dlock

Documentation

Index

• Variables
• type DelayFunc
• type ErrNodeTaken
  • func (err ErrNodeTaken) Error() string
• type ErrTaken
  • func (err ErrTaken) Error() string
• type Mutex
  • func (m *Mutex) Extend() (bool, error)
  • func (m *Mutex) ExtendContext(ctx context.Context) (bool, error)
  • func (m *Mutex) Lock() error
  • func (m *Mutex) LockContext(ctx context.Context) error
  • func (m *Mutex) Name() string
  • func (m *Mutex) TryLock() error
  • func (m *Mutex) TryLockContext(ctx context.Context) error
  • func (m *Mutex) Unlock() (bool, error)
  • func (m *Mutex) UnlockContext(ctx context.Context) (bool, error)
  • func (m *Mutex) Until() time.Time
  • func (m *Mutex) Value() string
• type MySync
  • func New(pools ...redis.Pool) *MySync
  • func (r *MySync) NewMutex(name string, options ...Option) *Mutex
• type Option
  • func WithDriftFactor(factor float64) Option
  • func WithExpiry(expiry time.Duration) Option
  • func WithFailFast(b bool) Option
  • func WithGenValueFunc(genValueFunc func() (string, error)) Option
  • func WithRetryDelay(delay time.Duration) Option
  • func WithRetryDelayFunc(delayFunc DelayFunc) Option
  • func WithSetNXOnExtend() Option
  • func WithShufflePools(b bool) Option
  • func WithTimeoutFactor(factor float64) Option
  • func WithTries(tries int) Option
  • func WithValue(v string) Option
• type OptionFunc
  • func (f OptionFunc) Apply(mutex *Mutex)
• type RedisError
  • func (e RedisError) Error() string
  • func (e RedisError) Unwrap() error

Variables

var ErrExtendFailed = errors.New("redsync: failed to extend lock")

ErrExtendFailed is the error resulting if Redsync fails to extend the lock.

var ErrFailed = errors.New("redsync: failed to acquire lock")

ErrFailed is the error resulting if Redsync fails to acquire the lock after exhausting all retries.

var ErrLockAlreadyExpired = errors.New("redsync: failed to unlock, lock was already expired")

ErrLockAlreadyExpired is the error resulting if trying to unlock the lock which already expired.

Types

type DelayFunc

type DelayFunc func(tries int) time.Duration

DelayFunc 设置重试时间

type ErrNodeTaken

type ErrNodeTaken struct {
	Node int
}

ErrNodeTaken is the error resulting if the lock is already taken in one of the cluster's nodes

func (ErrNodeTaken) Error

func (err ErrNodeTaken) Error() string

type ErrTaken

type ErrTaken struct {
	Nodes []int
}

ErrTaken happens when the lock is already taken in a quorum on nodes.

func (ErrTaken) Error

func (err ErrTaken) Error() string

type Mutex

type Mutex struct {
	// contains filtered or unexported fields
}

Mutex 分布式锁对象

func (*Mutex) Extend

func (m *Mutex) Extend() (bool, error)

Extend resets the mutex's expiry and returns the status of expiry extension.

func (*Mutex) ExtendContext

func (m *Mutex) ExtendContext(ctx context.Context) (bool, error)

func (*Mutex) Lock

func (m *Mutex) Lock() error

Lock locks m. In case it returns an error on failure, you may retry to acquire the lock by calling this method again.

func (*Mutex) LockContext

func (m *Mutex) LockContext(ctx context.Context) error

LockContext locks m. In case it returns an error on failure, you may retry to acquire the lock by calling this method again.

func (*Mutex) Name

func (m *Mutex) Name() string

Name returns mutex name (i.e. the Redis key).

func (*Mutex) TryLock

func (m *Mutex) TryLock() error

TryLock only attempts to lock m once and returns immediately regardless of success or failure without retrying.

func (*Mutex) TryLockContext

func (m *Mutex) TryLockContext(ctx context.Context) error

TryLockContext only attempts to lock m once and returns immediately regardless of success or failure without retrying.

func (*Mutex) Unlock

func (m *Mutex) Unlock() (bool, error)

Unlock unlocks m and returns the status of unlock.

func (*Mutex) UnlockContext

func (m *Mutex) UnlockContext(ctx context.Context) (bool, error)

UnlockContext unlocks m and returns the status of unlock.

func (*Mutex) Until

func (m *Mutex) Until() time.Time

Until returns the time of validity of acquired lock. The value will be zero value until a lock is acquired.

func (*Mutex) Value

func (m *Mutex) Value() string

Value returns the current random value. The value will be empty until a lock is acquired (or WithValue option is used).

type MySync

type MySync struct {
	// contains filtered or unexported fields
}

MySync 封装 通过redis连接池创建多个分布式锁

func New

func New(pools ...redis.Pool) *MySync

func (*MySync) NewMutex

func (r *MySync) NewMutex(name string, options ...Option) *Mutex

type Option

type Option interface {
	Apply(*Mutex)
}

func WithDriftFactor

func WithDriftFactor(factor float64) Option

WithDriftFactor can be used to set the clock drift factor. The default value is 0.01.

func WithExpiry

func WithExpiry(expiry time.Duration) Option

WithExpiry can be used to set the expiry of a mutex to the given value. The default is 8s.

func WithFailFast

func WithFailFast(b bool) Option

WithFailFast can be used to quickly acquire and release the lock. When some Redis servers are blocking, we do not need to wait for responses from all the Redis servers response. As long as the quorum is met, we can assume the lock is acquired. The effect of this parameter is to achieve low latency, avoid Redis blocking causing Lock/Unlock to not return for a long time.

func WithGenValueFunc

func WithGenValueFunc(genValueFunc func() (string, error)) Option

WithGenValueFunc can be used to set the custom value generator.

func WithRetryDelay

func WithRetryDelay(delay time.Duration) Option

WithRetryDelay can be used to set the amount of time to wait between retries. The default value is rand(50ms, 250ms).

func WithRetryDelayFunc

func WithRetryDelayFunc(delayFunc DelayFunc) Option

WithRetryDelayFunc can be used to override default delay behavior.

func WithSetNXOnExtend

func WithSetNXOnExtend() Option

WithSetNXOnExtend improves extending logic to extend the key if exist and if not, tries to set a new key in redis Useful if your redises restart often and you want to reduce the chances of losing the lock Read this MR for more info: https://github.com/go-redsync/redsync/pull/149

func WithShufflePools

func WithShufflePools(b bool) Option

WithShufflePools can be used to shuffle Redis pools to reduce centralized access in concurrent scenarios.

func WithTimeoutFactor

func WithTimeoutFactor(factor float64) Option

WithTimeoutFactor can be used to set the timeout factor. The default value is 0.05.

func WithTries

func WithTries(tries int) Option

WithTries can be used to set the number of times lock acquire is attempted. The default value is 32.

func WithValue

func WithValue(v string) Option

WithValue can be used to assign the random value without having to call lock. This allows the ownership of a lock to be "transferred" and allows the lock to be unlocked from elsewhere.

type OptionFunc

type OptionFunc func(*Mutex)

OptionFunc is a function that configures a mutex.

func (OptionFunc) Apply

func (f OptionFunc) Apply(mutex *Mutex)

Apply calls f(mutex)

type RedisError

type RedisError struct {
	Node int
	Err  error
}

A RedisError is an error communicating with one of the Redis nodes.

func (RedisError) Error

func (e RedisError) Error() string

func (RedisError) Unwrap

func (e RedisError) Unwrap() error