blog_backend_api/vendor/gopkg.in/redis.v3/cluster_pipeline.go

141 lines
3.0 KiB
Go

package redis
import (
"gopkg.in/redis.v3/internal/hashtag"
"gopkg.in/redis.v3/internal/pool"
)
// ClusterPipeline is not thread-safe.
type ClusterPipeline struct {
commandable
cluster *ClusterClient
cmds []Cmder
closed bool
}
// Pipeline creates a new pipeline which is able to execute commands
// against multiple shards. It's NOT safe for concurrent use by
// multiple goroutines.
func (c *ClusterClient) Pipeline() *ClusterPipeline {
pipe := &ClusterPipeline{
cluster: c,
cmds: make([]Cmder, 0, 10),
}
pipe.commandable.process = pipe.process
return pipe
}
func (c *ClusterClient) Pipelined(fn func(*ClusterPipeline) error) ([]Cmder, error) {
pipe := c.Pipeline()
if err := fn(pipe); err != nil {
return nil, err
}
cmds, err := pipe.Exec()
_ = pipe.Close()
return cmds, err
}
func (pipe *ClusterPipeline) process(cmd Cmder) {
pipe.cmds = append(pipe.cmds, cmd)
}
// Discard resets the pipeline and discards queued commands.
func (pipe *ClusterPipeline) Discard() error {
if pipe.closed {
return pool.ErrClosed
}
pipe.cmds = pipe.cmds[:0]
return nil
}
func (pipe *ClusterPipeline) Exec() (cmds []Cmder, retErr error) {
if pipe.closed {
return nil, pool.ErrClosed
}
if len(pipe.cmds) == 0 {
return []Cmder{}, nil
}
cmds = pipe.cmds
pipe.cmds = make([]Cmder, 0, 10)
cmdsMap := make(map[string][]Cmder)
for _, cmd := range cmds {
slot := hashtag.Slot(cmd.clusterKey())
addr := pipe.cluster.slotMasterAddr(slot)
cmdsMap[addr] = append(cmdsMap[addr], cmd)
}
for attempt := 0; attempt <= pipe.cluster.opt.getMaxRedirects(); attempt++ {
failedCmds := make(map[string][]Cmder)
for addr, cmds := range cmdsMap {
client, err := pipe.cluster.getClient(addr)
if err != nil {
setCmdsErr(cmds, err)
retErr = err
continue
}
cn, err := client.conn()
if err != nil {
setCmdsErr(cmds, err)
retErr = err
continue
}
failedCmds, err = pipe.execClusterCmds(cn, cmds, failedCmds)
if err != nil {
retErr = err
}
client.putConn(cn, err, false)
}
cmdsMap = failedCmds
}
return cmds, retErr
}
// Close closes the pipeline, releasing any open resources.
func (pipe *ClusterPipeline) Close() error {
pipe.Discard()
pipe.closed = true
return nil
}
func (pipe *ClusterPipeline) execClusterCmds(
cn *pool.Conn, cmds []Cmder, failedCmds map[string][]Cmder,
) (map[string][]Cmder, error) {
if err := writeCmd(cn, cmds...); err != nil {
setCmdsErr(cmds, err)
return failedCmds, err
}
var firstCmdErr error
for i, cmd := range cmds {
err := cmd.readReply(cn)
if err == nil {
continue
}
if isNetworkError(err) {
cmd.reset()
failedCmds[""] = append(failedCmds[""], cmds[i:]...)
break
} else if moved, ask, addr := isMovedError(err); moved {
pipe.cluster.lazyReloadSlots()
cmd.reset()
failedCmds[addr] = append(failedCmds[addr], cmd)
} else if ask {
cmd.reset()
failedCmds[addr] = append(failedCmds[addr], NewCmd("ASKING"), cmd)
} else if firstCmdErr == nil {
firstCmdErr = err
}
}
return failedCmds, firstCmdErr
}