sha1-file.c: don't freshen cruft packs

We don't bother to freshen objects stored in a cruft pack individually
by updating the `.mtimes` file. This is because we can't portably `mmap`
and write into the middle of a file (i.e., to update the mtime of just
one object). Instead, we would have to rewrite the entire `.mtimes` file
which may incur some wasted effort especially if there a lot of cruft
objects and they are freshened infrequently.

Instead, force the freshening code to avoid an optimizing write by
writing out the object loose and letting it pick up a current mtime.

This works because we prefer the mtime of the loose copy of an object
when both a loose and packed one exist (whether or not the packed copy
comes from a cruft pack or not).

This could certainly do with a test and/or be included earlier in this
series/PR, but I want to wait until after I have a chance to clean up
the overly-repetitive nature of the cruft pack tests in general.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/object-file.c b/object-file.c
index ff0cffe68ee17887c166a093ae9d2d3f3742b0da..495a3592009910662df5b14fb35e67b00d83d108 100644 (file)
--- a/object-file.c
+++ b/object-file.c
@@ -2035,6 +2035,8 @@ static int freshen_packed_object(const struct object_id *oid)
        struct pack_entry e;
        if (!find_pack_entry(the_repository, oid, &e))
                return 0;
+       if (e.p->is_cruft)
+               return 0;
        if (e.p->freshened)
                return 1;
        if (!freshen_file(e.p->pack_name))

diff --git a/t/t5329-pack-objects-cruft.sh b/t/t5329-pack-objects-cruft.sh
index 70a6a9553c71ce901d6d772b51ff9562f47bce1a..b481224b93decdaa106b11d5a27f79659ee05ee0 100755 (executable)
--- a/t/t5329-pack-objects-cruft.sh
+++ b/t/t5329-pack-objects-cruft.sh
@@ -711,4 +711,29 @@ test_expect_success 'MIDX bitmaps tolerate reachable cruft objects' '
        )
 '
 
+test_expect_success 'cruft objects are freshend via loose' '
+       git init repo &&
+       test_when_finished "rm -fr repo" &&
+       (
+               cd repo &&
+
+               echo "cruft" >contents &&
+               blob="$(git hash-object -w -t blob contents)" &&
+               loose="$objdir/$(test_oid_to_path $blob)" &&
+
+               test_commit base &&
+
+               git repack --cruft -d &&
+
+               test_path_is_missing "$loose" &&
+               test-tool pack-mtimes "$(basename "$(ls $packdir/pack-*.mtimes)")" >cruft &&
+               grep "$blob" cruft &&
+
+               # write the same object again
+               git hash-object -w -t blob contents &&
+
+               test_path_is_file "$loose"
+       )
+'
+
 test_done