dsync

Documentation

Index

• Variables
• func GetSeparator(servCtx service.Context) string
• func Path(servCtx service.Context, elems ...string) string
• type DelayFunc
• type DistMutexOptions
• type GenValueFunc
• type IDistMutex
  • func NewMutex(servCtx service.Context, name string, ...) IDistMutex
• type IDistSync
• type Option
  • func (Option) Default() option.Setting[DistMutexOptions]
  • func (Option) DriftFactor(factor float64) option.Setting[DistMutexOptions]
  • func (Option) Expiry(expiry time.Duration) option.Setting[DistMutexOptions]
  • func (Option) GenValueFunc(fn GenValueFunc) option.Setting[DistMutexOptions]
  • func (Option) RetryDelay(delay time.Duration) option.Setting[DistMutexOptions]
  • func (Option) RetryDelayFunc(fn DelayFunc) option.Setting[DistMutexOptions]
  • func (Option) TimeoutFactor(factor float64) option.Setting[DistMutexOptions]
  • func (Option) Tries(tries int) option.Setting[DistMutexOptions]
  • func (Option) Value(v string) option.Setting[DistMutexOptions]

Variables

var (
	Name  = plugin.Name
	Using = plugin.Using
)

var (
	// ErrDsync dsync errors.
	ErrDsync = errors.New("dsync")
	// ErrNotAcquired is an error indicating that the distributed lock was not acquired. It is returned by IDistMutex.Unlock and IDistMutex.Extend when the lock was not successfully acquired or has expired.
	ErrNotAcquired = fmt.Errorf("%w: lock is not acquired", ErrDsync)
)

Functions

func GetSeparator

func GetSeparator(servCtx service.Context) string

GetSeparator return name path separator.

func Path

func Path(servCtx service.Context, elems ...string) string

Path return name path.

Types

type DelayFunc

type DelayFunc = generic.Func1[int, time.Duration]

A DelayFunc is used to decide the amount of time to wait between retries.

type DistMutexOptions

type DistMutexOptions struct {
	Expiry        time.Duration
	Tries         int
	DelayFunc     DelayFunc
	DriftFactor   float64
	TimeoutFactor float64
	GenValueFunc  GenValueFunc
	Value         string
}

DistMutexOptions represents the options for acquiring a distributed mutex.

type GenValueFunc

type GenValueFunc = generic.PairFunc0[string, error]

GenValueFunc is used to generate a random value.

type IDistMutex

type IDistMutex interface {
	// Name returns mutex name.
	Name() string
	// Value returns the current random value. The value will be empty until a lock is acquired (or Value option is used).
	Value() string
	// Until returns the time of validity of acquired lock. The value will be zero value until a lock is acquired.
	Until() time.Time
	// Lock locks m. In case it returns an error on failure, you may retry to acquire the lock by calling this method again.
	Lock(ctx context.Context) error
	// Unlock unlocks m and returns the status of unlock.
	Unlock(ctx context.Context) error
	// Extend resets the mutex's expiry and returns the status of expiry extension.
	Extend(ctx context.Context) error
	// Valid returns true if the lock acquired through m is still valid. It may also return true erroneously if quorum is achieved during the call and at
	// least one node then takes long enough to respond for the lock to expire.
	Valid(ctx context.Context) (bool, error)
}

A IDistMutex is a distributed mutual exclusion lock. Avoid sharing the same IDistMutex instance among multiple goroutines. Create a separate IDistMutex instance for each goroutine.

func NewMutex

func NewMutex(servCtx service.Context, name string, settings ...option.Setting[DistMutexOptions]) IDistMutex

NewMutex returns a new distributed mutex with given name.

type IDistSync

type IDistSync interface {
	// NewMutex returns a new distributed mutex with given name.
	NewMutex(name string, settings ...option.Setting[DistMutexOptions]) IDistMutex
	// GetSeparator return name path separator.
	GetSeparator() string
}

IDistSync represents a distributed synchronization mechanism.

type Option

type Option struct{}

Option is a helper struct to provide default options.

func (Option) Default

func (Option) Default() option.Setting[DistMutexOptions]

Default sets the default options for acquiring a distributed mutex.

func (Option) DriftFactor

func (Option) DriftFactor(factor float64) option.Setting[DistMutexOptions]

DriftFactor can be used to set the clock drift factor.

func (Option) Expiry

func (Option) Expiry(expiry time.Duration) option.Setting[DistMutexOptions]

Expiry can be used to set the expiry of a mutex to the given value.

func (Option) GenValueFunc

func (Option) GenValueFunc(fn GenValueFunc) option.Setting[DistMutexOptions]

GenValueFunc can be used to set the custom value generator.

func (Option) RetryDelay

func (Option) RetryDelay(delay time.Duration) option.Setting[DistMutexOptions]

RetryDelay can be used to set the amount of time to wait between retries.

func (Option) RetryDelayFunc

func (Option) RetryDelayFunc(fn DelayFunc) option.Setting[DistMutexOptions]

RetryDelayFunc can be used to override default delay behavior.

func (Option) TimeoutFactor

func (Option) TimeoutFactor(factor float64) option.Setting[DistMutexOptions]

TimeoutFactor can be used to set the timeout factor.

func (Option) Tries

func (Option) Tries(tries int) option.Setting[DistMutexOptions]

Tries can be used to set the number of times lock acquire is attempted.

func (Option) Value

func (Option) Value(v string) option.Setting[DistMutexOptions]

Value 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.