r3200 - in /1.3: data/__init__.py test_suite/unit_tests/data/test___init__.py -- March 15, 2007 - 17:58

Author: macraild
Date: Thu Mar 15 17:58:23 2007
New Revision: 3200

URL: http://svn.gna.org/viewcvs/relax?rev=3200&view=rev
Log:
Alternative implimentation of the data object as a singleton.

As proposed here:
https://mail.gna.org/public/relax-devel/2007-03/msg00013.html

and agreed here:
https://mail.gna.org/public/relax-devel/2007-03/msg00058.html#
 

Modified:
    1.3/data/__init__.py
    1.3/test_suite/unit_tests/data/test___init__.py

Modified: 1.3/data/__init__.py
URL: 
http://svn.gna.org/viewcvs/relax/1.3/data/__init__.py?rev=3200&r1=3199&r2=3200&view=diff
==============================================================================
--- 1.3/data/__init__.py (original)
+++ 1.3/data/__init__.py Thu Mar 15 17:58:23 2007
@@ -37,28 +37,8 @@
 class Data(dict):
     """The relax data storage object."""
 
-    # Singleton initialisation, the reference to the single instance of this 
class.
-    __instance = None
-
     # The current data pipe.
     current_pipe = None
-
-
-    def __new__(self, *args, **kargs):
-        """Method for implementing the singleton design pattern.
-
-        If no other class instance currently exists, create a new instance 
of this class.  Otherwise
-        return the class instance.  See 
http://en.wikipedia.org/wiki/Singleton_pattern for a
-        description of this design pattern.
-        """
-
-        # Create a new instance if none exists.
-        if self.__instance is None:
-            self.__instance = dict.__new__(self, *args, **kargs)
-
-        # Return the class instance.
-        return self.__instance
-
 
     def __repr__(self):
         """The string representation of the object.
@@ -145,3 +125,6 @@
         # Change the current data pipe.
         self.current_pipe = pipe_name
 
+# Rebind the name Data with an instance to prevent accidental creation
+# of multiple instances of the Data class
+Data = Data()

Modified: 1.3/test_suite/unit_tests/data/test___init__.py
URL: 
http://svn.gna.org/viewcvs/relax/1.3/test_suite/unit_tests/data/test___init__.py?rev=3200&r1=3199&r2=3200&view=diff
==============================================================================
--- 1.3/test_suite/unit_tests/data/test___init__.py (original)
+++ 1.3/test_suite/unit_tests/data/test___init__.py Thu Mar 15 17:58:23 2007
@@ -27,9 +27,12 @@
 from data import Data
 
 
-class NewStore(Data):
-    """Subclass the relax data storage object for the isolation and creation 
of a new singleton."""
-
+class NewStore(dict):
+    """Dict subclass to act as proxy for the Singleton Data object."""
+    def __getattr__(self, attr):
+        """Delegate to the Data class to get methods for testing"""
+        return getattr(Data.__class__, attr)
+            
 
 class Empty_container:
     """An empty data container."""
@@ -53,15 +56,11 @@
         # Add an object to the data store object.
         self.data_store.test = 1
 
-        # Create a new reference.
-        self.new_ref = NewStore()
-
 
     def tearDown(self):
         """Destroy the subclassed data store."""
 
         # Delete all references (which should decrement the singleton's ref 
counter to 0, hence destroying it).
-        del self.new_ref
         del self.data_store
 
 
@@ -104,18 +103,3 @@
         self.assert_(hasattr(self.data_store, 'current_pipe'))
 
 
-    def test_singleton(self):
-        """Test that the relax data storage object is functioning as a 
singleton."""
-
-        # Test that the new reference to NewStore is the singleton instance 
reference.
-        self.assertEqual(self.data_store, self.new_ref)
-
-        # Delete all references (which should decrement the singleton's ref 
counter to 0, hence destroying it).
-        del self.new_ref
-        del self.data_store
-
-        # Create a new singleton.
-        new = NewStore()
-
-        # Test that the object 'test' from the original singleton does not 
exist.
-        self.assert_(not hasattr(new, 'test'))