Add WebSocket server framework hooked into http.

R=r, rsc
http://codereview.appspot.com/156071

Committer: Russ Cox <rsc@golang.org>

1 files changed, 138 insertions, 0 deletions

diff --git a/src/pkg/websocket/websocket.go b/src/pkg/websocket/websocket.go
new file mode 100644
index 000000000..0fd32cd4c
--- /dev/null
+++ b/src/pkg/websocket/websocket.go
@@ -0,0 +1,138 @@
+// Copyright 2009 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.
+
+// The websocket package implements Web Socket protocol server.
+package websocket
+
+// References:
+//   The Web Socket protocol: http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol
+
+// TODO(ukai):
+//   better logging.
+
+import (
+	"bufio";
+	"io";
+	"net";
+	"os";
+)
+
+type WebSocketAddr string
+
+func (addr WebSocketAddr) Network() string	{ return "websocket" }
+
+func (addr WebSocketAddr) String() string	{ return string(addr) }
+
+// Conn is an channels to communicate over Web Socket.
+type Conn struct {
+	// An origin URI of the Web Socket.
+	Origin	string;
+	// A location URI of the Web Socket.
+	Location	string;
+	// A subprotocol of the Web Socket.
+	Protocol	string;
+
+	buf	*bufio.ReadWriter;
+	rwc	io.ReadWriteCloser;
+}
+
+// newConn creates a new Web Socket.
+func newConn(origin, location, protocol string, buf *bufio.ReadWriter, rwc io.ReadWriteCloser) *Conn {
+	if buf == nil {
+		br := bufio.NewReader(rwc);
+		bw := bufio.NewWriter(rwc);
+		buf = bufio.NewReadWriter(br, bw);
+	}
+	ws := &Conn{origin, location, protocol, buf, rwc};
+	return ws;
+}
+
+func (ws *Conn) Read(msg []byte) (n int, err os.Error) {
+	for {
+		frameByte, err := ws.buf.ReadByte();
+		if err != nil {
+			return
+		}
+		if (frameByte & 0x80) == 0x80 {
+			length := 0;
+			for {
+				c, err := ws.buf.ReadByte();
+				if err != nil {
+					return
+				}
+				if (c & 0x80) == 0x80 {
+					length = length*128 + int(c&0x7f)
+				} else {
+					break
+				}
+			}
+			for length > 0 {
+				_, err := ws.buf.ReadByte();
+				if err != nil {
+					return
+				}
+				length--;
+			}
+		} else {
+			for {
+				c, err := ws.buf.ReadByte();
+				if err != nil {
+					return
+				}
+				if c == '\xff' {
+					return
+				}
+				if frameByte == 0 {
+					if n+1 <= cap(msg) {
+						msg = msg[0 : n+1]
+					}
+					msg[n] = c;
+					n++;
+				}
+				if n >= cap(msg) {
+					err = os.E2BIG;
+					return;
+				}
+			}
+		}
+	}
+	return;
+}
+
+func (ws *Conn) Write(msg []byte) (n int, err os.Error) {
+	ws.buf.WriteByte(0);
+	ws.buf.Write(msg);
+	ws.buf.WriteByte(0xff);
+	err = ws.buf.Flush();
+	return len(msg), err;
+}
+
+func (ws *Conn) Close() os.Error	{ return ws.rwc.Close() }
+
+func (ws *Conn) LocalAddr() net.Addr	{ return WebSocketAddr(ws.Origin) }
+
+func (ws *Conn) RemoteAddr() net.Addr	{ return WebSocketAddr(ws.Location) }
+
+func (ws *Conn) SetTimeout(nsec int64) os.Error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetTimeout(nsec)
+	}
+	return os.EINVAL;
+}
+
+func (ws *Conn) SetReadTimeout(nsec int64) os.Error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetReadTimeout(nsec)
+	}
+	return os.EINVAL;
+}
+
+func (ws *Conn) SetWriteTimeout(nsec int64) os.Error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetWriteTimeout(nsec)
+	}
+	return os.EINVAL;
+}
+
+var _ net.Conn = (*Conn)(nil)	// compile-time check that *Conn implements net.Conn.