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package redis
import (
"context"
"fmt"
"log"
"os"
"time"
"github.com/go-redis/redis/internal"
"github.com/go-redis/redis/internal/pool"
"github.com/go-redis/redis/internal/proto"
)
// Nil reply Redis returns when key does not exist.
const Nil = proto.Nil
func init() {
SetLogger(log.New(os.Stderr, "redis: ", log.LstdFlags|log.Lshortfile))
}
func SetLogger(logger *log.Logger) {
internal.Logger = logger
}
type baseClient struct {
opt *Options
connPool pool.Pooler
limiter Limiter
process func(Cmder) error
processPipeline func([]Cmder) error
processTxPipeline func([]Cmder) error
onClose func() error // hook called when client is closed
}
func (c *baseClient) init() {
c.process = c.defaultProcess
c.processPipeline = c.defaultProcessPipeline
c.processTxPipeline = c.defaultProcessTxPipeline
}
func (c *baseClient) String() string {
return fmt.Sprintf("Redis<%s db:%d>", c.getAddr(), c.opt.DB)
}
func (c *baseClient) newConn() (*pool.Conn, error) {
cn, err := c.connPool.NewConn()
if err != nil {
return nil, err
}
if cn.InitedAt.IsZero() {
if err := c.initConn(cn); err != nil {
_ = c.connPool.CloseConn(cn)
return nil, err
}
}
return cn, nil
}
func (c *baseClient) getConn() (*pool.Conn, error) {
if c.limiter != nil {
err := c.limiter.Allow()
if err != nil {
return nil, err
}
}
cn, err := c._getConn()
if err != nil {
if c.limiter != nil {
c.limiter.ReportResult(err)
}
return nil, err
}
return cn, nil
}
func (c *baseClient) _getConn() (*pool.Conn, error) {
cn, err := c.connPool.Get()
if err != nil {
return nil, err
}
if cn.InitedAt.IsZero() {
err := c.initConn(cn)
if err != nil {
c.connPool.Remove(cn)
return nil, err
}
}
return cn, nil
}
func (c *baseClient) releaseConn(cn *pool.Conn, err error) {
if c.limiter != nil {
c.limiter.ReportResult(err)
}
if internal.IsBadConn(err, false) {
c.connPool.Remove(cn)
} else {
c.connPool.Put(cn)
}
}
func (c *baseClient) releaseConnStrict(cn *pool.Conn, err error) {
if c.limiter != nil {
c.limiter.ReportResult(err)
}
if err == nil || internal.IsRedisError(err) {
c.connPool.Put(cn)
} else {
c.connPool.Remove(cn)
}
}
func (c *baseClient) initConn(cn *pool.Conn) error {
cn.InitedAt = time.Now()
if c.opt.Password == "" &&
c.opt.DB == 0 &&
!c.opt.readOnly &&
c.opt.OnConnect == nil {
return nil
}
conn := newConn(c.opt, cn)
_, err := conn.Pipelined(func(pipe Pipeliner) error {
if c.opt.Password != "" {
pipe.Auth(c.opt.Password)
}
if c.opt.DB > 0 {
pipe.Select(c.opt.DB)
}
if c.opt.readOnly {
pipe.ReadOnly()
}
return nil
})
if err != nil {
return err
}
if c.opt.OnConnect != nil {
return c.opt.OnConnect(conn)
}
return nil
}
// Do creates a Cmd from the args and processes the cmd.
func (c *baseClient) Do(args ...interface{}) *Cmd {
cmd := NewCmd(args...)
_ = c.Process(cmd)
return cmd
}
// WrapProcess wraps function that processes Redis commands.
func (c *baseClient) WrapProcess(
fn func(oldProcess func(cmd Cmder) error) func(cmd Cmder) error,
) {
c.process = fn(c.process)
}
func (c *baseClient) Process(cmd Cmder) error {
return c.process(cmd)
}
func (c *baseClient) defaultProcess(cmd Cmder) error {
for attempt := 0; attempt <= c.opt.MaxRetries; attempt++ {
if attempt > 0 {
time.Sleep(c.retryBackoff(attempt))
}
cn, err := c.getConn()
if err != nil {
cmd.setErr(err)
if internal.IsRetryableError(err, true) {
continue
}
return err
}
err = cn.WithWriter(c.opt.WriteTimeout, func(wr *proto.Writer) error {
return writeCmd(wr, cmd)
})
if err != nil {
c.releaseConn(cn, err)
cmd.setErr(err)
if internal.IsRetryableError(err, true) {
continue
}
return err
}
err = cn.WithReader(c.cmdTimeout(cmd), func(rd *proto.Reader) error {
return cmd.readReply(rd)
})
c.releaseConn(cn, err)
if err != nil && internal.IsRetryableError(err, cmd.readTimeout() == nil) {
continue
}
return err
}
return cmd.Err()
}
func (c *baseClient) retryBackoff(attempt int) time.Duration {
return internal.RetryBackoff(attempt, c.opt.MinRetryBackoff, c.opt.MaxRetryBackoff)
}
func (c *baseClient) cmdTimeout(cmd Cmder) time.Duration {
if timeout := cmd.readTimeout(); timeout != nil {
t := *timeout
if t == 0 {
return 0
}
return t + 10*time.Second
}
return c.opt.ReadTimeout
}
// Close closes the client, releasing any open resources.
//
// It is rare to Close a Client, as the Client is meant to be
// long-lived and shared between many goroutines.
func (c *baseClient) Close() error {
var firstErr error
if c.onClose != nil {
if err := c.onClose(); err != nil && firstErr == nil {
firstErr = err
}
}
if err := c.connPool.Close(); err != nil && firstErr == nil {
firstErr = err
}
return firstErr
}
func (c *baseClient) getAddr() string {
return c.opt.Addr
}
func (c *baseClient) WrapProcessPipeline(
fn func(oldProcess func([]Cmder) error) func([]Cmder) error,
) {
c.processPipeline = fn(c.processPipeline)
c.processTxPipeline = fn(c.processTxPipeline)
}
func (c *baseClient) defaultProcessPipeline(cmds []Cmder) error {
return c.generalProcessPipeline(cmds, c.pipelineProcessCmds)
}
func (c *baseClient) defaultProcessTxPipeline(cmds []Cmder) error {
return c.generalProcessPipeline(cmds, c.txPipelineProcessCmds)
}
type pipelineProcessor func(*pool.Conn, []Cmder) (bool, error)
func (c *baseClient) generalProcessPipeline(cmds []Cmder, p pipelineProcessor) error {
for attempt := 0; attempt <= c.opt.MaxRetries; attempt++ {
if attempt > 0 {
time.Sleep(c.retryBackoff(attempt))
}
cn, err := c.getConn()
if err != nil {
setCmdsErr(cmds, err)
return err
}
canRetry, err := p(cn, cmds)
c.releaseConnStrict(cn, err)
if !canRetry || !internal.IsRetryableError(err, true) {
break
}
}
return cmdsFirstErr(cmds)
}
func (c *baseClient) pipelineProcessCmds(cn *pool.Conn, cmds []Cmder) (bool, error) {
err := cn.WithWriter(c.opt.WriteTimeout, func(wr *proto.Writer) error {
return writeCmd(wr, cmds...)
})
if err != nil {
setCmdsErr(cmds, err)
return true, err
}
err = cn.WithReader(c.opt.ReadTimeout, func(rd *proto.Reader) error {
return pipelineReadCmds(rd, cmds)
})
return true, err
}
func pipelineReadCmds(rd *proto.Reader, cmds []Cmder) error {
for _, cmd := range cmds {
err := cmd.readReply(rd)
if err != nil && !internal.IsRedisError(err) {
return err
}
}
return nil
}
func (c *baseClient) txPipelineProcessCmds(cn *pool.Conn, cmds []Cmder) (bool, error) {
err := cn.WithWriter(c.opt.WriteTimeout, func(wr *proto.Writer) error {
return txPipelineWriteMulti(wr, cmds)
})
if err != nil {
setCmdsErr(cmds, err)
return true, err
}
err = cn.WithReader(c.opt.ReadTimeout, func(rd *proto.Reader) error {
err := txPipelineReadQueued(rd, cmds)
if err != nil {
setCmdsErr(cmds, err)
return err
}
return pipelineReadCmds(rd, cmds)
})
return false, err
}
func txPipelineWriteMulti(wr *proto.Writer, cmds []Cmder) error {
multiExec := make([]Cmder, 0, len(cmds)+2)
multiExec = append(multiExec, NewStatusCmd("MULTI"))
multiExec = append(multiExec, cmds...)
multiExec = append(multiExec, NewSliceCmd("EXEC"))
return writeCmd(wr, multiExec...)
}
func txPipelineReadQueued(rd *proto.Reader, cmds []Cmder) error {
// Parse queued replies.
var statusCmd StatusCmd
err := statusCmd.readReply(rd)
if err != nil {
return err
}
for range cmds {
err = statusCmd.readReply(rd)
if err != nil && !internal.IsRedisError(err) {
return err
}
}
// Parse number of replies.
line, err := rd.ReadLine()
if err != nil {
if err == Nil {
err = TxFailedErr
}
return err
}
switch line[0] {
case proto.ErrorReply:
return proto.ParseErrorReply(line)
case proto.ArrayReply:
// ok
default:
err := fmt.Errorf("redis: expected '*', but got line %q", line)
return err
}
return nil
}
//------------------------------------------------------------------------------
// Client is a Redis client representing a pool of zero or more
// underlying connections. It's safe for concurrent use by multiple
// goroutines.
type Client struct {
baseClient
cmdable
ctx context.Context
}
// NewClient returns a client to the Redis Server specified by Options.
func NewClient(opt *Options) *Client {
opt.init()
c := Client{
baseClient: baseClient{
opt: opt,
connPool: newConnPool(opt),
},
}
c.baseClient.init()
c.init()
return &c
}
func (c *Client) init() {
c.cmdable.setProcessor(c.Process)
}
func (c *Client) Context() context.Context {
if c.ctx != nil {
return c.ctx
}
return context.Background()
}
func (c *Client) WithContext(ctx context.Context) *Client {
if ctx == nil {
panic("nil context")
}
c2 := c.clone()
c2.ctx = ctx
return c2
}
func (c *Client) clone() *Client {
cp := *c
cp.init()
return &cp
}
// Options returns read-only Options that were used to create the client.
func (c *Client) Options() *Options {
return c.opt
}
func (c *Client) SetLimiter(l Limiter) *Client {
c.limiter = l
return c
}
type PoolStats pool.Stats
// PoolStats returns connection pool stats.
func (c *Client) PoolStats() *PoolStats {
stats := c.connPool.Stats()
return (*PoolStats)(stats)
}
func (c *Client) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
return c.Pipeline().Pipelined(fn)
}
func (c *Client) Pipeline() Pipeliner {
pipe := Pipeline{
exec: c.processPipeline,
}
pipe.statefulCmdable.setProcessor(pipe.Process)
return &pipe
}
func (c *Client) TxPipelined(fn func(Pipeliner) error) ([]Cmder, error) {
return c.TxPipeline().Pipelined(fn)
}
// TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
func (c *Client) TxPipeline() Pipeliner {
pipe := Pipeline{
exec: c.processTxPipeline,
}
pipe.statefulCmdable.setProcessor(pipe.Process)
return &pipe
}
func (c *Client) pubSub() *PubSub {
pubsub := &PubSub{
opt: c.opt,
newConn: func(channels []string) (*pool.Conn, error) {
return c.newConn()
},
closeConn: c.connPool.CloseConn,
}
pubsub.init()
return pubsub
}
// Subscribe subscribes the client to the specified channels.
// Channels can be omitted to create empty subscription.
// Note that this method does not wait on a response from Redis, so the
// subscription may not be active immediately. To force the connection to wait,
// you may call the Receive() method on the returned *PubSub like so:
//
// sub := client.Subscribe(queryResp)
// iface, err := sub.Receive()
// if err != nil {
// // handle error
// }
//
// // Should be *Subscription, but others are possible if other actions have been
// // taken on sub since it was created.
// switch iface.(type) {
// case *Subscription:
// // subscribe succeeded
// case *Message:
// // received first message
// case *Pong:
// // pong received
// default:
// // handle error
// }
//
// ch := sub.Channel()
func (c *Client) Subscribe(channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.Subscribe(channels...)
}
return pubsub
}
// PSubscribe subscribes the client to the given patterns.
// Patterns can be omitted to create empty subscription.
func (c *Client) PSubscribe(channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.PSubscribe(channels...)
}
return pubsub
}
//------------------------------------------------------------------------------
// Conn is like Client, but its pool contains single connection.
type Conn struct {
baseClient
statefulCmdable
}
func newConn(opt *Options, cn *pool.Conn) *Conn {
c := Conn{
baseClient: baseClient{
opt: opt,
connPool: pool.NewSingleConnPool(cn),
},
}
c.baseClient.init()
c.statefulCmdable.setProcessor(c.Process)
return &c
}
func (c *Conn) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
return c.Pipeline().Pipelined(fn)
}
func (c *Conn) Pipeline() Pipeliner {
pipe := Pipeline{
exec: c.processPipeline,
}
pipe.statefulCmdable.setProcessor(pipe.Process)
return &pipe
}
func (c *Conn) TxPipelined(fn func(Pipeliner) error) ([]Cmder, error) {
return c.TxPipeline().Pipelined(fn)
}
// TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
func (c *Conn) TxPipeline() Pipeliner {
pipe := Pipeline{
exec: c.processTxPipeline,
}
pipe.statefulCmdable.setProcessor(pipe.Process)
return &pipe
}