connectors/__init__.py
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Sun, 06 Jan 2019 01:22:46 +0300
changeset 2499 68f4f2d4516b
parent 2182 eeca1aff0691
child 2312 84b3cc18893b
permissions -rw-r--r--
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
# Copyright (C) 2017: Andrey Skvortsov
#
# 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.

# Package initialisation


from __future__ import absolute_import
from os import listdir, path
import util.paths as paths

_base_path = paths.AbsDir(__file__)


def _GetLocalConnectorClassFactory(name):
    return lambda: getattr(__import__(name, globals(), locals()), name + "_connector_factory")


def _GetLocalConnectorClassDialog(name):
    return lambda: getattr(__import__(name + '.dialog', globals(), locals(), fromlist=['dialog']), name + "_connector_dialog")


def _GetLocalConnectorURITypes(name):
    return lambda: getattr(__import__(name + '.dialog', globals(), locals(), fromlist=['dialog']), "URITypes", None)


connectors = {name:
              _GetLocalConnectorClassFactory(name)
              for name in listdir(_base_path)
              if (path.isdir(path.join(_base_path, name)) and
                  not name.startswith("__"))}

connectors_dialog = {name:
                     {"function": _GetLocalConnectorClassDialog(name), "URITypes": _GetLocalConnectorURITypes(name)}
                     for name in listdir(_base_path)
                     if (path.isdir(path.join(_base_path, name)) and
                         not name.startswith("__"))}


def ConnectorFactory(uri, confnodesroot):
    """
    Return a connector corresponding to the URI
    or None if cannot connect to URI
    """
    servicetype = uri.split("://")[0].upper()
    if servicetype == "LOCAL":
        # Local is special case
        # pyro connection to local runtime
        # started on demand, listening on random port
        servicetype = "PYRO"
        runtime_port = confnodesroot.AppFrame.StartLocalRuntime(
            taskbaricon=True)
        uri = "PYROLOC://127.0.0.1:" + str(runtime_port)
    elif servicetype in connectors:
        pass
    elif servicetype[-1] == 'S' and servicetype[:-1] in connectors:
        servicetype = servicetype[:-1]
    else:
        return None

    # import module according to uri type
    connectorclass = connectors[servicetype]()
    return connectorclass(uri, confnodesroot)


def ConnectorDialog(conn_type, confnodesroot):
    if conn_type not in connectors_dialog:
        return None

    connectorclass = connectors_dialog[conn_type]["function"]()
    return connectorclass(confnodesroot)


def GetConnectorFromURI(uri):
    typeOfConnector = None
    for conn_type in connectors_dialog:
        connectorTypes = connectors_dialog[conn_type]["URITypes"]()
        if connectorTypes and uri in connectorTypes:
            typeOfConnector = conn_type
            break

    return typeOfConnector