vendor files

vendor/google.golang.org/grpc/test/bufconn/bufconn.go

@@ -0,0 +1,244 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package bufconn provides a net.Conn implemented by a buffer and related
+// dialing and listening functionality.
+package bufconn
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"time"
+)
+
+// Listener implements a net.Listener that creates local, buffered net.Conns
+// via its Accept and Dial method.
+type Listener struct {
+	mu   sync.Mutex
+	sz   int
+	ch   chan net.Conn
+	done chan struct{}
+}
+
+var errClosed = fmt.Errorf("Closed")
+
+// Listen returns a Listener that can only be contacted by its own Dialers and
+// creates buffered connections between the two.
+func Listen(sz int) *Listener {
+	return &Listener{sz: sz, ch: make(chan net.Conn), done: make(chan struct{})}
+}
+
+// Accept blocks until Dial is called, then returns a net.Conn for the server
+// half of the connection.
+func (l *Listener) Accept() (net.Conn, error) {
+	select {
+	case <-l.done:
+		return nil, errClosed
+	case c := <-l.ch:
+		return c, nil
+	}
+}
+
+// Close stops the listener.
+func (l *Listener) Close() error {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	select {
+	case <-l.done:
+		// Already closed.
+		break
+	default:
+		close(l.done)
+	}
+	return nil
+}
+
+// Addr reports the address of the listener.
+func (l *Listener) Addr() net.Addr { return addr{} }
+
+// Dial creates an in-memory full-duplex network connection, unblocks Accept by
+// providing it the server half of the connection, and returns the client half
+// of the connection.
+func (l *Listener) Dial() (net.Conn, error) {
+	p1, p2 := newPipe(l.sz), newPipe(l.sz)
+	select {
+	case <-l.done:
+		return nil, errClosed
+	case l.ch <- &conn{p1, p2}:
+		return &conn{p2, p1}, nil
+	}
+}
+
+type pipe struct {
+	mu sync.Mutex
+
+	// buf contains the data in the pipe.  It is a ring buffer of fixed capacity,
+	// with r and w pointing to the offset to read and write, respsectively.
+	//
+	// Data is read between [r, w) and written to [w, r), wrapping around the end
+	// of the slice if necessary.
+	//
+	// The buffer is empty if r == len(buf), otherwise if r == w, it is full.
+	//
+	// w and r are always in the range [0, cap(buf)) and [0, len(buf)].
+	buf  []byte
+	w, r int
+
+	wwait sync.Cond
+	rwait sync.Cond
+
+	closed      bool
+	writeClosed bool
+}
+
+func newPipe(sz int) *pipe {
+	p := &pipe{buf: make([]byte, 0, sz)}
+	p.wwait.L = &p.mu
+	p.rwait.L = &p.mu
+	return p
+}
+
+func (p *pipe) empty() bool {
+	return p.r == len(p.buf)
+}
+
+func (p *pipe) full() bool {
+	return p.r < len(p.buf) && p.r == p.w
+}
+
+func (p *pipe) Read(b []byte) (n int, err error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// Block until p has data.
+	for {
+		if p.closed {
+			return 0, io.ErrClosedPipe
+		}
+		if !p.empty() {
+			break
+		}
+		if p.writeClosed {
+			return 0, io.EOF
+		}
+		p.rwait.Wait()
+	}
+	wasFull := p.full()
+
+	n = copy(b, p.buf[p.r:len(p.buf)])
+	p.r += n
+	if p.r == cap(p.buf) {
+		p.r = 0
+		p.buf = p.buf[:p.w]
+	}
+
+	// Signal a blocked writer, if any
+	if wasFull {
+		p.wwait.Signal()
+	}
+
+	return n, nil
+}
+
+func (p *pipe) Write(b []byte) (n int, err error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.closed {
+		return 0, io.ErrClosedPipe
+	}
+	for len(b) > 0 {
+		// Block until p is not full.
+		for {
+			if p.closed || p.writeClosed {
+				return 0, io.ErrClosedPipe
+			}
+			if !p.full() {
+				break
+			}
+			p.wwait.Wait()
+		}
+		wasEmpty := p.empty()
+
+		end := cap(p.buf)
+		if p.w < p.r {
+			end = p.r
+		}
+		x := copy(p.buf[p.w:end], b)
+		b = b[x:]
+		n += x
+		p.w += x
+		if p.w > len(p.buf) {
+			p.buf = p.buf[:p.w]
+		}
+		if p.w == cap(p.buf) {
+			p.w = 0
+		}
+
+		// Signal a blocked reader, if any.
+		if wasEmpty {
+			p.rwait.Signal()
+		}
+	}
+	return n, nil
+}
+
+func (p *pipe) Close() error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.closed = true
+	// Signal all blocked readers and writers to return an error.
+	p.rwait.Broadcast()
+	p.wwait.Broadcast()
+	return nil
+}
+
+func (p *pipe) closeWrite() error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.writeClosed = true
+	// Signal all blocked readers and writers to return an error.
+	p.rwait.Broadcast()
+	p.wwait.Broadcast()
+	return nil
+}
+
+type conn struct {
+	io.Reader
+	io.Writer
+}
+
+func (c *conn) Close() error {
+	err1 := c.Reader.(*pipe).Close()
+	err2 := c.Writer.(*pipe).closeWrite()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func (*conn) LocalAddr() net.Addr                  { return addr{} }
+func (*conn) RemoteAddr() net.Addr                 { return addr{} }
+func (c *conn) SetDeadline(t time.Time) error      { return fmt.Errorf("unsupported") }
+func (c *conn) SetReadDeadline(t time.Time) error  { return fmt.Errorf("unsupported") }
+func (c *conn) SetWriteDeadline(t time.Time) error { return fmt.Errorf("unsupported") }
+
+type addr struct{}
+
+func (addr) Network() string { return "bufconn" }
+func (addr) String() string  { return "bufconn" }