From 373c67da1df7fcd33593ca26e6d67f177152b21a Mon Sep 17 00:00:00 2001 From: Jeff King Date: Fri, 14 Mar 2014 22:38:29 -0400 Subject: [PATCH] pack-objects: turn off bitmaps when skipping objects The pack bitmap format requires that we have a single bit for each object in the pack, and that each object's bitmap represents its complete set of reachable objects. Therefore we have no way to represent the bitmap of an object which references objects outside the pack. We notice this problem while generating the bitmaps, as we try to find the offset of a particular object and realize that we do not have it. In this case we die, and neither the bitmap nor the pack is generated. This is correct, but perhaps a little unfriendly. If you have bitmaps turned on in the config, many repacks will fail which would otherwise succeed. E.g., incremental repacks, repacks with "-l" when you have alternates, ".keep" files. Instead, this patch notices early that we are omitting some objects from the pack and turns off bitmaps (with a warning). Note that this is not strictly correct, as it's possible that the object being omitted is not reachable from any other object in the pack. In practice, this is almost never the case, and there are two advantages to doing it this way: 1. The code is much simpler, as we do not have to cleanly abort the bitmap-generation process midway through. 2. We do not waste time partially generating bitmaps only to find out that some object deep in the history is not being packed. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- builtin/pack-objects.c | 12 +++++++++++- t/t5310-pack-bitmaps.sh | 5 ++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index fd741970e6..50d794f5d9 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -1000,6 +1000,10 @@ static void create_object_entry(const unsigned char *sha1, entry->no_try_delta = no_try_delta; } +static const char no_closure_warning[] = N_( +"disabling bitmap writing, as some objects are not being packed" +); + static int add_object_entry(const unsigned char *sha1, enum object_type type, const char *name, int exclude) { @@ -1010,8 +1014,14 @@ static int add_object_entry(const unsigned char *sha1, enum object_type type, if (have_duplicate_entry(sha1, exclude, &index_pos)) return 0; - if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) + if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) { + /* The pack is missing an object, so it will not have closure */ + if (write_bitmap_index) { + warning(_(no_closure_warning)); + write_bitmap_index = 0; + } return 0; + } create_object_entry(sha1, type, pack_name_hash(name), exclude, name && no_try_delta(name), diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh index d3a3afaba8..f13525caa3 100755 --- a/t/t5310-pack-bitmaps.sh +++ b/t/t5310-pack-bitmaps.sh @@ -91,7 +91,10 @@ test_expect_success 'fetch (partial bitmap)' ' test_expect_success 'incremental repack cannot create bitmaps' ' test_commit more-1 && - test_must_fail git repack -d + find .git/objects/pack -name "*.bitmap" >expect && + git repack -d && + find .git/objects/pack -name "*.bitmap" >actual && + test_cmp expect actual ' test_expect_success 'incremental repack can disable bitmaps' ' -- 2.11.4.GIT