libdar::compressor Class Reference

compression class for gzip and bzip2 algorithms More...

#include <compressor.hpp>

Inherits libdar::generic_file.

List of all members.

Public Member Functions
	compressor (compression algo, generic_file &compressed_side, U_I compression_level=9)
	compressor (compression algo, generic_file *compressed_side, U_I compression_level=9)
void	flush_write ()
void	flush_read ()
void	clean_read ()
void	clean_write ()
compression	get_algo () const
void	change_algo (compression new_algo, U_I new_compression_level)
	changes compression algorithm used by the compressor
void	change_algo (compression new_algo)
	changes the compression algorithm keeping the same compression level
bool	skip (const infinint &pos)
	skip at the absolute position
bool	skip_to_eof ()
	skip to the end of file
bool	skip_relative (S_I x)
	skip relatively to the current position
infinint	get_position ()
	get the current read/write position
Protected Member Functions
U_I	inherited_read (char *a, U_I size)
	implementation of read() operation
void	inherited_write (const char *a, U_I size)
	implementation of the write() operation
void	inherited_sync_write ()
	write down any pending data
void	inherited_terminate ()
	destructor-like call, except that it is allowed to throw exceptions

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Detailed Description

compression class for gzip and bzip2 algorithms

Definition at line 60 of file compressor.hpp.

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Member Function Documentation

void libdar::compressor::change_algo	(	compression	new_algo,
		U_I	new_compression_level
	)

changes compression algorithm used by the compressor

Parameters:

[in]	new_algo	defines the new algorithm to use
[in]	new_compression_level	defines the new compression level to use.

Note:

valid value for new_compression_level range from 0 (no compression) to 9 (maximum compression).

Referenced by change_algo().

U_I libdar::compressor::inherited_read	(	char *	a,
		U_I	size
	)		[inline, protected, virtual]

implementation of read() operation

Parameters:

[in,out]	a	where to put the data to read
[in]	size	says how much data to read

Returns:

the exact amount of data read and put into 'a'

Note:

read as much byte as requested, up to end of file stays blocked if not enough data is available and EOF not yet met. May return less data than requested only if EOF as been reached. in other worlds, EOF is reached when returned data is stricly less than the requested data Any problem shall be reported by throwing an exception.

Implements libdar::generic_file.

Definition at line 103 of file compressor.hpp.

void libdar::compressor::inherited_sync_write

(

)

[inline, protected, virtual]

write down any pending data

Note:

this method is called after read/write mode checking from sync_write() public method;

Implements libdar::generic_file.

Definition at line 105 of file compressor.hpp.

void libdar::compressor::inherited_terminate

(

)

[inline, protected, virtual]

destructor-like call, except that it is allowed to throw exceptions

Note:

this method must never be called directly but using terminate() instead, generic_file class manages it to never be called more than once

Implements libdar::generic_file.

Definition at line 106 of file compressor.hpp.

void libdar::compressor::inherited_write	(	const char *	a,
		U_I	size
	)		[inline, protected, virtual]

implementation of the write() operation

Parameters:

[in]	a	what data to write
[in]	size	amount of data to write

Note:

must either write all data or report an error by throwing an exception

Implements libdar::generic_file.

Definition at line 104 of file compressor.hpp.

bool libdar::compressor::skip

(

const infinint &

pos

)

[inline, virtual]

skip at the absolute position

Parameters:

[in]

pos

the offset in byte where next read/write operation must start

Returns:

true if operation was successfull and false if the requested position is not valid (after end of file)

Note:

if requested position is not valid the reading/writing cursor must be set to the closest valid position

Implements libdar::generic_file.

Definition at line 97 of file compressor.hpp.

References libdar::generic_file::skip().

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

• compressor.hpp