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.
"""
Minimal tab controller for a simple text editor
"""
from __future__ import absolute_import
import os
class MiniTextControler(object):
def __init__(self, filepath, controller):
self.FilePath = filepath
self.BaseController = controller
def __del__(self):
self.BaseController = None
def CTNFullName(self):
return ""
def SetEditedElementText(self, tagname, text):
file = open(self.FilePath, "w")
file.write(text)
file.close()
def GetEditedElementText(self, tagname, debug=False):
if os.path.isfile(self.FilePath):
file = open(self.FilePath, "r")
text = file.read()
file.close()
return text
return ""
def GetEditedElementInterfaceVars(self, tagname, tree=False, debug=False):
return []
def GetEditedElementType(self, tagname, debug=False):
return "program"
def GetBlockType(self, type, inputs=None, debug=False):
return self.BaseController.GetBlockType(type, inputs, debug)
def GetBlockTypes(self, tagname="", debug=False):
return self.BaseController.GetBlockTypes(tagname, debug)
def GetDataTypes(self, tagname="", basetypes=True, only_locatables=False, debug=False):
return self.BaseController.GetDataTypes(tagname, basetypes, only_locatables, debug)
def GetEnumeratedDataValues(self, debug=False):
return self.BaseController.GetEnumeratedDataValues(debug)
def StartBuffering(self):
pass
def EndBuffering(self):
pass
def BufferProject(self):
pass