Mercurial > hg-stable
changeset 27064:a29db426c5ba
context: avoid extra parents lookups
Resolving parents requires reading from the changelog, which is a few
attributes and function calls away. Parents lookup occurs surprisingly
often. Micro optimizing the code to avoid redundant lookups of parents
appears to make `hg log` on my Firefox repo a little faster:
before: 24.91s
after: 23.76s
delta: -1.15s (95.4% of original)
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Sat, 21 Nov 2015 19:21:01 -0800 |
| parents | 37e1fdcb271c |
| children | 93bcc73df8d5 |
| files | mercurial/context.py |
| diffstat | 1 files changed, 11 insertions(+), 9 deletions(-) [+] |
line wrap: on
line diff
--- a/mercurial/context.py Sat Nov 21 19:04:12 2015 -0800 +++ b/mercurial/context.py Sat Nov 21 19:21:01 2015 -0800 @@ -221,9 +221,10 @@ return self._parents[0] def p2(self): - if len(self._parents) == 2: - return self._parents[1] - return changectx(self._repo, -1) + parents = self._parents + if len(parents) == 2: + return parents[1] + return changectx(self._repo, nullrev) def _fileinfo(self, path): if '_manifest' in self.__dict__: @@ -1152,17 +1153,17 @@ # filesystem doesn't support them copiesget = self._repo.dirstate.copies().get - - if len(self._parents) < 2: + parents = self.parents() + if len(parents) < 2: # when we have one parent, it's easy: copy from parent - man = self._parents[0].manifest() + man = parents[0].manifest() def func(f): f = copiesget(f, f) return man.flags(f) else: # merges are tricky: we try to reconstruct the unstored # result from the merge (issue1802) - p1, p2 = self._parents + p1, p2 = parents pa = p1.ancestor(p2) m1, m2, ma = p1.manifest(), p2.manifest(), pa.manifest() @@ -1192,10 +1193,11 @@ an extra 'a'. This is used by manifests merge to see that files are different and by update logic to avoid deleting newly added files. """ + parents = self.parents() - man1 = self._parents[0].manifest() + man1 = parents[0].manifest() man = man1.copy() - if len(self._parents) > 1: + if len(parents) > 1: man2 = self.p2().manifest() def getman(f): if f in man1: