all connections. This will cause the receiving
+		// goroutine to exit.
+		psc.Unsubscribe()
+		psc.PUnsubscribe()
+	}()
+
+	wg.Wait()
+
+	// Output:
+	// Subscription: subscribe example 1
+	// Subscription: psubscribe p* 2
+	// Message: example hello
+	// Message: example world
+	// PMessage: p* pexample foo
+	// PMessage: p* pexample bar
+	// Subscription: unsubscribe example 1
+	// Subscription: punsubscribe p* 0
+}
+
+func expectPushed(t *testing.T, c redis.PubSubConn, message string, expected interface{}) {
+	actual := c.Receive()
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("%s = %v, want %v", message, actual, expected)
+	}
+}
+
+func TestPushed(t *testing.T) {
+	pc, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer pc.Close()
+
+	nc, err := net.Dial("tcp", ":6379")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer nc.Close()
+	nc.SetReadDeadline(time.Now().Add(4 * time.Second))
+
+	c := redis.PubSubConn{Conn: redis.NewConn(nc, 0, 0)}
+
+	c.Subscribe("c1")
+	expectPushed(t, c, "Subscribe(c1)", redis.Subscription{Kind: "subscribe", Channel: "c1", Count: 1})
+	c.Subscribe("c2")
+	expectPushed(t, c, "Subscribe(c2)", redis.Subscription{Kind: "subscribe", Channel: "c2", Count: 2})
+	c.PSubscribe("p1")
+	expectPushed(t, c, "PSubscribe(p1)", redis.Subscription{Kind: "psubscribe", Channel: "p1", Count: 3})
+	c.PSubscribe("p2")
+	expectPushed(t, c, "PSubscribe(p2)", redis.Subscription{Kind: "psubscribe", Channel: "p2", Count: 4})
+	c.PUnsubscribe()
+	expectPushed(t, c, "Punsubscribe(p1)", redis.Subscription{Kind: "punsubscribe", Channel: "p1", Count: 3})
+	expectPushed(t, c, "Punsubscribe()", redis.Subscription{Kind: "punsubscribe", Channel: "p2", Count: 2})
+
+	pc.Do("PUBLISH", "c1", "hello")
+	expectPushed(t, c, "PUBLISH c1 hello", redis.Message{Channel: "c1", Data: []byte("hello")})
+}

redis/redis.go

@@ -0,0 +1,44 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+// Error represents an error returned in a command reply.
+type Error string
+
+func (err Error) Error() string { return string(err) }
+
+// Conn represents a connection to a Redis server.
+type Conn interface {
+	// Close closes the connection.
+	Close() error
+
+	// Err returns a non-nil value if the connection is broken. The returned
+	// value is either the first non-nil value returned from the underlying
+	// network connection or a protocol parsing error. Applications should
+	// close broken connections.
+	Err() error
+
+	// Do sends a command to the server and returns the received reply.
+	Do(commandName string, args ...interface{}) (reply interface{}, err error)
+
+	// Send writes the command to the client's output buffer.
+	Send(commandName string, args ...interface{}) error
+
+	// Flush flushes the output buffer to the Redis server.
+	Flush() error
+
+	// Receive receives a single reply from the Redis server
+	Receive() (reply interface{}, err error)
+}

redis/reply.go

@@ -0,0 +1,312 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+)
+
+// ErrNil indicates that a reply value is nil.
+var ErrNil = errors.New("redigo: nil returned")
+
+// Int is a helper that converts a command reply to an integer. If err is not
+// equal to nil, then Int returns 0, err. Otherwise, Int converts the
+// reply to an int as follows:
+//
+//  Reply type    Result
+//  integer       int(reply), nil
+//  bulk string   parsed reply, nil
+//  nil           0, ErrNil
+//  other         0, error
+func Int(reply interface{}, err error) (int, error) {
+	if err != nil {
+		return 0, err
+	}
+	switch reply := reply.(type) {
+	case int64:
+		x := int(reply)
+		if int64(x) != reply {
+			return 0, strconv.ErrRange
+		}
+		return x, nil
+	case []byte:
+		n, err := strconv.ParseInt(string(reply), 10, 0)
+		return int(n), err
+	case nil:
+		return 0, ErrNil
+	case Error:
+		return 0, reply
+	}
+	return 0, fmt.Errorf("redigo: unexpected type for Int, got type %T", reply)
+}
+
+// Int64 is a helper that converts a command reply to 64 bit integer. If err is
+// not equal to nil, then Int returns 0, err. Otherwise, Int64 converts the
+// reply to an int64 as follows:
+//
+//  Reply type    Result
+//  integer       reply, nil
+//  bulk string   parsed reply, nil
+//  nil           0, ErrNil
+//  other         0, error
+func Int64(reply interface{}, err error) (int64, error) {
+	if err != nil {
+		return 0, err
+	}
+	switch reply := reply.(type) {
+	case int64:
+		return reply, nil
+	case []byte:
+		n, err := strconv.ParseInt(string(reply), 10, 64)
+		return n, err
+	case nil:
+		return 0, ErrNil
+	case Error:
+		return 0, reply
+	}
+	return 0, fmt.Errorf("redigo: unexpected type for Int64, got type %T", reply)
+}
+
+var errNegativeInt = errors.New("redigo: unexpected value for Uint64")
+
+// Uint64 is a helper that converts a command reply to 64 bit integer. If err is
+// not equal to nil, then Int returns 0, err. Otherwise, Int64 converts the
+// reply to an int64 as follows:
+//
+//  Reply type    Result
+//  integer       reply, nil
+//  bulk string   parsed reply, nil
+//  nil           0, ErrNil
+//  other         0, error
+func Uint64(reply interface{}, err error) (uint64, error) {
+	if err != nil {
+		return 0, err
+	}
+	switch reply := reply.(type) {
+	case int64:
+		if reply < 0 {
+			return 0, errNegativeInt
+		}
+		return uint64(reply), nil
+	case []byte:
+		n, err := strconv.ParseUint(string(reply), 10, 64)
+		return n, err
+	case nil:
+		return 0, ErrNil
+	case Error:
+		return 0, reply
+	}
+	return 0, fmt.Errorf("redigo: unexpected type for Uint64, got type %T", reply)
+}
+
+// Float64 is a helper that converts a command reply to 64 bit float. If err is
+// not equal to nil, then Float64 returns 0, err. Otherwise, Float64 converts
+// the reply to an int as follows:
+//
+//  Reply type    Result
+//  bulk string   parsed reply, nil
+//  nil           0, ErrNil
+//  other         0, error
+func Float64(reply interface{}, err error) (float64, error) {
+	if err != nil {
+		return 0, err
+	}
+	switch reply := reply.(type) {
+	case []byte:
+		n, err := strconv.ParseFloat(string(reply), 64)
+		return n, err
+	case nil:
+		return 0, ErrNil
+	case Error:
+		return 0, reply
+	}
+	return 0, fmt.Errorf("redigo: unexpected type for Float64, got type %T", reply)
+}
+
+// String is a helper that converts a command reply to a string. If err is not
+// equal to nil, then String returns "", err. Otherwise String converts the
+// reply to a string as follows:
+//
+//  Reply type      Result
+//  bulk string     string(reply), nil
+//  simple string   reply, nil
+//  nil             "",  ErrNil
+//  other           "",  error
+func String(reply interface{}, err error) (string, error) {
+	if err != nil {
+		return "", err
+	}
+	switch reply := reply.(type) {
+	case []byte:
+		return string(reply), nil
+	case string:
+		return reply, nil
+	case nil:
+		return "", ErrNil
+	case Error:
+		return "", reply
+	}
+	return "", fmt.Errorf("redigo: unexpected type for String, got type %T", reply)
+}
+
+// Bytes is a helper that converts a command reply to a slice of bytes. If err
+// is not equal to nil, then Bytes returns nil, err. Otherwise Bytes converts
+// the reply to a slice of bytes as follows:
+//
+//  Reply type      Result
+//  bulk string     reply, nil
+//  simple string   []byte(reply), nil
+//  nil             nil, ErrNil
+//  other           nil, error
+func Bytes(reply interface{}, err error) ([]byte, error) {
+	if err != nil {
+		return nil, err
+	}
+	switch reply := reply.(type) {
+	case []byte:
+		return reply, nil
+	case string:
+		return []byte(reply), nil
+	case nil:
+		return nil, ErrNil
+	case Error:
+		return nil, reply
+	}
+	return nil, fmt.Errorf("redigo: unexpected type for Bytes, got type %T", reply)
+}
+
+// Bool is a helper that converts a command reply to a boolean. If err is not
+// equal to nil, then Bool returns false, err. Otherwise Bool converts the
+// reply to boolean as follows:
+//
+//  Reply type      Result
+//  integer         value != 0, nil
+//  bulk string     strconv.ParseBool(reply)
+//  nil             false, ErrNil
+//  other           false, error
+func Bool(reply interface{}, err error) (bool, error) {
+	if err != nil {
+		return false, err
+	}
+	switch reply := reply.(type) {
+	case int64:
+		return reply != 0, nil
+	case []byte:
+		return strconv.ParseBool(string(reply))
+	case nil:
+		return false, ErrNil
+	case Error:
+		return false, reply
+	}
+	return false, fmt.Errorf("redigo: unexpected type for Bool, got type %T", reply)
+}
+
+// MultiBulk is deprecated. Use Values.
+func MultiBulk(reply interface{}, err error) ([]interface{}, error) { return Values(reply, err) }
+
+// Values is a helper that converts an array command reply to a []interface{}.
+// If err is not equal to nil, then Values returns nil, err. Otherwise, Values
+// converts the reply as follows:
+//
+//  Reply type      Result
+//  array           reply, nil
+//  nil             nil, ErrNil
+//  other           nil, error
+func Values(reply interface{}, err error) ([]interface{}, error) {
+	if err != nil {
+		return nil, err
+	}
+	switch reply := reply.(type) {
+	case []interface{}:
+		return reply, nil
+	case nil:
+		return nil, ErrNil
+	case Error:
+		return nil, reply
+	}
+	return nil, fmt.Errorf("redigo: unexpected type for Values, got type %T", reply)
+}
+
+// Strings is a helper that converts an array command reply to a []string. If
+// err is not equal to nil, then Strings returns nil, err. Nil array items are
+// converted to "" in the output slice. Strings returns an error if an array
+// item is not a bulk string or nil.
+func Strings(reply interface{}, err error) ([]string, error) {
+	if err != nil {
+		return nil, err
+	}
+	switch reply := reply.(type) {
+	case []interface{}:
+		result := make([]string, len(reply))
+		for i := range reply {
+			if reply[i] == nil {
+				continue
+			}
+			p, ok := reply[i].([]byte)
+			if !ok {
+				return nil, fmt.Errorf("redigo: unexpected element type for Strings, got type %T", reply[i])
+			}
+			result[i] = string(p)
+		}
+		return result, nil
+	case nil:
+		return nil, ErrNil
+	case Error:
+		return nil, reply
+	}
+	return nil, fmt.Errorf("redigo: unexpected type for Strings, got type %T", reply)
+}
+
+// Ints is a helper that converts an array command reply to a []int. If
+// err is not equal to nil, then Ints returns nil, err.
+func Ints(reply interface{}, err error) ([]int, error) {
+	var ints []int
+	if reply == nil {
+		return ints, ErrNil
+	}
+	values, err := Values(reply, err)
+	if err != nil {
+		return ints, err
+	}
+	if err := ScanSlice(values, &ints); err != nil {
+		return ints, err
+	}
+	return ints, nil
+}
+
+// StringMap is a helper that converts an array of strings (alternating key, value)
+// into a map[string]string. The HGETALL and CONFIG GET commands return replies in this format.
+// Requires an even number of values in result.
+func StringMap(result interface{}, err error) (map[string]string, error) {
+	values, err := Values(result, err)
+	if err != nil {
+		return nil, err
+	}
+	if len(values)%2 != 0 {
+		return nil, errors.New("redigo: StringMap expects even number of values result")
+	}
+	m := make(map[string]string, len(values)/2)
+	for i := 0; i < len(values); i += 2 {
+		key, okKey := values[i].([]byte)
+		value, okValue := values[i+1].([]byte)
+		if !okKey || !okValue {
+			return nil, errors.New("redigo: ScanMap key not a bulk string value")
+		}
+		m[string(key)] = string(value)
+	}
+	return m, nil
+}

redis/reply_test.go

@@ -0,0 +1,166 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+)
+
+type valueError struct {
+	v   interface{}
+	err error
+}
+
+func ve(v interface{}, err error) valueError {
+	return valueError{v, err}
+}
+
+var replyTests = []struct {
+	name     interface{}
+	actual   valueError
+	expected valueError
+}{
+	{
+		"ints([v1, v2])",
+		ve(redis.Ints([]interface{}{[]byte("4"), []byte("5")}, nil)),
+		ve([]int{4, 5}, nil),
+	},
+	{
+		"ints(nil)",
+		ve(redis.Ints(nil, nil)),
+		ve([]int(nil), redis.ErrNil),
+	},
+	{
+		"strings([v1, v2])",
+		ve(redis.Strings([]interface{}{[]byte("v1"), []byte("v2")}, nil)),
+		ve([]string{"v1", "v2"}, nil),
+	},
+	{
+		"strings(nil)",
+		ve(redis.Strings(nil, nil)),
+		ve([]string(nil), redis.ErrNil),
+	},
+	{
+		"values([v1, v2])",
+		ve(redis.Values([]interface{}{[]byte("v1"), []byte("v2")}, nil)),
+		ve([]interface{}{[]byte("v1"), []byte("v2")}, nil),
+	},
+	{
+		"values(nil)",
+		ve(redis.Values(nil, nil)),
+		ve([]interface{}(nil), redis.ErrNil),
+	},
+	{
+		"float64(1.0)",
+		ve(redis.Float64([]byte("1.0"), nil)),
+		ve(float64(1.0), nil),
+	},
+	{
+		"float64(nil)",
+		ve(redis.Float64(nil, nil)),
+		ve(float64(0.0), redis.ErrNil),
+	},
+	{
+		"uint64(1)",
+		ve(redis.Uint64(int64(1), nil)),
+		ve(uint64(1), nil),
+	},
+	{
+		"uint64(-1)",
+		ve(redis.Uint64(int64(-1), nil)),
+		ve(uint64(0), redis.ErrNegativeInt),
+	},
+}
+
+func TestReply(t *testing.T) {
+	for _, rt := range replyTests {
+		if rt.actual.err != rt.expected.err {
+			t.Errorf("%s returned err %v, want %v", rt.name, rt.actual.err, rt.expected.err)
+			continue
+		}
+		if !reflect.DeepEqual(rt.actual.v, rt.expected.v) {
+			t.Errorf("%s=%+v, want %+v", rt.name, rt.actual.v, rt.expected.v)
+		}
+	}
+}
+
+// dial wraps DialTestDB() with a more suitable function name for examples.
+func dial() (redis.Conn, error) {
+	return redistest.Dial()
+}
+
+func ExampleBool() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Do("SET", "foo", 1)
+	exists, _ := redis.Bool(c.Do("EXISTS", "foo"))
+	fmt.Printf("%#v\n", exists)
+	// Output:
+	// true
+}
+
+func ExampleInt() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Do("SET", "k1", 1)
+	n, _ := redis.Int(c.Do("GET", "k1"))
+	fmt.Printf("%#v\n", n)
+	n, _ = redis.Int(c.Do("INCR", "k1"))
+	fmt.Printf("%#v\n", n)
+	// Output:
+	// 1
+	// 2
+}
+
+func ExampleInts() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Do("SADD", "set_with_integers", 4, 5, 6)
+	ints, _ := redis.Ints(c.Do("SMEMBERS", "set_with_integers"))
+	fmt.Printf("%#v\n", ints)
+	// Output:
+	// []int{4, 5, 6}
+}
+
+func ExampleString() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Do("SET", "hello", "world")
+	s, err := redis.String(c.Do("GET", "hello"))
+	fmt.Printf("%#v\n", s)
+	// Output:
+	// "world"
+}

redis/scan.go

@@ -0,0 +1,513 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+func ensureLen(d reflect.Value, n int) {
+	if n > d.Cap() {
+		d.Set(reflect.MakeSlice(d.Type(), n, n))
+	} else {
+		d.SetLen(n)
+	}
+}
+
+func cannotConvert(d reflect.Value, s interface{}) error {
+	return fmt.Errorf("redigo: Scan cannot convert from %s to %s",
+		reflect.TypeOf(s), d.Type())
+}
+
+func convertAssignBytes(d reflect.Value, s []byte) (err error) {
+	switch d.Type().Kind() {
+	case reflect.Float32, reflect.Float64:
+		var x float64
+		x, err = strconv.ParseFloat(string(s), d.Type().Bits())
+		d.SetFloat(x)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		var x int64
+		x, err = strconv.ParseInt(string(s), 10, d.Type().Bits())
+		d.SetInt(x)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		var x uint64
+		x, err = strconv.ParseUint(string(s), 10, d.Type().Bits())
+		d.SetUint(x)
+	case reflect.Bool:
+		var x bool
+		x, err = strconv.ParseBool(string(s))
+		d.SetBool(x)
+	case reflect.String:
+		d.SetString(string(s))
+	case reflect.Slice:
+		if d.Type().Elem().Kind() != reflect.Uint8 {
+			err = cannotConvert(d, s)
+		} else {
+			d.SetBytes(s)
+		}
+	default:
+		err = cannotConvert(d, s)
+	}
+	return
+}
+
+func convertAssignInt(d reflect.Value, s int64) (err error) {
+	switch d.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		d.SetInt(s)
+		if d.Int() != s {
+			err = strconv.ErrRange
+			d.SetInt(0)
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		if s < 0 {
+			err = strconv.ErrRange
+		} else {
+			x := uint64(s)
+			d.SetUint(x)
+			if d.Uint() != x {
+				err = strconv.ErrRange
+				d.SetUint(0)
+			}
+		}
+	case reflect.Bool:
+		d.SetBool(s != 0)
+	default:
+		err = cannotConvert(d, s)
+	}
+	return
+}
+
+func convertAssignValue(d reflect.Value, s interface{}) (err error) {
+	switch s := s.(type) {
+	case []byte:
+		err = convertAssignBytes(d, s)
+	case int64:
+		err = convertAssignInt(d, s)
+	default:
+		err = cannotConvert(d, s)
+	}
+	return err
+}
+
+func convertAssignValues(d reflect.Value, s []interface{}) error {
+	if d.Type().Kind() != reflect.Slice {
+		return cannotConvert(d, s)
+	}
+	ensureLen(d, len(s))
+	for i := 0; i < len(s); i++ {
+		if err := convertAssignValue(d.Index(i), s[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func convertAssign(d interface{}, s interface{}) (err error) {
+	// Handle the most common destination types using type switches and
+	// fall back to reflection for all other types.
+	switch s := s.(type) {
+	case nil:
+		// ingore
+	case []byte:
+		switch d := d.(type) {
+		case *string:
+			*d = string(s)
+		case *int:
+			*d, err = strconv.Atoi(string(s))
+		case *bool:
+			*d, err = strconv.ParseBool(string(s))
+		case *[]byte:
+			*d = s
+		case *interface{}:
+			*d = s
+		case nil:
+			// skip value
+		default:
+			if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
+				err = cannotConvert(d, s)
+			} else {
+				err = convertAssignBytes(d.Elem(), s)
+			}
+		}
+	case int64:
+		switch d := d.(type) {
+		case *int:
+			x := int(s)
+			if int64(x) != s {
+				err = strconv.ErrRange
+				x = 0
+			}
+			*d = x
+		case *bool:
+			*d = s != 0
+		case *interface{}:
+			*d = s
+		case nil:
+			// skip value
+		default:
+			if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
+				err = cannotConvert(d, s)
+			} else {
+				err = convertAssignInt(d.Elem(), s)
+			}
+		}
+	case []interface{}:
+		switch d := d.(type) {
+		case *[]interface{}:
+			*d = s
+		case *interface{}:
+			*d = s
+		case nil:
+			// skip value
+		default:
+			if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
+				err = cannotConvert(d, s)
+			} else {
+				err = convertAssignValues(d.Elem(), s)
+			}
+		}
+	case Error:
+		err = s
+	default:
+		err = cannotConvert(reflect.ValueOf(d), s)
+	}
+	return
+}
+
+// Scan copies from src to the values pointed at by dest.
+//
+// The values pointed at by dest must be an integer, float, boolean, string,
+// []byte, interface{} or slices of these types. Scan uses the standard strconv
+// package to convert bulk strings to numeric and boolean types.
+//
+// If a dest value is nil, then the corresponding src value is skipped.
+//
+// If a src element is nil, then the corresponding dest value is not modified.
+//
+// To enable easy use of Scan in a loop, Scan returns the slice of src
+// following the copied values.
+func Scan(src []interface{}, dest ...interface{}) ([]interface{}, error) {
+	if len(src) < len(dest) {
+		return nil, errors.New("redigo: Scan array short")
+	}
+	var err error
+	for i, d := range dest {
+		err = convertAssign(d, src[i])
+		if err != nil {
+			break
+		}
+	}
+	return src[len(dest):], err
+}
+
+type fieldSpec struct {
+	name  string
+	index []int
+	//omitEmpty bool
+}
+
+type structSpec struct {
+	m map[string]*fieldSpec
+	l []*fieldSpec
+}
+
+func (ss *structSpec) fieldSpec(name []byte) *fieldSpec {
+	return ss.m[string(name)]
+}
+
+func compileStructSpec(t reflect.Type, depth map[string]int, index []int, ss *structSpec) {
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		switch {
+		case f.PkgPath != "":
+			// Ignore unexported fields.
+		case f.Anonymous:
+			// TODO: Handle pointers. Requires change to decoder and
+			// protection against infinite recursion.
+			if f.Type.Kind() == reflect.Struct {
+				compileStructSpec(f.Type, depth, append(index, i), ss)
+			}
+		default:
+			fs := &fieldSpec{name: f.Name}
+			tag := f.Tag.Get("redis")
+			p := strings.Split(tag, ",")
+			if len(p) > 0 {
+				if p[0] == "-" {
+					continue
+				}
+				if len(p[0]) > 0 {
+					fs.name = p[0]
+				}
+				for _, s := range p[1:] {
+					switch s {
+					//case "omitempty":
+					//  fs.omitempty = true
+					default:
+						panic(errors.New("redigo: unknown field flag " + s + " for type " + t.Name()))
+					}
+				}
+			}
+			d, found := depth[fs.name]
+			if !found {
+				d = 1 << 30
+			}
+			switch {
+			case len(index) == d:
+				// At same depth, remove from result.
+				delete(ss.m, fs.name)
+				j := 0
+				for i := 0; i < len(ss.l); i++ {
+					if fs.name != ss.l[i].name {
+						ss.l[j] = ss.l[i]
+						j += 1
+					}
+				}
+				ss.l = ss.l[:j]
+			case len(index) < d:
+				fs.index = make([]int, len(index)+1)
+				copy(fs.index, index)
+				fs.index[len(index)] = i
+				depth[fs.name] = len(index)
+				ss.m[fs.name] = fs
+				ss.l = append(ss.l, fs)
+			}
+		}
+	}
+}
+
+var (
+	structSpecMutex  sync.RWMutex
+	structSpecCache  = make(map[reflect.Type]*structSpec)
+	defaultFieldSpec = &fieldSpec{}
+)
+
+func structSpecForType(t reflect.Type) *structSpec {
+
+	structSpecMutex.RLock()
+	ss, found := structSpecCache[t]
+	structSpecMutex.RUnlock()
+	if found {
+		return ss
+	}
+
+	structSpecMutex.Lock()
+	defer structSpecMutex.Unlock()
+	ss, found = structSpecCache[t]
+	if found {
+		return ss
+	}
+
+	ss = &structSpec{m: make(map[string]*fieldSpec)}
+	compileStructSpec(t, make(map[string]int), nil, ss)
+	structSpecCache[t] = ss
+	return ss
+}
+
+var errScanStructValue = errors.New("redigo: ScanStruct value must be non-nil pointer to a struct")
+
+// ScanStruct scans alternating names and values from src to a struct. The
+// HGETALL and CONFIG GET commands return replies in this format.
+//
+// ScanStruct uses exported field names to match values in the response. Use
+// 'redis' field tag to override the name:
+//
+//      Field int `redis:"myName"`
+//
+// Fields with the tag redis:"-" are ignored.
+//
+// Integer, float, boolean, string and []byte fields are supported. Scan uses the
+// standard strconv package to convert bulk string values to numeric and
+// boolean types.
+//
+// If a src element is nil, then the corresponding field is not modified.
+func ScanStruct(src []interface{}, dest interface{}) error {
+	d := reflect.ValueOf(dest)
+	if d.Kind() != reflect.Ptr || d.IsNil() {
+		return errScanStructValue
+	}
+	d = d.Elem()
+	if d.Kind() != reflect.Struct {
+		return errScanStructValue
+	}
+	ss := structSpecForType(d.Type())
+
+	if len(src)%2 != 0 {
+		return errors.New("redigo: ScanStruct expects even number of values in values")
+	}
+
+	for i := 0; i < len(src); i += 2 {
+		s := src[i+1]
+		if s == nil {
+			continue
+		}
+		name, ok := src[i].([]byte)
+		if !ok {
+			return errors.New("redigo: ScanStruct key not a bulk string value")
+		}
+		fs := ss.fieldSpec(name)
+		if fs == nil {
+			continue
+		}
+		if err := convertAssignValue(d.FieldByIndex(fs.index), s); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+var (
+	errScanSliceValue = errors.New("redigo: ScanSlice dest must be non-nil pointer to a struct")
+)
+
+// ScanSlice scans src to the slice pointed to by dest. The elements the dest
+// slice must be integer, float, boolean, string, struct or pointer to struct
+// values.
+//
+// Struct fields must be integer, float, boolean or string values. All struct
+// fields are used unless a subset is specified using fieldNames.
+func ScanSlice(src []interface{}, dest interface{}, fieldNames ...string) error {
+	d := reflect.ValueOf(dest)
+	if d.Kind() != reflect.Ptr || d.IsNil() {
+		return errScanSliceValue
+	}
+	d = d.Elem()
+	if d.Kind() != reflect.Slice {
+		return errScanSliceValue
+	}
+
+	isPtr := false
+	t := d.Type().Elem()
+	if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
+		isPtr = true
+		t = t.Elem()
+	}
+
+	if t.Kind() != reflect.Struct {
+		ensureLen(d, len(src))
+		for i, s := range src {
+			if s == nil {
+				continue
+			}
+			if err := convertAssignValue(d.Index(i), s); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	ss := structSpecForType(t)
+	fss := ss.l
+	if len(fieldNames) > 0 {
+		fss = make([]*fieldSpec, len(fieldNames))
+		for i, name := range fieldNames {
+			fss[i] = ss.m[name]
+			if fss[i] == nil {
+				return errors.New("redigo: ScanSlice bad field name " + name)
+			}
+		}
+	}
+
+	if len(fss) == 0 {
+		return errors.New("redigo: ScanSlice no struct fields")
+	}
+
+	n := len(src) / len(fss)
+	if n*len(fss) != len(src) {
+		return errors.New("redigo: ScanSlice length not a multiple of struct field count")
+	}
+
+	ensureLen(d, n)
+	for i := 0; i < n; i++ {
+		d := d.Index(i)
+		if isPtr {
+			if d.IsNil() {
+				d.Set(reflect.New(t))
+			}
+			d = d.Elem()
+		}
+		for j, fs := range fss {
+			s := src[i*len(fss)+j]
+			if s == nil {
+				continue
+			}
+			if err := convertAssignValue(d.FieldByIndex(fs.index), s); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// Args is a helper for constructing command arguments from structured values.
+type Args []interface{}
+
+// Add returns the result of appending value to args.
+func (args Args) Add(value ...interface{}) Args {
+	return append(args, value...)
+}
+
+// AddFlat returns the result of appending the flattened value of v to args.
+//
+// Maps are flattened by appending the alternating keys and map values to args.
+//
+// Slices are flattened by appending the slice elements to args.
+//
+// Structs are flattened by appending the alternating names and values of
+// exported fields to args. If v is a nil struct pointer, then nothing is
+// appended. The 'redis' field tag overrides struct field names. See ScanStruct
+// for more information on the use of the 'redis' field tag.
+//
+// Other types are appended to args as is.
+func (args Args) AddFlat(v interface{}) Args {
+	rv := reflect.ValueOf(v)
+	switch rv.Kind() {
+	case reflect.Struct:
+		args = flattenStruct(args, rv)
+	case reflect.Slice:
+		for i := 0; i < rv.Len(); i++ {
+			args = append(args, rv.Index(i).Interface())
+		}
+	case reflect.Map:
+		for _, k := range rv.MapKeys() {
+			args = append(args, k.Interface(), rv.MapIndex(k).Interface())
+		}
+	case reflect.Ptr:
+		if rv.Type().Elem().Kind() == reflect.Struct {
+			if !rv.IsNil() {
+				args = flattenStruct(args, rv.Elem())
+			}
+		} else {
+			args = append(args, v)
+		}
+	default:
+		args = append(args, v)
+	}
+	return args
+}
+
+func flattenStruct(args Args, v reflect.Value) Args {
+	ss := structSpecForType(v.Type())
+	for _, fs := range ss.l {
+		fv := v.FieldByIndex(fs.index)
+		args = append(args, fs.name, fv.Interface())
+	}
+	return args
+}

redis/scan_test.go

@@ -0,0 +1,412 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"fmt"
+	"github.com/garyburd/redigo/redis"
+	"math"
+	"reflect"
+	"testing"
+)
+
+var scanConversionTests = []struct {
+	src  interface{}
+	dest interface{}
+}{
+	{[]byte("-inf"), math.Inf(-1)},
+	{[]byte("+inf"), math.Inf(1)},
+	{[]byte("0"), float64(0)},
+	{[]byte("3.14159"), float64(3.14159)},
+	{[]byte("3.14"), float32(3.14)},
+	{[]byte("-100"), int(-100)},
+	{[]byte("101"), int(101)},
+	{int64(102), int(102)},
+	{[]byte("103"), uint(103)},
+	{int64(104), uint(104)},
+	{[]byte("105"), int8(105)},
+	{int64(106), int8(106)},
+	{[]byte("107"), uint8(107)},
+	{int64(108), uint8(108)},
+	{[]byte("0"), false},
+	{int64(0), false},
+	{[]byte("f"), false},
+	{[]byte("1"), true},
+	{int64(1), true},
+	{[]byte("t"), true},
+	{[]byte("hello"), "hello"},
+	{[]byte("world"), []byte("world")},
+	{[]interface{}{[]byte("foo")}, []interface{}{[]byte("foo")}},
+	{[]interface{}{[]byte("foo")}, []string{"foo"}},
+	{[]interface{}{[]byte("hello"), []byte("world")}, []string{"hello", "world"}},
+	{[]interface{}{[]byte("bar")}, [][]byte{[]byte("bar")}},
+	{[]interface{}{[]byte("1")}, []int{1}},
+	{[]interface{}{[]byte("1"), []byte("2")}, []int{1, 2}},
+	{[]interface{}{[]byte("1"), []byte("2")}, []float64{1, 2}},
+	{[]interface{}{[]byte("1")}, []byte{1}},
+	{[]interface{}{[]byte("1")}, []bool{true}},
+}
+
+func TestScanConversion(t *testing.T) {
+	for _, tt := range scanConversionTests {
+		values := []interface{}{tt.src}
+		dest := reflect.New(reflect.TypeOf(tt.dest))
+		values, err := redis.Scan(values, dest.Interface())
+		if err != nil {
+			t.Errorf("Scan(%v) returned error %v", tt, err)
+			continue
+		}
+		if !reflect.DeepEqual(tt.dest, dest.Elem().Interface()) {
+			t.Errorf("Scan(%v) returned %v, want %v", tt, dest.Elem().Interface(), tt.dest)
+		}
+	}
+}
+
+var scanConversionErrorTests = []struct {
+	src  interface{}
+	dest interface{}
+}{
+	{[]byte("1234"), byte(0)},
+	{int64(1234), byte(0)},
+	{[]byte("-1"), byte(0)},
+	{int64(-1), byte(0)},
+	{[]byte("junk"), false},
+	{redis.Error("blah"), false},
+}
+
+func TestScanConversionError(t *testing.T) {
+	for _, tt := range scanConversionErrorTests {
+		values := []interface{}{tt.src}
+		dest := reflect.New(reflect.TypeOf(tt.dest))
+		values, err := redis.Scan(values, dest.Interface())
+		if err == nil {
+			t.Errorf("Scan(%v) did not return error", tt)
+		}
+	}
+}
+
+func ExampleScan() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Send("HMSET", "album:1", "title", "Red", "rating", 5)
+	c.Send("HMSET", "album:2", "title", "Earthbound", "rating", 1)
+	c.Send("HMSET", "album:3", "title", "Beat")
+	c.Send("LPUSH", "albums", "1")
+	c.Send("LPUSH", "albums", "2")
+	c.Send("LPUSH", "albums", "3")
+	values, err := redis.Values(c.Do("SORT", "albums",
+		"BY", "album:*->rating",
+		"GET", "album:*->title",
+		"GET", "album:*->rating"))
+	if err != nil {
+		panic(err)
+	}
+
+	for len(values) > 0 {
+		var title string
+		rating := -1 // initialize to illegal value to detect nil.
+		values, err = redis.Scan(values, &title, &rating)
+		if err != nil {
+			panic(err)
+		}
+		if rating == -1 {
+			fmt.Println(title, "not-rated")
+		} else {
+			fmt.Println(title, rating)
+		}
+	}
+	// Output:
+	// Beat not-rated
+	// Earthbound 1
+	// Red 5
+}
+
+type s0 struct {
+	X  int
+	Y  int `redis:"y"`
+	Bt bool
+}
+
+type s1 struct {
+	X  int    `redis:"-"`
+	I  int    `redis:"i"`
+	U  uint   `redis:"u"`
+	S  string `redis:"s"`
+	P  []byte `redis:"p"`
+	B  bool   `redis:"b"`
+	Bt bool
+	Bf bool
+	s0
+}
+
+var scanStructTests = []struct {
+	title string
+	reply []string
+	value interface{}
+}{
+	{"basic",
+		[]string{"i", "-1234", "u", "5678", "s", "hello", "p", "world", "b", "t", "Bt", "1", "Bf", "0", "X", "123", "y", "456"},
+		&s1{I: -1234, U: 5678, S: "hello", P: []byte("world"), B: true, Bt: true, Bf: false, s0: s0{X: 123, Y: 456}},
+	},
+}
+
+func TestScanStruct(t *testing.T) {
+	for _, tt := range scanStructTests {
+
+		var reply []interface{}
+		for _, v := range tt.reply {
+			reply = append(reply, []byte(v))
+		}
+
+		value := reflect.New(reflect.ValueOf(tt.value).Type().Elem())
+
+		if err := redis.ScanStruct(reply, value.Interface()); err != nil {
+			t.Fatalf("ScanStruct(%s) returned error %v", tt.title, err)
+		}
+
+		if !reflect.DeepEqual(value.Interface(), tt.value) {
+			t.Fatalf("ScanStruct(%s) returned %v, want %v", tt.title, value.Interface(), tt.value)
+		}
+	}
+}
+
+func TestBadScanStructArgs(t *testing.T) {
+	x := []interface{}{"A", "b"}
+	test := func(v interface{}) {
+		if err := redis.ScanStruct(x, v); err == nil {
+			t.Errorf("Expect error for ScanStruct(%T, %T)", x, v)
+		}
+	}
+
+	test(nil)
+
+	var v0 *struct{}
+	test(v0)
+
+	var v1 int
+	test(&v1)
+
+	x = x[:1]
+	v2 := struct{ A string }{}
+	test(&v2)
+}
+
+var scanSliceTests = []struct {
+	src        []interface{}
+	fieldNames []string
+	ok         bool
+	dest       interface{}
+}{
+	{
+		[]interface{}{[]byte("1"), nil, []byte("-1")},
+		nil,
+		true,
+		[]int{1, 0, -1},
+	},
+	{
+		[]interface{}{[]byte("1"), nil, []byte("2")},
+		nil,
+		true,
+		[]uint{1, 0, 2},
+	},
+	{
+		[]interface{}{[]byte("-1")},
+		nil,
+		false,
+		[]uint{1},
+	},
+	{
+		[]interface{}{[]byte("hello"), nil, []byte("world")},
+		nil,
+		true,
+		[][]byte{[]byte("hello"), nil, []byte("world")},
+	},
+	{
+		[]interface{}{[]byte("hello"), nil, []byte("world")},
+		nil,
+		true,
+		[]string{"hello", "", "world"},
+	},
+	{
+		[]interface{}{[]byte("a1"), []byte("b1"), []byte("a2"), []byte("b2")},
+		nil,
+		true,
+		[]struct{ A, B string }{{"a1", "b1"}, {"a2", "b2"}},
+	},
+	{
+		[]interface{}{[]byte("a1"), []byte("b1")},
+		nil,
+		false,
+		[]struct{ A, B, C string }{{"a1", "b1", ""}},
+	},
+	{
+		[]interface{}{[]byte("a1"), []byte("b1"), []byte("a2"), []byte("b2")},
+		nil,
+		true,
+		[]*struct{ A, B string }{{"a1", "b1"}, {"a2", "b2"}},
+	},
+	{
+		[]interface{}{[]byte("a1"), []byte("b1"), []byte("a2"), []byte("b2")},
+		[]string{"A", "B"},
+		true,
+		[]struct{ A, C, B string }{{"a1", "", "b1"}, {"a2", "", "b2"}},
+	},
+	{
+		[]interface{}{[]byte("a1"), []byte("b1"), []byte("a2"), []byte("b2")},
+		nil,
+		false,
+		[]struct{}{},
+	},
+}
+
+func TestScanSlice(t *testing.T) {
+	for _, tt := range scanSliceTests {
+
+		typ := reflect.ValueOf(tt.dest).Type()
+		dest := reflect.New(typ)
+
+		err := redis.ScanSlice(tt.src, dest.Interface(), tt.fieldNames...)
+		if tt.ok != (err == nil) {
+			t.Errorf("ScanSlice(%v, []%s, %v) returned error %v", tt.src, typ, tt.fieldNames, err)
+			continue
+		}
+		if tt.ok && !reflect.DeepEqual(dest.Elem().Interface(), tt.dest) {
+			t.Errorf("ScanSlice(src, []%s) returned %#v, want %#v", typ, dest.Elem().Interface(), tt.dest)
+		}
+	}
+}
+
+func ExampleScanSlice() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	c.Send("HMSET", "album:1", "title", "Red", "rating", 5)
+	c.Send("HMSET", "album:2", "title", "Earthbound", "rating", 1)
+	c.Send("HMSET", "album:3", "title", "Beat", "rating", 4)
+	c.Send("LPUSH", "albums", "1")
+	c.Send("LPUSH", "albums", "2")
+	c.Send("LPUSH", "albums", "3")
+	values, err := redis.Values(c.Do("SORT", "albums",
+		"BY", "album:*->rating",
+		"GET", "album:*->title",
+		"GET", "album:*->rating"))
+	if err != nil {
+		panic(err)
+	}
+
+	var albums []struct {
+		Title  string
+		Rating int
+	}
+	if err := redis.ScanSlice(values, &albums); err != nil {
+		panic(err)
+	}
+	fmt.Printf("%v\n", albums)
+	// Output:
+	// [{Earthbound 1} {Beat 4} {Red 5}]
+}
+
+var argsTests = []struct {
+	title    string
+	actual   redis.Args
+	expected redis.Args
+}{
+	{"struct ptr",
+		redis.Args{}.AddFlat(&struct {
+			I  int    `redis:"i"`
+			U  uint   `redis:"u"`
+			S  string `redis:"s"`
+			P  []byte `redis:"p"`
+			Bt bool
+			Bf bool
+		}{
+			-1234, 5678, "hello", []byte("world"), true, false,
+		}),
+		redis.Args{"i", int(-1234), "u", uint(5678), "s", "hello", "p", []byte("world"), "Bt", true, "Bf", false},
+	},
+	{"struct",
+		redis.Args{}.AddFlat(struct{ I int }{123}),
+		redis.Args{"I", 123},
+	},
+	{"slice",
+		redis.Args{}.Add(1).AddFlat([]string{"a", "b", "c"}).Add(2),
+		redis.Args{1, "a", "b", "c", 2},
+	},
+}
+
+func TestArgs(t *testing.T) {
+	for _, tt := range argsTests {
+		if !reflect.DeepEqual(tt.actual, tt.expected) {
+			t.Fatalf("%s is %v, want %v", tt.title, tt.actual, tt.expected)
+		}
+	}
+}
+
+func ExampleArgs() {
+	c, err := dial()
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	var p1, p2 struct {
+		Title  string `redis:"title"`
+		Author string `redis:"author"`
+		Body   string `redis:"body"`
+	}
+
+	p1.Title = "Example"
+	p1.Author = "Gary"
+	p1.Body = "Hello"
+
+	if _, err := c.Do("HMSET", redis.Args{}.Add("id1").AddFlat(&p1)...); err != nil {
+		panic(err)
+	}
+
+	m := map[string]string{
+		"title":  "Example2",
+		"author": "Steve",
+		"body":   "Map",
+	}
+
+	if _, err := c.Do("HMSET", redis.Args{}.Add("id2").AddFlat(m)...); err != nil {
+		panic(err)
+	}
+
+	for _, id := range []string{"id1", "id2"} {
+
+		v, err := redis.Values(c.Do("HGETALL", id))
+		if err != nil {
+			panic(err)
+		}
+
+		if err := redis.ScanStruct(v, &p2); err != nil {
+			panic(err)
+		}
+
+		fmt.Printf("%+v\n", p2)
+	}
+
+	// Output:
+	// {Title:Example Author:Gary Body:Hello}
+	// {Title:Example2 Author:Steve Body:Map}
+}

redis/script.go

@@ -0,0 +1,86 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"io"
+	"strings"
+)
+
+// Script encapsulates the source, hash and key count for a Lua script. See
+// http://redis.io/commands/eval for information on scripts in Redis.
+type Script struct {
+	keyCount int
+	src      string
+	hash     string
+}
+
+// NewScript returns a new script object. If keyCount is greater than or equal
+// to zero, then the count is automatically inserted in the EVAL command
+// argument list. If keyCount is less than zero, then the application supplies
+// the count as the first value in the keysAndArgs argument to the Do, Send and
+// SendHash methods.
+func NewScript(keyCount int, src string) *Script {
+	h := sha1.New()
+	io.WriteString(h, src)
+	return &Script{keyCount, src, hex.EncodeToString(h.Sum(nil))}
+}
+
+func (s *Script) args(spec string, keysAndArgs []interface{}) []interface{} {
+	var args []interface{}
+	if s.keyCount < 0 {
+		args = make([]interface{}, 1+len(keysAndArgs))
+		args[0] = spec
+		copy(args[1:], keysAndArgs)
+	} else {
+		args = make([]interface{}, 2+len(keysAndArgs))
+		args[0] = spec
+		args[1] = s.keyCount
+		copy(args[2:], keysAndArgs)
+	}
+	return args
+}
+
+// Do evaluates the script. Under the covers, Do optimistically evaluates the
+// script using the EVALSHA command. If the command fails because the script is
+// not loaded, then Do evaluates the script using the EVAL command (thus
+// causing the script to load).
+func (s *Script) Do(c Conn, keysAndArgs ...interface{}) (interface{}, error) {
+	v, err := c.Do("EVALSHA", s.args(s.hash, keysAndArgs)...)
+	if e, ok := err.(Error); ok && strings.HasPrefix(string(e), "NOSCRIPT ") {
+		v, err = c.Do("EVAL", s.args(s.src, keysAndArgs)...)
+	}
+	return v, err
+}
+
+// SendHash evaluates the script without waiting for the reply. The script is
+// evaluated with the EVALSHA command. The application must ensure that the
+// script is loaded by a previous call to Send, Do or Load methods.
+func (s *Script) SendHash(c Conn, keysAndArgs ...interface{}) error {
+	return c.Send("EVALSHA", s.args(s.hash, keysAndArgs)...)
+}
+
+// Send evaluates the script without waiting for the reply.
+func (s *Script) Send(c Conn, keysAndArgs ...interface{}) error {
+	return c.Send("EVAL", s.args(s.src, keysAndArgs)...)
+}
+
+// Load loads the script without evaluating it.
+func (s *Script) Load(c Conn) error {
+	_, err := c.Do("SCRIPT", "LOAD", s.src)
+	return err
+}

redis/script_test.go

@@ -0,0 +1,93 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+)
+
+func ExampleScript(c redis.Conn, reply interface{}, err error) {
+	// Initialize a package-level variable with a script.
+	var getScript = redis.NewScript(1, `return redis.call('get', KEYS[1])`)
+
+	// In a function, use the script Do method to evaluate the script. The Do
+	// method optimistically uses the EVALSHA command. If the script is not
+	// loaded, then the Do method falls back to the EVAL command.
+	reply, err = getScript.Do(c, "foo")
+}
+
+func TestScript(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	// To test fall back in Do, we make script unique by adding comment with current time.
+	script := fmt.Sprintf("--%d\nreturn {KEYS[1],KEYS[2],ARGV[1],ARGV[2]}", time.Now().UnixNano())
+	s := redis.NewScript(2, script)
+	reply := []interface{}{[]byte("key1"), []byte("key2"), []byte("arg1"), []byte("arg2")}
+
+	v, err := s.Do(c, "key1", "key2", "arg1", "arg2")
+	if err != nil {
+		t.Errorf("s.Do(c, ...) returned %v", err)
+	}
+
+	if !reflect.DeepEqual(v, reply) {
+		t.Errorf("s.Do(c, ..); = %v, want %v", v, reply)
+	}
+
+	err = s.Load(c)
+	if err != nil {
+		t.Errorf("s.Load(c) returned %v", err)
+	}
+
+	err = s.SendHash(c, "key1", "key2", "arg1", "arg2")
+	if err != nil {
+		t.Errorf("s.SendHash(c, ...) returned %v", err)
+	}
+
+	err = c.Flush()
+	if err != nil {
+		t.Errorf("c.Flush() returned %v", err)
+	}
+
+	v, err = c.Receive()
+	if !reflect.DeepEqual(v, reply) {
+		t.Errorf("s.SendHash(c, ..); c.Receive() = %v, want %v", v, reply)
+	}
+
+	err = s.Send(c, "key1", "key2", "arg1", "arg2")
+	if err != nil {
+		t.Errorf("s.Send(c, ...) returned %v", err)
+	}
+
+	err = c.Flush()
+	if err != nil {
+		t.Errorf("c.Flush() returned %v", err)
+	}
+
+	v, err = c.Receive()
+	if !reflect.DeepEqual(v, reply) {
+		t.Errorf("s.Send(c, ..); c.Receive() = %v, want %v", v, reply)
+	}
+
+}

redis/test_test.go

@@ -0,0 +1,38 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis
+
+import (
+	"bufio"
+	"net"
+	"time"
+)
+
+func SetNowFunc(f func() time.Time) {
+	nowFunc = f
+}
+
+type nopCloser struct{ net.Conn }
+
+func (nopCloser) Close() error { return nil }
+
+// NewConnBufio is a hook for tests.
+func NewConnBufio(rw bufio.ReadWriter) Conn {
+	return &conn{br: rw.Reader, bw: rw.Writer, conn: nopCloser{}}
+}
+
+var (
+	ErrNegativeInt = errNegativeInt
+)

redis/zpop_example_test.go

@@ -0,0 +1,113 @@
+// Copyright 2013 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redis_test
+
+import (
+	"fmt"
+	"github.com/garyburd/redigo/redis"
+)
+
+// zpop pops a value from the ZSET key using WATCH/MULTI/EXEC commands.
+func zpop(c redis.Conn, key string) (result string, err error) {
+
+	defer func() {
+		// Return connection to normal state on error.
+		if err != nil {
+			c.Do("DISCARD")
+		}
+	}()
+
+	// Loop until transaction is successful.
+	for {
+		if _, err := c.Do("WATCH", key); err != nil {
+			return "", err
+		}
+
+		members, err := redis.Strings(c.Do("ZRANGE", key, 0, 0))
+		if err != nil {
+			return "", err
+		}
+		if len(members) != 1 {
+			return "", redis.ErrNil
+		}
+
+		c.Send("MULTI")
+		c.Send("ZREM", key, members[0])
+		queued, err := c.Do("EXEC")
+		if err != nil {
+			return "", err
+		}
+
+		if queued != nil {
+			result = members[0]
+			break
+		}
+	}
+
+	return result, nil
+}
+
+// zpopScript pops a value from a ZSET.
+var zpopScript = redis.NewScript(1, `
+    local r = redis.call('ZRANGE', KEYS[1], 0, 0)
+    if r ~= nil then
+        r = r[1]
+        redis.call('ZREM', KEYS[1], r)
+    end
+    return r
+`)
+
+// This example implements ZPOP as described at
+// http://redis.io/topics/transactions using WATCH/MULTI/EXEC and scripting.
+func Example_zpop() {
+	c, err := dial()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	defer c.Close()
+
+	// Add test data using a pipeline.
+
+	for i, member := range []string{"red", "blue", "green"} {
+		c.Send("ZADD", "zset", i, member)
+	}
+	if _, err := c.Do(""); err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	// Pop using WATCH/MULTI/EXEC
+
+	v, err := zpop(c, "zset")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println(v)
+
+	// Pop using a script.
+
+	v, err = redis.String(zpopScript.Do(c, "zset"))
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println(v)
+
+	// Output:
+	// red
+	// blue
+}

redisx/connmux.go

@@ -0,0 +1,152 @@
+// Copyright 2014 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redisx
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/garyburd/redigo/internal"
+	"github.com/garyburd/redigo/redis"
+)
+
+// ConnMux multiplexes one or more connections to a single underlying
+// connection. The ConnMux connections do not support concurrency, commands
+// that associate server side state with the connection or commands that put
+// the connection in a special mode.
+type ConnMux struct {
+	c redis.Conn
+
+	sendMu sync.Mutex
+	sendID uint
+
+	recvMu   sync.Mutex
+	recvID   uint
+	recvWait map[uint]chan struct{}
+}
+
+func NewConnMux(c redis.Conn) *ConnMux {
+	return &ConnMux{c: c, recvWait: make(map[uint]chan struct{})}
+}
+
+// Get gets a connection. The application must close the returned connection.
+func (p *ConnMux) Get() redis.Conn {
+	c := &muxConn{p: p}
+	c.ids = c.buf[:0]
+	return c
+}
+
+// Close closes the underlying connection.
+func (p *ConnMux) Close() error {
+	return p.c.Close()
+}
+
+type muxConn struct {
+	p   *ConnMux
+	ids []uint
+	buf [8]uint
+}
+
+func (c *muxConn) send(flush bool, cmd string, args ...interface{}) error {
+	if internal.LookupCommandInfo(cmd).Set != 0 {
+		return errors.New("command not supported by mux pool")
+	}
+	p := c.p
+	p.sendMu.Lock()
+	id := p.sendID
+	c.ids = append(c.ids, id)
+	p.sendID++
+	err := p.c.Send(cmd, args...)
+	if flush {
+		err = p.c.Flush()
+	}
+	p.sendMu.Unlock()
+	return err
+}
+
+func (c *muxConn) Send(cmd string, args ...interface{}) error {
+	return c.send(false, cmd, args...)
+}
+
+func (c *muxConn) Flush() error {
+	p := c.p
+	p.sendMu.Lock()
+	err := p.c.Flush()
+	p.sendMu.Unlock()
+	return err
+}
+
+func (c *muxConn) Receive() (interface{}, error) {
+	if len(c.ids) == 0 {
+		return nil, errors.New("mux pool underflow")
+	}
+
+	id := c.ids[0]
+	c.ids = c.ids[1:]
+	if len(c.ids) == 0 {
+		c.ids = c.buf[:0]
+	}
+
+	p := c.p
+	p.recvMu.Lock()
+	if p.recvID != id {
+		ch := make(chan struct{})
+		p.recvWait[id] = ch
+		p.recvMu.Unlock()
+		<-ch
+		p.recvMu.Lock()
+		if p.recvID != id {
+			panic("out of sync")
+		}
+	}
+
+	v, err := p.c.Receive()
+
+	id++
+	p.recvID = id
+	ch, ok := p.recvWait[id]
+	if ok {
+		delete(p.recvWait, id)
+	}
+	p.recvMu.Unlock()
+	if ok {
+		ch <- struct{}{}
+	}
+
+	return v, err
+}
+
+func (c *muxConn) Close() error {
+	var err error
+	if len(c.ids) == 0 {
+		return nil
+	}
+	c.Flush()
+	for _ = range c.ids {
+		_, err = c.Receive()
+	}
+	return err
+}
+
+func (c *muxConn) Do(cmd string, args ...interface{}) (interface{}, error) {
+	if err := c.send(true, cmd, args...); err != nil {
+		return nil, err
+	}
+	return c.Receive()
+}
+
+func (c *muxConn) Err() error {
+	return c.p.c.Err()
+}

redisx/connmux_test.go

@@ -0,0 +1,259 @@
+// Copyright 2014 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package redisx_test
+
+import (
+	"net/textproto"
+	"sync"
+	"testing"
+
+	"github.com/garyburd/redigo/internal/redistest"
+	"github.com/garyburd/redigo/redis"
+	"github.com/garyburd/redigo/redisx"
+)
+
+func TestConnMux(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	m := redisx.NewConnMux(c)
+	defer m.Close()
+
+	c1 := m.Get()
+	c2 := m.Get()
+	c1.Send("ECHO", "hello")
+	c2.Send("ECHO", "world")
+	c1.Flush()
+	c2.Flush()
+	s, err := redis.String(c1.Receive())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s != "hello" {
+		t.Fatalf("echo returned %q, want %q", s, "hello")
+	}
+	s, err = redis.String(c2.Receive())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s != "world" {
+		t.Fatalf("echo returned %q, want %q", s, "world")
+	}
+	c1.Close()
+	c2.Close()
+}
+
+func TestConnMuxClose(t *testing.T) {
+	c, err := redistest.Dial()
+	if err != nil {
+		t.Fatalf("error connection to database, %v", err)
+	}
+	m := redisx.NewConnMux(c)
+	defer m.Close()
+
+	c1 := m.Get()
+	c2 := m.Get()
+
+	if err := c1.Send("ECHO", "hello"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c1.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := c2.Send("ECHO", "world"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c2.Flush(); err != nil {
+		t.Fatal(err)
+	}
+
+	s, err := redis.String(c2.Receive())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s != "world" {
+		t.Fatalf("echo returned %q, want %q", s, "world")
+	}
+	c2.Close()
+}
+
+func BenchmarkConn(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		if _, err := c.Do("PING"); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkConnMux(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatalf("error connection to database, %v", err)
+	}
+	m := redisx.NewConnMux(c)
+	defer m.Close()
+
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		c := m.Get()
+		if _, err := c.Do("PING"); err != nil {
+			b.Fatal(err)
+		}
+		c.Close()
+	}
+}
+
+func BenchmarkPool(b *testing.B) {
+	b.StopTimer()
+
+	p := redis.Pool{Dial: redistest.Dial, MaxIdle: 1}
+	defer p.Close()
+
+	// Fill the pool.
+	c := p.Get()
+	if err := c.Err(); err != nil {
+		b.Fatal(err)
+	}
+	c.Close()
+
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		c := p.Get()
+		if _, err := c.Do("PING"); err != nil {
+			b.Fatal(err)
+		}
+		c.Close()
+	}
+}
+
+const numConcurrent = 10
+
+func BenchmarkConnMuxConcurrent(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	m := redisx.NewConnMux(c)
+
+	var wg sync.WaitGroup
+	wg.Add(numConcurrent)
+
+	b.StartTimer()
+
+	for i := 0; i < numConcurrent; i++ {
+		go func() {
+			defer wg.Done()
+			for i := 0; i < b.N; i++ {
+				c := m.Get()
+				if _, err := c.Do("PING"); err != nil {
+					b.Fatal(err)
+				}
+				c.Close()
+			}
+		}()
+	}
+	wg.Wait()
+}
+
+func BenchmarkPoolConcurrent(b *testing.B) {
+	b.StopTimer()
+
+	p := redis.Pool{Dial: redistest.Dial, MaxIdle: numConcurrent}
+	defer p.Close()
+
+	// Fill the pool.
+	conns := make([]redis.Conn, numConcurrent)
+	for i := range conns {
+		c := p.Get()
+		if err := c.Err(); err != nil {
+			b.Fatal(err)
+		}
+		conns[i] = c
+	}
+	for _, c := range conns {
+		c.Close()
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(numConcurrent)
+
+	b.StartTimer()
+
+	for i := 0; i < numConcurrent; i++ {
+		go func() {
+			defer wg.Done()
+			for i := 0; i < b.N; i++ {
+				c := p.Get()
+				if _, err := c.Do("PING"); err != nil {
+					b.Fatal(err)
+				}
+				c.Close()
+			}
+		}()
+	}
+	wg.Wait()
+}
+
+func BenchmarkPipelineConcurrency(b *testing.B) {
+	b.StopTimer()
+	c, err := redistest.Dial()
+	if err != nil {
+		b.Fatalf("error connection to database, %v", err)
+	}
+	defer c.Close()
+
+	var wg sync.WaitGroup
+	wg.Add(numConcurrent)
+
+	var pipeline textproto.Pipeline
+
+	b.StartTimer()
+
+	for i := 0; i < numConcurrent; i++ {
+		go func() {
+			defer wg.Done()
+			for i := 0; i < b.N; i++ {
+				id := pipeline.Next()
+				pipeline.StartRequest(id)
+				c.Send("PING")
+				c.Flush()
+				pipeline.EndRequest(id)
+				pipeline.StartResponse(id)
+				_, err := c.Receive()
+				if err != nil {
+					b.Fatal(err)
+				}
+				pipeline.EndResponse(id)
+			}
+		}()
+	}
+	wg.Wait()
+}

redisx/doc.go

@@ -0,0 +1,17 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// Package redisx contains experimental features for Redigo. Features in this
+// package may be modified or deleted at any time.
+package redisx // import "github.com/garyburd/redigo/redisx"