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/*
*
* 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.
*
*/
#include <qpid/client/FailoverManager.h>
#include <qpid/client/Session.h>
#include <qpid/client/Message.h>
#include <qpid/client/SubscriptionManager.h>
#include <iostream>
#include <fstream>
using namespace qpid;
using namespace qpid::client;
using namespace qpid::framing;
using namespace std;
class Listener : public MessageListener,
public FailoverManager::Command,
public FailoverManager::ReconnectionStrategy
{
public:
Listener ( int report_frequency = 1000, int verbosity = 0 );
void received(Message& message);
void execute(AsyncSession& session, bool isRetry);
void check();
void editUrlList(std::vector<Url>& urls);
private:
Subscription subscription;
uint count;
uint received_twice;
uint lastSn;
bool gaps;
uint reportFrequency;
int verbosity;
bool done;
};
Listener::Listener(int freq, int verbosity)
: count(0),
received_twice(0),
lastSn(0),
gaps(false),
reportFrequency(freq),
verbosity(verbosity),
done(false)
{}
void Listener::received(Message & message)
{
if (message.getData() == "That's all, folks!")
{
done = true;
if(verbosity > 0 )
{
std::cout << "Shutting down listener for "
<< message.getDestination() << std::endl;
std::cout << "Listener received "
<< count
<< " messages ("
<< received_twice
<< " received_twice)"
<< endl;
}
subscription.cancel();
if ( verbosity > 0 )
std::cout << "LISTENER COMPLETED\n";
} else {
uint sn = message.getHeaders().getAsInt("sn");
if (lastSn < sn) {
if (sn - lastSn > 1) {
std::cerr << "Error: gap in sequence between " << lastSn << " and " << sn << std::endl;
gaps = true;
}
lastSn = sn;
++count;
if ( ! ( count % reportFrequency ) ) {
if ( verbosity > 0 )
std::cout << "Listener has received "
<< count
<< " messages.\n";
}
} else {
++received_twice;
}
}
}
void Listener::check()
{
if (gaps) throw Exception("Detected gaps in sequence; messages appear to have been lost.");
}
void Listener::execute(AsyncSession& session, bool isRetry) {
if (verbosity > 0)
std::cout << "resuming_receiver " << (isRetry ? "first " : "re-") << "connect." << endl;
if (!done) {
SubscriptionManager subs(session);
subscription = subs.subscribe(*this, "message_queue");
subs.run();
}
}
void Listener::editUrlList(std::vector<Url>& urls)
{
/**
* A more realistic algorithm would be to search through the list
* for prefered hosts and ensure they come first in the list.
*/
if (urls.size() > 1) std::rotate(urls.begin(), urls.begin() + 1, urls.end());
}
int main(int argc, char ** argv)
{
ConnectionSettings settings;
if ( argc != 5 )
{
std::cerr << "Usage: resuming_receiver host port report_frequency verbosity\n";
return 1;
}
settings.host = argv[1];
settings.port = atoi(argv[2]);
int reportFrequency = atoi(argv[3]);
int verbosity = atoi(argv[4]);
Listener listener(reportFrequency, verbosity);
FailoverManager connection(settings, &listener);
try {
connection.execute(listener);
connection.close();
listener.check();
return 0;
} catch(const std::exception& error) {
std::cerr << "Receiver failed: " << error.what() << std::endl;
}
return 1;
}
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