From: Linus Torvalds Date: Fri, 10 Aug 2007 19:21:20 +0000 (-0700) Subject: Optimize the common cases of git-read-tree X-Git-Tag: v1.5.3-rc5~37 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=288f072ec033cf917eed949119428db3626ddc71;p=git.git Optimize the common cases of git-read-tree This optimizes bind_merge() and oneway_merge() to not unnecessarily remove and re-add the old index entries when they can just get replaced by updated ones. This makes these operations much faster for large trees (where "large" is in the 50,000+ file range), because we don't unnecessarily move index entries around in the index array all the time. Using the "bummer" tree (a test-tree with 100,000 files) we get: Before: [torvalds@woody bummer]$ time git commit -m"Change one file" 50/500 real 0m9.470s user 0m8.729s sys 0m0.476s After: [torvalds@woody bummer]$ time git commit -m"Change one file" 50/500 real 0m1.173s user 0m0.720s sys 0m0.452s so for large trees this is easily very noticeable indeed. Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- diff --git a/unpack-trees.c b/unpack-trees.c index 5e457b0bc..d57b91c1b 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -887,7 +887,6 @@ int bind_merge(struct cache_entry **src, struct cache_entry *old = src[0]; struct cache_entry *a = src[1]; - remove_entry(remove); if (o->merge_size != 1) return error("Cannot do a bind merge of %d trees\n", o->merge_size); @@ -912,13 +911,14 @@ int oneway_merge(struct cache_entry **src, struct cache_entry *old = src[0]; struct cache_entry *a = src[1]; - remove_entry(remove); if (o->merge_size != 1) return error("Cannot do a oneway merge of %d trees", o->merge_size); - if (!a) + if (!a) { + remove_entry(remove); return deleted_entry(old, old, o); + } if (old && same(old, a)) { if (o->reset) { struct stat st;