/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.hedwig.server.proxy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import com.google.protobuf.ByteString;
import org.apache.hedwig.client.api.MessageHandler;
import org.apache.hedwig.client.api.Subscriber;
import org.apache.hedwig.exceptions.PubSubException;
import org.apache.hedwig.exceptions.PubSubException.ClientNotSubscribedException;
import org.apache.hedwig.protocol.PubSubProtocol.Message;
import org.apache.hedwig.protocol.PubSubProtocol.ProtocolVersion;
import org.apache.hedwig.protocol.PubSubProtocol.PubSubRequest;
import org.apache.hedwig.protocol.PubSubProtocol.PubSubResponse;
import org.apache.hedwig.protocol.PubSubProtocol.StatusCode;
import org.apache.hedwig.protoextensions.PubSubResponseUtils;
import org.apache.hedwig.server.handlers.Handler;
import org.apache.hedwig.server.netty.UmbrellaHandler;
import org.apache.hedwig.util.Callback;
public class ProxyStartDeliveryHandler implements Handler {
static final Logger logger = LoggerFactory.getLogger(ProxyStartDeliveryHandler.class);
Subscriber subscriber;
ChannelTracker tracker;
public ProxyStartDeliveryHandler(Subscriber subscriber, ChannelTracker tracker) {
this.subscriber = subscriber;
this.tracker = tracker;
}
@Override
public void handleRequest(PubSubRequest request, Channel channel) {
if (!request.hasStartDeliveryRequest()) {
UmbrellaHandler.sendErrorResponseToMalformedRequest(channel, request.getTxnId(),
"Missing start delivery request data");
return;
}
final ByteString topic = request.getTopic();
final ByteString subscriberId = request.getStartDeliveryRequest().getSubscriberId();
synchronized (tracker) {
// try {
// tracker.checkChannelMatches(topic, subscriberId, channel);
// } catch (PubSubException e) {
// channel.write(PubSubResponseUtils.getResponseForException(e,
// request.getTxnId()));
// return;
// }
final Channel subscribedChannel = tracker.getChannel(topic, subscriberId);
if (subscribedChannel == null) {
channel.write(PubSubResponseUtils.getResponseForException(
new PubSubException.ClientNotSubscribedException("no subscription to start delivery on"),
request.getTxnId()));
return;
}
MessageHandler handler = new MessageHandler() {
@Override
public void deliver(ByteString topic, ByteString subscriberId, Message msg,
final Callback<Void> callback, final Object context) {
PubSubResponse response = PubSubResponse.newBuilder().setProtocolVersion(
ProtocolVersion.VERSION_ONE).setStatusCode(StatusCode.SUCCESS).setTxnId(0).setMessage(msg)
.setTopic(topic).setSubscriberId(subscriberId).build();
ChannelFuture future = subscribedChannel.write(response);
future.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
// ignoring this failure, because this will
// only happen due to channel disconnect.
// Channel disconnect will in turn stop
// delivery, and stop these errors
return;
}
// Tell the hedwig client, that it can send me
// more messages
callback.operationFinished(context, null);
}
});
}
};
channel.write(PubSubResponseUtils.getSuccessResponse(request.getTxnId()));
try {
subscriber.startDelivery(topic, subscriberId, handler);
} catch (ClientNotSubscribedException e) {
// This should not happen, since we already checked the correct
// channel and so on
logger.error("Unexpected: No subscription when attempting to start delivery", e);
throw new RuntimeException(e);
}
}
}
}