Add getCounter logic to PathIndex

src/Products/PluginIndexes/PathIndex/PathIndex.py

@@ -31,14 +31,16 @@
     IQueryIndex,
     ISortIndex,
     IUniqueValueIndex,
+    IIndexCounter,
 )
 from Products.PluginIndexes.util import safe_callable
 from Products.ZCatalog.query import IndexQuery
 
 LOG = getLogger('Zope.PathIndex')
 
 
-@implementer(IPathIndex, IQueryIndex, IUniqueValueIndex, ISortIndex)
+@implementer(IPathIndex, IQueryIndex, IUniqueValueIndex,
+             ISortIndex, IIndexCounter)
 class PathIndex(Persistent, SimpleItem):
 
     """Index for paths returned by getPhysicalPath.
@@ -60,6 +62,7 @@ class PathIndex(Persistent, SimpleItem):
     operators = ('or', 'and')
     useOperator = 'or'
     query_options = ('query', 'level', 'operator')
+    _counter = None
 
     manage_options = (
         {'label': 'Settings', 'action': 'manage_main'},
@@ -128,6 +131,7 @@ def index_object(self, docid, obj, threshold=100):
         for i in range(len(comps)):
             self.insertEntry(comps[i], docid, i)
         self._unindex[docid] = path
+        self._increment_counter()
         return 1
 
     def unindex_object(self, docid):
@@ -154,6 +158,7 @@ def unindex_object(self, docid):
                           % docid)
 
         self._length.change(-1)
+        self._increment_counter()
         del self._unindex[docid]
 
     def _apply_index(self, request):
@@ -186,6 +191,15 @@ def query_index(self, record, resultset=None):
             return res
         return IISet()
 
+    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):
         """ See IPluggableIndex.
         """
@@ -203,6 +217,10 @@ def clear(self):
         self._index = OOBTree()
         self._unindex = IOBTree()
         self._length = Length(0)
+        if self._counter is None:
+            self._counter = Length(0)
+        else:
+            self._increment_counter()
 
     # IUniqueValueIndex implementation
 

src/Products/PluginIndexes/PathIndex/tests.py

@@ -533,3 +533,23 @@ def test__search_w_level_0(self):
         self.assertEqual(list(index._search('bb', 1)), [1])
         self.assertEqual(list(index._search('aa/bb', 0)), [1])
         self.assertEqual(list(index._search('aa/bb', 1)), [])
+
+    def test_getCounter(self):
+        index = self._makeOne()
+
+        self.assertEqual(index.getCounter(), 0)
+
+        doc = Dummy('/aa/bb')
+        index.index_object(1, doc)
+        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)