/*
* Copyright 2011 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.example.discard;
import java.util.logging.Level;
import java.util.logging.Logger;
import io.netty.buffer.ChannelBuffer;
import io.netty.buffer.ChannelBuffers;
import io.netty.channel.Channel;
import io.netty.channel.ChannelEvent;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelState;
import io.netty.channel.ChannelStateEvent;
import io.netty.channel.ExceptionEvent;
import io.netty.channel.MessageEvent;
import io.netty.channel.SimpleChannelUpstreamHandler;
import io.netty.channel.WriteCompletionEvent;
/**
* Handles a client-side channel.
*/
public class DiscardClientHandler extends SimpleChannelUpstreamHandler {
private static final Logger logger = Logger.getLogger(
DiscardClientHandler.class.getName());
private long transferredBytes;
private final byte[] content;
public DiscardClientHandler(int messageSize) {
if (messageSize <= 0) {
throw new IllegalArgumentException(
"messageSize: " + messageSize);
}
content = new byte[messageSize];
}
public long getTransferredBytes() {
return transferredBytes;
}
@Override
public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
if (e instanceof ChannelStateEvent) {
if (((ChannelStateEvent) e).getState() != ChannelState.INTEREST_OPS) {
logger.info(e.toString());
}
}
// Let SimpleChannelHandler call actual event handler methods below.
super.handleUpstream(ctx, e);
}
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
// Send the initial messages.
generateTraffic(e);
}
@Override
public void channelInterestChanged(ChannelHandlerContext ctx, ChannelStateEvent e) {
// Keep sending messages whenever the current socket buffer has room.
generateTraffic(e);
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
// Server is supposed to send nothing. Therefore, do nothing.
}
@Override
public void writeComplete(ChannelHandlerContext ctx, WriteCompletionEvent e) {
transferredBytes += e.getWrittenAmount();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
// Close the connection when an exception is raised.
logger.log(
Level.WARNING,
"Unexpected exception from downstream.",
e.getCause());
e.getChannel().close();
}
private void generateTraffic(ChannelStateEvent e) {
// Keep generating traffic until the channel is unwritable.
// A channel becomes unwritable when its internal buffer is full.
// If you keep writing messages ignoring this property,
// you will end up with an OutOfMemoryError.
Channel channel = e.getChannel();
while (channel.isWritable()) {
ChannelBuffer m = nextMessage();
if (m == null) {
break;
}
channel.write(m);
}
}
private ChannelBuffer nextMessage() {
return ChannelBuffers.wrappedBuffer(content);
}
}