Merge lp:~adeuring/launchpad/bug-746866 into lp:launchpad

[Abel Deuring]

[r=abentley][bug=746866] more efficient visibility query for BugBranchSet.getBranchesWithVisibleBugs()

This branch fixes bug 746866: Person:+branches timeout: sometimes-slow bug-branch link query.

Robert already analyzed the problem and suggested two fixes; I took the one from comment #4 in the bug report.

test: ./bin/test bugs -vvt test_bugbranch

no lint

[Aaron Bentley (abentley)]

This looks good. On line 30, I think the original spacing "where=subscribed" is correct.

review: Approve

=== modified file 'lib/lp/bugs/model/bugbranch.py'
--- lib/lp/bugs/model/bugbranch.py	2011-02-10 14:42:11 +0000
+++ lib/lp/bugs/model/bugbranch.py	2011-05-04 16:01:23 +0000
@@ -18,6 +18,7 @@
     )
 from storm.expr import (
     And,
+    Exists,
     Or,
     Select,
     )
@@ -99,14 +100,15 @@
             # ones they may be directly or indirectly subscribed to.
             subscribed = And(
                 TeamParticipation.teamID == BugSubscription.person_id,
-                TeamParticipation.personID == user.id)
+                TeamParticipation.personID == user.id,
+                Bug.id == BugSubscription.bug_id)
 
             visible = And(
                 Bug.id == BugBranch.bugID,
                 Or(
                     Bug.private == False,
-                    Bug.id.is_in(Select(
-                        columns=[BugSubscription.bug_id],
+                    Exists(Select(
+                        columns=[True],
                         tables=[BugSubscription, TeamParticipation],
                         where=subscribed))))