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author | Jeff King <peff@peff.net> | 2014-08-12 00:34:53 -0400 |
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committer | Junio C Hamano <gitster@pobox.com> | 2014-08-12 12:17:19 -0700 |
commit | f7f91086a376ba53f8270ea80b7bbbd8274c3c2d (patch) | |
tree | 37490af7d286faf5b7e5c1d7c0f8e3f05f24e456 | |
parent | 967f8c918465312cc6cc1bcbcfacafcf95152bd8 (diff) | |
download | git-f7f91086a376ba53f8270ea80b7bbbd8274c3c2d.tar.gz |
pack-objects: turn off bitmaps when we see --shallow linesjk/pack-shallow-always-without-bitmap
Reachability bitmaps do not work with shallow operations,
because they cache a view of the object reachability that
represents the true objects. Whereas a shallow repository
(or a shallow operation in a repository) is inherently
cutting off the object graph with a graft.
We explicitly disallow the use of bitmaps in shallow
repositories by checking is_repository_shallow(), and we
should continue to do that. However, we also want to
disallow bitmaps when we are serving a fetch to a shallow
client, since we momentarily take on their grafted view of
the world.
It used to be enough to call is_repository_shallow at the
start of pack-objects. Upload-pack wrote the other side's
shallow state to a temporary file and pointed the whole
pack-objects process at this state with "git --shallow-file",
and from the perspective of pack-objects, we really were
in a shallow repo. But since b790e0f (upload-pack: send
shallow info over stdin to pack-objects, 2014-03-11), we do
it differently: we send --shallow lines to pack-objects over
stdin, and it registers them itself.
This means that our is_repository_shallow check is way too
early (we have not been told about the shallowness yet), and
that it is insufficient (calling is_repository_shallow is
not enough, as the shallow grafts we register do not change
its return value). Instead, we can just turn off bitmaps
explicitly when we see these lines.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r-- | builtin/pack-objects.c | 1 | ||||
-rwxr-xr-x | t/t5311-pack-bitmaps-shallow.sh | 39 |
2 files changed, 40 insertions, 0 deletions
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index de36c60ca1..2c60ddf4a8 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -2498,6 +2498,7 @@ static void get_object_list(int ac, const char **av) if (get_sha1_hex(line + 10, sha1)) die("not an SHA-1 '%s'", line + 10); register_shallow(sha1); + use_bitmap_index = 0; continue; } die("not a rev '%s'", line); diff --git a/t/t5311-pack-bitmaps-shallow.sh b/t/t5311-pack-bitmaps-shallow.sh new file mode 100755 index 0000000000..872a95df33 --- /dev/null +++ b/t/t5311-pack-bitmaps-shallow.sh @@ -0,0 +1,39 @@ +#!/bin/sh + +test_description='check bitmap operation with shallow repositories' +. ./test-lib.sh + +# We want to create a situation where the shallow, grafted +# view of reachability does not match reality in a way that +# might cause us to send insufficient objects. +# +# We do this with a history that repeats a state, like: +# +# A -- B -- C +# file=1 file=2 file=1 +# +# and then create a shallow clone to the second commit, B. +# In a non-shallow clone, that would mean we already have +# the tree for A. But in a shallow one, we've grafted away +# A, and fetching A to B requires that the other side send +# us the tree for file=1. +test_expect_success 'setup shallow repo' ' + echo 1 >file && + git add file && + git commit -m orig && + echo 2 >file && + git commit -a -m update && + git clone --no-local --bare --depth=1 . shallow.git && + echo 1 >file && + git commit -a -m repeat +' + +test_expect_success 'turn on bitmaps in the parent' ' + git repack -adb +' + +test_expect_success 'shallow fetch from bitmapped repo' ' + (cd shallow.git && git fetch) +' + +test_done |