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
from __future__ import print_function
import sys
import traceback
from threading import Thread, Event
from builtins import str as text
from twisted.internet import reactor, threads
from autobahn.twisted import wamp
from autobahn.twisted.websocket import WampWebSocketClientFactory, connectWS
from autobahn.wamp import types
from autobahn.wamp.exception import TransportLost
from autobahn.wamp.serializer import MsgPackSerializer
from runtime import PlcStatus
_WampSession = None
_WampConnection = None
_WampSessionEvent = Event()
class WampSession(wamp.ApplicationSession):
def onJoin(self, details):
global _WampSession
_WampSession = self
_WampSessionEvent.set()
print('WAMP session joined for :', self.config.extra["ID"])
def onLeave(self, details):
global _WampSession
_WampSessionEvent.clear()
_WampSession = None
print('WAMP session left')
PLCObjDefaults = {
"StartPLC": False,
"GetTraceVariables": ("Broken", None),
"GetPLCstatus": (PlcStatus.Broken, None),
"RemoteExec": (-1, "RemoteExec script failed!")
}
def WAMP_connector_factory(uri, confnodesroot):
"""
WAMP://127.0.0.1:12345/path#realm#ID
WAMPS://127.0.0.1:12345/path#realm#ID
"""
servicetype, location = uri.split("://")
urlpath, realm, ID = location.split('#')
urlprefix = {"WAMP": "ws",
"WAMPS": "wss"}[servicetype]
url = urlprefix+"://"+urlpath
def RegisterWampClient():
# start logging to console
# log.startLogging(sys.stdout)
# create a WAMP application session factory
component_config = types.ComponentConfig(
realm=text(realm),
extra={"ID": ID})
session_factory = wamp.ApplicationSessionFactory(
config=component_config)
session_factory.session = WampSession
# create a WAMP-over-WebSocket transport client factory
transport_factory = WampWebSocketClientFactory(
session_factory,
url=url,
serializers=[MsgPackSerializer()])
# start the client from a Twisted endpoint
conn = connectWS(transport_factory)
confnodesroot.logger.write(_("WAMP connecting to URL : %s\n") % url)
return conn
AddToDoBeforeQuit = confnodesroot.AppFrame.AddToDoBeforeQuit
def ThreadProc():
global _WampConnection
_WampConnection = RegisterWampClient()
AddToDoBeforeQuit(reactor.stop)
reactor.run(installSignalHandlers=False)
def WampSessionProcMapper(funcname):
wampfuncname = text('.'.join((ID, funcname)))
def catcher_func(*args, **kwargs):
if _WampSession is not None:
try:
return threads.blockingCallFromThread(
reactor, _WampSession.call, wampfuncname,
*args, **kwargs)
except TransportLost:
confnodesroot.logger.write_error(_("Connection lost!\n"))
confnodesroot._SetConnector(None)
except Exception:
errmess = traceback.format_exc()
confnodesroot.logger.write_error(errmess+"\n")
print(errmess)
# confnodesroot._SetConnector(None)
return PLCObjDefaults.get(funcname)
return catcher_func
class WampPLCObjectProxy(object):
def __init__(self):
global _WampConnection
if not reactor.running:
Thread(target=ThreadProc).start()
else:
_WampConnection = threads.blockingCallFromThread(
reactor, RegisterWampClient)
if not _WampSessionEvent.wait(5):
_WampConnection.stopConnecting()
raise Exception(_("WAMP connection timeout"))
def __del__(self):
_WampConnection.disconnect()
#
# reactor.stop()
def __getattr__(self, attrName):
member = self.__dict__.get(attrName, None)
if member is None:
member = WampSessionProcMapper(attrName)
self.__dict__[attrName] = member
return member
# Try to get the proxy object
try:
return WampPLCObjectProxy()
except Exception:
confnodesroot.logger.write_error(_("WAMP connection to '%s' failed.\n") % location)
confnodesroot.logger.write_error(traceback.format_exc())
return None