redis/pipeline.go

89 lines
1.5 KiB
Go

package redis
import (
"errors"
"sync"
"gopkg.in/redis.v5/internal/pool"
)
type pipelineExecer func([]Cmder) error
// 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 pipelineExecer
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 nil, errors.New("redis: pipeline is empty")
}
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
}