[Zope-CVS] CVS: Packages/pypes/pypes - identity.py:1.13

[Casey Duncan]

Update of /cvs-repository/Packages/pypes/pypes
In directory cvs.zope.org:/tmp/cvs-serv16088

Modified Files:
	identity.py 
Log Message:
Use BTree.Length to optimize IdentitySet __len__


=== Packages/pypes/pypes/identity.py 1.12 => 1.13 ===
--- Packages/pypes/pypes/identity.py:1.12	Mon Mar  1 23:14:26 2004
+++ Packages/pypes/pypes/identity.py	Wed Mar  3 23:47:56 2004
@@ -145,6 +145,7 @@
         objs -- An iterable sequence of id-registered objects.
         """        
         self._idset = IITreeSet()
+        self._length = Length()
         if objs:
             self.update(objs)
     
@@ -163,6 +164,7 @@
             set._idset = idset
         if dbconn is not None:
             dbconn.add(set)
+        set._length = Length(len(idset))
         return set
     fromIdSet = classmethod(fromIdSet)
     
@@ -175,11 +177,13 @@
         if ident is None:
             raise IdentityError, obj
         isnew = self._idset.insert(ident)
-        if isnew and not isinstance(self._idset, IITreeSet):
-            # Set operations may result in _idset being an IISet
-            # For better database efficiency we upgrade it to an IITreeSet
-            # When we are mutated in place
-            self._idset = IITreeSet(self._idset)
+        if isnew:
+            self._length.change(1)
+            if not isinstance(self._idset, IITreeSet):
+                # Set operations may result in _idset being an IISet
+                # For better database efficiency we upgrade it to an IITreeSet
+                # When we are mutated in place
+                self._idset = IITreeSet(self._idset)
         return bool(isnew)
     
     def remove(self, obj):
@@ -191,6 +195,7 @@
         except KeyError:
             raise SetLookupError, obj
         else:
+            self._length.change(-1)
             if not isinstance(self._idset, IITreeSet):
                 # Upgrade to IITreeSet for storage efficiency when mutated
                 self._idset = IITreeSet(self._idset)
@@ -206,9 +211,11 @@
                 return
             self.add(first)
         insert = self._idset.insert
+        lenChange = self._length.change
         try:
             for ob in objs:
-                insert(ob._pypes_id_)
+                if insert(ob._pypes_id_):
+                    lenChange(1)
         except AttributeError:
             raise IdentityError, 'Set update received unregistered object(s)'
     
@@ -223,7 +230,7 @@
         return bool(self._idset)
     
     def __len__(self):
-        return len(self._idset) # XXX keep a length for efficiency?
+        return self._length()
     
     def __iter__(self):
         # If an object in the set is no longer registered None is substituted
@@ -313,7 +320,10 @@
         if not idsect:
             # Short circuit on empty intersect
             return IdentitySet()
-    return IdentitySet.fromIdSet(idsect, dbconn=dbconn)
+    if idsect is not None:
+        return IdentitySet.fromIdSet(idsect, dbconn=dbconn)
+    else:
+        return IdentitySet()
                 
 
 ## Id Event Messsage Types ##