compression class for gzip and bzip2 algorithms More...

#include <compressor.hpp>

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)
compression	get_algo () const
void	suspend_compression ()
void	resume_compression ()
bool	is_compression_suspended () const
bool	skippable (skippability direction, const infinint &amount)
bool	skip (const infinint &pos)
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 () const
	get the current read/write position
Protected Member Functions
void	inherited_read_ahead (const infinint &amount)
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_flush_read ()
void	inherited_terminate ()
	destructor-like call, except that it is allowed to throw exceptions

Detailed Description

compression class for gzip and bzip2 algorithms

Definition at line 61 of file compressor.hpp.

Member Function Documentation

void libdar::compressor::inherited_flush_read ( ) [inline, protected, virtual]

reset internal engine, flush caches in order to read the data at current position

Note:: when the object relies on external object or system object to fetch the data from for reading, when a call to (inherited_)flush_read() occurs, the current object must not assume that any previously read data is still valid if it has internal buffers or the like and it should flush them asap. This call must not propagate the flush_read to any other gneric_file object it could rely on

Implements libdar::generic_file.

Definition at line 91 of file compressor.hpp.

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 88 of file compressor.hpp.

void libdar::compressor::inherited_read_ahead ( const infinint & amount ) [inline, protected, virtual]

tells the object that several calls to read() will follow to probably obtain at least the given amount of data

Parameters:

[in] amount is the maximum expected amount of data that is known to be read

Note:: this call may be implemented as a do-nothing call, its presence is only to allow optimization when possible, like in multi-threaded environment

Implements libdar::generic_file.

Definition at line 87 of file compressor.hpp.

References libdar::generic_file::read_ahead().

void libdar::compressor::inherited_sync_write ( ) [inline, protected, virtual]

write down any pending data

Note:: called after sanity checks from generic_file::sync_write() this method's role is to write down any data pending for writing in the current object it has not to be propagated to other gneric_file object this object could rely on

Implements libdar::generic_file.

Definition at line 90 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 92 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 89 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 81 of file compressor.hpp.

References libdar::generic_file::skip().

bool libdar::compressor::skippable	(	skippability	direction,
		const infinint &	amount
	)		`[inline, virtual]`

whether the implementation is able to skip

Note:: the capability to skip does not mean that skip_relative() or skip() will succeed, but rather that the inherited class implementation does not by construction forbid the requested skip (like inherited class providing a generic_file interface of an anonymous pipe for example)

Implements libdar::generic_file.

Definition at line 80 of file compressor.hpp.

References libdar::generic_file::skippable().

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

compressor.hpp

Public Member Functions

Protected Member Functions

Detailed Description

Member Function Documentation