From f85e0d461fe80fe929eb5d82d9fec07eff810a93 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Sun, 16 Jul 2017 22:38:45 +0200 Subject: Add vendor --- vendor/golang.org/x/crypto/ssh/buffer.go | 98 ++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 vendor/golang.org/x/crypto/ssh/buffer.go (limited to 'vendor/golang.org/x/crypto/ssh/buffer.go') diff --git a/vendor/golang.org/x/crypto/ssh/buffer.go b/vendor/golang.org/x/crypto/ssh/buffer.go new file mode 100644 index 0000000..6931b51 --- /dev/null +++ b/vendor/golang.org/x/crypto/ssh/buffer.go @@ -0,0 +1,98 @@ +// Copyright 2012 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 ssh + +import ( + "io" + "sync" +) + +// buffer provides a linked list buffer for data exchange +// between producer and consumer. Theoretically the buffer is +// of unlimited capacity as it does no allocation of its own. +type buffer struct { + // protects concurrent access to head, tail and closed + *sync.Cond + + head *element // the buffer that will be read first + tail *element // the buffer that will be read last + + closed bool +} + +// An element represents a single link in a linked list. +type element struct { + buf []byte + next *element +} + +// newBuffer returns an empty buffer that is not closed. +func newBuffer() *buffer { + e := new(element) + b := &buffer{ + Cond: newCond(), + head: e, + tail: e, + } + return b +} + +// write makes buf available for Read to receive. +// buf must not be modified after the call to write. +func (b *buffer) write(buf []byte) { + b.Cond.L.Lock() + e := &element{buf: buf} + b.tail.next = e + b.tail = e + b.Cond.Signal() + b.Cond.L.Unlock() +} + +// eof closes the buffer. Reads from the buffer once all +// the data has been consumed will receive os.EOF. +func (b *buffer) eof() error { + b.Cond.L.Lock() + b.closed = true + b.Cond.Signal() + b.Cond.L.Unlock() + return nil +} + +// Read reads data from the internal buffer in buf. Reads will block +// if no data is available, or until the buffer is closed. +func (b *buffer) Read(buf []byte) (n int, err error) { + b.Cond.L.Lock() + defer b.Cond.L.Unlock() + + for len(buf) > 0 { + // if there is data in b.head, copy it + if len(b.head.buf) > 0 { + r := copy(buf, b.head.buf) + buf, b.head.buf = buf[r:], b.head.buf[r:] + n += r + continue + } + // if there is a next buffer, make it the head + if len(b.head.buf) == 0 && b.head != b.tail { + b.head = b.head.next + continue + } + + // if at least one byte has been copied, return + if n > 0 { + break + } + + // if nothing was read, and there is nothing outstanding + // check to see if the buffer is closed. + if b.closed { + err = io.EOF + break + } + // out of buffers, wait for producer + b.Cond.Wait() + } + return +} -- cgit v1.2.3