beremiz

use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

2019-01-06, Andrey Skvortsov
68f4f2d4516b
use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

This code could be possible reused on low-end targets with limited RAM.

code to generate lookup table:
[---------------------------------------------------------------------]

/* CRC lookup table and initial state. */
uint32_t crc32_table[256];

/* Generate CRC32 lookup table. */
void GenerateCRC32Table(void)
{
unsigned int i, j;
/* Use CRC-32-IEEE 802.3 polynomial 0x04C11DB7 (bit reflected). */
uint32_t poly = 0xEDB88320;

for (i = 0; i <= 0xFF; i++)
{
uint32_t c = i;
for (j = 0 ; j < 8 ; j++)
c = (c & 1) ? (c >> 1 ) ^ poly : (c >> 1);
crc32_table[i] = c;
}
}

void main(void)
{
GenerateCRC32Table();
int j=0;
for(int i=0; i<256; i++) {
printf("0x%08X, ", crc32_table[i]);
if (++j >= 8) {
j = 0;
printf("\n");
}
}
}
[---------------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import os
import subprocess
import wx
def get_inkscape_path():
""" Return the Inkscape path """
from six.moves import winreg
try:
svgexepath = winreg.QueryValue(winreg.HKEY_LOCAL_MACHINE,
'Software\\Classes\\svgfile\\shell\\Inkscape\\command')
except OSError:
svgexepath = winreg.QueryValue(winreg.HKEY_LOCAL_MACHINE,
'Software\\Classes\\inkscape.svg\\shell\\open\\command')
svgexepath = svgexepath.replace('"%1"', '')
return svgexepath.replace('"', '')
def open_win_svg(svgexepath, svgfile):
""" Open Inkscape on Windows platform """
popenargs = [svgexepath]
if svgfile is not None:
popenargs.append(svgfile)
subprocess.Popen(popenargs)
def open_lin_svg(svgexepath, svgfile):
""" Open Inkscape on Linux platform """
if os.path.isfile("/usr/bin/inkscape"):
os.system("%s %s &" % (svgexepath, svgfile))
def open_svg(svgfile):
""" Generic function to open SVG file """
if wx.Platform == '__WXMSW__':
try:
open_win_svg(get_inkscape_path(), svgfile)
except Exception:
wx.MessageBox("Inkscape is not found or installed !")
return None
else:
svgexepath = os.path.join("/usr/bin", "inkscape")
if os.path.isfile(svgexepath):
open_lin_svg(svgexepath, svgfile)
else:
wx.MessageBox("Inkscape is not found or installed !")
return None