idempotent

Documentation

Index

• Variables
• func FromRequest(req *http.Request, rec Recorder) (key string, seen bool)
• func SeenBefore(w http.ResponseWriter)
• type Recorder

Variables

var (
	ErrSeenBefore = errors.New("X-Idempotency-Key seen before")
)

Functions

func FromRequest

func FromRequest(req *http.Request, rec Recorder) (key string, seen bool)

FromRequest extracts the idempotency key from HTTP headers and records its presence in the provided Recorder.

A nil Recorder will always return idempotency keys as unseen.

func SeenBefore

func SeenBefore(w http.ResponseWriter)

SeenBefore sets a HTTP response code as an error for previously seen idempotency keys.

Types

type Recorder

type Recorder interface {
	SeenBefore(key string) bool
}

Recorder offers a method to determine if a given key has been seen before or not. Each invocation of SeenBefore needs to record each key found, but there's no minimum duration required.