Documentation
¶
Index ¶
- Variables
- type Lock
- type LockError
- type Redis
- func (r *Redis) ObtainLockDeadline(ctx context.Context, key string, ttl, wait, backoff time.Duration) (lock *Lock, cancel func(), lockError *LockError)
- func (r *Redis) ObtainLockOnce(ctx context.Context, key string, ttl time.Duration) (*Lock, *LockError)
- func (r *Redis) ObtainLockRetry(ctx context.Context, key string, ttl time.Duration, retryNum int, ...) (*Lock, *LockError)
Examples ¶
Constants ¶
This section is empty.
Variables ¶
View Source
var ErrLockNotExists = errors.New("lock not exists")
Functions ¶
This section is empty.
Types ¶
type Lock ¶
type Lock struct {
// contains filtered or unexported fields
}
type LockError ¶
type LockError struct {
// contains filtered or unexported fields
}
LockError 获取锁返回的错误 Err() 表示获取锁未成功（包括 redis 操作失败、锁被占用的情况下获取不到锁等）
如需要判断锁被占用的情况下，获取不到锁，使用 ErrNotObtained()
if lockErr.ErrNotObtained() {
锁被占用，获取不到锁
} else if lockErr.Err() != nil {
redis 操作失败
}
func (*LockError) ErrNotObtained ¶
ErrNotObtained 是否未成功获取到锁（锁被占用） true： 未获取到锁
type Redis ¶
func (*Redis) ObtainLockDeadline ¶
func (r *Redis) ObtainLockDeadline(ctx context.Context, key string, ttl, wait, backoff time.Duration) (lock *Lock, cancel func(), lockError *LockError)
ObtainLockDeadline 每 backoff 时间重试一次获取锁，直到 wait 时间，如果还未获取到锁则返回
example: ttl is 1s，Retry every 500ms, for up-to a minute ObtainLockDeadline(context.Background(), "key", time.Second, time.Minute, 500 * time.Millisecond)
Example ¶
lock, cancel, lockErr := redisClient.ObtainLockDeadline(
context.Background(),
"redis:key",
time.Second*5,
time.Second,
time.Millisecond*500,
)
if lockErr.ErrNotObtained() {
// 没有获取到锁
} else if lockErr.Err() != nil {
// 没有获取到锁，或者 redis 操作错误
log.Fatal(lockErr.Error())
}
// 取消获取锁
defer cancel()
// 释放锁
lock.Release()
func (*Redis) ObtainLockOnce ¶
func (r *Redis) ObtainLockOnce(ctx context.Context, key string, ttl time.Duration) (*Lock, *LockError)
ObtainLockOnce 直接获取锁，只获取一次，redis 处理失败或者获取不到锁（锁被占用）直接返回
Example ¶
var err error
redisClient, err = NewRedisClient(&redis2.Options{
Network: "tcp",
Addr: "127.0.0.1:6379",
Password: "",
DB: 0,
})
if err != nil {
panic(err)
}
lock, lockErr := redisClient.ObtainLockOnce(context.Background(), "redis:key", time.Millisecond*500)
if lockErr.ErrNotObtained() {
// 没有获取到锁
} else if lockErr.Err() != nil {
// 没有获取到锁，或者 redis 操作错误
log.Fatal(lockErr.Error())
}
// 释放锁
lock.Release()
// 返回剩余的生存时间
_, _ = lock.TTL()
func (*Redis) ObtainLockRetry ¶
func (r *Redis) ObtainLockRetry(ctx context.Context, key string, ttl time.Duration, retryNum int, backoff time.Duration) (*Lock, *LockError)
ObtainLockRetry 每 backoff 时间重试一次获取锁，最多重试 retryNum 次数，如果还未获取到锁则返回
example: Retry every 100ms, for up-to 3x ObtainLockRetry(context.Background(), "key", time.Second, 3, 100 * time.Millisecond)
Example ¶
lock, lockErr := redisClient.ObtainLockRetry(
context.Background(),
"redis:key",
time.Second*10,
5,
time.Second,
)
if lockErr.ErrNotObtained() {
// 没有获取到锁
} else if lockErr.Err() != nil {
// 没有获取到锁，或者 redis 操作错误
log.Fatal(lockErr.Error())
}
// 释放锁
lock.Release()
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