src/qpid/ha/RemoteBackup.h

#ifndef QPID_HA_REMOTEBACKUP_H
#define QPID_HA_REMOTEBACKUP_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 "LogPrefix.h"
#include "ReplicationTest.h"
#include "BrokerInfo.h"
#include "types.h"
#include "hash.h"
#include "qpid/sys/unordered_map.h"
#include <set>

namespace qpid {

namespace broker {
class Queue;
class QueueRegistry;
class Connection;
}

namespace ha {
class QueueGuard;

/**
 * Track readiness for a remote broker.
 * Creates queue guards on behalf of the remote broker to keep
 * queues safe till the ReplicatingSubscription is ready.
 *
 * THREAD UNSAFE: Caller must serialize.
 */
class RemoteBackup
{
  public:
    typedef boost::shared_ptr<QueueGuard> GuardPtr;
    typedef boost::shared_ptr<broker::Queue> QueuePtr;

    /** Note: isReady() can be true after construction
     *@param connected true if the backup is already connected.
     */
    RemoteBackup(const BrokerInfo&, broker::Connection*, const LogPrefix&);
    ~RemoteBackup();

    /** Return guard associated with a queue. Used to create ReplicatingSubscription. */
    GuardPtr guard(const QueuePtr&);

    /** Is the remote backup connected? */
    void setConnection(broker::Connection* c) { connection = c; }
    broker::Connection* getConnection() const { return connection; }

    /** ReplicatingSubscription associated with queue is ready.
     * Note: may set isReady()
     */
    void ready(const QueuePtr& queue);

    /** Called via BrokerObserver */
    void queueCreate(const QueuePtr&);

    /** Called via BrokerObserver. Note: may set isReady() */
    void queueDestroy(const QueuePtr&);

    /**@return true when all catch-up queues for this backup are ready. */
    bool isReady();

    /**@return true if isReady() and this is the first call to reportReady */
    bool reportReady();

    /**Cancel all queue guards, called if we are timed out. */
    void cancel();

    /** Set a catch-up queue for this backup.
     *@createGuard if true create a guard immediately.
     */
    void catchupQueue(const QueuePtr&, bool createGuard);

    BrokerInfo getBrokerInfo() const { return brokerInfo; }

    void startCatchup() { started = true; }

  private:
    typedef qpid::sys::unordered_map<
      QueuePtr, GuardPtr, Hasher<boost::shared_ptr<broker::Queue> >
      > GuardMap;

    typedef std::set<QueuePtr> QueueSet;

    LogPrefix2 logPrefix;
    BrokerInfo brokerInfo;
    ReplicationTest replicationTest;
    GuardMap guards;
    QueueSet catchupQueues;
    bool started;
    broker::Connection* connection;
    bool reportedReady;
};

}} // namespace qpid::ha

#endif  /*!QPID_HA_REMOTEBACKUP_H*/