cpp/lib/broker/QueueRegistry.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.
 *
 */
#ifndef _QueueRegistry_
#define _QueueRegistry_

#include <map>
#include <sys/Monitor.h>
#include <BrokerQueue.h>

namespace qpid {
namespace broker {

/**
 * A registry of queues indexed by queue name.
 *
 * Queues are reference counted using shared_ptr to ensure that they
 * are deleted when and only when they are no longer in use.
 *
 */
class QueueRegistry{
 
  public:
    QueueRegistry(MessageStore* const store = 0);
    ~QueueRegistry();

    /**
     * Declare a queue.
     *
     * @return The queue and a boolean flag which is true if the queue
     * was created by this declare call false if it already existed.
     */
    std::pair<Queue::shared_ptr, bool> declare(const string& name, bool durable = false, u_int32_t autodelete = 0, 
                                               const ConnectionToken* const owner = 0);

    /**
     * Destroy the named queue.
     *
     * Note: if the queue is in use it is not actually destroyed until
     * all shared_ptrs to it are destroyed. During that time it is
     * possible that a new queue with the same name may be
     * created. This should not create any problems as the new and
     * old queues exist independently. The registry has
     * forgotten the old queue so there can be no confusion for
     * subsequent calls to find or declare with the same name.
     *
     */
    void destroy(const string& name);

    /**
     * Find the named queue. Return 0 if not found.
     */
    Queue::shared_ptr find(const string& name);

    /**
     * Generate unique queue name.
     */
    string generateName();

    /**
     * Return the message store used.
     */
    MessageStore* const getStore() const;


  private:
    typedef std::map<string, Queue::shared_ptr> QueueMap;
    QueueMap queues;
    qpid::sys::Mutex lock;
    int counter;
    MessageStore* const store;
};

    
}
}


#endif