oMemoryMapped Class Reference

Portable read-only memory mapping (Windows and Linux) More...

#include <oMemoryMapped.hh>

Collaboration diagram for oMemoryMapped:

Public Types
enum	CacheHint { Normal, SequentialScan, RandomAccess }
	tweak performance More...
enum	MapRange { WholeFile = 0 }
	how much should be mappend More...

Public Member Functions
	oMemoryMapped ()
	do nothing, must use open() More...
	oMemoryMapped (const std::string &filename, size_t mappedBytes=WholeFile, CacheHint hint=Normal)
	open file, mappedBytes = 0 maps the whole file More...
	~oMemoryMapped ()
	close file (see close() ) More...
int	Open (const std::string &filename, size_t mappedBytes=WholeFile, CacheHint hint=Normal)
	open file, mappedBytes = 0 maps the whole file More...
void	Close ()
	close file More...
unsigned char	operator[] (size_t offset) const
	access position, no range checking (faster) More...
unsigned char	at (size_t offset) const
	access position, including range checking More...
const unsigned char *	GetData () const
	raw access More...
bool	IsValid () const
	true, if file successfully opened More...
uint64_t	size () const
	get file size More...
size_t	mappedSize () const
	get number of actually mapped bytes More...
int	Remap (uint64_t offset, size_t mappedBytes)
	replace mapping by a new one of the same file, offset MUST be a multiple of the page size More...

Private Types
typedef int	FileHandle
	define handle More...

Private Member Functions
	oMemoryMapped (const oMemoryMapped &)
	don't copy object More...
oMemoryMapped &	operator= (const oMemoryMapped &)
	don't copy object More...

Static Private Member Functions
static int	GetPageSize ()
	get OS page size (for remap) More...

Private Attributes
std::string	_filename
	file name More...
uint64_t	_filesize
	file size More...
CacheHint	_hint
	caching strategy More...
size_t	_mappedBytes
	mapped size More...
FileHandle	_file
	file handle More...
void *	_mappedView
	pointer to the file contents mapped into memory More...

Detailed Description

Portable read-only memory mapping (Windows and Linux)

Filesize limited by size_t, usually 2^32 or 2^64

Definition at line 51 of file oMemoryMapped.hh.

Member Typedef Documentation

FileHandle

typedef int oMemoryMapped::FileHandle

private

define handle

Definition at line 123 of file oMemoryMapped.hh.

Member Enumeration Documentation

CacheHint

enum oMemoryMapped::CacheHint

tweak performance

Enumerator
Normal	good overall performance
SequentialScan	read file only once with few seeks
RandomAccess	jump around

Definition at line 55 of file oMemoryMapped.hh.

MapRange

enum oMemoryMapped::MapRange

how much should be mappend

Enumerator
WholeFile	everything ... be careful when file is larger than memory

Definition at line 63 of file oMemoryMapped.hh.

Constructor & Destructor Documentation

oMemoryMapped() [1/3]

oMemoryMapped::oMemoryMapped

(

)

do nothing, must use open()

Definition at line 69 of file oMemoryMapped.cc.

oMemoryMapped() [2/3]

oMemoryMapped::oMemoryMapped	(	const std::string &	filename,
		size_t	mappedBytes = WholeFile,
		CacheHint	hint = Normal
	)

open file, mappedBytes = 0 maps the whole file

Definition at line 88 of file oMemoryMapped.cc.

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~oMemoryMapped()

oMemoryMapped::~oMemoryMapped

(

)

close file (see close() )

Definition at line 108 of file oMemoryMapped.cc.

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oMemoryMapped() [3/3]

oMemoryMapped::oMemoryMapped ( const oMemoryMapped &  )

private

don't copy object

Member Function Documentation

at()

unsigned char oMemoryMapped::at

(

size_t

offset

)

const

access position, including range checking

Definition at line 280 of file oMemoryMapped.cc.

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Close()

void oMemoryMapped::Close

(

)

close file

Definition at line 228 of file oMemoryMapped.cc.

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GetData()

const unsigned char * oMemoryMapped::GetData

(

)

const

raw access

Definition at line 297 of file oMemoryMapped.cc.

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GetPageSize()

int oMemoryMapped::GetPageSize ( )

staticprivate

get OS page size (for remap)

Definition at line 442 of file oMemoryMapped.cc.

IsValid()

bool oMemoryMapped::IsValid

(

)

const

true, if file successfully opened

Definition at line 308 of file oMemoryMapped.cc.

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mappedSize()

size_t oMemoryMapped::mappedSize

(

)

const

get number of actually mapped bytes

Definition at line 330 of file oMemoryMapped.cc.

Open()

int oMemoryMapped::Open	(	const std::string &	filename,
		size_t	mappedBytes = WholeFile,
		CacheHint	hint = Normal
	)

open file, mappedBytes = 0 maps the whole file

open file

Definition at line 119 of file oMemoryMapped.cc.

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operator=()

oMemoryMapped& oMemoryMapped::operator= ( const oMemoryMapped &  )

private

don't copy object

operator[]()

unsigned char oMemoryMapped::operator[]

(

size_t

offset

)

const

access position, no range checking (faster)

Definition at line 269 of file oMemoryMapped.cc.

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Remap()

int oMemoryMapped::Remap	(	uint64_t	offset,
		size_t	mappedBytes
	)

replace mapping by a new one of the same file, offset MUST be a multiple of the page size

Definition at line 341 of file oMemoryMapped.cc.

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size()

uint64_t oMemoryMapped::size

(

)

const

get file size

Definition at line 319 of file oMemoryMapped.cc.

Member Data Documentation

_file

FileHandle oMemoryMapped::_file

private

file handle

Definition at line 127 of file oMemoryMapped.hh.

_filename

std::string oMemoryMapped::_filename

private

file name

Definition at line 109 of file oMemoryMapped.hh.

_filesize

uint64_t oMemoryMapped::_filesize

private

file size

Definition at line 111 of file oMemoryMapped.hh.

_hint

CacheHint oMemoryMapped::_hint

private

caching strategy

Definition at line 113 of file oMemoryMapped.hh.

_mappedBytes

size_t oMemoryMapped::_mappedBytes

private

mapped size

Definition at line 115 of file oMemoryMapped.hh.

_mappedView

void* oMemoryMapped::_mappedView

private

pointer to the file contents mapped into memory

Definition at line 129 of file oMemoryMapped.hh.

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

• oMemoryMapped.hh
• oMemoryMapped.cc