/*
* Copyright 2013 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 org.jboss.netty.handler.codec.http.websocketx;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.TooLongFrameException;
import org.jboss.netty.handler.codec.oneone.OneToOneDecoder;
/**
* Handler that aggregate fragmented WebSocketFrame's.
*
* Be aware if PING/PONG/CLOSE frames are send in the middle of a fragmented {@link WebSocketFrame} they will
* just get forwarded to the next handler in the pipeline.
*/
public class WebSocketFrameAggregator extends OneToOneDecoder {
private final int maxFrameSize;
private WebSocketFrame currentFrame;
private boolean tooLongFrameFound;
/**
* Construct a new instance
*
* @param maxFrameSize If the size of the aggregated frame exceeds this value,
* a {@link TooLongFrameException} is thrown.
*/
public WebSocketFrameAggregator(int maxFrameSize) {
if (maxFrameSize < 1) {
throw new IllegalArgumentException("maxFrameSize must be > 0");
}
this.maxFrameSize = maxFrameSize;
}
@Override
protected Object decode(ChannelHandlerContext ctx, Channel channel, Object message) throws Exception {
if (!(message instanceof WebSocketFrame)) {
return message;
}
WebSocketFrame msg = (WebSocketFrame) message;
if (currentFrame == null) {
tooLongFrameFound = false;
if (msg.isFinalFragment()) {
return msg;
}
ChannelBuffer buf = msg.getBinaryData();
if (msg instanceof TextWebSocketFrame) {
currentFrame = new TextWebSocketFrame(true, msg.getRsv(), buf);
} else if (msg instanceof BinaryWebSocketFrame) {
currentFrame = new BinaryWebSocketFrame(true, msg.getRsv(), buf);
} else {
throw new IllegalStateException(
"WebSocket frame was not of type TextWebSocketFrame or BinaryWebSocketFrame");
}
return null;
}
if (msg instanceof ContinuationWebSocketFrame) {
if (tooLongFrameFound) {
if (msg.isFinalFragment()) {
currentFrame = null;
}
return null;
}
ChannelBuffer content = currentFrame.getBinaryData();
if (content.readableBytes() > maxFrameSize - msg.getBinaryData().readableBytes()) {
tooLongFrameFound = true;
throw new TooLongFrameException(
"WebSocketFrame length exceeded " + content +
" bytes.");
}
currentFrame.setBinaryData(ChannelBuffers.wrappedBuffer(content, msg.getBinaryData()));
if (msg.isFinalFragment()) {
WebSocketFrame currentFrame = this.currentFrame;
this.currentFrame = null;
return currentFrame;
} else {
return null;
}
}
// It is possible to receive CLOSE/PING/PONG frames during fragmented frames so just pass them to the next
// handler in the chain
return msg;
}
}