redis/pipeline.go

111 lines
2.0 KiB
Go

package redis
import (
"sync"
"gopkg.in/redis.v5/internal"
"gopkg.in/redis.v5/internal/pool"
)
// Pipeline implements pipelining as described in
// http://redis.io/topics/pipelining. It's safe for concurrent use
// by multiple goroutines.
type Pipeline struct {
cmdable
statefulCmdable
exec func([]Cmder) error
mu sync.Mutex
cmds []Cmder
closed bool
}
func (c *Pipeline) Process(cmd Cmder) error {
c.mu.Lock()
c.cmds = append(c.cmds, cmd)
c.mu.Unlock()
return nil
}
// Close closes the pipeline, releasing any open resources.
func (c *Pipeline) Close() error {
c.mu.Lock()
c.discard()
c.closed = true
c.mu.Unlock()
return nil
}
// Discard resets the pipeline and discards queued commands.
func (c *Pipeline) Discard() error {
c.mu.Lock()
err := c.discard()
c.mu.Unlock()
return err
}
func (c *Pipeline) discard() error {
if c.closed {
return pool.ErrClosed
}
c.cmds = c.cmds[:0]
return nil
}
// Exec executes all previously queued commands using one
// client-server roundtrip.
//
// Exec always returns list of commands and error of the first failed
// command if any.
func (c *Pipeline) Exec() ([]Cmder, error) {
defer c.mu.Unlock()
c.mu.Lock()
if c.closed {
return nil, pool.ErrClosed
}
if len(c.cmds) == 0 {
return c.cmds, nil
}
cmds := c.cmds
c.cmds = nil
return cmds, c.exec(cmds)
}
func (c *Pipeline) pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
if err := fn(c); err != nil {
return nil, err
}
cmds, err := c.Exec()
_ = c.Close()
return cmds, err
}
func execCmds(cn *pool.Conn, cmds []Cmder) ([]Cmder, error) {
if err := writeCmd(cn, cmds...); err != nil {
setCmdsErr(cmds, err)
return cmds, err
}
var firstCmdErr error
var failedCmds []Cmder
for _, cmd := range cmds {
err := cmd.readReply(cn)
if err == nil {
continue
}
if firstCmdErr == nil {
firstCmdErr = err
}
if internal.IsRetryableError(err) {
failedCmds = append(failedCmds, cmd)
}
}
return failedCmds, firstCmdErr
}