_content/talks/2014/gotham-context/interface.go

//go:build ignore && OMIT
// +build ignore,OMIT

package context

import "time"

// A Context carries a deadline, cancellation signal, and request-scoped values
// across API boundaries. Its methods are safe for simultaneous use by multiple
// goroutines.
type Context interface {
	Done() <-chan struct{}                   // closed when this Context is canceled
	Err() error                              // why this Context was canceled
	Deadline() (deadline time.Time, ok bool) // when this Context will be canceled
	Value(key interface{}) interface{}       // data associated with this Context
}

// WithCancel returns a copy of parent whose Done channel is closed as soon as
// parent.Done is closed or cancel is called.
func WithCancel(parent Context) (ctx Context, cancel CancelFunc)

// A CancelFunc cancels a Context.
type CancelFunc func()

// WithTimeout returns a copy of parent whose Done channel is closed as soon as
// parent.Done is closed, cancel is called, or timeout elapses. The new
// Context's Deadline is the sooner of now+timeout and the parent's deadline, if
// any. If the timer is still running, the cancel function releases its
// resources.
func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc)

// WithValue returns a copy of parent whose Value method returns val for key.
func WithValue(parent Context, key interface{}, val interface{}) Context

// Background returns an empty Context. It is never canceled, has no deadline,
// and has no values. Background is typically used in main, init, and tests,
// and as the top-level Context for incoming requests.
func Background() Context