Mercurial > hgrepos > Python > apps > py-cutils
diff cutils/crcmod/python2/predefined.py @ 180:d038f0a9ba49
Vendored crcmod2 into sub-package "cutils.crcmod" as pure-Python implementation of additional "digests": CRC sums.
Running python -m cutils.crcmod.test works successfully.
| author | Franz Glasner <fzglas.hg@dom66.de> |
|---|---|
| date | Mon, 13 Jan 2025 04:09:35 +0100 |
| parents | |
| children | 31d478ff4e09 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cutils/crcmod/python2/predefined.py Mon Jan 13 04:09:35 2025 +0100 @@ -0,0 +1,164 @@ +#----------------------------------------------------------------------------- +# Copyright (c) 2010 Craig McQueen +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +#----------------------------------------------------------------------------- +''' +crcmod.predefined defines some well-known CRC algorithms. + +To use it, e.g.: + import crcmod.predefined + + crc32func = crcmod.predefined.mkPredefinedCrcFun("crc-32") + crc32class = crcmod.predefined.PredefinedCrc("crc-32") + +crcmod.predefined.Crc is an alias for crcmod.predefined.PredefinedCrc +But if doing 'from crc.predefined import *', only PredefinedCrc is imported. +''' + +from __future__ import absolute_import + +# local imports +from . import crcmod + +__all__ = [ + 'PredefinedCrc', + 'mkPredefinedCrcFun', +] + +REVERSE = True +NON_REVERSE = False + +# The following table defines the parameters of well-known CRC algorithms. +# The "Check" value is the CRC for the ASCII byte sequence "123456789". It +# can be used for unit tests. +_crc_definitions_table = [ +# Name Identifier-name, Poly Reverse Init-value XOR-out Check + [ 'crc-8', 'Crc8', 0x107, NON_REVERSE, 0x00, 0x00, 0xF4, ], + [ 'crc-8-darc', 'Crc8Darc', 0x139, REVERSE, 0x00, 0x00, 0x15, ], + [ 'crc-8-i-code', 'Crc8ICode', 0x11D, NON_REVERSE, 0xFD, 0x00, 0x7E, ], + [ 'crc-8-itu', 'Crc8Itu', 0x107, NON_REVERSE, 0x55, 0x55, 0xA1, ], + [ 'crc-8-maxim', 'Crc8Maxim', 0x131, REVERSE, 0x00, 0x00, 0xA1, ], + [ 'crc-8-rohc', 'Crc8Rohc', 0x107, REVERSE, 0xFF, 0x00, 0xD0, ], + [ 'crc-8-wcdma', 'Crc8Wcdma', 0x19B, REVERSE, 0x00, 0x00, 0x25, ], + + [ 'crc-16', 'Crc16', 0x18005, REVERSE, 0x0000, 0x0000, 0xBB3D, ], + [ 'crc-16-buypass', 'Crc16Buypass', 0x18005, NON_REVERSE, 0x0000, 0x0000, 0xFEE8, ], + [ 'crc-16-dds-110', 'Crc16Dds110', 0x18005, NON_REVERSE, 0x800D, 0x0000, 0x9ECF, ], + [ 'crc-16-dect', 'Crc16Dect', 0x10589, NON_REVERSE, 0x0001, 0x0001, 0x007E, ], + [ 'crc-16-dnp', 'Crc16Dnp', 0x13D65, REVERSE, 0xFFFF, 0xFFFF, 0xEA82, ], + [ 'crc-16-en-13757', 'Crc16En13757', 0x13D65, NON_REVERSE, 0xFFFF, 0xFFFF, 0xC2B7, ], + [ 'crc-16-genibus', 'Crc16Genibus', 0x11021, NON_REVERSE, 0x0000, 0xFFFF, 0xD64E, ], + [ 'crc-16-maxim', 'Crc16Maxim', 0x18005, REVERSE, 0xFFFF, 0xFFFF, 0x44C2, ], + [ 'crc-16-mcrf4xx', 'Crc16Mcrf4xx', 0x11021, REVERSE, 0xFFFF, 0x0000, 0x6F91, ], + [ 'crc-16-riello', 'Crc16Riello', 0x11021, REVERSE, 0x554D, 0x0000, 0x63D0, ], + [ 'crc-16-t10-dif', 'Crc16T10Dif', 0x18BB7, NON_REVERSE, 0x0000, 0x0000, 0xD0DB, ], + [ 'crc-16-teledisk', 'Crc16Teledisk', 0x1A097, NON_REVERSE, 0x0000, 0x0000, 0x0FB3, ], + [ 'crc-16-usb', 'Crc16Usb', 0x18005, REVERSE, 0x0000, 0xFFFF, 0xB4C8, ], + [ 'x-25', 'CrcX25', 0x11021, REVERSE, 0x0000, 0xFFFF, 0x906E, ], + [ 'xmodem', 'CrcXmodem', 0x11021, NON_REVERSE, 0x0000, 0x0000, 0x31C3, ], + [ 'modbus', 'CrcModbus', 0x18005, REVERSE, 0xFFFF, 0x0000, 0x4B37, ], + + # Note definitions of CCITT are disputable. See: + # http://homepages.tesco.net/~rainstorm/crc-catalogue.htm + # http://web.archive.org/web/20071229021252/http://www.joegeluso.com/software/articles/ccitt.htm + [ 'kermit', 'CrcKermit', 0x11021, REVERSE, 0x0000, 0x0000, 0x2189, ], + [ 'crc-ccitt-false', 'CrcCcittFalse', 0x11021, NON_REVERSE, 0xFFFF, 0x0000, 0x29B1, ], + [ 'crc-aug-ccitt', 'CrcAugCcitt', 0x11021, NON_REVERSE, 0x1D0F, 0x0000, 0xE5CC, ], + + [ 'crc-24', 'Crc24', 0x1864CFB, NON_REVERSE, 0xB704CE, 0x000000, 0x21CF02, ], + [ 'crc-24-flexray-a', 'Crc24FlexrayA', 0x15D6DCB, NON_REVERSE, 0xFEDCBA, 0x000000, 0x7979BD, ], + [ 'crc-24-flexray-b', 'Crc24FlexrayB', 0x15D6DCB, NON_REVERSE, 0xABCDEF, 0x000000, 0x1F23B8, ], + + [ 'crc-32', 'Crc32', 0x104C11DB7, REVERSE, 0x00000000, 0xFFFFFFFF, 0xCBF43926, ], + [ 'crc-32-bzip2', 'Crc32Bzip2', 0x104C11DB7, NON_REVERSE, 0x00000000, 0xFFFFFFFF, 0xFC891918, ], + [ 'crc-32c', 'Crc32C', 0x11EDC6F41, REVERSE, 0x00000000, 0xFFFFFFFF, 0xE3069283, ], + [ 'crc-32d', 'Crc32D', 0x1A833982B, REVERSE, 0x00000000, 0xFFFFFFFF, 0x87315576, ], + [ 'crc-32-mpeg', 'Crc32Mpeg', 0x104C11DB7, NON_REVERSE, 0xFFFFFFFF, 0x00000000, 0x0376E6E7, ], + [ 'posix', 'CrcPosix', 0x104C11DB7, NON_REVERSE, 0xFFFFFFFF, 0xFFFFFFFF, 0x765E7680, ], + [ 'crc-32q', 'Crc32Q', 0x1814141AB, NON_REVERSE, 0x00000000, 0x00000000, 0x3010BF7F, ], + [ 'jamcrc', 'CrcJamCrc', 0x104C11DB7, REVERSE, 0xFFFFFFFF, 0x00000000, 0x340BC6D9, ], + [ 'xfer', 'CrcXfer', 0x1000000AF, NON_REVERSE, 0x00000000, 0x00000000, 0xBD0BE338, ], + +# 64-bit +# Name Identifier-name, Poly Reverse Init-value XOR-out Check + [ 'crc-64', 'Crc64', 0x1000000000000001B, REVERSE, 0x0000000000000000, 0x0000000000000000, 0x46A5A9388A5BEFFE, ], + [ 'crc-64-we', 'Crc64We', 0x142F0E1EBA9EA3693, NON_REVERSE, 0x0000000000000000, 0xFFFFFFFFFFFFFFFF, 0x62EC59E3F1A4F00A, ], + [ 'crc-64-jones', 'Crc64Jones', 0x1AD93D23594C935A9, REVERSE, 0xFFFFFFFFFFFFFFFF, 0x0000000000000000, 0xCAA717168609F281, ], +] + + +def _simplify_name(name): + """ + Reduce CRC definition name to a simplified form: + * lowercase + * dashes removed + * spaces removed + * any initial "CRC" string removed + """ + name = name.lower() + name = name.replace('-', '') + name = name.replace(' ', '') + if name.startswith('crc'): + name = name[len('crc'):] + return name + + +_crc_definitions_by_name = {} +_crc_definitions_by_identifier = {} +_crc_definitions = [] + +_crc_table_headings = [ 'name', 'identifier', 'poly', 'reverse', 'init', 'xor_out', 'check' ] + +for table_entry in _crc_definitions_table: + crc_definition = dict(zip(_crc_table_headings, table_entry)) + _crc_definitions.append(crc_definition) + name = _simplify_name(table_entry[0]) + if name in _crc_definitions_by_name: + raise Exception("Duplicate entry for '%s' in CRC table" % name) + _crc_definitions_by_name[name] = crc_definition + _crc_definitions_by_identifier[table_entry[1]] = crc_definition + + +def _get_definition_by_name(crc_name): + definition = _crc_definitions_by_name.get(_simplify_name(crc_name), None) + if not definition: + definition = _crc_definitions_by_identifier.get(crc_name, None) + if not definition: + raise KeyError("Unkown CRC name '%s'" % crc_name) + return definition + + +class PredefinedCrc(crcmod.Crc): + def __init__(self, crc_name): + definition = _get_definition_by_name(crc_name) + crcmod.Crc.__init__(self, poly=definition['poly'], initCrc=definition['init'], rev=definition['reverse'], xorOut=definition['xor_out']) + + +# crcmod.predefined.Crc is an alias for crcmod.predefined.PredefinedCrc +Crc = PredefinedCrc + + +def mkPredefinedCrcFun(crc_name): + definition = _get_definition_by_name(crc_name) + return crcmod.mkCrcFun(poly=definition['poly'], initCrc=definition['init'], rev=definition['reverse'], xorOut=definition['xor_out']) + + +# crcmod.predefined.mkCrcFun is an alias for crcmod.predefined.mkPredefinedCrcFun +mkCrcFun = mkPredefinedCrcFun
