From 3310e146cc54e7b4e76641c57272ba6c12367876 Mon Sep 17 00:00:00 2001 From: Martin Panter Date: Sat, 24 Dec 2016 07:36:44 +0000 Subject: Issue #29004: Document binascii.crc_hqx() implements CRC-CCITT --- Doc/library/binascii.rst | 6 ++++-- Modules/binascii.c | 4 ++-- Modules/clinic/binascii.c.h | 4 ++-- 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/Doc/library/binascii.rst b/Doc/library/binascii.rst index 878d8db..49da59a 100644 --- a/Doc/library/binascii.rst +++ b/Doc/library/binascii.rst @@ -115,8 +115,10 @@ The :mod:`binascii` module defines the following functions: .. function:: crc_hqx(data, value) - Compute the binhex4 crc value of *data*, starting with *value* as the - initial crc, and return the result. + Compute a 16-bit CRC value of *data*, starting with *value* as the + initial CRC, and return the result. This uses the CRC-CCITT polynomial + *x*:sup:`16` + *x*:sup:`12` + *x*:sup:`5` + 1, often represented as + 0x1021. This CRC is used in the binhex4 format. .. function:: crc32(data[, value]) diff --git a/Modules/binascii.c b/Modules/binascii.c index 1a40b41..125c1cb 100644 --- a/Modules/binascii.c +++ b/Modules/binascii.c @@ -915,12 +915,12 @@ binascii.crc_hqx -> unsigned_int crc: unsigned_int(bitwise=True) / -Compute hqx CRC incrementally. +Compute CRC-CCITT incrementally. [clinic start generated code]*/ static unsigned int binascii_crc_hqx_impl(PyObject *module, Py_buffer *data, unsigned int crc) -/*[clinic end generated code: output=8ec2a78590d19170 input=add8c53712ccceda]*/ +/*[clinic end generated code: output=8ec2a78590d19170 input=f18240ff8c705b79]*/ { unsigned char *bin_data; Py_ssize_t len; diff --git a/Modules/clinic/binascii.c.h b/Modules/clinic/binascii.c.h index e20cac2..6ace4d5 100644 --- a/Modules/clinic/binascii.c.h +++ b/Modules/clinic/binascii.c.h @@ -246,7 +246,7 @@ PyDoc_STRVAR(binascii_crc_hqx__doc__, "crc_hqx($module, data, crc, /)\n" "--\n" "\n" -"Compute hqx CRC incrementally."); +"Compute CRC-CCITT incrementally."); #define BINASCII_CRC_HQX_METHODDEF \ {"crc_hqx", (PyCFunction)binascii_crc_hqx, METH_VARARGS, binascii_crc_hqx__doc__}, @@ -516,4 +516,4 @@ exit: return return_value; } -/*[clinic end generated code: output=51173fc9718a5edc input=a9049054013a1b77]*/ +/*[clinic end generated code: output=6d70d5edd9373d92 input=a9049054013a1b77]*/ -- cgit v0.12