/*
* 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.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
/**
* 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 MessageToByteEncoder<WebSocketFrame> {
@Override
protected void encode(ChannelHandlerContext ctx, WebSocketFrame msg, ByteBuf out) throws Exception {
if (msg instanceof TextWebSocketFrame) {
// Text frame
ByteBuf data = msg.data();
out.writeByte((byte) 0x00);
out.writeBytes(data, data.readerIndex(), data.readableBytes());
out.writeByte((byte) 0xFF);
} else if (msg instanceof CloseWebSocketFrame) {
// Close frame
out.writeByte((byte) 0xFF);
out.writeByte((byte) 0x00);
} else {
// Binary frame
ByteBuf data = msg.data();
int dataLen = data.readableBytes();
out.ensureWritable(dataLen + 5);
// Encode type.
out.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) {
out.writeByte(b4);
} else {
out.writeByte(b3 | 0x80);
out.writeByte(b4);
}
} else {
out.writeByte(b2 | 0x80);
out.writeByte(b3 | 0x80);
out.writeByte(b4);
}
} else {
out.writeByte(b1 | 0x80);
out.writeByte(b2 | 0x80);
out.writeByte(b3 | 0x80);
out.writeByte(b4);
}
// Encode binary data.
out.writeBytes(data, data.readerIndex(), dataLen);
}
}
}