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.
# See COPYING file for copyrights details.
from __future__ import absolute_import
from plcopen.XSLTModelQuery import XSLTModelQuery, _StringValue, _BoolValue, _translate_args
from plcopen.types_enums import CLASS_TYPES, POU_TYPES, VAR_CLASS_INFOS
def class_extraction(value):
class_type = CLASS_TYPES.get(value)
if class_type is not None:
return class_type
pou_type = POU_TYPES.get(value)
if pou_type is not None:
return pou_type
var_type = VAR_CLASS_INFOS.get(value)
if var_type is not None:
return var_type[1]
return None
class _VariablesTreeItemInfos(object):
__slots__ = ["name", "var_class", "type", "edit", "debug", "variables"]
def __init__(self, *args):
for attr, value in zip(self.__slots__, args):
setattr(self, attr, value if value is not None else "")
def copy(self):
return _VariablesTreeItemInfos(*[getattr(self, attr) for attr in self.__slots__])
class VariablesTreeInfosFactory(object):
def __init__(self):
self.Root = None
def GetRoot(self):
return self.Root
def SetRoot(self, context, *args):
self.Root = _VariablesTreeItemInfos(
*([''] + _translate_args(
[class_extraction, _StringValue] + [_BoolValue] * 2,
args) + [[]]))
def AddVariable(self, context, *args):
if self.Root is not None:
self.Root.variables.append(_VariablesTreeItemInfos(
*(_translate_args(
[_StringValue, class_extraction, _StringValue] +
[_BoolValue] * 2, args) + [[]])))
class POUVariablesCollector(XSLTModelQuery):
def __init__(self, controller):
XSLTModelQuery.__init__(self,
controller,
"pou_variables.xslt",
[(name, self.FactoryCaller(name))
for name in ["SetRoot", "AddVariable"]])
def FactoryCaller(self, funcname):
def CallFactory(*args):
return getattr(self.factory, funcname)(*args)
return CallFactory
def Collect(self, root, debug):
self.factory = VariablesTreeInfosFactory()
self._process_xslt(root, debug)
res = self.factory.GetRoot()
self.factory = None
return res