From e1e8d058a33f7566f9c565d04b0d8b56f9645c35 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Wed, 25 Apr 2018 09:28:54 +0200 Subject: add vendor --- vendor/golang.org/x/net/context/context.go | 56 ++++ vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go | 74 +++++ .../x/net/context/ctxhttp/ctxhttp_pre17.go | 147 ++++++++++ vendor/golang.org/x/net/context/go17.go | 72 +++++ vendor/golang.org/x/net/context/go19.go | 20 ++ vendor/golang.org/x/net/context/pre_go17.go | 300 +++++++++++++++++++++ vendor/golang.org/x/net/context/pre_go19.go | 109 ++++++++ 7 files changed, 778 insertions(+) create mode 100644 vendor/golang.org/x/net/context/context.go create mode 100644 vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go create mode 100644 vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go create mode 100644 vendor/golang.org/x/net/context/go17.go create mode 100644 vendor/golang.org/x/net/context/go19.go create mode 100644 vendor/golang.org/x/net/context/pre_go17.go create mode 100644 vendor/golang.org/x/net/context/pre_go19.go (limited to 'vendor/golang.org/x/net/context') diff --git a/vendor/golang.org/x/net/context/context.go b/vendor/golang.org/x/net/context/context.go new file mode 100644 index 0000000..a3c021d --- /dev/null +++ b/vendor/golang.org/x/net/context/context.go @@ -0,0 +1,56 @@ +// 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. + +// Package context defines the Context type, which carries deadlines, +// cancelation signals, and other request-scoped values across API boundaries +// and between processes. +// As of Go 1.7 this package is available in the standard library under the +// name context. https://golang.org/pkg/context. +// +// Incoming requests to a server should create a Context, and outgoing calls to +// servers should accept a Context. The chain of function calls between must +// propagate the Context, optionally replacing it with a modified copy created +// using WithDeadline, WithTimeout, WithCancel, or WithValue. +// +// Programs that use Contexts should follow these rules to keep interfaces +// consistent across packages and enable static analysis tools to check context +// propagation: +// +// Do not store Contexts inside a struct type; instead, pass a Context +// explicitly to each function that needs it. The Context should be the first +// parameter, typically named ctx: +// +// func DoSomething(ctx context.Context, arg Arg) error { +// // ... use ctx ... +// } +// +// Do not pass a nil Context, even if a function permits it. Pass context.TODO +// if you are unsure about which Context to use. +// +// Use context Values only for request-scoped data that transits processes and +// APIs, not for passing optional parameters to functions. +// +// The same Context may be passed to functions running in different goroutines; +// Contexts are safe for simultaneous use by multiple goroutines. +// +// See http://blog.golang.org/context for example code for a server that uses +// Contexts. +package context // import "golang.org/x/net/context" + +// Background returns a non-nil, empty Context. It is never canceled, has no +// values, and has no deadline. It is typically used by the main function, +// initialization, and tests, and as the top-level Context for incoming +// requests. +func Background() Context { + return background +} + +// TODO returns a non-nil, empty Context. Code should use context.TODO when +// it's unclear which Context to use or it is not yet available (because the +// surrounding function has not yet been extended to accept a Context +// parameter). TODO is recognized by static analysis tools that determine +// whether Contexts are propagated correctly in a program. +func TODO() Context { + return todo +} diff --git a/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go new file mode 100644 index 0000000..606cf1f --- /dev/null +++ b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go @@ -0,0 +1,74 @@ +// 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 ctxhttp provides helper functions for performing context-aware HTTP requests. +package ctxhttp // import "golang.org/x/net/context/ctxhttp" + +import ( + "io" + "net/http" + "net/url" + "strings" + + "golang.org/x/net/context" +) + +// Do sends an HTTP request with the provided http.Client and returns +// an HTTP response. +// +// If the client is nil, http.DefaultClient is used. +// +// The provided ctx must be non-nil. If it is canceled or times out, +// ctx.Err() will be returned. +func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { + if client == nil { + client = http.DefaultClient + } + resp, err := client.Do(req.WithContext(ctx)) + // If we got an error, and the context has been canceled, + // the context's error is probably more useful. + if err != nil { + select { + case <-ctx.Done(): + err = ctx.Err() + default: + } + } + return resp, err +} + +// Get issues a GET request via the Do function. +func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Head issues a HEAD request via the Do function. +func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Post issues a POST request via the Do function. +func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { + req, err := http.NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", bodyType) + return Do(ctx, client, req) +} + +// PostForm issues a POST request via the Do function. +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())) +} diff --git a/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go new file mode 100644 index 0000000..926870c --- /dev/null +++ b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go @@ -0,0 +1,147 @@ +// Copyright 2015 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 ctxhttp // import "golang.org/x/net/context/ctxhttp" + +import ( + "io" + "net/http" + "net/url" + "strings" + + "golang.org/x/net/context" +) + +func nop() {} + +var ( + testHookContextDoneBeforeHeaders = nop + testHookDoReturned = nop + testHookDidBodyClose = nop +) + +// Do sends an HTTP request with the provided http.Client and returns an HTTP response. +// If the client is nil, http.DefaultClient is used. +// If the context is canceled or times out, ctx.Err() will be returned. +func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { + if client == nil { + client = http.DefaultClient + } + + // TODO(djd): Respect any existing value of req.Cancel. + cancel := make(chan struct{}) + req.Cancel = cancel + + type responseAndError struct { + resp *http.Response + err error + } + result := make(chan responseAndError, 1) + + // Make local copies of test hooks closed over by goroutines below. + // Prevents data races in tests. + testHookDoReturned := testHookDoReturned + testHookDidBodyClose := testHookDidBodyClose + + go func() { + resp, err := client.Do(req) + testHookDoReturned() + result <- responseAndError{resp, err} + }() + + var resp *http.Response + + select { + case <-ctx.Done(): + testHookContextDoneBeforeHeaders() + close(cancel) + // Clean up after the goroutine calling client.Do: + go func() { + if r := <-result; r.resp != nil { + testHookDidBodyClose() + r.resp.Body.Close() + } + }() + return nil, ctx.Err() + case r := <-result: + var err error + resp, err = r.resp, r.err + if err != nil { + return resp, err + } + } + + c := make(chan struct{}) + go func() { + select { + 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. +func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Head issues a HEAD request via the Do function. +func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Post issues a POST request via the Do function. +func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { + req, err := http.NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", bodyType) + return Do(ctx, client, req) +} + +// PostForm issues a POST request via the Do function. +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 +} diff --git a/vendor/golang.org/x/net/context/go17.go b/vendor/golang.org/x/net/context/go17.go new file mode 100644 index 0000000..d20f52b --- /dev/null +++ b/vendor/golang.org/x/net/context/go17.go @@ -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) +} diff --git a/vendor/golang.org/x/net/context/go19.go b/vendor/golang.org/x/net/context/go19.go new file mode 100644 index 0000000..d88bd1d --- /dev/null +++ b/vendor/golang.org/x/net/context/go19.go @@ -0,0 +1,20 @@ +// Copyright 2017 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 go1.9 + +package context + +import "context" // standard library's context, as of Go 1.7 + +// A Context carries a deadline, a cancelation signal, and other values across +// API boundaries. +// +// Context's methods may be called by multiple goroutines simultaneously. +type Context = context.Context + +// A CancelFunc tells an operation to abandon its work. +// A CancelFunc does not wait for the work to stop. +// After the first call, subsequent calls to a CancelFunc do nothing. +type CancelFunc = context.CancelFunc diff --git a/vendor/golang.org/x/net/context/pre_go17.go b/vendor/golang.org/x/net/context/pre_go17.go new file mode 100644 index 0000000..0f35592 --- /dev/null +++ b/vendor/golang.org/x/net/context/pre_go17.go @@ -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) +} diff --git a/vendor/golang.org/x/net/context/pre_go19.go b/vendor/golang.org/x/net/context/pre_go19.go new file mode 100644 index 0000000..b105f80 --- /dev/null +++ b/vendor/golang.org/x/net/context/pre_go19.go @@ -0,0 +1,109 @@ +// 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 !go1.9 + +package context + +import "time" + +// A Context carries a deadline, a cancelation signal, and other values across +// API boundaries. +// +// Context's methods may be called by multiple goroutines simultaneously. +type Context interface { + // Deadline returns the time when work done on behalf of this context + // should be canceled. Deadline returns ok==false when no deadline is + // set. Successive calls to Deadline return the same results. + Deadline() (deadline time.Time, ok bool) + + // Done returns a channel that's closed when work done on behalf of this + // context should be canceled. Done may return nil if this context can + // never be canceled. Successive calls to Done return the same value. + // + // WithCancel arranges for Done to be closed when cancel is called; + // WithDeadline arranges for Done to be closed when the deadline + // expires; WithTimeout arranges for Done to be closed when the timeout + // elapses. + // + // Done is provided for use in select statements: + // + // // Stream generates values with DoSomething and sends them to out + // // until DoSomething returns an error or ctx.Done is closed. + // func Stream(ctx context.Context, out chan<- Value) error { + // for { + // v, err := DoSomething(ctx) + // if err != nil { + // return err + // } + // select { + // case <-ctx.Done(): + // return ctx.Err() + // case out <- v: + // } + // } + // } + // + // See http://blog.golang.org/pipelines for more examples of how to use + // a Done channel for cancelation. + Done() <-chan struct{} + + // Err returns a non-nil error value after Done is closed. Err returns + // Canceled if the context was canceled or DeadlineExceeded if the + // context's deadline passed. No other values for Err are defined. + // After Done is closed, successive calls to Err return the same value. + Err() error + + // Value returns the value associated with this context for key, or nil + // if no value is associated with key. Successive calls to Value with + // the same key returns the same result. + // + // Use context values only for request-scoped data that transits + // processes and API boundaries, not for passing optional parameters to + // functions. + // + // A key identifies a specific value in a Context. Functions that wish + // to store values in Context typically allocate a key in a global + // variable then use that key as the argument to context.WithValue and + // Context.Value. A key can be any type that supports equality; + // packages should define keys as an unexported type to avoid + // collisions. + // + // Packages that define a Context key should provide type-safe accessors + // for the values stores using that key: + // + // // Package user defines a User type that's stored in Contexts. + // package user + // + // import "golang.org/x/net/context" + // + // // User is the type of value stored in the Contexts. + // type User struct {...} + // + // // key is an unexported type for keys defined in this package. + // // This prevents collisions with keys defined in other packages. + // type key int + // + // // userKey is the key for user.User values in Contexts. It is + // // unexported; clients use user.NewContext and user.FromContext + // // instead of using this key directly. + // var userKey key = 0 + // + // // NewContext returns a new Context that carries value u. + // func NewContext(ctx context.Context, u *User) context.Context { + // return context.WithValue(ctx, userKey, u) + // } + // + // // FromContext returns the User value stored in ctx, if any. + // func FromContext(ctx context.Context) (*User, bool) { + // u, ok := ctx.Value(userKey).(*User) + // return u, ok + // } + Value(key interface{}) interface{} +} + +// A CancelFunc tells an operation to abandon its work. +// A CancelFunc does not wait for the work to stop. +// After the first call, subsequent calls to a CancelFunc do nothing. +type CancelFunc func() -- cgit v1.2.3