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#ifndef QPID_BROKER_REPLICATINGSUBSCRIPTION_H
#define QPID_BROKER_REPLICATINGSUBSCRIPTION_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 "BrokerInfo.h"
#include "qpid/broker/SemanticState.h"
#include "qpid/broker/ConsumerFactory.h"
#include "qpid/types/Uuid.h"
#include <iosfwd>
namespace qpid {
namespace broker {
class Message;
class Queue;
struct QueuedMessage;
class OwnershipToken;
}
namespace framing {
class Buffer;
}
namespace ha {
class QueueGuard;
/**
* A susbcription that replicates to a remote backup.
*
* Runs on the primary. In conjunction with a QueueGuard, delays completion of
* messages till the backup has acknowledged, informs backup of locally dequeued
* messages.
*
* A ReplicatingSubscription is "ready" when all the messages on the queue have
* either been acknowledged by the backup, or are protected by the queue guard.
* On a primary broker the ReplicatingSubscription calls Primary::readyReplica
* when it is ready.
*
* THREAD SAFE: Called in subscription's connection thread but also in arbitrary
* connection threads via dequeued.
*
* Lifecycle: broker::Queue holds shared_ptrs to this as a consumer.
*
* Lock Hierarchy: ReplicatingSubscription MUS NOT call QueueGuard with it's lock held
* QueueGuard MAY call ReplicatingSubscription with it's lock held.
*/
class ReplicatingSubscription : public broker::SemanticState::ConsumerImpl
{
public:
typedef broker::SemanticState::ConsumerImpl ConsumerImpl;
struct Factory : public broker::ConsumerFactory {
boost::shared_ptr<broker::SemanticState::ConsumerImpl> create(
broker::SemanticState* parent,
const std::string& name, boost::shared_ptr<broker::Queue> ,
bool ack, bool acquire, bool exclusive, const std::string& tag,
const std::string& resumeId, uint64_t resumeTtl,
const framing::FieldTable& arguments);
};
// Argument names for consume command.
static const std::string QPID_REPLICATING_SUBSCRIPTION;
static const std::string QPID_BACK;
static const std::string QPID_FRONT;
static const std::string QPID_BROKER_INFO;
ReplicatingSubscription(broker::SemanticState* parent,
const std::string& name, boost::shared_ptr<broker::Queue> ,
bool ack, bool acquire, bool exclusive, const std::string& tag,
const std::string& resumeId, uint64_t resumeTtl,
const framing::FieldTable& arguments);
~ReplicatingSubscription();
// Called via QueueGuard::dequeued.
//@return true if the message requires completion.
void dequeued(const broker::Message&);
// Called during initial scan for dequeues.
void dequeued(framing::SequenceNumber first, framing::SequenceNumber last);
// Consumer overrides.
bool deliver(const broker::QueueCursor& cursor, const broker::Message& msg);
void cancel();
void acknowledged(const broker::DeliveryRecord&);
bool browseAcquired() const { return true; }
// Hide the "queue deleted" error for a ReplicatingSubscription when a
// queue is deleted, this is normal and not an error.
bool hideDeletedError() { return true; }
// Not counted for auto deletion and immediate message purposes.
bool isCounted() { return false; }
/** Initialization that must be done separately from construction
* because it requires a shared_ptr to this to exist.
*/
void initialize();
BrokerInfo getBrokerInfo() const { return info; }
protected:
bool doDispatch();
private:
std::string logPrefix;
framing::SequenceSet dequeues;
framing::SequenceNumber position;
framing::SequenceNumber backupPosition;
bool ready;
BrokerInfo info;
boost::shared_ptr<QueueGuard> guard;
void sendDequeueEvent(sys::Mutex::ScopedLock&);
void sendPositionEvent(framing::SequenceNumber, sys::Mutex::ScopedLock&);
void setReady();
void sendEvent(const std::string& key, framing::Buffer&);
friend struct Factory;
};
}} // namespace qpid::broker
#endif /*!QPID_BROKER_REPLICATINGSUBSCRIPTION_H*/
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