A data store that keeps data in memory up to a certain limit, and switches to a temporary file if the limit is exceeded. More...

#include <libppbase/base/MemFile.h>

Inheritance diagram for base::MemFile:

List of all members.

Public Member Functions
	MemFile (size_t limit=1048576)
	Constructor.
	~MemFile ()
	Destructor.
MemFile *	clone () const
	Clones a mem file.
size_t	getPos () const
	Returns the file position.
const char *	getSourceBuffer (size_t *rsize=NULL) const
	Returns the source memory buffer.
File *	getSourceFile () const
	Returns the source file.
String *	getSourceString () const
	Returns the source memory buffer of type string.
bool	isInMemory () const
	Checks if the data is in memory.
const char *	loadIntoMemory (size_t *rsize=NULL)
	Loads the data into memory, if it is not there already.
size_t	read (void *buf, size_t count, bool exact=false)
	Reads some bytes from the data.
size_t	read (String &buf, size_t count, bool exact=false)
	Reads some bytes from the data.
bool	readln (String &rbuf, bool strip=false)
	Reads a line of data.
File *	saveToFile ()
	Saves the data to a file, if it is not there already.
void	seek (size_t pos)
	Sets the file positon.
void	seekBOF ()
	Sets the file position to the beginning of the data.
void	seekEOF ()
	Sets the file position to the end of the data.
void	setLimit (size_t limit)
	Sets the memory limit.
void	setSource (const MemFile *source)
	Sets the data source from another memfile object.
void	setSourceBuffer (const char *buf, size_t bufsize, bool own=false)
	Associates this object with a new data source.
void	setSourceFile (File *file, bool own=false)
	Associates this object with a new data source.
void	setSourceFile (const String &name, int flags=File::ofReadOnly)
	Associates this object with a new data source.
void	setSourceString (String *str, bool own=false)
	Associates this object with a new data source.
size_t	size () const
	Returns the file size.
void	truncate (size_t len)
	Truncates the data to a given size.
size_t	write (const void *buf, size_t count, bool exact=true)
	Writes some bytes to the file.
size_t	write (const String &buf, bool exact=true)
	Writes some bytes to the file.

Detailed Description

A data store that keeps data in memory up to a certain limit, and switches to a temporary file if the limit is exceeded.

Author:: Christoph Schwarz

Version:: $Id: MemFile.h 21 2010-09-05 04:18:17Z cschwarz1 $

Constructor & Destructor Documentation

base::MemFile::MemFile ( size_t limit = 1048576 )

Constructor.

Parameters:

limit

memory limit in bytes

Member Function Documentation

MemFile* base::MemFile::clone ( ) const

Clones a mem file.

The cloned mem file starts at position 0. If this mem file owns the underlying data source, it generates a clone of the data source too. If not, the original data source is just passed.

Returns:: the clone

size_t base::MemFile::getPos ( ) const

Returns the file position.

Returns:: the file position

const char* base::MemFile::getSourceBuffer ( size_t * rsize = NULL ) const

Returns the source memory buffer.

Parameters:

rsize

returns the data size in bytes

Returns:: the memory buffer, in case the data is still in memory

File* base::MemFile::getSourceFile ( ) const

Returns the source file.

Returns:: the file, in case the memory limit has been exceeded

String* base::MemFile::getSourceString ( ) const

Returns the source memory buffer of type string.

Returns:: the memory buffer

bool base::MemFile::isInMemory ( ) const

Checks if the data is in memory.

Returns:: true if the data is in memory, false if it is in the temp file

const char* base::MemFile::loadIntoMemory ( size_t * rsize = NULL )

Loads the data into memory, if it is not there already.

Parameters:

rsize

returns the data size in bytes

Returns:: a pointer to the data in memory

size_t base::MemFile::read	(	void *	buf,
		size_t	count,
		bool	exact = `false`
	)

Reads some bytes from the data.

Parameters:

	buf	buffer to read bytes into
	count	number of bytes to read
	exact	flag: read exactly this many bytes

Returns:: number of bytes read

size_t base::MemFile::read	(	String &	buf,
		size_t	count,
		bool	exact = `false`
	)

Reads some bytes from the data.

Parameters:

	buf	buffer to read bytes into
	count	number of bytes to read
	exact	flag: read exactly this many bytes

Returns:: number of bytes read

bool base::MemFile::readln	(	String &	rbuf,
		bool	strip = `false`
	)

Reads a line of data.

Parameters:

	rbuf	buffer to read the line into
	strip	flag: strip CR/LF from the end of the line

Returns:: false if there is no more line

File* base::MemFile::saveToFile ( )

Saves the data to a file, if it is not there already.

Returns:: the file

void base::MemFile::seek ( size_t pos )

Sets the file positon.

Parameters:

pos

byte offset of new file position

void base::MemFile::setLimit ( size_t limit )

Sets the memory limit.

Parameters:

limit

new memory limit in bytes

void base::MemFile::setSource ( const MemFile * source )

Sets the data source from another memfile object.

Parameters:

source

the data source

void base::MemFile::setSourceBuffer	(	const char *	buf,
		size_t	bufsize,
		bool	own = `false`
	)

Associates this object with a new data source.

Parameters:

	buf	the source buffer
	bufsize	the number of bytes in the buffer
	own	true if this object owns the buffer (=frees it when it is destroyed)

void base::MemFile::setSourceFile	(	File *	file,
		bool	own = `false`
	)

Associates this object with a new data source.

Parameters:

	file	an open file object
	own	true if this object owns the file (=deletes it when it is destroyed)

void base::MemFile::setSourceFile	(	const String &	name,
		int	flags = `File::ofReadOnly`
	)

Associates this object with a new data source.

Parameters:

	name	the file name
	flags	open flags

void base::MemFile::setSourceString	(	String *	str,
		bool	own = `false`
	)

Associates this object with a new data source.

Parameters:

	str	the source buffer
	own	true if this object owns the string (=frees it when it is destroyed)

size_t base::MemFile::size ( ) const

Returns the file size.

Returns:: file size in bytes

Reimplemented in base_http::HTTPPart, and base_http::HTTPRequest.

void base::MemFile::truncate ( size_t len )

Truncates the data to a given size.

Parameters:

len

the size to truncate the data to

size_t base::MemFile::write	(	const void *	buf,
		size_t	count,
		bool	exact = `true`
	)

Writes some bytes to the file.

Parameters:

	buf	bytes to write
	count	number of bytes to write
	exact	flag: write exactly this many bytes, throw an error if they cannot be written

Returns:: number of bytes written

size_t base::MemFile::write	(	const String &	buf,
		bool	exact = `true`
	)

Writes some bytes to the file.

Parameters:

	buf	bytes to write
	exact	flag: write exactly this many bytes, throw an error if they cannot be written

Returns:: number of bytes written

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

libppbase/base/MemFile.h

base::MemFile Class Reference

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation