Merge "Handle events with conditions and match_fn"

ovsdbapp/backend/ovs_idl/event.py

@@ -20,6 +20,16 @@ LOG = logging.getLogger(__name__)
 
 class RowEvent(ovsdb_event.RowEvent):  # pylint: disable=abstract-method
     def match_fn(self, event, row, old):
+        """User-overridable custom matching function
+
+        This method takes the same arguments as the RowEvent API call
+        `matches` and allows for more complex matching criteria. This
+        method will apply additional checks to those specified in the
+        creation of the RowEvent
+        """
+        return True
+
+    def base_match(self, event, row, old):
         if self.conditions and not idlutils.row_match(row, self.conditions):
             return False
         if self.old_conditions:
@@ -38,6 +48,8 @@ class RowEvent(ovsdb_event.RowEvent):  # pylint: disable=abstract-method
             return False
         if row._table.name != self.table:
             return False
+        if not self.base_match(event, row, old):
+            return False
         if not self.match_fn(event, row, old):
             return False
         LOG.debug("Matched %s: %r to row=%s old=%s", event.upper(), self,

ovsdbapp/tests/functional/schema/ovn_southbound/event.py

@@ -28,3 +28,14 @@ class ExceptionalMatchFnEvent(WaitForPortBindingEvent):
 
     def match_fn(self, event, row, old):
         raise Exception()
+
+
+class MatchFnConditionsEvent(event.WaitEvent):
+    def __init__(self, *args, timeout=1, **kwargs):
+        super().__init__(*args, timeout=timeout, **kwargs)
+
+    def match_fn(self, event, row, old):
+        # This should only be called if we pass all other conditions
+        # so make sure wait() returns False if we see any other events. This
+        # ensures that adding a match_fn() doesn't skip the conditions checks.
+        return True

ovsdbapp/tests/functional/schema/ovn_southbound/test_impl_idl.py

@@ -138,3 +138,19 @@ class OvnSouthboundTest(base.FunctionalTestCase):
     def test_lsp_unbind_if_exists(self):
         pname = utils.get_rand_device_name()
         self.api.lsp_unbind(pname, if_exists=True).execute(check_error=True)
+
+    def test_event_with_match_fn_and_conditions(self):
+        cond_event = event.MatchFnConditionsEvent(
+            events=(event.MatchFnConditionsEvent.ROW_UPDATE,),
+            table="SB_Global",
+            conditions=(("external_ids", "=", {"foo": "bar"}),))
+        self.handler.watch_event(cond_event)
+        # Test that we match on condition with an Event that has a match_fn()
+        cmd = self.api.db_set("SB_Global", ".", external_ids={"foo": "bar"})
+        cmd.execute(check_error=True)
+        self.assertTrue(cond_event.wait())
+        cond_event.event.clear()
+        # Test that we don't ignore the condition when match_fn() returns True
+        cmd = self.api.db_set("SB_Global", ".", external_ids={"bar": "bar"})
+        cmd.execute(check_error=True)
+        self.assertFalse(cond_event.wait())