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gitea/vendor/gopkg.in/redis.v2/multi.go

139 lines
2.6 KiB
Go

package redis
import (
"errors"
"fmt"
)
var errDiscard = errors.New("redis: Discard can be used only inside Exec")
// Not thread-safe.
type Multi struct {
*Client
}
func (c *Client) Multi() *Multi {
return &Multi{
Client: &Client{
baseClient: &baseClient{
opt: c.opt,
connPool: newSingleConnPool(c.connPool, true),
},
},
}
}
func (c *Multi) Close() error {
if err := c.Unwatch().Err(); err != nil {
return err
}
return c.Client.Close()
}
func (c *Multi) Watch(keys ...string) *StatusCmd {
args := append([]string{"WATCH"}, keys...)
cmd := NewStatusCmd(args...)
c.Process(cmd)
return cmd
}
func (c *Multi) Unwatch(keys ...string) *StatusCmd {
args := append([]string{"UNWATCH"}, keys...)
cmd := NewStatusCmd(args...)
c.Process(cmd)
return cmd
}
func (c *Multi) Discard() error {
if c.cmds == nil {
return errDiscard
}
c.cmds = c.cmds[:1]
return nil
}
// Exec always returns list of commands. If transaction fails
// TxFailedErr is returned. Otherwise Exec returns error of the first
// failed command or nil.
func (c *Multi) Exec(f func() error) ([]Cmder, error) {
c.cmds = []Cmder{NewStatusCmd("MULTI")}
if err := f(); err != nil {
return nil, err
}
c.cmds = append(c.cmds, NewSliceCmd("EXEC"))
cmds := c.cmds
c.cmds = nil
if len(cmds) == 2 {
return []Cmder{}, nil
}
cn, err := c.conn()
if err != nil {
setCmdsErr(cmds[1:len(cmds)-1], err)
return cmds[1 : len(cmds)-1], err
}
err = c.execCmds(cn, cmds)
if err != nil {
c.freeConn(cn, err)
return cmds[1 : len(cmds)-1], err
}
c.putConn(cn)
return cmds[1 : len(cmds)-1], nil
}
func (c *Multi) execCmds(cn *conn, cmds []Cmder) error {
err := c.writeCmd(cn, cmds...)
if err != nil {
setCmdsErr(cmds[1:len(cmds)-1], err)
return err
}
statusCmd := NewStatusCmd()
// Omit last command (EXEC).
cmdsLen := len(cmds) - 1
// Parse queued replies.
for i := 0; i < cmdsLen; i++ {
if err := statusCmd.parseReply(cn.rd); err != nil {
setCmdsErr(cmds[1:len(cmds)-1], err)
return err
}
}
// Parse number of replies.
line, err := readLine(cn.rd)
if err != nil {
setCmdsErr(cmds[1:len(cmds)-1], err)
return err
}
if line[0] != '*' {
err := fmt.Errorf("redis: expected '*', but got line %q", line)
setCmdsErr(cmds[1:len(cmds)-1], err)
return err
}
if len(line) == 3 && line[1] == '-' && line[2] == '1' {
setCmdsErr(cmds[1:len(cmds)-1], TxFailedErr)
return TxFailedErr
}
var firstCmdErr error
// Parse replies.
// Loop starts from 1 to omit MULTI cmd.
for i := 1; i < cmdsLen; i++ {
cmd := cmds[i]
if err := cmd.parseReply(cn.rd); err != nil {
if firstCmdErr == nil {
firstCmdErr = err
}
}
}
return firstCmdErr
}