From 1d18e891253ec934c114cb5d102c458d3a49e598 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Mon, 26 Apr 2010 10:36:05 -0700
Subject: [PATCH] net: add Pipe

R=r
CC=golang-dev
https://golang.org/cl/1004043
---
 src/pkg/net/Makefile     |  1 +
 src/pkg/net/pipe.go      | 62 ++++++++++++++++++++++++++++++++++++++++
 src/pkg/net/pipe_test.go | 57 ++++++++++++++++++++++++++++++++++++
 3 files changed, 120 insertions(+)
 create mode 100644 src/pkg/net/pipe.go
 create mode 100644 src/pkg/net/pipe_test.go

diff --git a/src/pkg/net/Makefile b/src/pkg/net/Makefile
index f5e78fb84c8..95360539b6e 100644
--- a/src/pkg/net/Makefile
+++ b/src/pkg/net/Makefile
@@ -16,6 +16,7 @@ GOFILES=\
 	ipsock.go\
 	net.go\
 	parse.go\
+	pipe.go\
 	port.go\
 	sock.go\
 	tcpsock.go\
diff --git a/src/pkg/net/pipe.go b/src/pkg/net/pipe.go
new file mode 100644
index 00000000000..c0bbd356b30
--- /dev/null
+++ b/src/pkg/net/pipe.go
@@ -0,0 +1,62 @@
+package net
+
+import (
+	"io"
+	"os"
+)
+
+// Pipe creates a synchronous, in-memory, full duplex
+// network connection; both ends implement the Conn interface.
+// Reads on one end are matched with writes on the other,
+// copying data directly between the two; there is no internal
+// buffering.
+func Pipe() (Conn, Conn) {
+	r1, w1 := io.Pipe()
+	r2, w2 := io.Pipe()
+
+	return &pipe{r1, w2}, &pipe{r2, w1}
+}
+
+type pipe struct {
+	*io.PipeReader
+	*io.PipeWriter
+}
+
+type pipeAddr int
+
+func (pipeAddr) Network() string {
+	return "pipe"
+}
+
+func (pipeAddr) String() string {
+	return "pipe"
+}
+
+func (p *pipe) Close() os.Error {
+	err := p.PipeReader.Close()
+	err1 := p.PipeWriter.Close()
+	if err == nil {
+		err = err1
+	}
+	return err
+}
+
+func (p *pipe) LocalAddr() Addr {
+	return pipeAddr(0)
+}
+
+func (p *pipe) RemoteAddr() Addr {
+	return pipeAddr(0)
+}
+
+func (p *pipe) SetTimeout(nsec int64) os.Error {
+	return os.NewError("net.Pipe does not support timeouts")
+}
+
+func (p *pipe) SetReadTimeout(nsec int64) os.Error {
+	return os.NewError("net.Pipe does not support timeouts")
+}
+
+func (p *pipe) SetWriteTimeout(nsec int64) os.Error {
+	return os.NewError("net.Pipe does not support timeouts")
+}
diff --git a/src/pkg/net/pipe_test.go b/src/pkg/net/pipe_test.go
new file mode 100644
index 00000000000..7e4c6db4434
--- /dev/null
+++ b/src/pkg/net/pipe_test.go
@@ -0,0 +1,57 @@
+// Copyright 2010 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 net
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"testing"
+)
+
+func checkWrite(t *testing.T, w io.Writer, data []byte, c chan int) {
+	n, err := w.Write(data)
+	if err != nil {
+		t.Errorf("write: %v", err)
+	}
+	if n != len(data) {
+		t.Errorf("short write: %d != %d", n, len(data))
+	}
+	c <- 0
+}
+
+func checkRead(t *testing.T, r io.Reader, data []byte, wantErr os.Error) {
+	buf := make([]byte, len(data)+10)
+	n, err := r.Read(buf)
+	if err != wantErr {
+		t.Errorf("read: %v", err)
+		return
+	}
+	if n != len(data) || !bytes.Equal(buf[0:n], data) {
+		t.Errorf("bad read: got %q", buf[0:n])
+		return
+	}
+}
+
+// Test a simple read/write/close sequence.
+// Assumes that the underlying io.Pipe implementation
+// is solid and we're just testing the net wrapping.
+
+func TestPipe(t *testing.T) {
+	c := make(chan int)
+	cli, srv := Pipe()
+	go checkWrite(t, cli, []byte("hello, world"), c)
+	checkRead(t, srv, []byte("hello, world"), nil)
+	<-c
+	go checkWrite(t, srv, []byte("line 2"), c)
+	checkRead(t, cli, []byte("line 2"), nil)
+	<-c
+	go checkWrite(t, cli, []byte("a third line"), c)
+	checkRead(t, srv, []byte("a third line"), nil)
+	<-c
+	go srv.Close()
+	checkRead(t, cli, nil, os.EOF)
+	cli.Close()
+}