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// 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"
"crypto/tls"
"errors"
"fmt"
"io"
"net"
"net/url"
"regexp"
"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
}
// DialTimeout acts like Dial but takes timeouts for establishing the
// connection to the server, writing a command and reading a reply.
//
// Deprecated: Use Dial with options instead.
func DialTimeout(network, address string, connectTimeout, readTimeout, writeTimeout time.Duration) (Conn, error) {
return Dial(network, address,
DialConnectTimeout(connectTimeout),
DialReadTimeout(readTimeout),
DialWriteTimeout(writeTimeout))
}
// DialOption specifies an option for dialing a Redis server.
type DialOption struct {
f func(*dialOptions)
}
type dialOptions struct {
readTimeout time.Duration
writeTimeout time.Duration
dial func(network, addr string) (net.Conn, error)
db int
password string
dialTLS bool
skipVerify bool
tlsConfig *tls.Config
}
// DialReadTimeout specifies the timeout for reading a single command reply.
func DialReadTimeout(d time.Duration) DialOption {
return DialOption{func(do *dialOptions) {
do.readTimeout = d
}}
}
// DialWriteTimeout specifies the timeout for writing a single command.
func DialWriteTimeout(d time.Duration) DialOption {
return DialOption{func(do *dialOptions) {
do.writeTimeout = d
}}
}
// DialConnectTimeout specifies the timeout for connecting to the Redis server.
func DialConnectTimeout(d time.Duration) DialOption {
return DialOption{func(do *dialOptions) {
dialer := net.Dialer{Timeout: d}
do.dial = dialer.Dial
}}
}
// DialNetDial specifies a custom dial function for creating TCP
// connections. If this option is left out, then net.Dial is
// used. DialNetDial overrides DialConnectTimeout.
func DialNetDial(dial func(network, addr string) (net.Conn, error)) DialOption {
return DialOption{func(do *dialOptions) {
do.dial = dial
}}
}
// DialDatabase specifies the database to select when dialing a connection.
func DialDatabase(db int) DialOption {
return DialOption{func(do *dialOptions) {
do.db = db
}}
}
// DialPassword specifies the password to use when connecting to
// the Redis server.
func DialPassword(password string) DialOption {
return DialOption{func(do *dialOptions) {
do.password = password
}}
}
// DialTLSConfig specifies the config to use when a TLS connection is dialed.
// Has no effect when not dialing a TLS connection.
func DialTLSConfig(c *tls.Config) DialOption {
return DialOption{func(do *dialOptions) {
do.tlsConfig = c
}}
}
// DialTLSSkipVerify to disable server name verification when connecting
// over TLS. Has no effect when not dialing a TLS connection.
func DialTLSSkipVerify(skip bool) DialOption {
return DialOption{func(do *dialOptions) {
do.skipVerify = skip
}}
}
// Dial connects to the Redis server at the given network and
// address using the specified options.
func Dial(network, address string, options ...DialOption) (Conn, error) {
do := dialOptions{
dial: net.Dial,
}
for _, option := range options {
option.f(&do)
}
netConn, err := do.dial(network, address)
if err != nil {
return nil, err
}
if do.dialTLS {
tlsConfig := cloneTLSClientConfig(do.tlsConfig, do.skipVerify)
if tlsConfig.ServerName == "" {
host, _, err := net.SplitHostPort(address)
if err != nil {
netConn.Close()
return nil, err
}
tlsConfig.ServerName = host
}
tlsConn := tls.Client(netConn, tlsConfig)
if err := tlsConn.Handshake(); err != nil {
netConn.Close()
return nil, err
}
netConn = tlsConn
}
c := &conn{
conn: netConn,
bw: bufio.NewWriter(netConn),
br: bufio.NewReader(netConn),
readTimeout: do.readTimeout,
writeTimeout: do.writeTimeout,
}
if do.password != "" {
if _, err := c.Do("AUTH", do.password); err != nil {
netConn.Close()
return nil, err
}
}
if do.db != 0 {
if _, err := c.Do("SELECT", do.db); err != nil {
netConn.Close()
return nil, err
}
}
return c, nil
}
func dialTLS(do *dialOptions) {
do.dialTLS = true
}
var pathDBRegexp = regexp.MustCompile(`/(\d*)\z`)
// DialURL connects to a Redis server at the given URL using the Redis
// URI scheme. URLs should follow the draft IANA specification for the
// scheme (https://www.iana.org/assignments/uri-schemes/prov/redis).
func DialURL(rawurl string, options ...DialOption) (Conn, error) {
u, err := url.Parse(rawurl)
if err != nil {
return nil, err
}
if u.Scheme != "redis" && u.Scheme != "rediss" {
return nil, fmt.Errorf("invalid redis URL scheme: %s", u.Scheme)
}
// As per the IANA draft spec, the host defaults to localhost and
// the port defaults to 6379.
host, port, err := net.SplitHostPort(u.Host)
if err != nil {
// assume port is missing
host = u.Host
port = "6379"
}
if host == "" {
host = "localhost"
}
address := net.JoinHostPort(host, port)
if u.User != nil {
password, isSet := u.User.Password()
if isSet {
options = append(options, DialPassword(password))
}
}
match := pathDBRegexp.FindStringSubmatch(u.Path)
if len(match) == 2 {
db := 0
if len(match[1]) > 0 {
db, err = strconv.Atoi(match[1])
if err != nil {
return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
}
}
if db != 0 {
options = append(options, DialDatabase(db))
}
} else if u.Path != "" {
return nil, fmt.Errorf("invalid database: %s", u.Path[1:])
}
if u.Scheme == "rediss" {
options = append([]DialOption{{dialTLS}}, options...)
}
return Dial("tcp", address, options...)
}
// 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 != "" {
if err := c.writeCommand(cmd, args); err != nil {
return nil, c.fatal(err)
}
}
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
}