/*
* 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.handler.region;
import java.nio.channels.WritableByteChannel;
import io.netty.buffer.ChannelBuffer;
import io.netty.channel.ChannelDownstreamHandler;
import io.netty.channel.ChannelEvent;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.FileRegion;
import io.netty.channel.MessageEvent;
/**
* {@link ChannelDownstreamHandler} implementation which encodes a {@link FileRegion} to {@link ChannelBuffer}'s if one of the given {@link ChannelHandler} was found in the {@link ChannelPipeline}.
*
* This {@link ChannelDownstreamHandler} should be used if you plan to write {@link FileRegion} objects and also have some {@link ChannelDownstreamHandler} in the {@link ChannelPipeline} which needs to transform
* the to be written {@link ChannelBuffer} in any case. This could be for example {@link ChannelDownstreamHandler}'s which needs to encrypt or compress messages.
*
* Users of this {@link FileRegionEncoder} should add / remove this {@link ChannelDownstreamHandler} on the fly to get the best performance out of their system.
*
*
*/
@ChannelHandler.Sharable
public class FileRegionEncoder implements ChannelDownstreamHandler {
@Override
public void handleDownstream(
ChannelHandlerContext ctx, ChannelEvent evt) throws Exception {
if (!(evt instanceof MessageEvent)) {
ctx.sendDownstream(evt);
return;
}
MessageEvent e = (MessageEvent) evt;
Object originalMessage = e.getMessage();
if (originalMessage instanceof FileRegion) {
FileRegion fr = (FileRegion) originalMessage;
WritableByteChannel bchannel = new ChannelWritableByteChannel(ctx, e);
int length = 0;
long i = 0;
while ((i = fr.transferTo(bchannel, length)) > 0) {
length += i;
if (length >= fr.getCount()) {
break;
}
}
} else {
// no converting is needed so just sent the event downstream
ctx.sendDownstream(evt);
}
}
}