singleflight

Documentation

Overview

Package singleflight provides a duplicate function call suppression mechanism.

Index

• type Group
  • func (g *Group) Do(key string, fn func() (interface{}, error)) (v interface{}, count int, err error)
• type Result

Types

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(key string, fn func() (interface{}, error)) (v interface{}, count int, 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 of Count indicates how many tiems v was given to multiple callers. Count will be zero for requests are shared and only be non-zero for the originating request.

type Result

type Result struct {
	Val   interface{}
	Err   error
	Count bool
}

Result holds the results of Do, so they can be passed on a channel.