Compression Functions

Collaboration diagram for Compression Functions:

Modules
	Compression Constants
	Compression Stream Transformations

Functions
binary	Qore::bunzip2_to_binary (binary bin)
	Uncompresses the given data with the bzip2 algorithm and returns the uncompressed data as a binary object. More...
nothing	Qore::bunzip2_to_binary ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
string	Qore::bunzip2_to_string (binary bin, *string encoding)
	Uncompresses the given data with the bzip2 algorithm and returns the uncompressed data as a string. More...
nothing	Qore::bunzip2_to_string ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
binary	Qore::bzip2 (binary bin, softint level=BZ2_DEFAULT_COMPRESSION)
	Compresses the given data with the bzip2 algorithm and returns the compressed data as a binary. More...
binary	Qore::bzip2 (string str, softint level=BZ2_DEFAULT_COMPRESSION)
	Compresses the given data with the bzip2 algorithm and returns the compressed data as a binary. More...
nothing	Qore::bzip2 ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
binary	Qore::compress (string str, int level=Z_DEFAULT_COMPRESSION)
	Performs zlib-based "deflate" data compression (RFC 1951) and returns a binary object of the compressed data. More...
binary	Qore::compress (binary bin, int level=Z_DEFAULT_COMPRESSION)
	Performs zlib-based "deflate" data compression (RFC 1951) and returns a binary object of the compressed data. More...
nothing	Qore::compress ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
Transform	Qore::get_compressor (string alg, int level=COMPRESSION_LEVEL_DEFAULT)
	Returns a Transform object for compressing data using the given algorithm for use with TransformInputStream and TransformOutputStream. More...
Transform	Qore::get_decompressor (string alg)
	Returns a Transform object for decompressing data using the given algorithm for use with TransformInputStream and TransformOutputStream. More...
binary	Qore::gunzip_to_binary (binary bin)
	Performs zlib-based decompression of data compressed with the "gzip" algorithm (RFC 1952) and returns a binary object of the uncompressed data. More...
nothing	Qore::gunzip_to_binary ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
string	Qore::gunzip_to_string (binary bin, *string encoding)
	Performs zlib-based decompression of data compressed with the "gzip" algorithm (RFC 1952) and returns a string of the uncompressed datas. More...
nothing	Qore::gunzip_to_string ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
binary	Qore::gzip (string str, int level=Z_DEFAULT_COMPRESSION)
	Performs zlib-based "gzip" data compression (RFC 1952) and returns a binary object of the compressed data. More...
binary	Qore::gzip (binary bin, int level=Z_DEFAULT_COMPRESSION)
	Performs zlib-based "gzip" data compression (RFC 1952) and returns a binary object of the compressed data. More...
nothing	Qore::gzip ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
binary	Qore::uncompress_to_binary (binary bin)
	Performs zlib-based decompression of data compressed by the "deflate" algorithm (RFC 1951) and returns a binary object of the decompressed data. More...
nothing	Qore::uncompress_to_binary ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...
string	Qore::uncompress_to_string (binary bin, *string encoding)
	Performs zlib-based decompression of data compressed by the "deflate" algorithm (RFC 1951) and returns a string of the decompressed data. More...
nothing	Qore::uncompress_to_string ()
	This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments. More...

Detailed Description

These functions work with compression and decompression

Function Documentation

bunzip2_to_binary() [1/2]

nothing Qore::bunzip2_to_binary

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

bunzip2_to_binary() [2/2]

binary Qore::bunzip2_to_binary

(

binary

bin

)

Uncompresses the given data with the bzip2 algorithm and returns the uncompressed data as a binary object.

Parameters

bin	the compressed data to decompress

Returns

the uncompressed data as a binary object

Example:

binary bin = bunzip2_to_binary(bzip2_string);

Exceptions

BZIP2-DECOMPRESS-ERROR

the bzip2 library returned an internal error during processing (possibly due to corrupt input data)

bunzip2_to_string() [1/2]

nothing Qore::bunzip2_to_string

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

bunzip2_to_string() [2/2]

string Qore::bunzip2_to_string	(	binary	bin,
		*string	encoding
	)

Uncompresses the given data with the bzip2 algorithm and returns the uncompressed data as a string.

Parameters

bin	the compressed data to decompress
encoding	the character encoding tag for the string return value; if not present, the default character encoding is assumed.

Returns

the uncompressed data as a string

Example:

string str = bunzip2_to_string(bzip2_string, "iso-8859-1");

Exceptions

BZIP2-DECOMPRESS-ERROR

the bzip2 library returned an internal error during processing (possibly due to corrupt input data)

bzip2() [1/3]

nothing Qore::bzip2

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

bzip2() [2/3]

binary Qore::bzip2	(	binary	bin,
		softint	level = BZ2_DEFAULT_COMPRESSION
	)

Compresses the given data with the bzip2 algorithm and returns the compressed data as a binary.

Parameters

bin	the data to compress
level	the compression level, must be a value between 1 and 9 inclusive, 1 = the least compression (and taking the least memory), 9 = the most compression (using the most memory). An invalid option passed to this argument will result in a BZLIB2-LEVEL-ERROR exception being raised.

Returns

the compressed data as a binary object

Example:

binary bin = bzip2(data);

Exceptions

BZLIB2-LEVEL-ERROR	level must be between 1 - 9
BZIP2-COMPRESS-ERROR	the bzip2 library returned an error during processing

bzip2() [3/3]

binary Qore::bzip2	(	string	str,
		softint	level = BZ2_DEFAULT_COMPRESSION
	)

Compresses the given data with the bzip2 algorithm and returns the compressed data as a binary.

Strings are compressed without the trailing null character

Parameters

str	the data to compress
level	the compression level, must be a value between 1 and 9 inclusive, 1 = the least compression (and taking the least memory), 9 = the most compression (using the most memory). An invalid option passed to this argument will result in a BZLIB2-LEVEL-ERROR exception being raised.

Returns

the compressed data as a binary object

Example:

binary bin = bzip2(str);

Exceptions

BZLIB2-LEVEL-ERROR	level must be between 1 - 9
BZIP2-COMPRESS-ERROR	the bzip2 library returned an error during processing

compress() [1/3]

nothing Qore::compress

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

compress() [2/3]

binary Qore::compress	(	binary	bin,
		int	level = Z_DEFAULT_COMPRESSION
	)

Performs zlib-based "deflate" data compression (RFC 1951) and returns a binary object of the compressed data.

Note that strings are compressed without the trailing null character.

Parameters

bin	The binary object to compress
level	Specifies the compression level; must be an integer between 1 and 9, 9 meaning the highest compression level. The default value Z_DEFAULT_COMPRESSION gives a tradeoff between speed and compression size

Returns

a binary object of the compressed data

Example:

binary bin = compress(bin_data);

Exceptions

ZLIB-LEVEL-ERROR	level must be between 1 - 9 or -1
ZLIB-ERROR	zlib returned an error while processing

compress() [3/3]

binary Qore::compress	(	string	str,
		int	level = Z_DEFAULT_COMPRESSION
	)

Performs zlib-based "deflate" data compression (RFC 1951) and returns a binary object of the compressed data.

Note that strings are compressed without the trailing null character.

Parameters

str	The string to compress
level	Specifies the compression level; must be an integer between 1 and 9, 9 meaning the highest compression level. The default value Z_DEFAULT_COMPRESSION gives a tradeoff between speed and compression size

Returns

a binary object of the compressed data

Example:

binary bin = compress(str_data);

Exceptions

ZLIB-LEVEL-ERROR	level must be between 1 - 9 or -1
ZLIB-ERROR	zlib returned an error while processing

get_compressor()

Transform Qore::get_compressor	(	string	alg,
		int	level = COMPRESSION_LEVEL_DEFAULT
	)

Returns a Transform object for compressing data using the given algorithm for use with TransformInputStream and TransformOutputStream.

Example:

Qore::FileOutputStream of("my-file.txt.bz2");
Qore::TransformOutputStream ts(of, get_compressor(Qore::COMPRESSION_ALG_BZIP2));

Parameters

alg	the transformation algorithm; see Compression Stream Transformations for possible values
level	compression level as defined by the algorithm or COMPRESSION_LEVEL_DEFAULT to use the default compression level

Returns

a Transform object for compressing data using the given algorithm for use with TransformInputStream and TransformOutputStream

See also

Qore::get_decompressor()

Since

Qore 0.8.13

get_decompressor()

Transform Qore::get_decompressor

(

string

alg

)

Returns a Transform object for decompressing data using the given algorithm for use with TransformInputStream and TransformOutputStream.

Example:

Qore::FileOutputStream of("my-file.txt.bz2");
Qore::TransformOutputStream ts(of, get_decompressor(Qore::COMPRESSION_ALG_BZIP2));

Parameters

alg	the transformation algorithm; see Compression Stream Transformations for possible values

Returns

a Transform object for decompressing data using the given algorithm for use with TransformInputStream and TransformOutputStream

See also

Qore::get_compressor()

Since

Qore 0.8.13

gunzip_to_binary() [1/2]

nothing Qore::gunzip_to_binary

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

gunzip_to_binary() [2/2]

binary Qore::gunzip_to_binary

(

binary

bin

)

Performs zlib-based decompression of data compressed with the "gzip" algorithm (RFC 1952) and returns a binary object of the uncompressed data.

Parameters

bin	the compressed data to decompress

Returns

the uncompressed data as a binary object

Example:

binary bin = gunzip_to_binary(data);

Exceptions

ZLIB-ERROR

The zlib library returned an error during processing (possibly due to corrupt input data)

gunzip_to_string() [1/2]

nothing Qore::gunzip_to_string

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

gunzip_to_string() [2/2]

string Qore::gunzip_to_string	(	binary	bin,
		*string	encoding
	)

Performs zlib-based decompression of data compressed with the "gzip" algorithm (RFC 1952) and returns a string of the uncompressed datas.

Parameters

bin	the compressed data to decompress
encoding	the character encoding tag for the string return value; if not present, the default character encoding is assumed.

Returns

the uncompressed data as a string

Example:

string str = gunzip_to_string(bin, "iso-8859-1");

Exceptions

ZLIB-ERROR

The zlib library returned an error during processing (possibly due to corrupt input data)

gzip() [1/3]

nothing Qore::gzip

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

gzip() [2/3]

binary Qore::gzip	(	binary	bin,
		int	level = Z_DEFAULT_COMPRESSION
	)

Performs zlib-based "gzip" data compression (RFC 1952) and returns a binary object of the compressed data.

Parameters

bin	the data to compress
level	the compression level, must be a value between 1 and 9 inclusive, 1 = the least compression (and taking the least memory), 9 = the most compression (using the most memory). An invalid option passed to this argument will result in a ZLIB-LEVEL-ERROR exception being raised.

Returns

the compressed data as a binary object

Example:

binary data = gzip(bin);

Exceptions

ZLIB-LEVEL-ERROR	level must be between 1 - 9 or -1
ZLIB-ERROR	The zlib library returned an error during processing (should not normally happen during compression)

gzip() [3/3]

binary Qore::gzip	(	string	str,
		int	level = Z_DEFAULT_COMPRESSION
	)

Performs zlib-based "gzip" data compression (RFC 1952) and returns a binary object of the compressed data.

Strings are compressed without the trailing null character

Parameters

str	the data to compress
level	the compression level, must be a value between 1 and 9 inclusive, 1 = the least compression (and taking the least memory), 9 = the most compression (using the most memory). An invalid option passed to this argument will result in a ZLIB-LEVEL-ERROR exception being raised.

Returns

the compressed data as a binary object

Example:

binary data = gzip(str);

Exceptions

ZLIB-LEVEL-ERROR	level must be between 1 - 9 or -1
ZLIB-ERROR	The zlib library returned an error during processing (should not normally happen during compression)

uncompress_to_binary() [1/2]

nothing Qore::uncompress_to_binary

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

uncompress_to_binary() [2/2]

binary Qore::uncompress_to_binary

(

binary

bin

)

Performs zlib-based decompression of data compressed by the "deflate" algorithm (RFC 1951) and returns a binary object of the decompressed data.

Parameters

bin	the data to decompress

Returns

a binary object of the decompressed data

Example:

binary bin = uncompress_to_binary(data);

Exceptions

ZLIB-ERROR

The zlib library returned an error during processing (possibly due to corrupt input data)

uncompress_to_string() [1/2]

nothing Qore::uncompress_to_string

(

)

This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments.

Code Flags:

RUNTIME_NOOP

uncompress_to_string() [2/2]

string Qore::uncompress_to_string	(	binary	bin,
		*string	encoding
	)

Performs zlib-based decompression of data compressed by the "deflate" algorithm (RFC 1951) and returns a string of the decompressed data.

Parameters

bin	the compressed data to decompress
encoding	the character encoding tag for the string return value; if not present, the default character encoding is assumed.

Returns

the uncompressed data as a string

Example:

string str = uncompress_to_string(bin, "iso-8859-1");

Exceptions

ZLIB-ERROR

The zlib library returned an error during processing (possibly due to corrupt input data)