forked from mirror/redis
136 lines
2.5 KiB
Go
136 lines
2.5 KiB
Go
package redis
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import (
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"sync"
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"sync/atomic"
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)
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// Pipeline implements pipelining as described in
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// http://redis.io/topics/pipelining. It's safe for concurrent use
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// by multiple goroutines.
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type Pipeline struct {
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commandable
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client *baseClient
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mu sync.Mutex // protects cmds
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cmds []Cmder
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closed int32
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}
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func (c *Client) Pipeline() *Pipeline {
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pipe := &Pipeline{
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client: c.baseClient,
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cmds: make([]Cmder, 0, 10),
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}
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pipe.commandable.process = pipe.process
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return pipe
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}
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func (c *Client) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
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pipe := c.Pipeline()
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if err := fn(pipe); err != nil {
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return nil, err
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}
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cmds, err := pipe.Exec()
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_ = pipe.Close()
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return cmds, err
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}
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func (pipe *Pipeline) process(cmd Cmder) {
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pipe.mu.Lock()
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pipe.cmds = append(pipe.cmds, cmd)
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pipe.mu.Unlock()
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}
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// Close closes the pipeline, releasing any open resources.
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func (pipe *Pipeline) Close() error {
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atomic.StoreInt32(&pipe.closed, 1)
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pipe.Discard()
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return nil
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}
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func (pipe *Pipeline) isClosed() bool {
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return atomic.LoadInt32(&pipe.closed) == 1
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}
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// Discard resets the pipeline and discards queued commands.
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func (pipe *Pipeline) Discard() error {
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defer pipe.mu.Unlock()
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pipe.mu.Lock()
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if pipe.isClosed() {
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return errClosed
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}
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pipe.cmds = pipe.cmds[:0]
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return nil
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}
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// Exec executes all previously queued commands using one
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// client-server roundtrip.
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//
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// Exec always returns list of commands and error of the first failed
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// command if any.
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func (pipe *Pipeline) Exec() (cmds []Cmder, retErr error) {
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if pipe.isClosed() {
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return nil, errClosed
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}
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defer pipe.mu.Unlock()
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pipe.mu.Lock()
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if len(pipe.cmds) == 0 {
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return pipe.cmds, nil
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}
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cmds = pipe.cmds
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pipe.cmds = make([]Cmder, 0, 10)
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failedCmds := cmds
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for i := 0; i <= pipe.client.opt.MaxRetries; i++ {
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cn, _, err := pipe.client.conn()
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if err != nil {
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setCmdsErr(failedCmds, err)
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return cmds, err
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}
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if i > 0 {
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resetCmds(failedCmds)
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}
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failedCmds, err = execCmds(cn, failedCmds)
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pipe.client.putConn(cn, err)
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if err != nil && retErr == nil {
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retErr = err
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}
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if len(failedCmds) == 0 {
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break
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}
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}
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return cmds, retErr
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}
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func execCmds(cn *conn, cmds []Cmder) ([]Cmder, error) {
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if err := cn.writeCmds(cmds...); err != nil {
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setCmdsErr(cmds, err)
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return cmds, err
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}
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var firstCmdErr error
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var failedCmds []Cmder
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for _, cmd := range cmds {
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err := cmd.readReply(cn)
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if err == nil {
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continue
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}
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if firstCmdErr == nil {
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firstCmdErr = err
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}
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if shouldRetry(err) {
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failedCmds = append(failedCmds, cmd)
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}
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}
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return failedCmds, firstCmdErr
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}
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