/*
* Copyright 2016 Anton Tananaev (anton@traccar.org)
*
* Licensed 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.traccar.protocol;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
public class TelicFrameDecoder extends FrameDecoder {
@Override
protected Object decode(
ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
if (buf.readableBytes() < 4) {
return null;
}
long length = buf.getUnsignedInt(buf.readerIndex());
if (length < 1024) {
if (buf.readableBytes() >= length + 4) {
buf.readUnsignedInt();
return buf.readBytes((int) length);
}
} else {
int endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) 0);
if (endIndex >= 0) {
ChannelBuffer frame = buf.readBytes(endIndex - buf.readerIndex());
buf.readByte();
if (frame.readableBytes() > 0) {
return frame;
}
}
}
return null;
}
}