[Checkins] SVN: relstorage/trunk/relstorage/ Fixed handling of future checkpoints when no checkpoints are

[Shane Hathaway]

Log message for revision 105181:
  Fixed handling of future checkpoints when no checkpoints are
  currently set.
  

Changed:
  U   relstorage/trunk/relstorage/cache.py
  U   relstorage/trunk/relstorage/tests/test_cache.py

-=-
Modified: relstorage/trunk/relstorage/cache.py
===================================================================
--- relstorage/trunk/relstorage/cache.py	2009-10-20 20:49:17 UTC (rev 105180)
+++ relstorage/trunk/relstorage/cache.py	2009-10-20 21:19:11 UTC (rev 105181)
@@ -389,6 +389,8 @@
             # checkpoint0 is in a future that this instance can't
             # yet see.  Ignore the checkpoint change for now.
             new_checkpoints = self.checkpoints
+            if not new_checkpoints:
+                new_checkpoints = (new_tid_int, new_tid_int)
             allow_shift = False
 
         if (new_checkpoints == self.checkpoints
@@ -412,15 +414,16 @@
             # Rebuild delta_after0 and delta_after1.
             new_delta_after0 = {}
             new_delta_after1 = {}
-            # poller.list_changes provides an iterator of (oid, tid) where
-            # tid > after_tid and tid <= last_tid.
-            changes = self.adapter.poller.list_changes(
-                cursor, cp1, new_tid_int)
-            for oid_int, tid_int in changes:
-                if tid_int > cp0:
-                    new_delta_after0[oid_int] = tid_int
-                elif tid_int > cp1:
-                    new_delta_after1[oid_int] = tid_int
+            if cp0 <= new_tid_int:
+                # poller.list_changes provides an iterator of
+                # (oid, tid) where tid > after_tid and tid <= last_tid.
+                changes = self.adapter.poller.list_changes(
+                    cursor, cp1, new_tid_int)
+                for oid_int, tid_int in changes:
+                    if tid_int > cp0:
+                        new_delta_after0[oid_int] = tid_int
+                    elif tid_int > cp1:
+                        new_delta_after1[oid_int] = tid_int
             self.checkpoints = new_checkpoints
             self.delta_after0 = new_delta_after0
             self.delta_after1 = new_delta_after1

Modified: relstorage/trunk/relstorage/tests/test_cache.py
===================================================================
--- relstorage/trunk/relstorage/tests/test_cache.py	2009-10-20 20:49:17 UTC (rev 105180)
+++ relstorage/trunk/relstorage/tests/test_cache.py	2009-10-20 21:19:11 UTC (rev 105181)
@@ -253,7 +253,7 @@
         self.assertEqual(c.checkpoints, (50, 50))
         self.assertEqual(data['myprefix:checkpoints'], '40 30')
 
-    def test_after_poll_future_checkpoints(self):
+    def test_after_poll_future_checkpoints_when_cp_exist(self):
         from relstorage.tests.fakecache import data
         data['myprefix:checkpoints'] = '90 80'
         c = self._makeOne()
@@ -267,6 +267,18 @@
         self.assertEqual(c.delta_after0, {2: 45})
         self.assertEqual(c.delta_after1, {})
 
+    def test_after_poll_future_checkpoints_when_cp_nonexistent(self):
+        from relstorage.tests.fakecache import data
+        data['myprefix:checkpoints'] = '90 80'
+        c = self._makeOne()
+        c.after_poll(None, 40, 50, [(2, 45)])
+        # This instance can't yet see txn 90, and there aren't any
+        # existing checkpoints, so fall back to the current tid.
+        self.assertEqual(c.checkpoints, (50, 50))
+        self.assertEqual(data['myprefix:checkpoints'], '90 80')
+        self.assertEqual(c.delta_after0, {})
+        self.assertEqual(c.delta_after1, {})
+
     def test_after_poll_retain_checkpoints(self):
         from relstorage.tests.fakecache import data
         data['myprefix:checkpoints'] = '40 30'