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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.
*
*/
#ifndef _MessageStore_
#define _MessageStore_
#include <BrokerMessage.h>
#include <RecoveryManager.h>
#include <TransactionalStore.h>
namespace qpid {
namespace broker {
struct MessageStoreSettings
{
/**
* Messages whose content length is larger than this value
* will be staged (i.e. will have thier data written to
* disk as it arrives) and will load their data lazily. On
* recovery therefore, only the headers should be loaded.
*/
u_int64_t stagingThreshold;
};
/**
* An abstraction of the persistent storage for messages.
*/
class MessageStore : public TransactionalStore{
public:
/**
* Record the existance of a durable queue
*/
virtual void create(const Queue& queue) = 0;
/**
* Destroy a durable queue
*/
virtual void destroy(const Queue& queue) = 0;
/**
* Request recovery of queue and message state from store
*/
virtual void recover(RecoveryManager& queues, const MessageStoreSettings* const settings = 0) = 0;
/**
* Stores a messages before it has been enqueued
* (enqueueing automatically stores the message so this is
* only required if storage is required prior to that
* point). If the message has not yet been stored it will
* store the headers as well as any content passed in. A
* persistence id will be set on the message which can be
* used to load the content or to append to it.
*/
virtual void stage(Message::shared_ptr& msg) = 0;
/**
* Destroys a previously staged message. This only needs
* to be called if the message is never enqueued. (Once
* enqueued, deletion will be automatic when the message
* is dequeued from all queues it was enqueued onto).
*/
virtual void destroy(Message::shared_ptr& msg) = 0;
/**
* Appends content to a previously staged message
*/
virtual void appendContent(Message* const msg, const std::string& data) = 0;
/**
* Loads (a section) of content data for the specified
* message (previously stored through a call to stage or
* enqueue) into data. The offset refers to the content
* only (i.e. an offset of 0 implies that the start of the
* content should be loaded, not the headers or related
* meta-data).
*/
virtual void loadContent(Message* const msg, std::string& data, u_int64_t offset, u_int32_t length) = 0;
/**
* Enqueues a message, storing the message if it has not
* been previously stored and recording that the given
* message is on the given queue.
*
* @param msg the message to enqueue
* @param queue the name of the queue onto which it is to be enqueued
* @param xid (a pointer to) an identifier of the
* distributed transaction in which the operation takes
* place or null for 'local' transactions
*/
virtual void enqueue(TransactionContext* ctxt, Message::shared_ptr& msg, const Queue& queue, const std::string * const xid) = 0;
/**
* Dequeues a message, recording that the given message is
* no longer on the given queue and deleting the message
* if it is no longer on any other queue.
*
* @param msg the message to dequeue
* @param queue the name of th queue from which it is to be dequeued
* @param xid (a pointer to) an identifier of the
* distributed transaction in which the operation takes
* place or null for 'local' transactions
*/
virtual void dequeue(TransactionContext* ctxt, Message::shared_ptr& msg, const Queue& queue, const std::string * const xid) = 0;
/**
* Treat all enqueue/dequeues where this xid was specified as being committed.
*/
virtual void committed(const std::string * const xid) = 0;
/**
* Treat all enqueue/dequeues where this xid was specified as being aborted.
*/
virtual void aborted(const std::string * const xid) = 0;
virtual ~MessageStore(){}
};
}
}
#endif
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