/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.codec.http.websocketx;
import io.netty.buffer.
ByteBuf;
import io.netty.buffer.
Unpooled;
import io.netty.channel.
ChannelHandler.
Sharable;
import io.netty.channel.
ChannelHandlerContext;
import io.netty.handler.codec.
MessageToMessageEncoder;
import java.util.
List;
/**
* Encodes a {@link WebSocketFrame} into a {@link ByteBuf}.
* <p>
* For the detailed instruction on adding add Web Socket support to your HTTP server, take a look into the
* <tt>WebSocketServer</tt> example located in the {@code io.netty.example.http.websocket} package.
*/
@
Sharable
public class
WebSocket00FrameEncoder extends
MessageToMessageEncoder<
WebSocketFrame> implements
WebSocketFrameEncoder {
private static final
ByteBuf _0X00 =
Unpooled.
unreleasableBuffer(
Unpooled.
directBuffer(1, 1).
writeByte((byte) 0x00));
private static final
ByteBuf _0XFF =
Unpooled.
unreleasableBuffer(
Unpooled.
directBuffer(1, 1).
writeByte((byte) 0xFF));
private static final
ByteBuf _0XFF_0X00 =
Unpooled.
unreleasableBuffer(
Unpooled.
directBuffer(2, 2).
writeByte((byte) 0xFF).
writeByte((byte) 0x00));
@
Override
protected void
encode(
ChannelHandlerContext ctx,
WebSocketFrame msg,
List<
Object>
out) throws
Exception {
if (
msg instanceof
TextWebSocketFrame) {
// Text frame
ByteBuf data =
msg.
content();
out.
add(
_0X00.
duplicate());
out.
add(
data.
retain());
out.
add(
_0XFF.
duplicate());
} else if (
msg instanceof
CloseWebSocketFrame) {
// Close frame, needs to call duplicate to allow multiple writes.
// See https://github.com/netty/netty/issues/2768
out.
add(
_0XFF_0X00.
duplicate());
} else {
// Binary frame
ByteBuf data =
msg.
content();
int
dataLen =
data.
readableBytes();
ByteBuf buf =
ctx.
alloc().
buffer(5);
boolean
release = true;
try {
// Encode type.
buf.
writeByte((byte) 0x80);
// Encode length.
int
b1 =
dataLen >>> 28 & 0x7F;
int
b2 =
dataLen >>> 14 & 0x7F;
int
b3 =
dataLen >>> 7 & 0x7F;
int
b4 =
dataLen & 0x7F;
if (
b1 == 0) {
if (
b2 == 0) {
if (
b3 == 0) {
buf.
writeByte(
b4);
} else {
buf.
writeByte(
b3 | 0x80);
buf.
writeByte(
b4);
}
} else {
buf.
writeByte(
b2 | 0x80);
buf.
writeByte(
b3 | 0x80);
buf.
writeByte(
b4);
}
} else {
buf.
writeByte(
b1 | 0x80);
buf.
writeByte(
b2 | 0x80);
buf.
writeByte(
b3 | 0x80);
buf.
writeByte(
b4);
}
// Encode binary data.
out.
add(
buf);
out.
add(
data.
retain());
release = false;
} finally {
if (
release) {
buf.
release();
}
}
}
}
}