From 62554752c60221ae6cd9ec0dfa531f83d9a70d37 Mon Sep 17 00:00:00 2001 From: Bryan O'Sullivan Date: Thu, 12 Apr 2012 20:26:33 -0700 Subject: [PATCH] revlog: avoid an expensive string copy This showed up in a statprof profile of "hg svn rebuildmeta", which is read-intensive on the changelog. This two-line patch improved the performance of that command by 10%. --- mercurial/revlog.py | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mercurial/revlog.py b/mercurial/revlog.py index bc43eb85d3..f75d072fd8 100644 --- a/mercurial/revlog.py +++ b/mercurial/revlog.py @@ -818,7 +818,7 @@ class revlog(object): df.close() self._addchunk(offset, d) if readahead > length: - return d[:length] + return util.buffer(d, 0, length) return d def _getchunk(self, offset, length): @@ -831,7 +831,7 @@ class revlog(object): if cachestart >= 0 and cacheend <= l: if cachestart == 0 and cacheend == l: return d # avoid a copy - return d[cachestart:cacheend] + return util.buffer(d, cachestart, cacheend - cachestart) return self._loadchunk(offset, length) @@ -864,7 +864,7 @@ class revlog(object): def revdiff(self, rev1, rev2): """return or calculate a delta between two revisions""" if rev1 != nullrev and self.deltaparent(rev2) == rev1: - return self._chunk(rev2) + return str(self._chunk(rev2)) return mdiff.textdiff(self.revision(self.node(rev1)), self.revision(self.node(rev2))) @@ -921,7 +921,7 @@ class revlog(object): self._chunkraw(base, rev) if text is None: - text = self._chunkbase(base) + text = str(self._chunkbase(base)) bins = [self._chunk(r) for r in chain] text = mdiff.patches(text, bins)