[PATCH 6 of 6] revset: use localrepo revbranchcache for branch name filtering

[Mads Kiilerich]

# HG changeset patch
# User Mads Kiilerich <madski at unity3d.com>
# Date 1418581984 -3600
#      Sun Dec 14 19:33:04 2014 +0100
# Node ID a51d095337085bc74398b39a3b0d2c6e43e3cb80
# Parent  186394f5dbf37adf268fa034fc897201fd2dbe0d
revset: use localrepo revbranchcache for branch name filtering

Branch name filtering in revsets was expensive. For every rev it created a
changectx and called .branch().

Instead, use the new localrepo revbranchcache.

perfrevset 'branch(mobile)' on mozilla-central, before:
! wall 10.904967 comb 10.900000 user 10.860000 sys 0.040000 (best of 3)
After:
! wall 1.065556 comb 1.060000 user 1.060000 sys 0.000000 (best of 10)

diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py
--- a/mercurial/branchmap.py
+++ b/mercurial/branchmap.py
@@ -381,6 +381,10 @@
         self._dirty = True
         return butf8, close
 
+    def branchlocal(self, rev):
+        """Return branch name of rev in local encoding."""
+        return encoding.tolocal(self.branchinfoutf8(rev)[0])
+
     def save(self):
         """Save branch cache if it is dirty."""
         if self._dirty:
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -452,6 +452,7 @@
     a regular expression. To match a branch that actually starts with `re:`,
     use the prefix `literal:`.
     """
+    branch = repo.revbranchcache.branchlocal
     try:
         b = getstring(x, '')
     except error.ParseError:
@@ -463,16 +464,16 @@
             # note: falls through to the revspec case if no branch with
             # this name exists
             if pattern in repo.branchmap():
-                return subset.filter(lambda r: matcher(repo[r].branch()))
+                return subset.filter(lambda r: matcher(branch(r)))
         else:
-            return subset.filter(lambda r: matcher(repo[r].branch()))
+            return subset.filter(lambda r: matcher(branch(r)))
 
     s = getset(repo, spanset(repo), x)
     b = set()
     for r in s:
-        b.add(repo[r].branch())
+        b.add(branch(r))
     c = s.__contains__
-    return subset.filter(lambda r: c(r) or repo[r].branch() in b)
+    return subset.filter(lambda r: c(r) or branch(r) in b)
 
 def bumped(repo, subset, x):
     """``bumped()``
@@ -1431,7 +1432,7 @@
     getfieldfuncs = []
     _funcs = {
         'user': lambda r: repo[r].user(),
-        'branch': lambda r: repo[r].branch(),
+        'branch': repo.revbranchcache.branchlocal,
         'date': lambda r: repo[r].date(),
         'description': lambda r: repo[r].description(),
         'files': lambda r: repo[r].files(),
@@ -1534,9 +1535,9 @@
             elif k == '-rev':
                 e.append(-r)
             elif k == 'branch':
-                e.append(c.branch())
+                e.append(repo.revbranchcache.branchlocal(r))
             elif k == '-branch':
-                e.append(invert(c.branch()))
+                e.append(invert(repo.revbranchcache.branchlocal(r)))
             elif k == 'desc':
                 e.append(c.description())
             elif k == '-desc':
diff --git a/tests/test-branches.t b/tests/test-branches.t
--- a/tests/test-branches.t
+++ b/tests/test-branches.t
@@ -520,4 +520,75 @@
    }
   ]
 
+revision branch name caching implementation
+
+cache creation
+  $ rm .hg/cache/revbranchnames
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  b90894765458b0298f0c822fb5193c1e  .hg/cache/revbranchnames
+recovery from invalid cache file
+  $ echo > .hg/cache/revbranchnames
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  b90894765458b0298f0c822fb5193c1e  .hg/cache/revbranchnames
+recovery from other corruption - extra trailing data
+  $ echo >> .hg/cache/revbranchnames
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  b90894765458b0298f0c822fb5193c1e  .hg/cache/revbranchnames
+lazy update after commit
+  $ hg tag tag
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  807c628e9f3f9040cc1da7124c4cb2d8  .hg/cache/revbranchnames
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  807c628e9f3f9040cc1da7124c4cb2d8  .hg/cache/revbranchnames
+update after rollback - cache keeps stripped revs until written for other reasons
+  $ hg up -qr '.^'
+  $ hg rollback -qf
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  807c628e9f3f9040cc1da7124c4cb2d8  .hg/cache/revbranchnames
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  807c628e9f3f9040cc1da7124c4cb2d8  .hg/cache/revbranchnames
+handle history mutations that doesn't change the tip node - this is a problem
+with the cache invalidation scheme used by branchmap
+  $ hg log -r tip+b -T'{rev}:{node|short} {branch}\n'
+  14:f894c25619d3 c
+  13:e23b5505d1ad b
+  $ hg bundle -q --all bu.hg
+  $ hg --config extensions.strip= strip --no-b -qr -1:
+  $ hg up -q tip
+  $ hg branch
+  b
+  $ hg branch -q hacked
+  $ hg ci --amend -qm 'hacked'
+  $ hg pull -q bu.hg -r f894c25619d3
+  $ hg log -r tip+b -T'{rev}:{node|short} {branch}\n'
+  14:f894c25619d3 c
+  12:e3d49c0575d8 b
+  $ hg debugrevspec 'branch("hacked")'
+  13
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  b4401727ffd84a7c339faf8a6e470671  .hg/cache/revbranchnames
+cleanup, restore old state
+  $ hg --config extensions.strip= strip --no-b -qr -2:
+  $ hg pull -q bu.hg
+  $ rm bu.hg
+  $ hg up -qr tip
+  $ hg log -r tip -T'{rev}:{node|short}\n'
+  14:f894c25619d3
+the cache file do not go back to the old state - it still contains the
+now unused 'hacked' branch name)
+  $ hg debugrevspec 'branch("re:a ")'
+  7
+  $ "$TESTDIR/md5sum.py" .hg/cache/revbranchnames
+  e1a76da810555ed88e3b2f467395e2ff  .hg/cache/revbranchnames
+
   $ cd ..