BaseHardwareObjects.py

import logging
import types
from dispatcher import *
from CommandContainer import CommandContainer
import HardwareRepository

      
class PropertySet(dict):
    def __init__(self):
        dict.__init__(self)

        self.__propertiesChanged = {}
        self.__propertiesPath = {}
        

    def setPropertyPath(self, name, path):
        name = str(name)
        self.__propertiesPath[name] = path
        

    def getPropertiesPath(self):
        return self.__propertiesPath.iteritems()
        
    
    def __setitem__(self, name, value):
        name = str(name)
       
        if name in self and str(value) != str(self[name]):
            self.__propertiesChanged[name] = str(value)
                            
        dict.__setitem__(self, str(name), value)


    def getChanges(self):
        for propertyName, value in self.__propertiesChanged.iteritems():
            yield (self.__propertiesPath[propertyName], value)
            
        self.__propertiesChanged = {} #reset changes at commit
    
        
class HardwareObjectNode:
    def __init__(self, nodeName):
        """Constructor"""
        self.__dict__['_propertySet'] = PropertySet()
        self.__objectsNames = []
        self.__objects = []
        self._objectsByRole = {}
        self._path = ''
        self.__name = nodeName
        self.__references = []
 

    def __setstate__(self, dict):
        self.__dict__.update(dict)
    
    
    def name(self):
        return self.__name
    

    def setName(self, name):
        self.__name = name
     
   
    def getRoles(self):
        return self._objectsByRole.keys()


    def setPath(self, path):
        """Set the 'path' of the Hardware Object in the XML file describing it
        (the path follows the XPath syntax)

        Parameters :
          path -- string representing the path of the Hardware Object in its file"""
        self._path = path
                       
        
    def __iter__(self):
        for i in range(len(self.__objectsNames)):
            for object in self.__objects[i]:
                yield object
        

    def __len__(self):
        return sum(map(len, self.__objects))
    
    
    def __getattr__(self, attr):
        if attr.startswith("__"):
            raise AttributeError, attr

        try:
            return self._propertySet[attr]
        except KeyError:
            raise AttributeError, attr


    def __setattr__(self, attr, value):
        if not attr in self.__dict__ and attr in self._propertySet:
	    self.setProperty(attr, value)
        else:
            self.__dict__[attr] = value

        
    def __getitem__(self, key):
        if type(key) == types.StringType:
            objectName = key
            
            try:
                i = self.__objectsNames.index(objectName)
            except:
                raise IndexError
            else:
                obj = self.__objects[i]
                if len(obj) == 1:
                    return obj[0]
                else:
                    return obj
        elif type(key) == types.IntType:
            i = key

            if i < len(self.__objectsNames):
                obj = self.__objects[i]
                if len(obj) == 1:
                    return obj[0]
                else:
                    return obj
            else:
                raise IndexError
        else:
            raise IndexError


    def addReference(self, name, reference, role = None):
        role = str(role).lower()

        try:
            i = self.__objectsNames.index(name)
        except ValueError:
            objectsNamesIndex = len(self.__objectsNames)
            self.__objectsNames.append(None)
            objectsIndex = len(self.__objects)
            self.__objects.append(None)
            objectsIndex2 = -1
        else:
            objectsNamesIndex = -1
            objectsIndex = i
            objectsIndex2 = len(self.__objects[i])
            self.__objects[i].append(None)

        self.__references.append( (reference, name, role, objectsNamesIndex, objectsIndex, objectsIndex2) )
        

    def resolveReferences(self):
        while len(self.__references) > 0:
            reference, name, role, objectsNamesIndex, objectsIndex, objectsIndex2 = self.__references.pop()

            object = HardwareRepository.HardwareRepository().getHardwareObject(reference)

            if object is not None:
                self._objectsByRole[role] = object
                object.__role = role

                if objectsNamesIndex >= 0:
                    self.__objectsNames[objectsNamesIndex] = name
                    self.__objects[objectsIndex] = [ object ]
                else:
                    self.__objects[objectsIndex][objectsIndex2] = object
            else:
                if objectsNamesIndex >= 0:
                    del self.__objectsNames[objectsNamesIndex]
                    del self.__objects[objectsIndex]
                else:
                    del self.__objects[objectsIndex][objectsIndex2]
                    if len(self.objects[objectsIndex]) == 0:
                        del self.objects[objectsIndex]
                
        for object in self:
            object.resolveReferences()
            
        
    def addObject(self, name, object, role = None):
        if object is None:
            return
        elif role is not None:
            role = str(role).lower()
            self._objectsByRole[role] = object
            object.__role = role
        
        try:
            i = self.__objectsNames.index(name)
        except ValueError:
            self.__objectsNames.append(name)
            self.__objects.append([ object ])
        else:
            self.__objects[i].append(object)
            

    def hasObject(self, objectName):
        return objectName in self.__objectsNames


    def getObjects(self, objectName):
        try:
            i = self.__objectsNames.index(objectName)
        except ValueError:
            pass
        else:
            for obj in self.__objects[i]:
                yield obj
        

    def getObjectByRole(self, role):
        object = None
        obj = self
        objects = []
        role = str(role).lower()

        while True:
            if role in obj._objectsByRole:
                return obj._objectsByRole[role]
                                            
            for object in obj:
                objects.append(object)
           
            try:
                obj = objects.pop()
            except IndexError:
                break
            else:
                object = obj.getObjectByRole(role)
                if object is not None:
                    return object

                if len(objects) > 0:
                    obj = objects.pop()
                else:
                    break

                    
    def objectsNames(self):
        return self.__objectsNames[:]
      

    def setProperty(self, name, value):
        name = str(name)
        value = str(value)
        
        if value=='None':
          value=None
        else:
          #
          # try to convert buffer to the appropriate type
          # 
          try:
              value = int(value)
          except:
              try:
                  value = float(value)
              except:
                  if value == 'True':
                      value = True
                  elif value == 'False':
                      value = False

        self._propertySet[name] = value
        self._propertySet.setPropertyPath(name, self._path+'/'+str(name))
        

    def getProperty(self, name):
	try:
            return self._propertySet[str(name)]
        except:
            return None


    def getProperties(self):
        return self._propertySet
            

class HardwareObject(HardwareObjectNode, CommandContainer):
    def __init__(self, rootName):
        HardwareObjectNode.__init__(self, rootName)
        CommandContainer.__init__(self)
 

    def _init(self):
        #'protected' post-initialization method
        pass

       
    def init(self):
        #'public' post-initialization method
        pass

    
    def __nonzero__(self):
        return True
        

    def __getattr__(self, attr):
        if attr.startswith("__"):
           raise AttributeError, attr
        try:
            return CommandContainer.__getattr__(self, attr)
        except AttributeError:
            try:
                return HardwareObjectNode.__getattr__(self, attr)
            except AttributeError:
                raise AttributeError, attr
    

    def emit(self, signal, *args):
        signal =  str(signal)
    
        if len(args)==1:
          if type(args[0])==types.TupleType:
            args=args[0]
    
        dispatcher.send(signal, self, *args)  

    
    def connect(self, sender, signal, slot=None):
        if slot is None:
            if type(sender) == types.StringType:
                # provides syntactic sugar ; for
                # self.connect(self, "signal", slot)
                # it is possible to do
                # self.connect("signal", slot)
                slot = signal
                signal = sender
                sender = self
            else:
                raise ValueError, "invalid slot (None)"

        signal = str(signal)
            
        dispatcher.connect(slot, signal, sender)
 
        if hasattr(sender, "connectNotify"):
            sender.connectNotify(signal)


    def disconnect(self, sender, signal, slot=None):
        if slot is None:
            if type(sender) == types.StringType:
                # provides syntactic sugar ; for
                # self.connect(self, "signal", slot)
                # it is possible to do
                # self.connect("signal", slot)
                slot = signal
                signal = sender
                sender = self
            else:
                raise ValueError, "invalid slot (None)"

        signal = str(signal)
            
        dispatcher.disconnect(slot, signal, sender) 
        
        if hasattr(sender, "disconnectNotify"):
            sender.disconnectNotify(signal)
        
 
    def connectNotify(self, signal):
	pass


    def disconnectNotify(self, signal):
        pass
    

    def commitChanges(self):
        """Commit last changes"""
        def getChanges(node):
          updates = list(node._propertySet.getChanges())
          if len(node) > 0:
            for n in node:
              updates+=getChanges(n)

          if isinstance(node, HardwareObject):
            if len(updates) > 0:
              HardwareRepository.HardwareRepository().update(node.name(),updates)
            return []
          else: 
            return updates

        getChanges(self)
 
    def rewrite_xml(self, xml):
        """Rewrite XML file"""
        HardwareRepository.HardwareRepository().rewrite_xml(self.name(), xml)


    def xml_source(self):
        """Get XML source code"""
        return HardwareRepository.HardwareRepository().xml_source[self.name()]
    
class Procedure(HardwareObject):
    def __init__(self, name):
        HardwareObject.__init__(self, name)


    def addCommand(self, *args, **kwargs):
        return HardwareObject.addCommand(self, *args, **kwargs)


    def userName(self):
        uname = self.getProperty('username')
        if uname is None:
            return str(self.name())
        else:
            return uname


    def GUI(self, parent):
        pass


class Device(HardwareObject):
    (NOTREADY, READY) = (0, 1)  # device states

    def __init__(self, name):
        HardwareObject.__init__(self, name)

        self.state = Device.NOTREADY
        
    
    def setIsReady(self, ready):
        if ready and self.state == Device.NOTREADY:
            self.state = Device.READY
            self.emit('deviceReady')
        elif not ready and self.state == Device.READY:
            self.state = Device.NOTREADY
            self.emit('deviceNotReady')

            
    def isReady(self):
        return self.state == Device.READY


    def userName(self):
        uname = self.getProperty('username')
        if uname is None:
            return str(self.name())
        else:
            return uname


class DeviceContainer:
    def __init__(self):
        pass

    
    def getDevices(self):
        devices = []

        for object in self:
            if isinstance(object, Device):
                devices.append(object)
            elif isinstance(object, DeviceContainer):
                devices += object.getDevices()
                                   
        return devices
        

    def getDevice(self, deviceName):
        devices = self.getDevices()
        
        for device in devices:
            if str(device.name()) == deviceName:
                return device


    def getDeviceByRole(self, role):
        object = self.getObjectByRole(role)

        if isinstance(object, Device):
            return object


class DeviceContainerNode(HardwareObjectNode, DeviceContainer):
    pass

                          
class Equipment(HardwareObject, DeviceContainer):
    def __init__(self, name):
        HardwareObject.__init__(self, name)
        DeviceContainer.__init__(self)

        self.__ready = None
    
        
    def _init(self): 
        for device in self.getDevices():
            self.connect(device, 'deviceReady', self.__deviceReady)
            self.connect(device, 'deviceNotReady', self.__deviceNotReady)

        self.__deviceReady()
      
    
    def __deviceReady(self):
        ready = True
        for device in self.getDevices():
            ready = ready and device.isReady()
            if not ready:
                break

        if self.__ready != ready:
            self.__ready = ready

            if self.isReady():
                self.emit('equipmentReady')
            else:
                self.emit('equipmentNotReady')


    def __deviceNotReady(self):
        if self.__ready:
            self.__ready = False
            self.emit('equipmentNotReady')


    def isReady(self):
        return self.isValid() and self.__ready


    def isValid(self):
        return True
                

    def userName(self):
        uname = self.getProperty('username')
        if uname is None:
            return str(self.name())
        else:
            return uname


class Null:
    """
    This class ignores all parameters passed when constructing or 
    calling instances and traps all attribute and method requests. 
    Instances of it always (and reliably) do 'nothing'.

    The code might benefit from implementing some further special 
    Python methods depending on the context in which its instances 
    are used. Especially when comparing and coercing Null objects
    the respective methods' implementation will depend very much
    on the environment and, hence, these special methods are not
    provided here.
    """
    def __init__(self, *args, **kwargs):
        "Ignore parameters."
        return None


    def __call__(self, *args, **kwargs):
        "Ignore method calls."
        return self


    def __nonzero__(self):
        return 0
    
    
    def __getattr__(self, mname):
        "Ignore attribute requests."
        return self


    def __setattr__(self, name, value):
        "Ignore attribute setting."
        return self


    def __delattr__(self, name):
        "Ignore deleting attributes."
        return self


    def __repr__(self):
        "Return a string representation."
        return "<Null>"


    def __str__(self):
        "Convert to a string and return it."
        return "Null"