singleflight

Documentation

Overview

Package singleflight provides a duplicate function call suppression mechanism.

Index

• type DoFunc
• type Group
  • func (g *Group) Do(ctx context.Context, key interface{}, ...) (v interface{}, shared bool, err error)
  • func (g *Group) Forget(key string)

Types

type DoFunc

type DoFunc func(ctx context.Context) (interface{}, error)

type Group

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

Group represents a class of work and forms a namespace in which units of work can be executed with duplicate suppression.

func (*Group) Do

func (g *Group) Do(ctx context.Context, key interface{}, fn func(ctx context.Context) (interface{}, error)) (v interface{}, shared bool, err error)

Do executes and returns the results of the given function, making sure that only one execution is in-flight for a given key at a time. If a duplicate comes in, the duplicate caller waits for the original to complete and receives the same results. The return value shared indicates whether v was given to multiple callers.

func (*Group) Forget

func (g *Group) Forget(key string)

Forget tells the singleflight to forget about a key. Future calls to Do for this key will call the function rather than waiting for an earlier call to complete.