go-common/app/job/live/xlottery/internal/dao/cache.go
2019-04-22 18:49:16 +08:00

71 lines
1.5 KiB
Go

package dao
import (
"context"
"math/rand"
"time"
"go-common/library/cache/redis"
"go-common/library/log"
)
func randomString(l int) string {
str := "0123456789abcdefghijklmnopqrstuvwxyz"
bytes := []byte(str)
result := []byte{}
r := rand.New(rand.NewSource(time.Now().UnixNano()))
for i := 0; i < l; i++ {
result = append(result, bytes[r.Intn(len(bytes))])
}
return string(result)
}
// Lock .
func (d *Dao) Lock(ctx context.Context, realKey string, ttl int, retry int, retryDelay int) (gotLock bool, lockValue string, err error) {
if retry <= 0 {
retry = 1
}
lockValue = "locked:" + randomString(5)
retryTimes := 0
conn := d.redis.Get(ctx)
defer conn.Close()
for ; retryTimes < retry; retryTimes++ {
var res interface{}
res, err = conn.Do("SET", realKey, lockValue, "PX", ttl, "NX")
if err != nil {
log.Error("redis_lock failed:%s:%s", realKey, err.Error())
break
}
if res != nil {
gotLock = true
break
}
time.Sleep(time.Duration(retryDelay * 1000))
}
return
}
// UnLock .
func (d *Dao) UnLock(ctx context.Context, realKey string, lockValue string) (err error) {
conn := d.redis.Get(ctx)
defer conn.Close()
res, err := redis.String(conn.Do("GET", realKey))
if err != nil {
log.Error("redis_unlock get error:%s:%v", realKey, err)
return
}
if res != lockValue {
err = ErrUnLockGet
return
}
_, err = conn.Do("DEL", realKey)
if err != nil {
log.Error("redis_unlock del error:%s:%v", realKey, err)
}
return
}