Add getCounter logic to TopicIndex

src/Products/PluginIndexes/TopicIndex/FilteredSet.py

@@ -41,10 +41,7 @@ def index_object(self, documentId, obj):
         raise RuntimeError('index_object not defined')
 
     def unindex_object(self, documentId):
-        try:
-            self.ids.remove(documentId)
-        except KeyError:
-            pass
+        self.ids.remove(documentId)
 
     def getId(self):
         return self.id
@@ -75,19 +72,23 @@ class PythonFilteredSet(FilteredSetBase):
     meta_type = 'PythonFilteredSet'
 
     def index_object(self, documentId, o):
+        res = 0
         try:
             if RestrictionCapableEval(self.expr).eval({'o': o}):
                 self.ids.insert(documentId)
+                res = 1
             else:
                 try:
                     self.ids.remove(documentId)
+                    res = 1
                 except KeyError:
                     pass
         except ConflictError:
             raise
         except Exception:
             LOG.warn('eval() failed Object: %s, expr: %s' %
                      (o.getId(), self.expr), exc_info=sys.exc_info())
+        return res
 
 
 def factory(f_id, f_type, expr):

src/Products/PluginIndexes/TopicIndex/TopicIndex.py

@@ -18,13 +18,15 @@
 from BTrees.IIBTree import intersection
 from BTrees.IIBTree import union
 from BTrees.OOBTree import OOBTree
+from BTrees.Length import Length
 from OFS.SimpleItem import SimpleItem
 from Persistence import Persistent
 from zope.interface import implementer
 
 from Products.PluginIndexes.interfaces import (
     IQueryIndex,
     ITopicIndex,
+    IIndexCounter,
 )
 from Products.PluginIndexes.TopicIndex.FilteredSet import factory
 from Products.ZCatalog.query import IndexQuery
@@ -33,7 +35,7 @@
 LOG = getLogger('Zope.TopicIndex')
 
 
-@implementer(ITopicIndex, IQueryIndex)
+@implementer(ITopicIndex, IQueryIndex, IIndexCounter)
 class TopicIndex(Persistent, SimpleItem):
     """A TopicIndex maintains a set of FilteredSet objects.
 
@@ -43,6 +45,7 @@ class TopicIndex(Persistent, SimpleItem):
 
     meta_type = "TopicIndex"
     query_options = ('query', 'operator')
+    _counter = None
 
     manage_options = (
         {'label': 'FilteredSets', 'action': 'manage_main'},
@@ -51,6 +54,7 @@ class TopicIndex(Persistent, SimpleItem):
     def __init__(self, id, caller=None):
         self.id = id
         self.filteredSets = OOBTree()
+        self._counter = Length()
         self.operators = ('or', 'and')
         self.defaultOperator = 'or'
 
@@ -60,22 +64,44 @@ def getId(self):
     def clear(self):
         for fs in self.filteredSets.values():
             fs.clear()
+        self._increment_counter()
 
     def index_object(self, docid, obj, threshold=100):
         """ hook for (Z)Catalog """
+        res = 0
         for fid, filteredSet in self.filteredSets.items():
-            filteredSet.index_object(docid, obj)
-        return 1
+            res += filteredSet.index_object(docid, obj)
+
+        if res > 0:
+            self._increment_counter()
+            return 1
+
+        return 0
 
     def unindex_object(self, docid):
         """ hook for (Z)Catalog """
+        res = 0
         for fs in self.filteredSets.values():
             try:
                 fs.unindex_object(docid)
+                res += 1
             except KeyError:
                 LOG.debug('Attempt to unindex document'
                           ' with id %s failed' % docid)
-        return 1
+        if res > 0:
+            self._increment_counter()
+            return 1
+
+        return 0
+
+    def _increment_counter(self):
+        if self._counter is None:
+            self._counter = Length()
+        self._counter.change(1)
+
+    def getCounter(self):
+        """Return a counter which is increased on index changes"""
+        return self._counter is not None and self._counter() or 0
 
     def numObjects(self):
         """Return the number of indexed objects."""

src/Products/PluginIndexes/TopicIndex/tests.py

@@ -92,3 +92,23 @@ def testRemoval(self):
         self.TI.index_object(1, Obj('1', 'doc2'))
         self._searchOr('doc1', [2])
         self._searchOr('doc2', [1, 3, 4])
+
+    def test_getCounter(self):
+        index = self.TI
+        index._counter.set(0)
+
+        self.assertEqual(index.getCounter(), 0)
+
+        index.index_object(1, Obj(1, 'doc1'))
+        self.assertEqual(index.getCounter(), 1)
+
+        index.unindex_object(1)
+        self.assertEqual(index.getCounter(), 2)
+
+        # unknown id
+        index.unindex_object(1)
+        self.assertEqual(index.getCounter(), 2)
+
+        # clear changes the index
+        index.clear()
+        self.assertEqual(index.getCounter(), 3)