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 52 of file oMemoryMapped.hh.

Member Typedef Documentation

typedef int oMemoryMapped::FileHandle

private

define handle

Definition at line 124 of file oMemoryMapped.hh.

Member Enumeration Documentation

enum oMemoryMapped::CacheHint

tweak performance

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

Definition at line 56 of file oMemoryMapped.hh.

enum oMemoryMapped::MapRange

how much should be mappend

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

Definition at line 64 of file oMemoryMapped.hh.

Constructor & Destructor Documentation

oMemoryMapped::oMemoryMapped

(

)

do nothing, must use open()

Definition at line 70 of file oMemoryMapped.cc.

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

open file, mappedBytes = 0 maps the whole file

Definition at line 89 of file oMemoryMapped.cc.

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oMemoryMapped::~oMemoryMapped

(

)

close file (see close() )

Definition at line 109 of file oMemoryMapped.cc.

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oMemoryMapped::oMemoryMapped ( const oMemoryMapped &  )

private

don't copy object

Member Function Documentation

unsigned char oMemoryMapped::at

(

size_t

offset

)

const

access position, including range checking

Definition at line 279 of file oMemoryMapped.cc.

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void oMemoryMapped::Close

(

)

close file

Definition at line 227 of file oMemoryMapped.cc.

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const unsigned char * oMemoryMapped::GetData

(

)

const

raw access

Definition at line 296 of file oMemoryMapped.cc.

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int oMemoryMapped::GetPageSize ( )

staticprivate

get OS page size (for remap)

Definition at line 439 of file oMemoryMapped.cc.

bool oMemoryMapped::IsValid

(

)

const

true, if file successfully opened

Definition at line 307 of file oMemoryMapped.cc.

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size_t oMemoryMapped::mappedSize

(

)

const

get number of actually mapped bytes

Definition at line 329 of file oMemoryMapped.cc.

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 120 of file oMemoryMapped.cc.

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

private

don't copy object

unsigned char oMemoryMapped::operator[]

(

size_t

offset

)

const

access position, no range checking (faster)

Definition at line 268 of file oMemoryMapped.cc.

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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 340 of file oMemoryMapped.cc.

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uint64_t oMemoryMapped::size

(

)

const

get file size

Definition at line 318 of file oMemoryMapped.cc.

Member Data Documentation

FileHandle oMemoryMapped::_file

private

file handle

Definition at line 128 of file oMemoryMapped.hh.

std::string oMemoryMapped::_filename

private

file name

Definition at line 110 of file oMemoryMapped.hh.

uint64_t oMemoryMapped::_filesize

private

file size

Definition at line 112 of file oMemoryMapped.hh.

CacheHint oMemoryMapped::_hint

private

caching strategy

Definition at line 114 of file oMemoryMapped.hh.

size_t oMemoryMapped::_mappedBytes

private

mapped size

Definition at line 116 of file oMemoryMapped.hh.

void* oMemoryMapped::_mappedView

private

pointer to the file contents mapped into memory

Definition at line 130 of file oMemoryMapped.hh.

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

• oMemoryMapped.hh
• oMemoryMapped.cc