def from_header(header):
"""
docstring
"""
header = header[0:ZISOFS.get_header_size()]
# Make sure is bytes
if not isinstance(header, (bytes, bytearray)):
raise ValueError
# Header magic
if header[0:8] != ZISOFS.hdr_magic:
raise NotCompressedFile
# Correct size
if len(header) != 4 * iso711_to_int(ZISOFS.hdr_size):
raise IllegalZisofsFormat
# Header size
if header[12:13] != ZISOFS.hdr_size:
raise IllegalZisofsFormat
zisofs_obj = ZISOFS()
# File size
zisofs_obj.size = header[8:12]
# Blocksize
if iso711_to_int(header[13:14]) not in default_block_sizes:
raise IllegalZisofsFormat
zisofs_obj.blocksize = header[13:14]
return zisofs_obj
def from_header(header):
"""
docstring
"""
header = header[0:ZISOFSv2.get_header_size()]
# Make sure is bytes
if not isinstance(header, (bytes, bytearray)):
raise ValueError
# Header magic
if header[0:8] != ZISOFSv2.hdr_magic:
raise NotCompressedFile
# Correct size
if len(header) != 4 * iso711_to_int(ZISOFSv2.hdr_size):
raise IllegalZisofsFormat
# Header size
if header[9:10] != ZISOFSv2.hdr_size:
raise IllegalZisofsFormat
zisofs_obj = ZISOFSv2()
# Algorithm
if iso711_to_int(header[10:11]) == 0:
raise IllegalZisofsFormat
zisofs_obj.alg_id = header[10:11]
# Blocksize
if iso711_to_int(header[11:12]) not in default_block_sizes:
raise IllegalZisofsFormat
zisofs_obj.blocksize = header[11:12]
# File size
zisofs_obj.size = header[12:20]
return zisofs_obj
def __len__(self):
return 4 * iso711_to_int(self.hdr_size)
def get_blocksize(self):
# ZISOFS.blocksize = int_to_iso711(int(math.log(blocksize, 2)))
return 2**iso711_to_int(self.blocksize)
def get_header_size(cls):
"""
docstring
"""
return 4 * iso711_to_int(cls.hdr_size)
def get_algorithm(self):
"""
docstring
"""
return Algorithm(iso711_to_int(self.alg_id))