[Checkins] SVN: relstorage/trunk/relstorage/relstorage.py Fixed KeyError reporting to not trip over a related KeyError while

[Shane Hathaway]

Log message for revision 94992:
  Fixed KeyError reporting to not trip over a related KeyError while 
  logging.  Also expanded a docstring.
  

Changed:
  U   relstorage/trunk/relstorage/relstorage.py

-=-
Modified: relstorage/trunk/relstorage/relstorage.py
===================================================================
--- relstorage/trunk/relstorage/relstorage.py	2009-01-25 00:03:00 UTC (rev 94991)
+++ relstorage/trunk/relstorage/relstorage.py	2009-01-25 00:46:35 UTC (rev 94992)
@@ -238,7 +238,9 @@
     def _get_oid_cache_key(self, oid_int):
         """Return the cache key for finding the current tid.
 
-        This is overridden by BoundRelStorage.
+        This is overridden by BoundRelStorage.  This version always returns
+        None because a non-bound storage does not have a prev_polled_tid,
+        which is required for cache invalidation.
         """
         return None
 
@@ -261,12 +263,18 @@
         else:
             msg.append("Current transaction is %d" % row[0])
 
-        rows = adapter.iter_object_history(cursor, oid_int)
         tids = []
-        for row in rows:
-            tids.append(row[0])
-            if len(tids) >= 10:
-                break
+        try:
+            rows = adapter.iter_object_history(cursor, oid_int)
+        except KeyError:
+            # The object has no history, at least from the point of view
+            # of the current database load connection.
+            pass
+        else:
+            for row in rows:
+                tids.append(row[0])
+                if len(tids) >= 10:
+                    break
         msg.append("Recent object tids: %s" % repr(tids))
         log.warning('; '.join(msg))