Merge pull request #1641 from prometheus/beorn7/vendoring
Update vendoring of golang.org/x/net/context/...
This commit is contained in:
commit
d9394eb359
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@ -36,12 +36,7 @@
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// Contexts.
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package context // import "golang.org/x/net/context"
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import (
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"errors"
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"fmt"
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"sync"
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"time"
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)
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import "time"
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// A Context carries a deadline, a cancelation signal, and other values across
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// API boundaries.
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@ -66,7 +61,7 @@ type Context interface {
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//
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// // Stream generates values with DoSomething and sends them to out
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// // until DoSomething returns an error or ctx.Done is closed.
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// func Stream(ctx context.Context, out <-chan Value) error {
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// func Stream(ctx context.Context, out chan<- Value) error {
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// for {
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// v, err := DoSomething(ctx)
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// if err != nil {
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@ -138,48 +133,6 @@ type Context interface {
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Value(key interface{}) interface{}
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}
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// Canceled is the error returned by Context.Err when the context is canceled.
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var Canceled = errors.New("context canceled")
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// DeadlineExceeded is the error returned by Context.Err when the context's
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// deadline passes.
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var DeadlineExceeded = errors.New("context deadline exceeded")
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// An emptyCtx is never canceled, has no values, and has no deadline. It is not
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// struct{}, since vars of this type must have distinct addresses.
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type emptyCtx int
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func (*emptyCtx) Deadline() (deadline time.Time, ok bool) {
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return
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}
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func (*emptyCtx) Done() <-chan struct{} {
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return nil
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}
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func (*emptyCtx) Err() error {
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return nil
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}
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func (*emptyCtx) Value(key interface{}) interface{} {
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return nil
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}
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func (e *emptyCtx) String() string {
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switch e {
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case background:
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return "context.Background"
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case todo:
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return "context.TODO"
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}
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return "unknown empty Context"
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}
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var (
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background = new(emptyCtx)
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todo = new(emptyCtx)
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)
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// Background returns a non-nil, empty Context. It is never canceled, has no
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// values, and has no deadline. It is typically used by the main function,
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// initialization, and tests, and as the top-level Context for incoming
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@ -189,7 +142,7 @@ func Background() Context {
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}
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// TODO returns a non-nil, empty Context. Code should use context.TODO when
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// it's unclear which Context to use or it's is not yet available (because the
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// it's unclear which Context to use or it is not yet available (because the
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// surrounding function has not yet been extended to accept a Context
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// parameter). TODO is recognized by static analysis tools that determine
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// whether Contexts are propagated correctly in a program.
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@ -201,247 +154,3 @@ func TODO() Context {
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// A CancelFunc does not wait for the work to stop.
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// After the first call, subsequent calls to a CancelFunc do nothing.
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type CancelFunc func()
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// WithCancel returns a copy of parent with a new Done channel. The returned
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// context's Done channel is closed when the returned cancel function is called
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// or when the parent context's Done channel is closed, whichever happens first.
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//
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// Canceling this context releases resources associated with it, so code should
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// call cancel as soon as the operations running in this Context complete.
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func WithCancel(parent Context) (ctx Context, cancel CancelFunc) {
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c := newCancelCtx(parent)
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propagateCancel(parent, &c)
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return &c, func() { c.cancel(true, Canceled) }
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}
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// newCancelCtx returns an initialized cancelCtx.
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func newCancelCtx(parent Context) cancelCtx {
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return cancelCtx{
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Context: parent,
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done: make(chan struct{}),
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}
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}
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// propagateCancel arranges for child to be canceled when parent is.
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func propagateCancel(parent Context, child canceler) {
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if parent.Done() == nil {
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return // parent is never canceled
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}
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if p, ok := parentCancelCtx(parent); ok {
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p.mu.Lock()
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if p.err != nil {
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// parent has already been canceled
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child.cancel(false, p.err)
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} else {
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if p.children == nil {
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p.children = make(map[canceler]bool)
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}
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p.children[child] = true
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}
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p.mu.Unlock()
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} else {
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go func() {
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select {
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case <-parent.Done():
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child.cancel(false, parent.Err())
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case <-child.Done():
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}
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}()
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}
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}
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// parentCancelCtx follows a chain of parent references until it finds a
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// *cancelCtx. This function understands how each of the concrete types in this
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// package represents its parent.
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func parentCancelCtx(parent Context) (*cancelCtx, bool) {
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for {
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switch c := parent.(type) {
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case *cancelCtx:
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return c, true
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case *timerCtx:
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return &c.cancelCtx, true
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case *valueCtx:
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parent = c.Context
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default:
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return nil, false
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}
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}
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}
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// removeChild removes a context from its parent.
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func removeChild(parent Context, child canceler) {
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p, ok := parentCancelCtx(parent)
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if !ok {
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return
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}
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p.mu.Lock()
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if p.children != nil {
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delete(p.children, child)
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}
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p.mu.Unlock()
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}
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// A canceler is a context type that can be canceled directly. The
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// implementations are *cancelCtx and *timerCtx.
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type canceler interface {
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cancel(removeFromParent bool, err error)
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Done() <-chan struct{}
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}
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// A cancelCtx can be canceled. When canceled, it also cancels any children
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// that implement canceler.
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type cancelCtx struct {
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Context
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done chan struct{} // closed by the first cancel call.
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mu sync.Mutex
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children map[canceler]bool // set to nil by the first cancel call
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err error // set to non-nil by the first cancel call
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}
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func (c *cancelCtx) Done() <-chan struct{} {
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return c.done
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}
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func (c *cancelCtx) Err() error {
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c.mu.Lock()
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defer c.mu.Unlock()
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return c.err
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}
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func (c *cancelCtx) String() string {
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return fmt.Sprintf("%v.WithCancel", c.Context)
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}
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// cancel closes c.done, cancels each of c's children, and, if
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// removeFromParent is true, removes c from its parent's children.
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func (c *cancelCtx) cancel(removeFromParent bool, err error) {
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if err == nil {
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panic("context: internal error: missing cancel error")
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}
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c.mu.Lock()
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if c.err != nil {
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c.mu.Unlock()
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return // already canceled
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}
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c.err = err
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close(c.done)
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for child := range c.children {
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// NOTE: acquiring the child's lock while holding parent's lock.
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child.cancel(false, err)
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}
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c.children = nil
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c.mu.Unlock()
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if removeFromParent {
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removeChild(c.Context, c)
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}
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}
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// WithDeadline returns a copy of the parent context with the deadline adjusted
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// to be no later than d. If the parent's deadline is already earlier than d,
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// WithDeadline(parent, d) is semantically equivalent to parent. The returned
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// context's Done channel is closed when the deadline expires, when the returned
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// cancel function is called, or when the parent context's Done channel is
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// closed, whichever happens first.
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//
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// Canceling this context releases resources associated with it, so code should
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// call cancel as soon as the operations running in this Context complete.
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func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) {
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if cur, ok := parent.Deadline(); ok && cur.Before(deadline) {
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// The current deadline is already sooner than the new one.
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return WithCancel(parent)
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}
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c := &timerCtx{
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cancelCtx: newCancelCtx(parent),
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deadline: deadline,
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}
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propagateCancel(parent, c)
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d := deadline.Sub(time.Now())
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if d <= 0 {
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c.cancel(true, DeadlineExceeded) // deadline has already passed
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return c, func() { c.cancel(true, Canceled) }
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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if c.err == nil {
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c.timer = time.AfterFunc(d, func() {
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c.cancel(true, DeadlineExceeded)
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})
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}
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return c, func() { c.cancel(true, Canceled) }
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}
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// A timerCtx carries a timer and a deadline. It embeds a cancelCtx to
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// implement Done and Err. It implements cancel by stopping its timer then
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// delegating to cancelCtx.cancel.
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type timerCtx struct {
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cancelCtx
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timer *time.Timer // Under cancelCtx.mu.
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deadline time.Time
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}
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func (c *timerCtx) Deadline() (deadline time.Time, ok bool) {
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return c.deadline, true
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}
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func (c *timerCtx) String() string {
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return fmt.Sprintf("%v.WithDeadline(%s [%s])", c.cancelCtx.Context, c.deadline, c.deadline.Sub(time.Now()))
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}
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func (c *timerCtx) cancel(removeFromParent bool, err error) {
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c.cancelCtx.cancel(false, err)
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if removeFromParent {
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// Remove this timerCtx from its parent cancelCtx's children.
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removeChild(c.cancelCtx.Context, c)
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}
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c.mu.Lock()
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if c.timer != nil {
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c.timer.Stop()
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c.timer = nil
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}
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c.mu.Unlock()
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}
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// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).
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//
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// Canceling this context releases resources associated with it, so code should
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// call cancel as soon as the operations running in this Context complete:
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//
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// func slowOperationWithTimeout(ctx context.Context) (Result, error) {
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// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
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// defer cancel() // releases resources if slowOperation completes before timeout elapses
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// return slowOperation(ctx)
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// }
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func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) {
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return WithDeadline(parent, time.Now().Add(timeout))
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}
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// WithValue returns a copy of parent in which the value associated with key is
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// val.
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//
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// Use context Values only for request-scoped data that transits processes and
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// APIs, not for passing optional parameters to functions.
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func WithValue(parent Context, key interface{}, val interface{}) Context {
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return &valueCtx{parent, key, val}
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}
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// A valueCtx carries a key-value pair. It implements Value for that key and
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// delegates all other calls to the embedded Context.
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type valueCtx struct {
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Context
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key, val interface{}
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}
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func (c *valueCtx) String() string {
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return fmt.Sprintf("%v.WithValue(%#v, %#v)", c.Context, c.key, c.val)
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}
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func (c *valueCtx) Value(key interface{}) interface{} {
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if c.key == key {
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return c.val
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}
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return c.Context.Value(key)
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}
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@ -1,18 +0,0 @@
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build go1.5
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package ctxhttp
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import "net/http"
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func canceler(client *http.Client, req *http.Request) func() {
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ch := make(chan struct{})
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req.Cancel = ch
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return func() {
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close(ch)
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}
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}
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@ -1,23 +0,0 @@
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build !go1.5
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package ctxhttp
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import "net/http"
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type requestCanceler interface {
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CancelRequest(*http.Request)
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}
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func canceler(client *http.Client, req *http.Request) func() {
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rc, ok := client.Transport.(requestCanceler)
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if !ok {
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return func() {}
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}
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return func() {
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rc.CancelRequest(req)
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}
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}
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@ -14,6 +14,14 @@ import (
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"golang.org/x/net/context"
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)
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func nop() {}
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var (
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testHookContextDoneBeforeHeaders = nop
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testHookDoReturned = nop
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testHookDidBodyClose = nop
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)
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// Do sends an HTTP request with the provided http.Client and returns an HTTP response.
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// If the client is nil, http.DefaultClient is used.
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// If the context is canceled or times out, ctx.Err() will be returned.
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|
@ -22,8 +30,9 @@ func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Resp
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client = http.DefaultClient
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}
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// Request cancelation changed in Go 1.5, see cancelreq.go and cancelreq_go14.go.
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cancel := canceler(client, req)
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// TODO(djd): Respect any existing value of req.Cancel.
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cancel := make(chan struct{})
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req.Cancel = cancel
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|
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type responseAndError struct {
|
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resp *http.Response
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|
@ -31,18 +40,51 @@ func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Resp
|
|||
}
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result := make(chan responseAndError, 1)
|
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|
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// Make local copies of test hooks closed over by goroutines below.
|
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// Prevents data races in tests.
|
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testHookDoReturned := testHookDoReturned
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testHookDidBodyClose := testHookDidBodyClose
|
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|
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go func() {
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resp, err := client.Do(req)
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testHookDoReturned()
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result <- responseAndError{resp, err}
|
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}()
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|
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var resp *http.Response
|
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|
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select {
|
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case <-ctx.Done():
|
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cancel()
|
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testHookContextDoneBeforeHeaders()
|
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close(cancel)
|
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// Clean up after the goroutine calling client.Do:
|
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go func() {
|
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if r := <-result; r.resp != nil {
|
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testHookDidBodyClose()
|
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r.resp.Body.Close()
|
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}
|
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}()
|
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return nil, ctx.Err()
|
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case r := <-result:
|
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return r.resp, r.err
|
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var err error
|
||||
resp, err = r.resp, r.err
|
||||
if err != nil {
|
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return resp, err
|
||||
}
|
||||
}
|
||||
|
||||
c := make(chan struct{})
|
||||
go func() {
|
||||
select {
|
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case <-ctx.Done():
|
||||
close(cancel)
|
||||
case <-c:
|
||||
// The response's Body is closed.
|
||||
}
|
||||
}()
|
||||
resp.Body = ¬ifyingReader{resp.Body, c}
|
||||
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
// Get issues a GET request via the Do function.
|
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|
@ -77,3 +119,28 @@ func Post(ctx context.Context, client *http.Client, url string, bodyType string,
|
|||
func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) {
|
||||
return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
|
||||
}
|
||||
|
||||
// notifyingReader is an io.ReadCloser that closes the notify channel after
|
||||
// Close is called or a Read fails on the underlying ReadCloser.
|
||||
type notifyingReader struct {
|
||||
io.ReadCloser
|
||||
notify chan<- struct{}
|
||||
}
|
||||
|
||||
func (r *notifyingReader) Read(p []byte) (int, error) {
|
||||
n, err := r.ReadCloser.Read(p)
|
||||
if err != nil && r.notify != nil {
|
||||
close(r.notify)
|
||||
r.notify = nil
|
||||
}
|
||||
return n, err
|
||||
}
|
||||
|
||||
func (r *notifyingReader) Close() error {
|
||||
err := r.ReadCloser.Close()
|
||||
if r.notify != nil {
|
||||
close(r.notify)
|
||||
r.notify = nil
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
|
|
@ -0,0 +1,72 @@
|
|||
// Copyright 2016 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// +build go1.7
|
||||
|
||||
package context
|
||||
|
||||
import (
|
||||
"context" // standard library's context, as of Go 1.7
|
||||
"time"
|
||||
)
|
||||
|
||||
var (
|
||||
todo = context.TODO()
|
||||
background = context.Background()
|
||||
)
|
||||
|
||||
// Canceled is the error returned by Context.Err when the context is canceled.
|
||||
var Canceled = context.Canceled
|
||||
|
||||
// DeadlineExceeded is the error returned by Context.Err when the context's
|
||||
// deadline passes.
|
||||
var DeadlineExceeded = context.DeadlineExceeded
|
||||
|
||||
// WithCancel returns a copy of parent with a new Done channel. The returned
|
||||
// context's Done channel is closed when the returned cancel function is called
|
||||
// or when the parent context's Done channel is closed, whichever happens first.
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete.
|
||||
func WithCancel(parent Context) (ctx Context, cancel CancelFunc) {
|
||||
ctx, f := context.WithCancel(parent)
|
||||
return ctx, CancelFunc(f)
|
||||
}
|
||||
|
||||
// WithDeadline returns a copy of the parent context with the deadline adjusted
|
||||
// to be no later than d. If the parent's deadline is already earlier than d,
|
||||
// WithDeadline(parent, d) is semantically equivalent to parent. The returned
|
||||
// context's Done channel is closed when the deadline expires, when the returned
|
||||
// cancel function is called, or when the parent context's Done channel is
|
||||
// closed, whichever happens first.
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete.
|
||||
func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) {
|
||||
ctx, f := context.WithDeadline(parent, deadline)
|
||||
return ctx, CancelFunc(f)
|
||||
}
|
||||
|
||||
// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete:
|
||||
//
|
||||
// func slowOperationWithTimeout(ctx context.Context) (Result, error) {
|
||||
// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
|
||||
// defer cancel() // releases resources if slowOperation completes before timeout elapses
|
||||
// return slowOperation(ctx)
|
||||
// }
|
||||
func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) {
|
||||
return WithDeadline(parent, time.Now().Add(timeout))
|
||||
}
|
||||
|
||||
// WithValue returns a copy of parent in which the value associated with key is
|
||||
// val.
|
||||
//
|
||||
// Use context Values only for request-scoped data that transits processes and
|
||||
// APIs, not for passing optional parameters to functions.
|
||||
func WithValue(parent Context, key interface{}, val interface{}) Context {
|
||||
return context.WithValue(parent, key, val)
|
||||
}
|
|
@ -0,0 +1,300 @@
|
|||
// Copyright 2014 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// +build !go1.7
|
||||
|
||||
package context
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"fmt"
|
||||
"sync"
|
||||
"time"
|
||||
)
|
||||
|
||||
// An emptyCtx is never canceled, has no values, and has no deadline. It is not
|
||||
// struct{}, since vars of this type must have distinct addresses.
|
||||
type emptyCtx int
|
||||
|
||||
func (*emptyCtx) Deadline() (deadline time.Time, ok bool) {
|
||||
return
|
||||
}
|
||||
|
||||
func (*emptyCtx) Done() <-chan struct{} {
|
||||
return nil
|
||||
}
|
||||
|
||||
func (*emptyCtx) Err() error {
|
||||
return nil
|
||||
}
|
||||
|
||||
func (*emptyCtx) Value(key interface{}) interface{} {
|
||||
return nil
|
||||
}
|
||||
|
||||
func (e *emptyCtx) String() string {
|
||||
switch e {
|
||||
case background:
|
||||
return "context.Background"
|
||||
case todo:
|
||||
return "context.TODO"
|
||||
}
|
||||
return "unknown empty Context"
|
||||
}
|
||||
|
||||
var (
|
||||
background = new(emptyCtx)
|
||||
todo = new(emptyCtx)
|
||||
)
|
||||
|
||||
// Canceled is the error returned by Context.Err when the context is canceled.
|
||||
var Canceled = errors.New("context canceled")
|
||||
|
||||
// DeadlineExceeded is the error returned by Context.Err when the context's
|
||||
// deadline passes.
|
||||
var DeadlineExceeded = errors.New("context deadline exceeded")
|
||||
|
||||
// WithCancel returns a copy of parent with a new Done channel. The returned
|
||||
// context's Done channel is closed when the returned cancel function is called
|
||||
// or when the parent context's Done channel is closed, whichever happens first.
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete.
|
||||
func WithCancel(parent Context) (ctx Context, cancel CancelFunc) {
|
||||
c := newCancelCtx(parent)
|
||||
propagateCancel(parent, c)
|
||||
return c, func() { c.cancel(true, Canceled) }
|
||||
}
|
||||
|
||||
// newCancelCtx returns an initialized cancelCtx.
|
||||
func newCancelCtx(parent Context) *cancelCtx {
|
||||
return &cancelCtx{
|
||||
Context: parent,
|
||||
done: make(chan struct{}),
|
||||
}
|
||||
}
|
||||
|
||||
// propagateCancel arranges for child to be canceled when parent is.
|
||||
func propagateCancel(parent Context, child canceler) {
|
||||
if parent.Done() == nil {
|
||||
return // parent is never canceled
|
||||
}
|
||||
if p, ok := parentCancelCtx(parent); ok {
|
||||
p.mu.Lock()
|
||||
if p.err != nil {
|
||||
// parent has already been canceled
|
||||
child.cancel(false, p.err)
|
||||
} else {
|
||||
if p.children == nil {
|
||||
p.children = make(map[canceler]bool)
|
||||
}
|
||||
p.children[child] = true
|
||||
}
|
||||
p.mu.Unlock()
|
||||
} else {
|
||||
go func() {
|
||||
select {
|
||||
case <-parent.Done():
|
||||
child.cancel(false, parent.Err())
|
||||
case <-child.Done():
|
||||
}
|
||||
}()
|
||||
}
|
||||
}
|
||||
|
||||
// parentCancelCtx follows a chain of parent references until it finds a
|
||||
// *cancelCtx. This function understands how each of the concrete types in this
|
||||
// package represents its parent.
|
||||
func parentCancelCtx(parent Context) (*cancelCtx, bool) {
|
||||
for {
|
||||
switch c := parent.(type) {
|
||||
case *cancelCtx:
|
||||
return c, true
|
||||
case *timerCtx:
|
||||
return c.cancelCtx, true
|
||||
case *valueCtx:
|
||||
parent = c.Context
|
||||
default:
|
||||
return nil, false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// removeChild removes a context from its parent.
|
||||
func removeChild(parent Context, child canceler) {
|
||||
p, ok := parentCancelCtx(parent)
|
||||
if !ok {
|
||||
return
|
||||
}
|
||||
p.mu.Lock()
|
||||
if p.children != nil {
|
||||
delete(p.children, child)
|
||||
}
|
||||
p.mu.Unlock()
|
||||
}
|
||||
|
||||
// A canceler is a context type that can be canceled directly. The
|
||||
// implementations are *cancelCtx and *timerCtx.
|
||||
type canceler interface {
|
||||
cancel(removeFromParent bool, err error)
|
||||
Done() <-chan struct{}
|
||||
}
|
||||
|
||||
// A cancelCtx can be canceled. When canceled, it also cancels any children
|
||||
// that implement canceler.
|
||||
type cancelCtx struct {
|
||||
Context
|
||||
|
||||
done chan struct{} // closed by the first cancel call.
|
||||
|
||||
mu sync.Mutex
|
||||
children map[canceler]bool // set to nil by the first cancel call
|
||||
err error // set to non-nil by the first cancel call
|
||||
}
|
||||
|
||||
func (c *cancelCtx) Done() <-chan struct{} {
|
||||
return c.done
|
||||
}
|
||||
|
||||
func (c *cancelCtx) Err() error {
|
||||
c.mu.Lock()
|
||||
defer c.mu.Unlock()
|
||||
return c.err
|
||||
}
|
||||
|
||||
func (c *cancelCtx) String() string {
|
||||
return fmt.Sprintf("%v.WithCancel", c.Context)
|
||||
}
|
||||
|
||||
// cancel closes c.done, cancels each of c's children, and, if
|
||||
// removeFromParent is true, removes c from its parent's children.
|
||||
func (c *cancelCtx) cancel(removeFromParent bool, err error) {
|
||||
if err == nil {
|
||||
panic("context: internal error: missing cancel error")
|
||||
}
|
||||
c.mu.Lock()
|
||||
if c.err != nil {
|
||||
c.mu.Unlock()
|
||||
return // already canceled
|
||||
}
|
||||
c.err = err
|
||||
close(c.done)
|
||||
for child := range c.children {
|
||||
// NOTE: acquiring the child's lock while holding parent's lock.
|
||||
child.cancel(false, err)
|
||||
}
|
||||
c.children = nil
|
||||
c.mu.Unlock()
|
||||
|
||||
if removeFromParent {
|
||||
removeChild(c.Context, c)
|
||||
}
|
||||
}
|
||||
|
||||
// WithDeadline returns a copy of the parent context with the deadline adjusted
|
||||
// to be no later than d. If the parent's deadline is already earlier than d,
|
||||
// WithDeadline(parent, d) is semantically equivalent to parent. The returned
|
||||
// context's Done channel is closed when the deadline expires, when the returned
|
||||
// cancel function is called, or when the parent context's Done channel is
|
||||
// closed, whichever happens first.
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete.
|
||||
func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) {
|
||||
if cur, ok := parent.Deadline(); ok && cur.Before(deadline) {
|
||||
// The current deadline is already sooner than the new one.
|
||||
return WithCancel(parent)
|
||||
}
|
||||
c := &timerCtx{
|
||||
cancelCtx: newCancelCtx(parent),
|
||||
deadline: deadline,
|
||||
}
|
||||
propagateCancel(parent, c)
|
||||
d := deadline.Sub(time.Now())
|
||||
if d <= 0 {
|
||||
c.cancel(true, DeadlineExceeded) // deadline has already passed
|
||||
return c, func() { c.cancel(true, Canceled) }
|
||||
}
|
||||
c.mu.Lock()
|
||||
defer c.mu.Unlock()
|
||||
if c.err == nil {
|
||||
c.timer = time.AfterFunc(d, func() {
|
||||
c.cancel(true, DeadlineExceeded)
|
||||
})
|
||||
}
|
||||
return c, func() { c.cancel(true, Canceled) }
|
||||
}
|
||||
|
||||
// A timerCtx carries a timer and a deadline. It embeds a cancelCtx to
|
||||
// implement Done and Err. It implements cancel by stopping its timer then
|
||||
// delegating to cancelCtx.cancel.
|
||||
type timerCtx struct {
|
||||
*cancelCtx
|
||||
timer *time.Timer // Under cancelCtx.mu.
|
||||
|
||||
deadline time.Time
|
||||
}
|
||||
|
||||
func (c *timerCtx) Deadline() (deadline time.Time, ok bool) {
|
||||
return c.deadline, true
|
||||
}
|
||||
|
||||
func (c *timerCtx) String() string {
|
||||
return fmt.Sprintf("%v.WithDeadline(%s [%s])", c.cancelCtx.Context, c.deadline, c.deadline.Sub(time.Now()))
|
||||
}
|
||||
|
||||
func (c *timerCtx) cancel(removeFromParent bool, err error) {
|
||||
c.cancelCtx.cancel(false, err)
|
||||
if removeFromParent {
|
||||
// Remove this timerCtx from its parent cancelCtx's children.
|
||||
removeChild(c.cancelCtx.Context, c)
|
||||
}
|
||||
c.mu.Lock()
|
||||
if c.timer != nil {
|
||||
c.timer.Stop()
|
||||
c.timer = nil
|
||||
}
|
||||
c.mu.Unlock()
|
||||
}
|
||||
|
||||
// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).
|
||||
//
|
||||
// Canceling this context releases resources associated with it, so code should
|
||||
// call cancel as soon as the operations running in this Context complete:
|
||||
//
|
||||
// func slowOperationWithTimeout(ctx context.Context) (Result, error) {
|
||||
// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
|
||||
// defer cancel() // releases resources if slowOperation completes before timeout elapses
|
||||
// return slowOperation(ctx)
|
||||
// }
|
||||
func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) {
|
||||
return WithDeadline(parent, time.Now().Add(timeout))
|
||||
}
|
||||
|
||||
// WithValue returns a copy of parent in which the value associated with key is
|
||||
// val.
|
||||
//
|
||||
// Use context Values only for request-scoped data that transits processes and
|
||||
// APIs, not for passing optional parameters to functions.
|
||||
func WithValue(parent Context, key interface{}, val interface{}) Context {
|
||||
return &valueCtx{parent, key, val}
|
||||
}
|
||||
|
||||
// A valueCtx carries a key-value pair. It implements Value for that key and
|
||||
// delegates all other calls to the embedded Context.
|
||||
type valueCtx struct {
|
||||
Context
|
||||
key, val interface{}
|
||||
}
|
||||
|
||||
func (c *valueCtx) String() string {
|
||||
return fmt.Sprintf("%v.WithValue(%#v, %#v)", c.Context, c.key, c.val)
|
||||
}
|
||||
|
||||
func (c *valueCtx) Value(key interface{}) interface{} {
|
||||
if c.key == key {
|
||||
return c.val
|
||||
}
|
||||
return c.Context.Value(key)
|
||||
}
|
|
@ -267,14 +267,16 @@
|
|||
"revisionTime": "2013-09-23T16:52:12+02:00"
|
||||
},
|
||||
{
|
||||
"checksumSHA1": "9jjO5GjLa0XF/nfWihF02RoH4qc=",
|
||||
"path": "golang.org/x/net/context",
|
||||
"revision": "2cba614e8ff920c60240d2677bc019af32ee04e5",
|
||||
"revisionTime": "2015-10-21T11:20:37-06:00"
|
||||
"revision": "8aacbecd63e105fa5f07afbd49472fd3e17a19d1",
|
||||
"revisionTime": "2016-05-18T19:54:31Z"
|
||||
},
|
||||
{
|
||||
"checksumSHA1": "Do+l129/Bafh54VFaquooqtCcfk=",
|
||||
"path": "golang.org/x/net/context/ctxhttp",
|
||||
"revision": "2cba614e8ff920c60240d2677bc019af32ee04e5",
|
||||
"revisionTime": "2015-10-21T11:20:37-06:00"
|
||||
"revision": "8aacbecd63e105fa5f07afbd49472fd3e17a19d1",
|
||||
"revisionTime": "2016-05-18T19:54:31Z"
|
||||
},
|
||||
{
|
||||
"path": "gopkg.in/fsnotify.v1",
|
||||
|
|
Loading…
Reference in New Issue