Move the len() calculation into the stop watch class

src/Products/ZCatalog/Catalog.py

@@ -528,14 +528,14 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
                 # once we don't need to support the "return everything" case
                 # anymore
                 if r is not None and not r:
-                    cr.split(i, 0)
+                    cr.split(i, None)
                     return LazyCat([])
-                cr.split(i, len(r))
+                cr.split(i, r)
                 w, rs = weightedIntersection(rs, r)
                 if not rs:
                     break
             else:
-                cr.split(i, 0)
+                cr.split(i, None)
 
         cr.stop()
 

src/Products/ZCatalog/report.py

@@ -117,7 +117,7 @@ class StopWatch(object):
         self.init()
         self.start_time = time.time()
 
-    def split(self, label, result_length=None):
+    def split(self, label, result=None):
         current = time.time()
         start_time, stop_time = self.interim.get(label, (None, None))
 
@@ -125,8 +125,12 @@ class StopWatch(object):
             self.interim[label] = (current, None)
             return
 
+        length = 0
+        if result is not None:
+            # TODO: calculating the length can be expensive
+            length = len(result)
         self.interim[label] = (start_time, current)
-        self.res.append((label, current - start_time, result_length))
+        self.res.append((label, current - start_time, length))
 
     def stop(self):
         self.end_time = time.time()