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
# -------------------------------------------------------------------------------
# Helpers object for generating pou var list
# -------------------------------------------------------------------------------
class _VariableInfos(object):
__slots__ = ["Name", "Class", "Option", "Location", "InitialValue",
"Edit", "Documentation", "Type", "Tree", "Number"]
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 _VariableInfos(*[getattr(self, attr) for attr in self.__slots__])
class VariablesInfosFactory(object):
""" Helpers object for generating pou var list """
def __init__(self, variables):
self.Variables = variables
self.TreeStack = []
self.Type = None
self.Dimensions = None
def SetType(self, context, *args):
self.Type = args[0][0]
def GetType(self):
if len(self.Dimensions) > 0:
return ("array", self.Type, self.Dimensions)
return self.Type
def GetTree(self):
return (self.TreeStack.pop(-1), self.Dimensions)
def AddDimension(self, context, *args):
self.Dimensions.append(tuple(
_translate_args([_StringValue] * 2, args)))
def AddTree(self, context, *args):
self.TreeStack.append([])
self.Dimensions = []
def AddVarToTree(self, context, *args):
var = (args[0][0], self.Type, self.GetTree())
self.TreeStack[-1].append(var)
def AddVariable(self, context, *args):
self.Variables.append(_VariableInfos(*(
_translate_args([_StringValue] * 5 + [_BoolValue] + [_StringValue], args) +
[self.GetType(), self.GetTree()])))
class VariableInfoCollector(XSLTModelQuery):
def __init__(self, controller):
XSLTModelQuery.__init__(self,
controller,
"variables_infos.xslt",
[(name, self.FactoryCaller(name))
for name in [
"SetType",
"AddDimension",
"AddTree",
"AddVarToTree",
"AddVariable"]])
def FactoryCaller(self, funcname):
def CallFactory(*args):
return getattr(self.factory, funcname)(*args)
return CallFactory
def Collect(self, root, debug, variables, tree):
self.factory = VariablesInfosFactory(variables)
self._process_xslt(root, debug, tree=str(tree))
res = self.factory
self.factory = None
return res