package recipe

import "go.etcd.io/etcd/client/v3/experimental/recipes"

Package recipe contains experimental client-side distributed synchronization primitives.

Index ¶

• Variables
• func WaitEvents(c *clientv3.Client, key string, rev int64, evs []mvccpb.Event_EventType) (*clientv3.Event, error)
• func WaitPrefixEvents(c *clientv3.Client, prefix string, rev int64, evs []mvccpb.Event_EventType) (*clientv3.Event, error)
• type Barrier
• func NewBarrier(client *v3.Client, key string) *Barrier
• func (b *Barrier) Hold() error
• func (b *Barrier) Release() error
• func (b *Barrier) Wait() error
• type DoubleBarrier
• func NewDoubleBarrier(s *concurrency.Session, key string, count int) *DoubleBarrier
• func (b *DoubleBarrier) Enter() error
• func (b *DoubleBarrier) Leave() error
• type EphemeralKV
• type PriorityQueue
• func NewPriorityQueue(client *v3.Client, key string) *PriorityQueue
• func (q *PriorityQueue) Dequeue() (string, error)
• func (q *PriorityQueue) Enqueue(val string, pr uint16) error
• type Queue
• func NewQueue(client *v3.Client, keyPrefix string) *Queue
• func (q *Queue) Dequeue() (string, error)
• func (q *Queue) Enqueue(val string) error
• type RWMutex
• func NewRWMutex(s *concurrency.Session, prefix string) *RWMutex
• func (rwm *RWMutex) Lock() error
• func (rwm *RWMutex) RLock() error
• func (rwm *RWMutex) RUnlock() error
• func (rwm *RWMutex) Unlock() error
• type RemoteKV
• func (rk *RemoteKV) Delete() error
• func (rk *RemoteKV) Key() string
• func (rk *RemoteKV) Put(val string) error
• func (rk *RemoteKV) Revision() int64
• func (rk *RemoteKV) Value() string

Variables ¶

var (
	ErrKeyExists      = errors.New("key already exists")
	ErrWaitMismatch   = errors.New("unexpected wait result")
	ErrTooManyClients = errors.New("too many clients")
	ErrNoWatcher      = errors.New("no watcher channel")
)

Functions ¶

func WaitEvents ¶

func WaitEvents(c *clientv3.Client, key string, rev int64, evs []mvccpb.Event_EventType) (*clientv3.Event, error)

WaitEvents waits on a key until it observes the given events and returns the final one.

func WaitPrefixEvents ¶

func WaitPrefixEvents(c *clientv3.Client, prefix string, rev int64, evs []mvccpb.Event_EventType) (*clientv3.Event, error)

Types ¶

type Barrier ¶

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

Barrier creates a key in etcd to block processes, then deletes the key to release all blocked processes.

func NewBarrier ¶

func NewBarrier(client *v3.Client, key string) *Barrier

func (*Barrier) Hold ¶

func (b *Barrier) Hold() error

Hold creates the barrier key causing processes to block on Wait.

func (*Barrier) Release ¶

func (b *Barrier) Release() error

Release deletes the barrier key to unblock all waiting processes.

func (*Barrier) Wait ¶

func (b *Barrier) Wait() error

Wait blocks on the barrier key until it is deleted. If there is no key, Wait assumes Release has already been called and returns immediately.

type DoubleBarrier ¶

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

DoubleBarrier blocks processes on Enter until an expected count enters, then blocks again on Leave until all processes have left.

func NewDoubleBarrier ¶

func NewDoubleBarrier(s *concurrency.Session, key string, count int) *DoubleBarrier

func (*DoubleBarrier) Enter ¶

func (b *DoubleBarrier) Enter() error

Enter waits for "count" processes to enter the barrier then returns

func (*DoubleBarrier) Leave ¶

func (b *DoubleBarrier) Leave() error

Leave waits for "count" processes to leave the barrier then returns

type EphemeralKV ¶

type EphemeralKV struct{ RemoteKV }

EphemeralKV is a new key associated with a session lease

type PriorityQueue ¶

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

PriorityQueue implements a multi-reader, multi-writer distributed queue.

func NewPriorityQueue ¶

func NewPriorityQueue(client *v3.Client, key string) *PriorityQueue

NewPriorityQueue creates an etcd priority queue.

func (*PriorityQueue) Dequeue ¶

func (q *PriorityQueue) Dequeue() (string, error)

Dequeue returns Enqueue()'d items in FIFO order. If the queue is empty, Dequeue blocks until items are available.

func (*PriorityQueue) Enqueue ¶

func (q *PriorityQueue) Enqueue(val string, pr uint16) error

Enqueue puts a value into a queue with a given priority.

type Queue ¶

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

Queue implements a multi-reader, multi-writer distributed queue.

func NewQueue ¶

func NewQueue(client *v3.Client, keyPrefix string) *Queue

func (*Queue) Dequeue ¶

func (q *Queue) Dequeue() (string, error)

Dequeue returns Enqueue()'d elements in FIFO order. If the queue is empty, Dequeue blocks until elements are available.

func (*Queue) Enqueue ¶

func (q *Queue) Enqueue(val string) error

type RWMutex ¶

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

func NewRWMutex ¶

func NewRWMutex(s *concurrency.Session, prefix string) *RWMutex

func (*RWMutex) Lock ¶

func (rwm *RWMutex) Lock() error

func (*RWMutex) RLock ¶

func (rwm *RWMutex) RLock() error

func (*RWMutex) RUnlock ¶

func (rwm *RWMutex) RUnlock() error

func (*RWMutex) Unlock ¶

func (rwm *RWMutex) Unlock() error

type RemoteKV ¶

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

RemoteKV is a key/revision pair created by the client and stored on etcd

func (*RemoteKV) Delete ¶

func (rk *RemoteKV) Delete() error

func (*RemoteKV) Key ¶

func (rk *RemoteKV) Key() string

func (*RemoteKV) Put ¶

func (rk *RemoteKV) Put(val string) error

func (*RemoteKV) Revision ¶

func (rk *RemoteKV) Revision() int64

func (*RemoteKV) Value ¶

func (rk *RemoteKV) Value() string

Source Files ¶

barrier.go client.go doc.go double_barrier.go key.go priority_queue.go queue.go rwmutex.go watch.go