Re: [PATCH] pack-objects: re-validate data we copy from elsewhere.

[Junio C Hamano <junkio@cox.net>]

Linus Torvalds <torvalds@osdl.org> writes:

> On Fri, 1 Sep 2006, Junio C Hamano wrote:
>> 
>> But "git repack -a -d", which you now consider almost being
>> free, in the recent kernel repository counts 300k objects, and
>> reuses 298k objects or so.  That means we expand and recompress
>> that many objects, totalling 120MB.
>
> Sure. Do we have data for how expensive that is (ie did you apply the 
> patch and time it)?

Quite bad.  For the kernel archive of today (I usually am nearly
fully packed):

$ /usr/bin/time ~/git-master/bin/git-pack-objects p1 </var/tmp/1
Generating pack...
Done counting 301361 objects.
Deltifying 301361 objects.
 100% (301361/301361) done
Writing 301361 objects.
 100% (301361/301361) done
a13dc6646622537d29af92b4cfc6d49b82e77e49
Total 301361, written 301361 (delta 238935), reused 300995 (delta 238663)
3.58user 0.84system 0:04.44elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+62727minor)pagefaults 0swaps

$ /usr/bin/time ../git.junio/git-pack-objects p2 </var/tmp/1
Generating pack...
Done counting 301361 objects.
Deltifying 301361 objects.
 100% (301361/301361) done
Writing 301361 objects.
 100% (301361/301361) done
a13dc6646622537d29af92b4cfc6d49b82e77e49
Total 301361, written 301361 (delta 238935), reused 300995 (delta 238663)
57.84user 3.39system 1:01.36elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+1022768minor)pagefaults 0swaps

By the way, the one in "next" has a thinko I just noticed.

-- >8 --
[PATCH] pack-objects: fix thinko in revalidate code

When revalidating an entry from an existing pack entry->size and
entry->type are not necessarily the size of the final object
when the entry is deltified, but for base objects they must
match.

Signed-off-by: Junio C Hamano <junkio@cox.net>
---
 builtin-pack-objects.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 11cc3c8..5e42387 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -247,12 +247,13 @@ static int revalidate_one(struct object_
 			  void *data, char *type, unsigned long size)
 {
 	int err;
-	if (!data)
-		return -1;
-	if (size != entry->size)
-		return -1;
-	err = check_sha1_signature(entry->sha1, data, size,
-				   type_names[entry->type]);
+	if ((!data) ||
+	    ((entry->type != OBJ_DELTA) &&
+	     ( (size != entry->size) ||
+	       strcmp(type_names[entry->type], type))))
+		err = -1;
+	else
+		err = check_sha1_signature(entry->sha1, data, size, type);
 	free(data);
 	return err;
 }
-- 
1.4.2.g99d7d



-- 
VGER BF report: U 0.528006