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author | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
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committer | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
commit | 6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005 (patch) | |
tree | 5564a47257bf6e85aaef711980c5b0fcb4d07dcc /vendor/golang.org/x/net/http2/pipe.go | |
parent | c042ffa460296587579aff54b157a5109e022f7e (diff) | |
parent | 1e1a5e5e85240f25c4faddcb24c5a29a915fe6e4 (diff) | |
download | chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.gz chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.bz2 chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.zip |
Merge branch 'plugins-2'
Diffstat (limited to 'vendor/golang.org/x/net/http2/pipe.go')
-rw-r--r-- | vendor/golang.org/x/net/http2/pipe.go | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/pipe.go b/vendor/golang.org/x/net/http2/pipe.go new file mode 100644 index 000000000..a6140099c --- /dev/null +++ b/vendor/golang.org/x/net/http2/pipe.go @@ -0,0 +1,163 @@ +// 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 http2 + +import ( + "errors" + "io" + "sync" +) + +// pipe is a goroutine-safe io.Reader/io.Writer pair. It's like +// io.Pipe except there are no PipeReader/PipeWriter halves, and the +// underlying buffer is an interface. (io.Pipe is always unbuffered) +type pipe struct { + mu sync.Mutex + c sync.Cond // c.L lazily initialized to &p.mu + b pipeBuffer // nil when done reading + err error // read error once empty. non-nil means closed. + breakErr error // immediate read error (caller doesn't see rest of b) + donec chan struct{} // closed on error + readFn func() // optional code to run in Read before error +} + +type pipeBuffer interface { + Len() int + io.Writer + io.Reader +} + +func (p *pipe) Len() int { + p.mu.Lock() + defer p.mu.Unlock() + if p.b == nil { + return 0 + } + return p.b.Len() +} + +// Read waits until data is available and copies bytes +// from the buffer into p. +func (p *pipe) Read(d []byte) (n int, err error) { + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + for { + if p.breakErr != nil { + return 0, p.breakErr + } + if p.b != nil && p.b.Len() > 0 { + return p.b.Read(d) + } + if p.err != nil { + if p.readFn != nil { + p.readFn() // e.g. copy trailers + p.readFn = nil // not sticky like p.err + } + p.b = nil + return 0, p.err + } + p.c.Wait() + } +} + +var errClosedPipeWrite = errors.New("write on closed buffer") + +// Write copies bytes from p into the buffer and wakes a reader. +// It is an error to write more data than the buffer can hold. +func (p *pipe) Write(d []byte) (n int, err error) { + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + defer p.c.Signal() + if p.err != nil { + return 0, errClosedPipeWrite + } + if p.breakErr != nil { + return len(d), nil // discard when there is no reader + } + return p.b.Write(d) +} + +// CloseWithError causes the next Read (waking up a current blocked +// Read if needed) to return the provided err after all data has been +// read. +// +// The error must be non-nil. +func (p *pipe) CloseWithError(err error) { p.closeWithError(&p.err, err, nil) } + +// BreakWithError causes the next Read (waking up a current blocked +// Read if needed) to return the provided err immediately, without +// waiting for unread data. +func (p *pipe) BreakWithError(err error) { p.closeWithError(&p.breakErr, err, nil) } + +// closeWithErrorAndCode is like CloseWithError but also sets some code to run +// in the caller's goroutine before returning the error. +func (p *pipe) closeWithErrorAndCode(err error, fn func()) { p.closeWithError(&p.err, err, fn) } + +func (p *pipe) closeWithError(dst *error, err error, fn func()) { + if err == nil { + panic("err must be non-nil") + } + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + defer p.c.Signal() + if *dst != nil { + // Already been done. + return + } + p.readFn = fn + if dst == &p.breakErr { + p.b = nil + } + *dst = err + p.closeDoneLocked() +} + +// requires p.mu be held. +func (p *pipe) closeDoneLocked() { + if p.donec == nil { + return + } + // Close if unclosed. This isn't racy since we always + // hold p.mu while closing. + select { + case <-p.donec: + default: + close(p.donec) + } +} + +// Err returns the error (if any) first set by BreakWithError or CloseWithError. +func (p *pipe) Err() error { + p.mu.Lock() + defer p.mu.Unlock() + if p.breakErr != nil { + return p.breakErr + } + return p.err +} + +// Done returns a channel which is closed if and when this pipe is closed +// with CloseWithError. +func (p *pipe) Done() <-chan struct{} { + p.mu.Lock() + defer p.mu.Unlock() + if p.donec == nil { + p.donec = make(chan struct{}) + if p.err != nil || p.breakErr != nil { + // Already hit an error. + p.closeDoneLocked() + } + } + return p.donec +} |