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#
# p7zr library
#
# Copyright (c) 2019-2021 Hiroshi Miura <miurahr@linux.com>
# Copyright (c) 2004-2015 by Joachim Bauch, mail@joachim-bauch.de
# 7-Zip Copyright (C) 1999-2010 Igor Pavlov
# LZMA SDK Copyright (C) 1999-2010 Igor Pavlov
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
import binascii
import lzma
import platform
import sys
import psutil # type: ignore
MAGIC_7Z = binascii.unhexlify("377abcaf271c")
FINISH_7Z = binascii.unhexlify("377abcaf271d")
COMMAND_HELP_STRING = """<Commands>
c : Create archive with files
i : Show information about supported formats
l : List contents of archive
t : Test integrity of archive
x : eXtract files with full paths
"""
def is_64bit() -> bool:
"""check if running platform is 64bit python."""
return sys.maxsize > 1e32
def is_pypy369later() -> bool:
"""check if running platform is PyPY and python 3.6.9 and later"""
return platform.python_implementation() == "PyPy" and sys.version_info >= (3, 6, 9)
def get_default_blocksize() -> int:
"""
Return a safe buffer size for pass to decompress/compress modules.
We check several conditions;
1. 32bit python
It sometimes fails with memory_error
when decompress/compress large file (hundreds of MiB) on 32bit python.
We reduce buffer size smaller to avoid memory_error.
@see issue https://github.com/miurahr/py7zr/issues/370
2. CPython
CPython implementation of 3.7.5 fixed a lzma module bug
that is not respect max_length parameter.
When buffer size is larger than default of the module,
max_length can be a value to lead the bug, so we set it
lzma module default = 32768 bytes.
@see BPO-21872: LZMA library sometimes fails to decompress a file
https://bugs.python.org/issue21872
@see https://github.com/miurahr/py7zr/issues/272
3. PyPy
PyPy 7.2 (python 3.6.9) fixed a lzma module's bug as same as
CPython above.
We set buffer size is as default size of the module to avoid the bugs.
@see PyPy3-3090: lzma.LZMADecomporessor.decompress does not respect max_length
https://foss.heptapod.net/pypy/pypy/-/issues/3090
@see https://github.com/miurahr/py7zr/pull/114
:return: recommended buffer size as int.
"""
if is_64bit() and (is_pypy369later() or sys.version_info >= (3, 7, 5)):
return 1048576
else:
return 32768
def get_memory_limit():
"""
Get memory limit for allocating decompression chunk buffer.
:return: allowed chunk size in bytes.
"""
default_limit = int(128e6)
if sys.platform.startswith("win"):
return default_limit
else:
import resource
soft, _ = resource.getrlimit(resource.RLIMIT_AS)
if soft == -1:
avmem = psutil.virtual_memory().available
return min(default_limit, (avmem - int(256e6)) >> 2)
else:
return min(default_limit, (soft - int(256e6)) >> 2)
# Exposed constants
FILTER_LZMA = lzma.FILTER_LZMA1
FILTER_LZMA2 = lzma.FILTER_LZMA2
FILTER_DELTA = lzma.FILTER_DELTA
FILTER_ARM = lzma.FILTER_ARM
FILTER_ARMTHUMB = lzma.FILTER_ARMTHUMB
FILTER_IA64 = lzma.FILTER_IA64
FILTER_POWERPC = lzma.FILTER_POWERPC
FILTER_SPARC = lzma.FILTER_SPARC
FILTER_X86 = lzma.FILTER_X86
CHECK_CRC32 = lzma.CHECK_CRC32
CHECK_CRC64 = lzma.CHECK_CRC64
CHECK_SHA256 = lzma.CHECK_SHA256
CHECK_NONE = lzma.CHECK_NONE
CHECK_ID_MAX = lzma.CHECK_ID_MAX
CHECK_UNKNOWN = lzma.CHECK_UNKNOWN
PRESET_DEFAULT = lzma.PRESET_DEFAULT
PRESET_EXTREME = lzma.PRESET_EXTREME
FILTER_CRYPTO_AES256_SHA256 = 0x06F10701
FILTER_CRYPTO_ZIP = 0x06F10101
FILTER_CRYPTO_RAR29 = 0x06F10303
FILTER_BZIP2 = 0x31
FILTER_DEFLATE = 0x32
FILTER_COPY = 0x33
FILTER_ZSTD = 0x35
FILTER_PPMD = 0x36
FILTER_BROTLI = 0x37
FILTER_DEFLATE64 = 0x38
class Constant:
"""Constant base class."""
def __setattr__(self, *_):
pass
class DefaultFilters(Constant):
"""Default filter values."""
ARCHIVE_FILTER = [{"id": FILTER_X86}, {"id": FILTER_LZMA2, "preset": 7 | PRESET_DEFAULT}]
ENCODED_HEADER_FILTER = [{"id": FILTER_LZMA2, "preset": 7 | PRESET_DEFAULT}]
ENCRYPTED_ARCHIVE_FILTER = [{"id": FILTER_LZMA2, "preset": 7 | PRESET_DEFAULT}, {"id": FILTER_CRYPTO_AES256_SHA256}]
ENCRYPTED_HEADER_FILTER = [{"id": FILTER_CRYPTO_AES256_SHA256}]
DEFAULT_FILTERS = DefaultFilters()
class Property(Constant):
"""Hold 7zip property fixed values."""
END = binascii.unhexlify("00")
HEADER = binascii.unhexlify("01")
ARCHIVE_PROPERTIES = binascii.unhexlify("02")
ADDITIONAL_STREAMS_INFO = binascii.unhexlify("03")
MAIN_STREAMS_INFO = binascii.unhexlify("04")
FILES_INFO = binascii.unhexlify("05")
PACK_INFO = binascii.unhexlify("06")
UNPACK_INFO = binascii.unhexlify("07")
SUBSTREAMS_INFO = binascii.unhexlify("08")
SIZE = binascii.unhexlify("09")
CRC = binascii.unhexlify("0a")
FOLDER = binascii.unhexlify("0b")
CODERS_UNPACK_SIZE = binascii.unhexlify("0c")
NUM_UNPACK_STREAM = binascii.unhexlify("0d")
EMPTY_STREAM = binascii.unhexlify("0e")
EMPTY_FILE = binascii.unhexlify("0f")
ANTI = binascii.unhexlify("10")
NAME = binascii.unhexlify("11")
CREATION_TIME = binascii.unhexlify("12")
LAST_ACCESS_TIME = binascii.unhexlify("13")
LAST_WRITE_TIME = binascii.unhexlify("14")
ATTRIBUTES = binascii.unhexlify("15")
COMMENT = binascii.unhexlify("16")
ENCODED_HEADER = binascii.unhexlify("17")
START_POS = binascii.unhexlify("18")
DUMMY = binascii.unhexlify("19")
PROPERTY = Property()
class CompressionMethod(Constant):
"""Hold fixed values for method parameter."""
COPY = binascii.unhexlify("00")
DELTA = binascii.unhexlify("03")
BCJ = binascii.unhexlify("04")
PPC = binascii.unhexlify("05")
IA64 = binascii.unhexlify("06")
ARM = binascii.unhexlify("07")
ARMT = binascii.unhexlify("08")
SPARC = binascii.unhexlify("09")
# SWAP = 02..
SWAP2 = binascii.unhexlify("020302")
SWAP4 = binascii.unhexlify("020304")
# 7Z = 03..
LZMA = binascii.unhexlify("030101")
PPMD = binascii.unhexlify("030401")
P7Z_BCJ = binascii.unhexlify("03030103")
P7Z_BCJ2 = binascii.unhexlify("0303011B")
BCJ_PPC = binascii.unhexlify("03030205")
BCJ_IA64 = binascii.unhexlify("03030401")
BCJ_ARM = binascii.unhexlify("03030501")
BCJ_ARMT = binascii.unhexlify("03030701")
BCJ_SPARC = binascii.unhexlify("03030805")
LZMA2 = binascii.unhexlify("21")
# MISC : 04..
MISC_ZIP = binascii.unhexlify("0401")
MISC_BZIP2 = binascii.unhexlify("040202")
MISC_DEFLATE = binascii.unhexlify("040108")
MISC_DEFLATE64 = binascii.unhexlify("040109")
MISC_Z = binascii.unhexlify("0405")
MISC_LZH = binascii.unhexlify("0406")
NSIS_DEFLATE = binascii.unhexlify("040901")
NSIS_BZIP2 = binascii.unhexlify("040902")
#
MISC_ZSTD = binascii.unhexlify("04f71101")
MISC_BROTLI = binascii.unhexlify("04f71102")
MISC_LZ4 = binascii.unhexlify("04f71104")
MISC_LZS = binascii.unhexlify("04f71105")
MISC_LIZARD = binascii.unhexlify("04f71106")
# CRYPTO 06..
CRYPT_ZIPCRYPT = binascii.unhexlify("06f10101")
CRYPT_RAR29AES = binascii.unhexlify("06f10303")
CRYPT_AES256_SHA256 = binascii.unhexlify("06f10701")
COMPRESSION_METHOD = CompressionMethod()
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