syncevolution/src/syncevo/TmpFile.h
2012-10-25 16:43:08 +02:00

129 lines
3.3 KiB
C++

/*
* Copyright (C) 2012 Intel Corporation
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) version 3.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#ifndef INCL_SYNCEVOLUTION_TMPFILE
#define INCL_SYNCEVOLUTION_TMPFILE
#include <stdexcept>
#include <string>
#include <pcrecpp.h>
/**
* Exception class for TmpFile.
*/
class TmpFileException : public std::runtime_error
{
public:
TmpFileException(const std::string &what)
: std::runtime_error(what)
{ }
};
/**
* Class for handling temporary files, either read/write access
* or memory mapped.
*
* Closing and removing a mapped file is supported by calling close()
* after map().
*/
class TmpFile
{
protected:
int m_fd;
void *m_mapptr;
size_t m_mapsize;
std::string m_filename;
public:
TmpFile();
virtual ~TmpFile();
/**
* Create a temporary file.
*/
void create();
/**
* Map a view of file and optionally return pointer and/or size.
*
* File should already have a correct size.
*
* @param mapptr Pointer to variable for mapped pointer. (can be NULL)
* @param mapsize Pointer to variable for mapped size. (can be NULL)
*/
void map(void **mapptr = 0, size_t *mapsize = 0);
/**
* Unmap a view of file.
*/
void unmap();
/**
* Remove and close the file.
*
* Calling this after map() will make the file disappear from
* filesystem but the mapping will be valid until unmapped or
* instance of this class is destroyed.
*/
void close();
/**
* Retrieve file name of the file.
*
* @return file name
*/
const std::string & filename() const
{ return m_filename; }
/**
* Retrieve descriptor of the file.
*
* @return descriptor
*/
int fd()
{ return m_fd; }
/**
* Size of the mapping.
*
* @return mapped size
*/
size_t size() const
{ return m_mapsize; }
/**
* Pointer to the mapping.
*
* @return pointer to the mapping
*/
operator void *()
{ return m_mapptr; }
/**
* @overload
*/
operator const void *() const
{ return m_mapptr; }
/**
* Retrieve pcrecpp::StringPiece object for the mapped view.
*
* @return pcrecpp::StringPiece of the mapped view
*/
pcrecpp::StringPiece stringPiece();
};
#endif // INCL_SYNCEVOLUTION_TMPFILE