# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@logilab.fr>
# Date 1357327145 -3600
# Node ID a2d54f68e13cb68132a161617b8e5386eec49047
# Parent  95ef7a87c0536dab946cd2e4e57e7f4aa34ea759
performance: speedup computation of unserved revisions

In their current state, revset calls can be very costly, as we test
predicates on the entire repository. The "unserved" filter is used
in multiple applications, and in particular in some branch cache
loading operations. We need to make it fast.

This change drops revset calls in favor of direct testing of the
phase of a changeset.

Performance test on my Mercurial checkout

- 19857 total changesets,
- 1584 obsolete changesets,
- 13310 obsolescence markers.

Before:
  ! unserved
  ! wall 0.030477

After:
  ! unserved
  ! wall 0.011844

Performance test on a Mozilla central checkout:

- 117293 total changesets,
- 1 obsolete changeset,
- 1 obsolescence marker.

Before:
  ! unserved
  ! wall 0.111259

After:
  ! unserved
  ! wall 0.000084

diff -r 95ef7a87c053 -r a2d54f68e13c mercurial/repoview.py
--- a/mercurial/repoview.py	Fri Jan 04 05:44:01 2013 +0100
+++ b/mercurial/repoview.py	Fri Jan 04 20:19:05 2013 +0100
@@ -38,8 +38,17 @@
     Secret and hidden changeset should not pretend to be here."""
     assert not repo.changelog.filteredrevs
     # fast path in simple case to avoid impact of non optimised code
-    if phases.hassecret(repo) or repo.obsstore:
-        return frozenset(repo.revs('hidden() + secret()'))
+    hiddens = filteredrevs(repo, 'hidden')
+    if phases.hassecret(repo):
+        cl = repo.changelog
+        secret = phases.secret
+        getphase = repo._phasecache.phase
+        first = min(cl.rev(n) for n in repo._phasecache.phaseroots[secret])
+        revs = cl.revs(start=first)
+        secrets = set(r for r in revs if getphase(repo, r) >= secret)
+        return frozenset(hiddens | secrets)
+    else:
+        return hiddens
     return frozenset()
 
 def computemutable(repo):