HGKeeper

#!/usr/bin/env python

# -*- coding: utf-8 -*-

#See COPYING file for copyrights details.

#This library 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 2.1 of the License, or (at your option) any later version.

#This library 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 library; if not, write to the Free Software

#Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

import Pyro.core as pyro

from Pyro.errors import PyroError

import traceback

from time import sleep

import copy

def PYRO_connector_factory(uri, pluginsroot):

"""

This returns the connector to Pyro style PLCobject

"""

pluginsroot.logger.write("Connecting to URI : %s\n"%uri)

servicetype, location = uri.split("://")

# Try to get the proxy object

try :

RemotePLCObjectProxy = pyro.getAttrProxyForURI("PYROLOC://"+location+"/PLCObject")

except Exception, msg:

pluginsroot.logger.write_error("Wrong URI, please check it !\n")

pluginsroot.logger.write_error(traceback.format_exc())

return None

def PyroCatcher(func, default=None):

"""

A function that catch a pyro exceptions, write error to logger

and return defaul value when it happen

"""

def catcher_func(*args,**kwargs):

try:

return func(*args,**kwargs)

except PyroError,e:

#pluginsroot.logger.write_error(traceback.format_exc())

pluginsroot.logger.write_error(str(e))

pluginsroot._Disconnect()

return default

return catcher_func

# Check connection is effective.

# lambda is for getattr of GetPLCstatus to happen inside catcher

if PyroCatcher(lambda:RemotePLCObjectProxy.GetPLCstatus())() == None:

pluginsroot.logger.write_error("Cannot get PLC status - connection failed.\n")

return None

# for safe use in from debug thread, must create a copy

RemotePLCObjectProxyCopy = copy.copy(RemotePLCObjectProxy)

class PyroProxyProxy:

"""

A proxy proxy class to handle Beremiz Pyro interface specific behavior.

And to put pyro exception catcher in between caller and pyro proxy

"""

def GetPyroProxy(self):

"""

This func returns the real Pyro Proxy.

Use this if you musn't keep reference to it.

"""

return RemotePLCObjectProxy

def _PyroStartPLC(self, *args, **kwargs):

"""

pluginsroot._connector.GetPyroProxy() is used

rather than RemotePLCObjectProxy because

object is recreated meanwhile,

so we must not keep ref to it here

"""

if pluginsroot._connector.GetPyroProxy().GetPLCstatus() == "Dirty":

"""

Some bad libs with static symbols may polute PLC

ask runtime to suicide and come back again

"""

pluginsroot.logger.write("Force runtime reload\n")

pluginsroot._connector.GetPyroProxy().ForceReload()

pluginsroot._Disconnect()

# let remote PLC time to resurect.(freeze app)

sleep(0.5)

pluginsroot._Connect()

return pluginsroot._connector.GetPyroProxy().StartPLC(*args, **kwargs)

StartPLC = PyroCatcher(_PyroStartPLC, False)

def _PyroGetTraceVariables(self):

"""

for safe use in from debug thread, must use the copy

"""

if RemotePLCObjectProxyCopy.GetPLCstatus() == "Started":

return RemotePLCObjectProxyCopy.GetTraceVariables()

else:

return None,None

GetTraceVariables = PyroCatcher(_PyroGetTraceVariables)

def __getattr__(self, attrName):

member = self.__dict__.get(attrName, None)

if member is None:

def my_local_func(*args,**kwargs):

return RemotePLCObjectProxy.__getattr__(attrName)(*args,**kwargs)

member = PyroCatcher(my_local_func, None)

self.__dict__[attrName] = member

return member

return PyroProxyProxy()

beremiz