object_registry.py

import PythonBridge.bridge_globals
from uuid import uuid1

def ensure_global_registry():
 if not hasattr(PythonBridge.bridge_globals, 'ObjectRegistry'):
 PythonBridge.bridge_globals.ObjectRegistry = Registry()

def registry():
 return PythonBridge.bridge_globals.ObjectRegistry

primitive = (int, str, bool)

def is_primitive(obj):
 return isinstance(obj, primitive)

class Registry():

 def __init__(self):
 self.idToObjMap = {}
 self.objToIdMap = {}

 def hasId(self, anId):
 return anId in self.idToObjMap

 def createNewObjId(self):
 return uuid1().hex
 
 def register(self, obj):
 if obj is None or is_primitive(obj):
 return 0
 if id(obj) in self.objToIdMap:
 return self.objToIdMap[id(obj)]
 else:
 return self._register(obj, self.createNewObjId())
 
 def register_with_id(self, obj, newObjId):
 if obj is None or is_primitive(obj):
 return RegisterForbiddenObject(obj)
 if id(obj) in self.objToIdMap:
 objId = self.objToIdMap[id(obj)]
 if objId == newObjId:
 return newObjId
 else:
 raise RegisterWithDifferentIdError(obj, newObjId)
 else:
 return self._register(obj, newObjId)

 def resolve(self, objId):
 if objId in self.idToObjMap:
 return self.idToObjMap[objId]
 else:
 raise ResolveUnknownObject(objId)

 def _register(self, obj, newObjId):
 self.idToObjMap[newObjId] = obj
 self.objToIdMap[id(obj)] = newObjId
 return newObjId

 def clean(self, objId):
 obj = self.idToObjMap[objId]
 del self.idToObjMap[objId]
 del self.objToIdMap[id(obj)]

class RegistryError(Exception):
 pass

class RegisterWithDifferentIdError(RegistryError):
 def __init__(self, obj, newId):
 RegistryError.__init__(self,"Attempting to register object {0} with ID {1} with different ID {2}.".format(type(obj).__name__, registry().register(obj), newId))

class ResolveUnknownObject(RegistryError):
 def __init__(self, objId):
 RegistryError.__init__(self,"Attempting to resolve unknown object with id {0}.".format(objId))

class RegisterForbiddenObject(RegistryError):
 def __init__(self, obj):
 RegistryError.__init__(self,"Attempting to register forbidden object of type {0}.".format(type(obj).__name__))

ensure_global_registry()