redis/redis.go

745 lines
16 KiB
Go

package redis
import (
"context"
"fmt"
"time"
"github.com/go-redis/redis/v8/internal"
"github.com/go-redis/redis/v8/internal/pool"
"github.com/go-redis/redis/v8/internal/proto"
)
// Nil reply returned by Redis when key does not exist.
const Nil = proto.Nil
func SetLogger(logger internal.Logging) {
internal.Logger = logger
}
//------------------------------------------------------------------------------
type Hook interface {
BeforeProcess(ctx context.Context, cmd Cmder) (context.Context, error)
AfterProcess(ctx context.Context, cmd Cmder) error
BeforeProcessPipeline(ctx context.Context, cmds []Cmder) (context.Context, error)
AfterProcessPipeline(ctx context.Context, cmds []Cmder) error
}
type hooks struct {
hooks []Hook
}
func (hs *hooks) lock() {
hs.hooks = hs.hooks[:len(hs.hooks):len(hs.hooks)]
}
func (hs hooks) clone() hooks {
clone := hs
clone.lock()
return clone
}
func (hs *hooks) AddHook(hook Hook) {
hs.hooks = append(hs.hooks, hook)
}
func (hs hooks) process(
ctx context.Context, cmd Cmder, fn func(context.Context, Cmder) error,
) error {
if len(hs.hooks) == 0 {
return fn(ctx, cmd)
}
var hookIndex int
var retErr error
for ; hookIndex < len(hs.hooks) && retErr == nil; hookIndex++ {
ctx, retErr = hs.hooks[hookIndex].BeforeProcess(ctx, cmd)
if retErr != nil {
cmd.SetErr(retErr)
}
}
if retErr == nil {
retErr = fn(ctx, cmd)
}
for hookIndex--; hookIndex >= 0; hookIndex-- {
if err := hs.hooks[hookIndex].AfterProcess(ctx, cmd); err != nil {
retErr = err
cmd.SetErr(retErr)
}
}
return retErr
}
func (hs hooks) processPipeline(
ctx context.Context, cmds []Cmder, fn func(context.Context, []Cmder) error,
) error {
if len(hs.hooks) == 0 {
return fn(ctx, cmds)
}
var hookIndex int
var retErr error
for ; hookIndex < len(hs.hooks) && retErr == nil; hookIndex++ {
ctx, retErr = hs.hooks[hookIndex].BeforeProcessPipeline(ctx, cmds)
if retErr != nil {
setCmdsErr(cmds, retErr)
}
}
if retErr == nil {
retErr = fn(ctx, cmds)
}
for hookIndex--; hookIndex >= 0; hookIndex-- {
if err := hs.hooks[hookIndex].AfterProcessPipeline(ctx, cmds); err != nil {
retErr = err
setCmdsErr(cmds, retErr)
}
}
return retErr
}
func (hs hooks) processTxPipeline(
ctx context.Context, cmds []Cmder, fn func(context.Context, []Cmder) error,
) error {
cmds = wrapMultiExec(ctx, cmds)
return hs.processPipeline(ctx, cmds, fn)
}
//------------------------------------------------------------------------------
type baseClient struct {
opt *Options
connPool pool.Pooler
onClose func() error // hook called when client is closed
}
func newBaseClient(opt *Options, connPool pool.Pooler) *baseClient {
return &baseClient{
opt: opt,
connPool: connPool,
}
}
func (c *baseClient) clone() *baseClient {
clone := *c
return &clone
}
func (c *baseClient) withTimeout(timeout time.Duration) *baseClient {
opt := c.opt.clone()
opt.ReadTimeout = timeout
opt.WriteTimeout = timeout
clone := c.clone()
clone.opt = opt
return clone
}
func (c *baseClient) String() string {
return fmt.Sprintf("Redis<%s db:%d>", c.getAddr(), c.opt.DB)
}
func (c *baseClient) newConn(ctx context.Context) (*pool.Conn, error) {
cn, err := c.connPool.NewConn(ctx)
if err != nil {
return nil, err
}
err = c.initConn(ctx, cn)
if err != nil {
_ = c.connPool.CloseConn(cn)
return nil, err
}
return cn, nil
}
func (c *baseClient) getConn(ctx context.Context) (*pool.Conn, error) {
if c.opt.Limiter != nil {
err := c.opt.Limiter.Allow()
if err != nil {
return nil, err
}
}
cn, err := c._getConn(ctx)
if err != nil {
if c.opt.Limiter != nil {
c.opt.Limiter.ReportResult(err)
}
return nil, err
}
return cn, nil
}
func (c *baseClient) _getConn(ctx context.Context) (*pool.Conn, error) {
cn, err := c.connPool.Get(ctx)
if err != nil {
return nil, err
}
if cn.Inited {
return cn, nil
}
err = internal.WithSpan(ctx, "init_conn", func(ctx context.Context) error {
return c.initConn(ctx, cn)
})
if err != nil {
c.connPool.Remove(ctx, cn, err)
if err := internal.Unwrap(err); err != nil {
return nil, err
}
return nil, err
}
return cn, nil
}
func (c *baseClient) initConn(ctx context.Context, cn *pool.Conn) error {
if cn.Inited {
return nil
}
cn.Inited = true
if c.opt.Password == "" &&
c.opt.DB == 0 &&
!c.opt.readOnly &&
c.opt.OnConnect == nil {
return nil
}
connPool := pool.NewSingleConnPool(c.connPool, cn)
conn := newConn(ctx, c.opt, connPool)
_, err := conn.Pipelined(ctx, func(pipe Pipeliner) error {
if c.opt.Password != "" {
if c.opt.Username != "" {
pipe.AuthACL(ctx, c.opt.Username, c.opt.Password)
} else {
pipe.Auth(ctx, c.opt.Password)
}
}
if c.opt.DB > 0 {
pipe.Select(ctx, c.opt.DB)
}
if c.opt.readOnly {
pipe.ReadOnly(ctx)
}
return nil
})
if err != nil {
return err
}
if c.opt.OnConnect != nil {
return c.opt.OnConnect(ctx, conn)
}
return nil
}
func (c *baseClient) releaseConn(ctx context.Context, cn *pool.Conn, err error) {
if c.opt.Limiter != nil {
c.opt.Limiter.ReportResult(err)
}
if isBadConn(err, false) {
c.connPool.Remove(ctx, cn, err)
} else {
c.connPool.Put(ctx, cn)
}
}
func (c *baseClient) withConn(
ctx context.Context, fn func(context.Context, *pool.Conn) error,
) error {
return internal.WithSpan(ctx, "with_conn", func(ctx context.Context) error {
cn, err := c.getConn(ctx)
if err != nil {
return err
}
defer func() {
c.releaseConn(ctx, cn, err)
}()
err = fn(ctx, cn)
return err
})
}
func (c *baseClient) process(ctx context.Context, cmd Cmder) error {
err := c._process(ctx, cmd)
if err != nil {
cmd.SetErr(err)
return err
}
return nil
}
func (c *baseClient) _process(ctx context.Context, cmd Cmder) error {
var lastErr error
for attempt := 0; attempt <= c.opt.MaxRetries; attempt++ {
attempt := attempt
var retry bool
err := internal.WithSpan(ctx, "process", func(ctx context.Context) error {
if attempt > 0 {
if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
return err
}
}
retryTimeout := true
err := c.withConn(ctx, func(ctx context.Context, cn *pool.Conn) error {
err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
return writeCmd(wr, cmd)
})
if err != nil {
return err
}
err = cn.WithReader(ctx, c.cmdTimeout(cmd), cmd.readReply)
if err != nil {
retryTimeout = cmd.readTimeout() == nil
return err
}
return nil
})
if err == nil {
return nil
}
retry = shouldRetry(err, retryTimeout)
return err
})
if err == nil || !retry {
return err
}
lastErr = err
}
return lastErr
}
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 = 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) processPipeline(ctx context.Context, cmds []Cmder) error {
return c.generalProcessPipeline(ctx, cmds, c.pipelineProcessCmds)
}
func (c *baseClient) processTxPipeline(ctx context.Context, cmds []Cmder) error {
return c.generalProcessPipeline(ctx, cmds, c.txPipelineProcessCmds)
}
type pipelineProcessor func(context.Context, *pool.Conn, []Cmder) (bool, error)
func (c *baseClient) generalProcessPipeline(
ctx context.Context, cmds []Cmder, p pipelineProcessor,
) error {
err := c._generalProcessPipeline(ctx, cmds, p)
if err != nil {
setCmdsErr(cmds, err)
return err
}
return cmdsFirstErr(cmds)
}
func (c *baseClient) _generalProcessPipeline(
ctx context.Context, cmds []Cmder, p pipelineProcessor,
) error {
var lastErr error
for attempt := 0; attempt <= c.opt.MaxRetries; attempt++ {
if attempt > 0 {
if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
return err
}
}
var canRetry bool
lastErr = c.withConn(ctx, func(ctx context.Context, cn *pool.Conn) error {
var err error
canRetry, err = p(ctx, cn, cmds)
return err
})
if lastErr == nil || !canRetry || !shouldRetry(lastErr, true) {
return lastErr
}
}
return lastErr
}
func (c *baseClient) pipelineProcessCmds(
ctx context.Context, cn *pool.Conn, cmds []Cmder,
) (bool, error) {
err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
return writeCmds(wr, cmds)
})
if err != nil {
return true, err
}
err = cn.WithReader(ctx, 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 && !isRedisError(err) {
return err
}
}
return nil
}
func (c *baseClient) txPipelineProcessCmds(
ctx context.Context, cn *pool.Conn, cmds []Cmder,
) (bool, error) {
err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
return writeCmds(wr, cmds)
})
if err != nil {
return true, err
}
err = cn.WithReader(ctx, c.opt.ReadTimeout, func(rd *proto.Reader) error {
statusCmd := cmds[0].(*StatusCmd)
// Trim multi and exec.
cmds = cmds[1 : len(cmds)-1]
err := txPipelineReadQueued(rd, statusCmd, cmds)
if err != nil {
return err
}
return pipelineReadCmds(rd, cmds)
})
return false, err
}
func wrapMultiExec(ctx context.Context, cmds []Cmder) []Cmder {
if len(cmds) == 0 {
panic("not reached")
}
cmds = append(cmds, make([]Cmder, 2)...)
copy(cmds[1:], cmds[:len(cmds)-2])
cmds[0] = NewStatusCmd(ctx, "multi")
cmds[len(cmds)-1] = NewSliceCmd(ctx, "exec")
return cmds
}
func txPipelineReadQueued(rd *proto.Reader, statusCmd *StatusCmd, cmds []Cmder) error {
// Parse queued replies.
if err := statusCmd.readReply(rd); err != nil {
return err
}
for range cmds {
if err := statusCmd.readReply(rd); err != nil && !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
hooks
ctx context.Context
}
// NewClient returns a client to the Redis Server specified by Options.
func NewClient(opt *Options) *Client {
opt.init()
c := Client{
baseClient: newBaseClient(opt, newConnPool(opt)),
ctx: context.Background(),
}
c.cmdable = c.Process
return &c
}
func (c *Client) clone() *Client {
clone := *c
clone.cmdable = clone.Process
clone.hooks.lock()
return &clone
}
func (c *Client) WithTimeout(timeout time.Duration) *Client {
clone := c.clone()
clone.baseClient = c.baseClient.withTimeout(timeout)
return clone
}
func (c *Client) Context() context.Context {
return c.ctx
}
func (c *Client) WithContext(ctx context.Context) *Client {
if ctx == nil {
panic("nil context")
}
clone := c.clone()
clone.ctx = ctx
return clone
}
func (c *Client) Conn(ctx context.Context) *Conn {
return newConn(ctx, c.opt, pool.NewStickyConnPool(c.connPool))
}
// Do creates a Cmd from the args and processes the cmd.
func (c *Client) Do(ctx context.Context, args ...interface{}) *Cmd {
cmd := NewCmd(ctx, args...)
_ = c.Process(ctx, cmd)
return cmd
}
func (c *Client) Process(ctx context.Context, cmd Cmder) error {
return c.hooks.process(ctx, cmd, c.baseClient.process)
}
func (c *Client) processPipeline(ctx context.Context, cmds []Cmder) error {
return c.hooks.processPipeline(ctx, cmds, c.baseClient.processPipeline)
}
func (c *Client) processTxPipeline(ctx context.Context, cmds []Cmder) error {
return c.hooks.processTxPipeline(ctx, cmds, c.baseClient.processTxPipeline)
}
// Options returns read-only Options that were used to create the client.
func (c *Client) Options() *Options {
return c.opt
}
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(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
return c.Pipeline().Pipelined(ctx, fn)
}
func (c *Client) Pipeline() Pipeliner {
pipe := Pipeline{
ctx: c.ctx,
exec: c.processPipeline,
}
pipe.init()
return &pipe
}
func (c *Client) TxPipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
return c.TxPipeline().Pipelined(ctx, fn)
}
// TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
func (c *Client) TxPipeline() Pipeliner {
pipe := Pipeline{
ctx: c.ctx,
exec: c.processTxPipeline,
}
pipe.init()
return &pipe
}
func (c *Client) pubSub() *PubSub {
pubsub := &PubSub{
opt: c.opt,
newConn: func(ctx context.Context, channels []string) (*pool.Conn, error) {
return c.newConn(ctx)
},
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(ctx context.Context, channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.Subscribe(ctx, channels...)
}
return pubsub
}
// PSubscribe subscribes the client to the given patterns.
// Patterns can be omitted to create empty subscription.
func (c *Client) PSubscribe(ctx context.Context, channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.PSubscribe(ctx, channels...)
}
return pubsub
}
//------------------------------------------------------------------------------
type conn struct {
baseClient
cmdable
statefulCmdable
}
// Conn is like Client, but its pool contains single connection.
type Conn struct {
*conn
ctx context.Context
}
func newConn(ctx context.Context, opt *Options, connPool pool.Pooler) *Conn {
c := Conn{
conn: &conn{
baseClient: baseClient{
opt: opt,
connPool: connPool,
},
},
ctx: ctx,
}
c.cmdable = c.Process
c.statefulCmdable = c.Process
return &c
}
func (c *Conn) Process(ctx context.Context, cmd Cmder) error {
return c.baseClient.process(ctx, cmd)
}
func (c *Conn) Pipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
return c.Pipeline().Pipelined(ctx, fn)
}
func (c *Conn) Pipeline() Pipeliner {
pipe := Pipeline{
ctx: c.ctx,
exec: c.processPipeline,
}
pipe.init()
return &pipe
}
func (c *Conn) TxPipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
return c.TxPipeline().Pipelined(ctx, fn)
}
// TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
func (c *Conn) TxPipeline() Pipeliner {
pipe := Pipeline{
ctx: c.ctx,
exec: c.processTxPipeline,
}
pipe.init()
return &pipe
}