1 files changed, 451 insertions, 0 deletions
diff --git a/third_party/git/t/t5310-pack-bitmaps.sh b/third_party/git/t/t5310-pack-bitmaps.sh
new file mode 100755
index 000000000000..8318781d2bbf
--- /dev/null
+++ b/third_party/git/t/t5310-pack-bitmaps.sh
@@ -0,0 +1,451 @@
+#!/bin/sh
+
+test_description='exercise basic bitmap functionality'
+. ./test-lib.sh
+
+objpath () {
+	echo ".git/objects/$(echo "$1" | sed -e 's|\(..\)|\1/|')"
+}
+
+# show objects present in pack ($1 should be associated *.idx)
+list_packed_objects () {
+	git show-index <"$1" >object-list &&
+	cut -d' ' -f2 object-list
+}
+
+# has_any pattern-file content-file
+# tests whether content-file has any entry from pattern-file with entries being
+# whole lines.
+has_any () {
+	grep -Ff "$1" "$2"
+}
+
+test_expect_success 'setup repo with moderate-sized history' '
+	test_commit_bulk --id=file 100 &&
+	git checkout -b other HEAD~5 &&
+	test_commit_bulk --id=side 10 &&
+	git checkout master &&
+	bitmaptip=$(git rev-parse master) &&
+	blob=$(echo tagged-blob | git hash-object -w --stdin) &&
+	git tag tagged-blob $blob &&
+	git config repack.writebitmaps true
+'
+
+test_expect_success 'full repack creates bitmaps' '
+	git repack -ad &&
+	ls .git/objects/pack/ | grep bitmap >output &&
+	test_line_count = 1 output
+'
+
+test_expect_success 'rev-list --test-bitmap verifies bitmaps' '
+	git rev-list --test-bitmap HEAD
+'
+
+rev_list_tests() {
+	state=$1
+
+	test_expect_success "counting commits via bitmap ($state)" '
+		git rev-list --count HEAD >expect &&
+		git rev-list --use-bitmap-index --count HEAD >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "counting partial commits via bitmap ($state)" '
+		git rev-list --count HEAD~5..HEAD >expect &&
+		git rev-list --use-bitmap-index --count HEAD~5..HEAD >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "counting commits with limit ($state)" '
+		git rev-list --count -n 1 HEAD >expect &&
+		git rev-list --use-bitmap-index --count -n 1 HEAD >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "counting non-linear history ($state)" '
+		git rev-list --count other...master >expect &&
+		git rev-list --use-bitmap-index --count other...master >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "counting commits with limiting ($state)" '
+		git rev-list --count HEAD -- 1.t >expect &&
+		git rev-list --use-bitmap-index --count HEAD -- 1.t >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "counting objects via bitmap ($state)" '
+		git rev-list --count --objects HEAD >expect &&
+		git rev-list --use-bitmap-index --count --objects HEAD >actual &&
+		test_cmp expect actual
+	'
+
+	test_expect_success "enumerate commits ($state)" '
+		git rev-list --use-bitmap-index HEAD >actual &&
+		git rev-list HEAD >expect &&
+		test_bitmap_traversal --no-confirm-bitmaps expect actual
+	'
+
+	test_expect_success "enumerate --objects ($state)" '
+		git rev-list --objects --use-bitmap-index HEAD >actual &&
+		git rev-list --objects HEAD >expect &&
+		test_bitmap_traversal expect actual
+	'
+
+	test_expect_success "bitmap --objects handles non-commit objects ($state)" '
+		git rev-list --objects --use-bitmap-index HEAD tagged-blob >actual &&
+		grep $blob actual
+	'
+}
+
+rev_list_tests 'full bitmap'
+
+test_expect_success 'clone from bitmapped repository' '
+	git clone --no-local --bare . clone.git &&
+	git rev-parse HEAD >expect &&
+	git --git-dir=clone.git rev-parse HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'partial clone from bitmapped repository' '
+	test_config uploadpack.allowfilter true &&
+	git clone --no-local --bare --filter=blob:none . partial-clone.git &&
+	(
+		cd partial-clone.git &&
+		pack=$(echo objects/pack/*.pack) &&
+		git verify-pack -v "$pack" >have &&
+		awk "/blob/ { print \$1 }" <have >blobs &&
+		# we expect this single blob because of the direct ref
+		git rev-parse refs/tags/tagged-blob >expect &&
+		test_cmp expect blobs
+	)
+'
+
+test_expect_success 'setup further non-bitmapped commits' '
+	test_commit_bulk --id=further 10
+'
+
+rev_list_tests 'partial bitmap'
+
+test_expect_success 'fetch (partial bitmap)' '
+	git --git-dir=clone.git fetch origin master:master &&
+	git rev-parse HEAD >expect &&
+	git --git-dir=clone.git rev-parse HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'incremental repack fails when bitmaps are requested' '
+	test_commit more-1 &&
+	test_must_fail git repack -d 2>err &&
+	test_i18ngrep "Incremental repacks are incompatible with bitmap" err
+'
+
+test_expect_success 'incremental repack can disable bitmaps' '
+	test_commit more-2 &&
+	git repack -d --no-write-bitmap-index
+'
+
+test_expect_success 'pack-objects respects --local (non-local loose)' '
+	git init --bare alt.git &&
+	echo $(pwd)/alt.git/objects >.git/objects/info/alternates &&
+	echo content1 >file1 &&
+	# non-local loose object which is not present in bitmapped pack
+	altblob=$(GIT_DIR=alt.git git hash-object -w file1) &&
+	# non-local loose object which is also present in bitmapped pack
+	git cat-file blob $blob | GIT_DIR=alt.git git hash-object -w --stdin &&
+	git add file1 &&
+	test_tick &&
+	git commit -m commit_file1 &&
+	echo HEAD | git pack-objects --local --stdout --revs >1.pack &&
+	git index-pack 1.pack &&
+	list_packed_objects 1.idx >1.objects &&
+	printf "%s\n" "$altblob" "$blob" >nonlocal-loose &&
+	! has_any nonlocal-loose 1.objects
+'
+
+test_expect_success 'pack-objects respects --honor-pack-keep (local non-bitmapped pack)' '
+	echo content2 >file2 &&
+	blob2=$(git hash-object -w file2) &&
+	git add file2 &&
+	test_tick &&
+	git commit -m commit_file2 &&
+	printf "%s\n" "$blob2" "$bitmaptip" >keepobjects &&
+	pack2=$(git pack-objects pack2 <keepobjects) &&
+	mv pack2-$pack2.* .git/objects/pack/ &&
+	>.git/objects/pack/pack2-$pack2.keep &&
+	rm $(objpath $blob2) &&
+	echo HEAD | git pack-objects --honor-pack-keep --stdout --revs >2a.pack &&
+	git index-pack 2a.pack &&
+	list_packed_objects 2a.idx >2a.objects &&
+	! has_any keepobjects 2a.objects
+'
+
+test_expect_success 'pack-objects respects --local (non-local pack)' '
+	mv .git/objects/pack/pack2-$pack2.* alt.git/objects/pack/ &&
+	echo HEAD | git pack-objects --local --stdout --revs >2b.pack &&
+	git index-pack 2b.pack &&
+	list_packed_objects 2b.idx >2b.objects &&
+	! has_any keepobjects 2b.objects
+'
+
+test_expect_success 'pack-objects respects --honor-pack-keep (local bitmapped pack)' '
+	ls .git/objects/pack/ | grep bitmap >output &&
+	test_line_count = 1 output &&
+	packbitmap=$(basename $(cat output) .bitmap) &&
+	list_packed_objects .git/objects/pack/$packbitmap.idx >packbitmap.objects &&
+	test_when_finished "rm -f .git/objects/pack/$packbitmap.keep" &&
+	>.git/objects/pack/$packbitmap.keep &&
+	echo HEAD | git pack-objects --honor-pack-keep --stdout --revs >3a.pack &&
+	git index-pack 3a.pack &&
+	list_packed_objects 3a.idx >3a.objects &&
+	! has_any packbitmap.objects 3a.objects
+'
+
+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 &&
+	list_packed_objects 3b.idx >3b.objects &&
+	! has_any packbitmap.objects 3b.objects
+'
+
+test_expect_success 'pack-objects to file can use bitmap' '
+	# make sure we still have 1 bitmap index from previous tests
+	ls .git/objects/pack/ | grep bitmap >output &&
+	test_line_count = 1 output &&
+	# verify equivalent packs are generated with/without using bitmap index
+	packasha1=$(git pack-objects --no-use-bitmap-index --all packa </dev/null) &&
+	packbsha1=$(git pack-objects --use-bitmap-index --all packb </dev/null) &&
+	list_packed_objects packa-$packasha1.idx >packa.objects &&
+	list_packed_objects packb-$packbsha1.idx >packb.objects &&
+	test_cmp packa.objects packb.objects
+'
+
+test_expect_success 'full repack, reusing previous bitmaps' '
+	git repack -ad &&
+	ls .git/objects/pack/ | grep bitmap >output &&
+	test_line_count = 1 output
+'
+
+test_expect_success 'fetch (full bitmap)' '
+	git --git-dir=clone.git fetch origin master:master &&
+	git rev-parse HEAD >expect &&
+	git --git-dir=clone.git rev-parse HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create objects for missing-HAVE tests' '
+	blob=$(echo "missing have" | git hash-object -w --stdin) &&
+	tree=$(printf "100644 blob $blob\tfile\n" | git mktree) &&
+	parent=$(echo parent | git commit-tree $tree) &&
+	commit=$(echo commit | git commit-tree $tree -p $parent) &&
+	cat >revs <<-EOF
+	HEAD
+	^HEAD^
+	^$commit
+	EOF
+'
+
+test_expect_success 'pack-objects respects --incremental' '
+	cat >revs2 <<-EOF &&
+	HEAD
+	$commit
+	EOF
+	git pack-objects --incremental --stdout --revs <revs2 >4.pack &&
+	git index-pack 4.pack &&
+	list_packed_objects 4.idx >4.objects &&
+	test_line_count = 4 4.objects &&
+	git rev-list --objects $commit >revlist &&
+	cut -d" " -f1 revlist |sort >objects &&
+	test_cmp 4.objects objects
+'
+
+test_expect_success 'pack with missing blob' '
+	rm $(objpath $blob) &&
+	git pack-objects --stdout --revs <revs >/dev/null
+'
+
+test_expect_success 'pack with missing tree' '
+	rm $(objpath $tree) &&
+	git pack-objects --stdout --revs <revs >/dev/null
+'
+
+test_expect_success 'pack with missing parent' '
+	rm $(objpath $parent) &&
+	git pack-objects --stdout --revs <revs >/dev/null
+'
+
+test_expect_success JGIT 'we can read jgit bitmaps' '
+	git clone --bare . compat-jgit.git &&
+	(
+		cd compat-jgit.git &&
+		rm -f objects/pack/*.bitmap &&
+		jgit gc &&
+		git rev-list --test-bitmap HEAD
+	)
+'
+
+test_expect_success JGIT 'jgit can read our bitmaps' '
+	git clone --bare . compat-us.git &&
+	(
+		cd compat-us.git &&
+		git repack -adb &&
+		# jgit gc will barf if it does not like our bitmaps
+		jgit gc
+	)
+'
+
+test_expect_success 'splitting packs does not generate bogus bitmaps' '
+	test-tool genrandom foo $((1024 * 1024)) >rand &&
+	git add rand &&
+	git commit -m "commit with big file" &&
+	git -c pack.packSizeLimit=500k repack -adb &&
+	git init --bare no-bitmaps.git &&
+	git -C no-bitmaps.git fetch .. HEAD
+'
+
+test_expect_success 'set up reusable pack' '
+	rm -f .git/objects/pack/*.keep &&
+	git repack -adb &&
+	reusable_pack () {
+		git for-each-ref --format="%(objectname)" |
+		git pack-objects --delta-base-offset --revs --stdout "$@"
+	}
+'
+
+test_expect_success 'pack reuse respects --honor-pack-keep' '
+	test_when_finished "rm -f .git/objects/pack/*.keep" &&
+	for i in .git/objects/pack/*.pack
+	do
+		>${i%.pack}.keep
+	done &&
+	reusable_pack --honor-pack-keep >empty.pack &&
+	git index-pack empty.pack &&
+	git show-index <empty.idx >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'pack reuse respects --local' '
+	mv .git/objects/pack/* alt.git/objects/pack/ &&
+	test_when_finished "mv alt.git/objects/pack/* .git/objects/pack/" &&
+	reusable_pack --local >empty.pack &&
+	git index-pack empty.pack &&
+	git show-index <empty.idx >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'pack reuse respects --incremental' '
+	reusable_pack --incremental >empty.pack &&
+	git index-pack empty.pack &&
+	git show-index <empty.idx >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'truncated bitmap fails gracefully' '
+	git repack -ad &&
+	git rev-list --use-bitmap-index --count --all >expect &&
+	bitmap=$(ls .git/objects/pack/*.bitmap) &&
+	test_when_finished "rm -f $bitmap" &&
+	test_copy_bytes 512 <$bitmap >$bitmap.tmp &&
+	mv -f $bitmap.tmp $bitmap &&
+	git rev-list --use-bitmap-index --count --all >actual 2>stderr &&
+	test_cmp expect actual &&
+	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