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 wx
from dialogs.DurationEditorDialog import DurationEditorDialog
class DurationCellControl(wx.PyControl):
'''
Custom cell editor control with a text box and a button that launches
the DurationEditorDialog.
'''
def __init__(self, parent):
wx.PyControl.__init__(self, parent)
main_sizer = wx.FlexGridSizer(cols=2, hgap=0, rows=1, vgap=0)
main_sizer.AddGrowableCol(0)
main_sizer.AddGrowableRow(0)
# create location text control
self.Duration = wx.TextCtrl(self, size=wx.Size(0, -1),
style=wx.TE_PROCESS_ENTER)
self.Duration.Bind(wx.EVT_KEY_DOWN, self.OnDurationChar)
main_sizer.AddWindow(self.Duration, flag=wx.GROW)
# create browse button
self.EditButton = wx.Button(self, label='...', size=wx.Size(30, -1))
self.Bind(wx.EVT_BUTTON, self.OnEditButtonClick, self.EditButton)
main_sizer.AddWindow(self.EditButton, flag=wx.GROW)
self.Bind(wx.EVT_SIZE, self.OnSize)
self.SetSizer(main_sizer)
self.Default = None
def SetValue(self, value):
self.Default = value
self.Duration.SetValue(value)
def GetValue(self):
return self.Duration.GetValue()
def OnSize(self, event):
self.Layout()
def OnEditButtonClick(self, event):
# pop up the Duration Editor dialog
dialog = DurationEditorDialog(self)
dialog.SetDuration(self.Duration.GetValue())
if dialog.ShowModal() == wx.ID_OK:
# set the duration
self.Duration.SetValue(dialog.GetDuration())
dialog.Destroy()
self.Duration.SetFocus()
def OnDurationChar(self, event):
keycode = event.GetKeyCode()
if keycode in [wx.WXK_RETURN, wx.WXK_TAB]:
self.Parent.Parent.ProcessEvent(event)
elif keycode == wx.WXK_ESCAPE:
self.Duration.SetValue(self.Default)
self.Parent.Parent.CloseEditControl()
else:
event.Skip()
def SetInsertionPoint(self, i):
self.Duration.SetInsertionPoint(i)
def SetFocus(self):
self.Duration.SetFocus()
class DurationCellEditor(wx.grid.PyGridCellEditor):
'''
Grid cell editor that uses DurationCellControl to display an edit button.
'''
def __init__(self, table, colname):
wx.grid.PyGridCellEditor.__init__(self)
self.Table = table
self.Colname = colname
def __del__(self):
self.CellControl = None
def Create(self, parent, id, evt_handler):
self.CellControl = DurationCellControl(parent)
self.SetControl(self.CellControl)
if evt_handler:
self.CellControl.PushEventHandler(evt_handler)
def BeginEdit(self, row, col, grid):
self.CellControl.Enable()
self.CellControl.SetValue(self.Table.GetValueByName(row, self.Colname))
self.CellControl.SetFocus()
def EndEditInternal(self, row, col, grid, old_duration):
duration = self.CellControl.GetValue()
changed = duration != old_duration
if changed:
self.Table.SetValueByName(row, self.Colname, duration)
self.CellControl.Disable()
return changed
if wx.VERSION >= (3, 0, 0):
def EndEdit(self, row, col, grid, oldval):
return self.EndEditInternal(row, col, grid, oldval)
else:
def EndEdit(self, row, col, grid):
oldval = self.Table.GetValueByName(row, self.Colname)
return self.EndEditInternal(row, col, grid, oldval)
def SetSize(self, rect):
self.CellControl.SetDimensions(rect.x + 1, rect.y,
rect.width, rect.height,
wx.SIZE_ALLOW_MINUS_ONE)
def Clone(self):
return DurationCellEditor(self.Table, self.Colname)