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#ifndef QPID_SYS_MEMORYMAPPEDFILE_H
#define QPID_SYS_MEMORYMAPPEDFILE_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/CommonImportExport.h"
#include <string>
namespace qpid {
namespace sys {
class MemoryMappedFilePrivate;
/**
* Abstraction of memory mapping functionality
*/
class MemoryMappedFile {
public:
QPID_COMMON_EXTERN MemoryMappedFile();
QPID_COMMON_EXTERN ~MemoryMappedFile();
/**
* Opens a file that can be mapped by region into memory
*/
QPID_COMMON_EXTERN void open(const std::string& name, const std::string& directory);
/**
* Closes and removes the file that can be mapped by region into memory
*/
QPID_COMMON_EXTERN void close();
/**
* Returns the page size
*/
QPID_COMMON_EXTERN size_t getPageSize();
/**
* Load a portion of the file into memory
*/
QPID_COMMON_EXTERN char* map(size_t offset, size_t size);
/**
* Evict a portion of the file from memory
*/
QPID_COMMON_EXTERN void unmap(char* region, size_t size);
/**
* Flush any changes to a previously mapped region of the file
* back to disk
*/
QPID_COMMON_EXTERN void flush(char* region, size_t size);
/**
* Expand the capacity of the file
*/
QPID_COMMON_EXTERN void expand(size_t offset);
/**
* Returns true if memory mapping is supported, false otherwise
*/
QPID_COMMON_EXTERN static bool isSupported();
private:
MemoryMappedFilePrivate* state;
MemoryMappedFile(const MemoryMappedFile&);
MemoryMappedFile& operator=(const MemoryMappedFile&);
};
}} // namespace qpid::sys
#endif /*!QPID_SYS_MEMORYMAPPEDFILE_H*/
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