lunchbox::MemoryMap Class Reference

Helper to map a file to a memory address (mmap). More...

#include <memoryMap.h>

Inheritance diagram for lunchbox::MemoryMap:

Collaboration diagram for lunchbox::MemoryMap:

Public Member Functions
	MemoryMap ()
	Construct a new memory map. More...
	MemoryMap (const std::string &filename)
	Construct and initialize a new, readonly memory map. More...
	MemoryMap (const std::string &filename, const size_t size)
	Construct and initialize a new, read-write memory map. More...
	~MemoryMap ()
	Destruct the memory map. More...
const void *	map (const std::string &filename)
	Map a file to a memory address. More...
const void *	remap (const std::string &filename)
	Remap a different file for this memory map. More...
void *	create (const std::string &filename, const size_t size)
	Create a writable file to a memory address. More...
void *	recreate (const std::string &filename, const size_t size)
	Recreate a different writable file for this memory map. More...
void	unmap ()
	Unmap the file. More...
const void *	getAddress () const
void *	getAddress ()
template<class T >
const T *	getAddress () const
template<class T >
T *	getAddress ()
size_t	getSize () const

Detailed Description

Helper to map a file to a memory address (mmap).

Deprecated:

Use boost::iostreams::mapped_file_source

Example:

/* Copyright (c) 2013-2016 Stefan.Eilemann@epfl.ch
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * 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.
 */

#include <test.h>
#include <lunchbox/memoryMap.h>

using lunchbox::MemoryMap;
#define MAP_SIZE LB_10MB
#define STRIDE 23721

int main( int, char** )
{
    MemoryMap map( "foo.mmap", MAP_SIZE );
    TESTINFO( map.getSize() == MAP_SIZE, map.getSize( ));
    TEST( map.recreate(  "foo.mmap", MAP_SIZE ));

    uint8_t* writePtr = map.getAddress< uint8_t >();
    TEST( writePtr );

    for( size_t i=0; i < MAP_SIZE; i += STRIDE )
        writePtr[i] = uint8_t( i );
    map.unmap();

    const void* noPtr = map.map( "foo.map" );
    TEST( noPtr == 0 );
    TEST( map.getSize() == 0 );

    TEST( map.map( "foo.mmap" ));
    TEST( !map.map( "foo.mmap" ));
    TEST( map.remap( "foo.mmap" ));
    const uint8_t* readPtr = map.getAddress< uint8_t >();
    TEST( readPtr );
    TEST( map.getSize() == MAP_SIZE );

    for( size_t i=0; i < MAP_SIZE; i += STRIDE )
        TEST( readPtr[i] == uint8_t( i ));

    return EXIT_SUCCESS;
}

Definition at line 36 of file memoryMap.h.

Constructor & Destructor Documentation

lunchbox::MemoryMap::MemoryMap

(

)

Construct a new memory map.

Version

1.0

lunchbox::MemoryMap::MemoryMap ( const std::string &  filename )

explicit

Construct and initialize a new, readonly memory map.

Version

1.7.1

lunchbox::MemoryMap::MemoryMap	(	const std::string &	filename,
		const size_t	size
	)

Construct and initialize a new, read-write memory map.

Version

1.9.1

lunchbox::MemoryMap::~MemoryMap

(

)

Destruct the memory map.

Unmaps the file, if it is still mapped.

See also

unmap()

Version

1.0

Member Function Documentation

void* lunchbox::MemoryMap::create	(	const std::string &	filename,
		const size_t	size
	)

Create a writable file to a memory address.

The file is mapped read-write. An existing file will be overwritten. The file is automatically unmapped when the memory map is deleted.

Parameters

filename	The filename of the file to map.
size	this size of the file.

Returns

the pointer to the mapped file, or 0 upon error.

Version

1.9.1

const void* lunchbox::MemoryMap::getAddress

(

)

const

Returns

the pointer to the memory map.

Version

1.0

Referenced by getAddress().

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void* lunchbox::MemoryMap::getAddress

(

)

Returns

the pointer to the memory map.

Version

1.9.1

template<class T >

const T* lunchbox::MemoryMap::getAddress ( ) const

inline

Returns

the pointer to the memory map.

Version

1.9.1

Definition at line 116 of file memoryMap.h.

References getAddress().

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template<class T >

T* lunchbox::MemoryMap::getAddress ( )

inline

Returns

the pointer to the memory map.

Version

1.9.1

Definition at line 120 of file memoryMap.h.

References getAddress().

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size_t lunchbox::MemoryMap::getSize

(

)

const

Returns

the size of the memory map.

Version

1.0

const void* lunchbox::MemoryMap::map

(

const std::string &

filename

)

Map a file to a memory address.

The file is only mapped read-only. The file is automatically unmapped when the memory map is deleted.

Parameters

filename

The filename of the file to map.

Returns

the pointer to the mapped file, or 0 upon error.

Version

1.0

void* lunchbox::MemoryMap::recreate	(	const std::string &	filename,
		const size_t	size
	)

Recreate a different writable file for this memory map.

The file is only mapped read-write. An existing map is unmapped.

Parameters

filename	The filename of the file to map.
size	this size of the file.

Returns

the pointer to the mapped file, or 0 upon error.

Version

1.0

const void* lunchbox::MemoryMap::remap

(

const std::string &

filename

)

Remap a different file for this memory map.

The file is only mapped read-only. An existing map is unmapped.

Parameters

filename

The filename of the file to map.

Returns

the pointer to the mapped file, or 0 upon error.

Version

1.9.1

void lunchbox::MemoryMap::unmap

(

)

Unmap the file.

Version

1.0

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The documentation for this class was generated from the following file:

• memoryMap.h