[파이썬] 파이썬 - C로 확장 프로그래밍 라이브러리 만들기
[파이썬] 파이썬 - C로 확장 프로그래밍 라이브러리 만들기
라이브러리 만들기 예제가 없다.
왜?
만들 정도의 실력자가 없거나.....
만들 필요가 없거나....
둘중에 하나이겠다.
파이썬3 에 대한 내용만 다룬다.
https://github.com/gtrafimenkov/pycrc16
을 다운받아서 압축을 풀면......
src 폴더 안에
_crc16module.c 파일이 있다.
/* Implementation of _crc16 module */
/* **************************************************************************
*
* Copyright (C) Gennady Trafimenkov, 2011
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 program. If not, see <http://www.gnu.org/licenses/>.
*
* **************************************************************************/
#include <Python.h>
/* table for calculating CRC
* this particular table was generated using pycrc v0.7.6, http://www.tty1.net/pycrc/
* using the configuration:
* Width = 16
* Poly = 0x1021
* XorIn = 0x0000
* ReflectIn = False
* XorOut = 0x0000
* ReflectOut = False
* Algorithm = table-driven
* by following command:
* python pycrc.py --model xmodem --algorithm table-driven --generate c
*/
static const unsigned short CRC16_XMODEM_TABLE[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
/* Calculate CRC16 using table-driven method
* crc - initial value of CRC
* data - data
* data_len - lenght of the data
* crc_table - table for calculating CRC (array of 256 numbers)
*/
unsigned short calculateCRC16(unsigned short crc,
const unsigned char *data,
int data_len,
const unsigned short * crc_table)
{
while (data_len-- > 0)
crc = (crc_table[((crc >> 8) ^ *data++) & 0xff] ^ (crc << 8)) & 0xffff;
return crc & 0xffff;
}
static PyObject *
_crc16_crc16xmodem(PyObject *self, PyObject *args)
{
const unsigned char* data;
int data_len;
unsigned int crc = 0;
unsigned int result;
#if PY_MAJOR_VERSION >= 3
if (!PyArg_ParseTuple(args, "y#|I:crc16xmodem", &data, &data_len, &crc))
return NULL;
#else
if (!PyArg_ParseTuple(args, "s#|I:crc16xmodem", &data, &data_len, &crc))
return NULL;
#endif /* PY_MAJOR_VERSION */
result = calculateCRC16(crc & 0xffff, data, data_len, CRC16_XMODEM_TABLE);
return Py_BuildValue("I", result);
}
/* method table */
static PyMethodDef _crc16Methods[] = {
{ "crc16xmodem", _crc16_crc16xmodem, METH_VARARGS,
"Calculate CRC-CCITT (XModem) of CRC16." },
{ NULL, NULL, 0, NULL } /* Sentinel */
};
/* module documentation */
PyDoc_STRVAR(_crc16_doc, "Calculation of CRC16");
#if PY_MAJOR_VERSION >= 3
/* module definition structure */
static struct PyModuleDef _crc16module = {
PyModuleDef_HEAD_INIT,
"_crc16", /* name of module */
_crc16_doc, /* module documentation, may be NULL */
-1, /* size of per-interpreter state of the module */
_crc16Methods
};
/* initialization function for Python 3 */
PyMODINIT_FUNC
PyInit__crc16(void)
{
return PyModule_Create(&_crc16module);
}
#else
/* initialization function for Python 2 */
PyMODINIT_FUNC
init_crc16(void)
{
(void)Py_InitModule3("_crc16", _crc16Methods, _crc16_doc);
}
#endif /* PY_MAJOR_VERSION */