package org.webbitserver.netty;
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.channel.ChannelPipeline;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
import org.jboss.netty.util.CharsetUtil;
import java.util.concurrent.Executor;
/**
* Checks the received {@link org.jboss.netty.buffer.ChannelBuffer
* ChannelBuffer}s for Flash policy file requests.
* <p/>
* <p>
* If this decoder detects a Flash policy file request it adds a
* {@link FlashPolicyFileHandler} to the
* {@link org.jboss.netty.channel.ChannelPipeline ChannelPipeline} and removes
* itself from the pipeline. If a Flash policy file request is not detected in
* the first 23 bytes of the buffer, the decoder removes itself from the
* pipeline.
* <p>
* <p/>
* <p>
* This implementation is based on the
* "replacing a decoder with another decoder in a pipeline" section of the
* {@link org.jboss.netty.handler.codec.frame.FrameDecoder FrameDecoder}
* documentation.
* </p>
*/
public class FlashPolicyFileDecoder extends FrameDecoder {
private static final ChannelBuffer FLASH_POLICY_REQUEST = ChannelBuffers
.copiedBuffer("<policy-file-request/>\0", CharsetUtil.US_ASCII);
private final Executor executor;
private final Thread.UncaughtExceptionHandler exceptionHandler;
private final Thread.UncaughtExceptionHandler ioExceptionHandler;
private final int publicPort;
public FlashPolicyFileDecoder(Executor executor, Thread.UncaughtExceptionHandler exceptionHandler, Thread.UncaughtExceptionHandler ioExceptionHandler, int publicPort) {
super(true);
this.publicPort = publicPort;
this.executor = executor;
this.exceptionHandler = exceptionHandler;
this.ioExceptionHandler = ioExceptionHandler;
}
@Override
protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
// Will use the first 23 bytes to detect the policy file request.
if (buffer.readableBytes() >= 23) {
ChannelPipeline p = ctx.getPipeline();
ChannelBuffer firstMessage = buffer.readBytes(23);
if (FLASH_POLICY_REQUEST.equals(firstMessage)) {
p.addAfter("flashpolicydecoder", "flashpolicyhandler",
new FlashPolicyFileHandler(executor, exceptionHandler, ioExceptionHandler, this.publicPort));
}
p.remove(this);
if (buffer.readable()) {
return new Object[]{firstMessage, buffer.readBytes(buffer.readableBytes())};
} else {
return firstMessage;
}
}
// Forward the current buffer as is to handlers.
return buffer.readBytes(buffer.readableBytes());
}
}