sha1-file: split OBJECT_INFO_FOR_PREFETCH

[thirdparty/git.git] / t / t5310-pack-bitmaps.sh

diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh
index 7bff7923f2a91165b5a0b5251351798519d63270..82d7f7f6a5bbdc5609e0b76c97a3ae14f6a53a92 100755 (executable)
--- a/t/t5310-pack-bitmaps.sh
+++ b/t/t5310-pack-bitmaps.sh
@@ -191,6 +191,7 @@ test_expect_success 'pack-objects respects --honor-pack-keep (local bitmapped pa
 
 test_expect_success 'pack-objects respects --local (non-local bitmapped pack)' '
        mv .git/objects/pack/$packbitmap.* alt.git/objects/pack/ &&
+       rm -f .git/objects/pack/multi-pack-index &&
        test_when_finished "mv alt.git/objects/pack/$packbitmap.* .git/objects/pack/" &&
        echo HEAD | git pack-objects --local --stdout --revs >3b.pack &&
        git index-pack 3b.pack &&
@@ -342,4 +343,97 @@ test_expect_success 'truncated bitmap fails gracefully' '
        test_i18ngrep corrupt stderr
 '
 
+# have_delta <obj> <expected_base>
+#
+# Note that because this relies on cat-file, it might find _any_ copy of an
+# object in the repository. The caller is responsible for making sure
+# there's only one (e.g., via "repack -ad", or having just fetched a copy).
+have_delta () {
+       echo $2 >expect &&
+       echo $1 | git cat-file --batch-check="%(deltabase)" >actual &&
+       test_cmp expect actual
+}
+
+# Create a state of history with these properties:
+#
+#  - refs that allow a client to fetch some new history, while sharing some old
+#    history with the server; we use branches delta-reuse-old and
+#    delta-reuse-new here
+#
+#  - the new history contains an object that is stored on the server as a delta
+#    against a base that is in the old history
+#
+#  - the base object is not immediately reachable from the tip of the old
+#    history; finding it would involve digging down through history we know the
+#    other side has
+#
+# This should result in a state where fetching from old->new would not
+# traditionally reuse the on-disk delta (because we'd have to dig to realize
+# that the client has it), but we will do so if bitmaps can tell us cheaply
+# that the other side has it.
+test_expect_success 'set up thin delta-reuse parent' '
+       # This first commit contains the buried base object.
+       test-tool genrandom delta 16384 >file &&
+       git add file &&
+       git commit -m "delta base" &&
+       base=$(git rev-parse --verify HEAD:file) &&
+
+       # These intermediate commits bury the base back in history.
+       # This becomes the "old" state.
+       for i in 1 2 3 4 5
+       do
+               echo $i >file &&
+               git commit -am "intermediate $i" || return 1
+       done &&
+       git branch delta-reuse-old &&
+
+       # And now our new history has a delta against the buried base. Note
+       # that this must be smaller than the original file, since pack-objects
+       # prefers to create deltas from smaller objects to larger.
+       test-tool genrandom delta 16300 >file &&
+       git commit -am "delta result" &&
+       delta=$(git rev-parse --verify HEAD:file) &&
+       git branch delta-reuse-new &&
+
+       # Repack with bitmaps and double check that we have the expected delta
+       # relationship.
+       git repack -adb &&
+       have_delta $delta $base
+'
+
+# Now we can sanity-check the non-bitmap behavior (that the server is not able
+# to reuse the delta). This isn't strictly something we care about, so this
+# test could be scrapped in the future. But it makes sure that the next test is
+# actually triggering the feature we want.
+#
+# Note that our tools for working with on-the-wire "thin" packs are limited. So
+# we actually perform the fetch, retain the resulting pack, and inspect the
+# result.
+test_expect_success 'fetch without bitmaps ignores delta against old base' '
+       test_config pack.usebitmaps false &&
+       test_when_finished "rm -rf client.git" &&
+       git init --bare client.git &&
+       (
+               cd client.git &&
+               git config transfer.unpackLimit 1 &&
+               git fetch .. delta-reuse-old:delta-reuse-old &&
+               git fetch .. delta-reuse-new:delta-reuse-new &&
+               have_delta $delta $ZERO_OID
+       )
+'
+
+# And do the same for the bitmap case, where we do expect to find the delta.
+test_expect_success 'fetch with bitmaps can reuse old base' '
+       test_config pack.usebitmaps true &&
+       test_when_finished "rm -rf client.git" &&
+       git init --bare client.git &&
+       (
+               cd client.git &&
+               git config transfer.unpackLimit 1 &&
+               git fetch .. delta-reuse-old:delta-reuse-old &&
+               git fetch .. delta-reuse-new:delta-reuse-new &&
+               have_delta $delta $base
+       )
+'
+
 test_done