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#ifndef QPID_BROKER_PAGEDQUEUE_H
#define QPID_BROKER_PAGEDQUEUE_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 "qpid/broker/Messages.h"
#include "qpid/broker/Message.h"
#include "qpid/framing/SequenceSet.h"
#include "qpid/sys/MemoryMappedFile.h"
#include <deque>
#include <list>
#include <map>
namespace qpid {
namespace broker {
class ProtocolRegistry;
/**
*
*/
class PagedQueue : public Messages {
public:
PagedQueue(const std::string& name, const std::string& directory, uint maxLoaded, uint pageFactor, ProtocolRegistry& protocols);
~PagedQueue();
size_t size();
bool deleted(const QueueCursor&);
void publish(const Message& added);
Message* next(QueueCursor& cursor);
Message* release(const QueueCursor& cursor);
Message* find(const framing::SequenceNumber&, QueueCursor*);
Message* find(const QueueCursor&);
void foreach(Functor);
private:
class Page {
public:
Page(size_t size, size_t offset);
void read();//decode messages from memory mapped file
void write();//encode messages into memory mapped file
bool isLoaded() const;
bool empty() const;
void deleted(qpid::framing::SequenceNumber);
Message* release(qpid::framing::SequenceNumber);
bool add(const Message&);
Message* next(uint32_t version, QueueCursor&);
Message* find(qpid::framing::SequenceNumber);
void load(qpid::sys::MemoryMappedFile&,ProtocolRegistry&);
void unload(qpid::sys::MemoryMappedFile&);
void clear(qpid::sys::MemoryMappedFile&);
size_t available() const;
private:
size_t size;
size_t offset;
char* region;//0 implies not mapped
qpid::framing::SequenceSet contents;
qpid::framing::SequenceSet acquired;
std::deque<Message> messages;//decoded representation
size_t used;//amount of data used to encode current set of messages held
};
qpid::sys::MemoryMappedFile file;
std::string name;
std::string path;
const size_t pageSize;
const uint maxLoaded;
ProtocolRegistry& protocols;
size_t offset;
typedef std::map<qpid::framing::SequenceNumber, Page> Used;
Used used;
std::list<Page> free;
uint loaded;
uint32_t version;
void addPages(size_t count);
Page& newPage(qpid::framing::SequenceNumber);
Used::iterator findPage(const QueueCursor& cursor);
Used::iterator findPage(qpid::framing::SequenceNumber n, bool loadIfRequired);
void load(Page&);
void unload(Page&);
bool deleted(qpid::framing::SequenceNumber);
};
}} // namespace qpid::broker
#endif /*!QPID_BROKER_PAGEDQUEUE_H*/
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