Edit File: c_pyzstd.py
from collections import namedtuple from enum import IntEnum from functools import lru_cache from ._zstd import * from . import _zstd __all__ = (# From this file 'compressionLevel_values', 'get_frame_info', 'CParameter', 'DParameter', 'Strategy', # From _zstd 'ZstdCompressor', 'RichMemZstdCompressor', 'ZstdDecompressor', 'EndlessZstdDecompressor', 'ZstdDict', 'ZstdError', 'decompress', 'get_frame_size', 'compress_stream', 'decompress_stream', 'zstd_version', 'zstd_version_info', 'zstd_support_multithread') # Used in __init__.py _ZSTD_DStreamInSize = _zstd._ZSTD_DStreamInSize _train_dict = _zstd._train_dict _finalize_dict = _zstd._finalize_dict # compressionLevel_values _nt_values = namedtuple('values', ['default', 'min', 'max']) compressionLevel_values = _nt_values(_zstd._ZSTD_defaultCLevel, _zstd._ZSTD_minCLevel, _zstd._ZSTD_maxCLevel) _nt_frame_info = namedtuple('frame_info', ['decompressed_size', 'dictionary_id']) def get_frame_info(frame_buffer): """Get zstd frame infomation from a frame header. Parameter frame_buffer: A bytes-like object. It should starts from the beginning of a frame, and needs to include at least the frame header (6 to 18 bytes). Return a two-items namedtuple: (decompressed_size, dictionary_id) If decompressed_size is None, decompressed size is unknown. dictionary_id is a 32-bit unsigned integer value. 0 means dictionary ID was not recorded in the frame header, the frame may or may not need a dictionary to be decoded, and the ID of such a dictionary is not specified. It's possible to append more items to the namedtuple in the future.""" ret_tuple = _zstd._get_frame_info(frame_buffer) return _nt_frame_info(*ret_tuple) class CParameter(IntEnum): """Compression parameters""" compressionLevel = _zstd._ZSTD_c_compressionLevel windowLog = _zstd._ZSTD_c_windowLog hashLog = _zstd._ZSTD_c_hashLog chainLog = _zstd._ZSTD_c_chainLog searchLog = _zstd._ZSTD_c_searchLog minMatch = _zstd._ZSTD_c_minMatch targetLength = _zstd._ZSTD_c_targetLength strategy = _zstd._ZSTD_c_strategy enableLongDistanceMatching = _zstd._ZSTD_c_enableLongDistanceMatching ldmHashLog = _zstd._ZSTD_c_ldmHashLog ldmMinMatch = _zstd._ZSTD_c_ldmMinMatch ldmBucketSizeLog = _zstd._ZSTD_c_ldmBucketSizeLog ldmHashRateLog = _zstd._ZSTD_c_ldmHashRateLog contentSizeFlag = _zstd._ZSTD_c_contentSizeFlag checksumFlag = _zstd._ZSTD_c_checksumFlag dictIDFlag = _zstd._ZSTD_c_dictIDFlag nbWorkers = _zstd._ZSTD_c_nbWorkers jobSize = _zstd._ZSTD_c_jobSize overlapLog = _zstd._ZSTD_c_overlapLog @lru_cache(maxsize=None) def bounds(self): """Return lower and upper bounds of a compression parameter, both inclusive.""" # 1 means compression parameter return _zstd._get_param_bounds(1, self.value) class DParameter(IntEnum): """Decompression parameters""" windowLogMax = _zstd._ZSTD_d_windowLogMax @lru_cache(maxsize=None) def bounds(self): """Return lower and upper bounds of a decompression parameter, both inclusive.""" # 0 means decompression parameter return _zstd._get_param_bounds(0, self.value) class Strategy(IntEnum): """Compression strategies, listed from fastest to strongest. Note : new strategies _might_ be added in the future, only the order (from fast to strong) is guaranteed. """ fast = _zstd._ZSTD_fast dfast = _zstd._ZSTD_dfast greedy = _zstd._ZSTD_greedy lazy = _zstd._ZSTD_lazy lazy2 = _zstd._ZSTD_lazy2 btlazy2 = _zstd._ZSTD_btlazy2 btopt = _zstd._ZSTD_btopt btultra = _zstd._ZSTD_btultra btultra2 = _zstd._ZSTD_btultra2 # Set CParameter/DParameter types for validity check _zstd._set_parameter_types(CParameter, DParameter)
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