#ifndef QPID_HA_QUEUESNAPSHOTS_H
#define QPID_HA_QUEUESNAPSHOTS_H

/*
 *
 * 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 "QueueSnapshot.h"
#include "hash.h"

#include "qpid/assert.h"
#include "qpid/broker/BrokerObserver.h"
#include "qpid/broker/Queue.h"
#include "qpid/sys/Mutex.h"

#include <boost/shared_ptr.hpp>

namespace qpid {
namespace ha {

/**
 * BrokerObserver that maintains a map of the QueueSnapshot for each queue.
 * THREAD SAFE.
 */
class QueueSnapshots : public broker::BrokerObserver
{
  public:
    boost::shared_ptr<QueueSnapshot> get(const boost::shared_ptr<broker::Queue>& q) const {
        boost::shared_ptr<QueueSnapshot> qs;
        q->eachObserver(
            boost::bind(QueueSnapshots::saveQueueSnapshot, _1, boost::ref(qs)));
        return qs;
    }

    // BrokerObserver overrides.
    void queueCreate(const boost::shared_ptr<broker::Queue>& q) {
        q->addObserver(boost::shared_ptr<QueueSnapshot>(new QueueSnapshot));
    }

    void queueDestroy(const boost::shared_ptr<broker::Queue>& q) {
        q->removeObserver(get(q));
    }

  private:
    static void saveQueueSnapshot(
        const boost::shared_ptr<broker::QueueObserver>& observer,
        boost::shared_ptr<QueueSnapshot>& out)
    {
        if (!out) out = boost::dynamic_pointer_cast<QueueSnapshot>(observer);
    }
};


}} // namespace qpid::ha

#endif  /*!QPID_HA_QUEUESNAPSHOTS_H*/
