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55 lines
2.3 KiB
Go
55 lines
2.3 KiB
Go
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// Copyright 2014 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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// Package context defines the Context type, which carries deadlines,
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// cancelation signals, and other request-scoped values across API boundaries
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// and between processes.
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//
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// Incoming requests to a server should create a Context, and outgoing calls to
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// servers should accept a Context. The chain of function calls between must
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// propagate the Context, optionally replacing it with a modified copy created
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// using WithDeadline, WithTimeout, WithCancel, or WithValue.
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//
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// Programs that use Contexts should follow these rules to keep interfaces
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// consistent across packages and enable static analysis tools to check context
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// propagation:
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//
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// Do not store Contexts inside a struct type; instead, pass a Context
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// explicitly to each function that needs it. The Context should be the first
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// parameter, typically named ctx:
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//
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// func DoSomething(ctx context.Context, arg Arg) error {
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// // ... use ctx ...
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// }
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//
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// Do not pass a nil Context, even if a function permits it. Pass context.TODO
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// if you are unsure about which Context to use.
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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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//
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// The same Context may be passed to functions running in different goroutines;
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// Contexts are safe for simultaneous use by multiple goroutines.
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//
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// See http://blog.golang.org/context for example code for a server that uses
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// Contexts.
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package context // import "golang.org/x/net/context"
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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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// requests.
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func Background() Context {
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return background
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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 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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func TODO() Context {
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return todo
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}
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