dfvfs.compression package

Submodules

dfvfs.compression.bzip2_decompressor module

The BZIP2 decompressor implementation.

class dfvfs.compression.bzip2_decompressor.BZIP2Decompressor

Bases: Decompressor

BZIP2 decompressor using bz2.

COMPRESSION_METHOD = 'bzip2'

Decompress(compressed_data)

Decompresses the compressed data.

Parameters:

compressed_data (bytes) – compressed data.

Returns:

uncompressed data and remaining compressed data.

Return type:

tuple(bytes, bytes)

Raises:

BackEndError – if the BZIP2 compressed stream cannot be decompressed.

__init__()

Initializes a decompressor.

dfvfs.compression.decompressor module

The decompressor interface.

class dfvfs.compression.decompressor.Decompressor

Bases: object

Decompressor interface.

abstract Decompress(compressed_data)

Decompresses the compressed data.

Parameters:

compressed_data (bytes) – compressed data.

Returns:

uncompressed data and remaining compressed data.

Return type:

tuple(bytes, bytes)

dfvfs.compression.manager module

The compression manager.

class dfvfs.compression.manager.CompressionManager

Bases: object

Compression manager.

classmethod DeregisterDecompressor(decompressor)

Deregisters a decompressor for a specific compression method.

Parameters:

decompressor (type) – decompressor class.

Raises:

KeyError – if the corresponding decompressor is not set.

classmethod GetDecompressor(compression_method)

Retrieves the decompressor object for a specific compression method.

Parameters:

compression_method (str) – compression method identifier.

Returns:

decompressor or None if the compression method does

not exists.

Return type:

Decompressor

classmethod RegisterDecompressor(decompressor)

Registers a decompressor for a specific compression method.

Parameters:

decompressor (type) – decompressor class.

Raises:

KeyError – if the corresponding decompressor is already set.

classmethod RegisterDecompressors(decompressors)

Registers decompressors.

The decompressors are identified based on their lower case compression method.

Parameters:

decompressors (list[type]) – decompressor classes.

Raises:

KeyError – if decompressor is already set for the corresponding compression method.

dfvfs.compression.xz_decompressor module

The LZMA and XZ decompressor implementations.

class dfvfs.compression.xz_decompressor.LZMADecompressor

Bases: XZDecompressor

LZMA decompressor using lzma.

COMPRESSION_METHOD = 'lzma'

__init__()

Initializes a decompressor.

class dfvfs.compression.xz_decompressor.XZDecompressor

Bases: Decompressor

XZ decompressor using lzma.

COMPRESSION_METHOD = 'xz'

Decompress(compressed_data)

Decompresses the compressed data.

Parameters:

compressed_data (bytes) – compressed data.

Returns:

uncompressed data and remaining compressed data.

Return type:

tuple(bytes, bytes)

Raises:

BackEndError – if the XZ compressed stream cannot be decompressed.

__init__()

Initializes a decompressor.

dfvfs.compression.zlib_decompressor module

The zlib and DEFLATE decompressor implementations.

class dfvfs.compression.zlib_decompressor.DeflateDecompressor

Bases: ZlibDecompressor

DEFLATE without zlib data decompressor using zlib.

COMPRESSION_METHOD = 'deflate'

__init__()

Initializes a decompressor.

class dfvfs.compression.zlib_decompressor.ZlibDecompressor(window_size=15)

Bases: Decompressor

DEFLATE with zlib data decompressor using zlib.

COMPRESSION_METHOD = 'zlib'

Decompress(compressed_data)

Decompresses the compressed data.

Parameters:

compressed_data (bytes) – compressed data.

Returns:

uncompressed data and remaining compressed data.

Return type:

tuple(bytes, bytes)

Raises:

BackEndError – if the zlib compressed stream cannot be decompressed.

__init__(window_size=15)

Initializes a decompressor.

Parameters:

window_size (Optional[int]) – base two logarithm of the size of the compression history buffer (aka window size). When the value is negative, the standard zlib data header is suppressed.

property unused_data

data past the end of the compressed data.

Type:

bytes

Module contents

Imports for the compression manager.