t/t5310-pack-bitmaps.sh - jrn/git - Git at Google

 #!/bin/sh

 test_description='exercise basic bitmap functionality'

 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-bitmap.sh

 # t5310 deals only with single-pack bitmaps, so don't write MIDX bitmaps in
 # their place.
 GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0

 # Likewise, allow individual tests to control whether or not they use
 # the boundary-based traversal.
 sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

 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_bitmap_cases () {
 	writeLookupTable=false
 	for i in "$@"
 	do
 		case "$i" in
 		"pack.writeBitmapLookupTable") writeLookupTable=true;;
 		esac
 	done

 	test_expect_success 'setup test repository' '
 		rm -fr * .git &&
 		git init &&
 		git config pack.writeBitmapLookupTable '"$writeLookupTable"'
 	'
 	setup_bitmap_history

 	test_expect_success 'setup writing bitmaps during repack' '
 		git config repack.writeBitmaps true
 	'

 	test_expect_success 'full repack creates bitmaps' '
 		GIT_TRACE2_EVENT="$(pwd)/trace" \
 			git repack -ad &&
 		ls .git/objects/pack/ | grep bitmap >output &&
 		test_line_count = 1 output &&
 		grep "\"key\":\"num_selected_commits\",\"value\":\"106\"" trace &&
 		grep "\"key\":\"num_maximal_commits\",\"value\":\"107\"" trace
 	'

 	basic_bitmap_tests

 	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 second:second &&
 		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,SHA1 '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,SHA1 'jgit can read our bitmaps' '
 		git clone --bare . compat-us.git &&
 		(
 			cd compat-us.git &&
 			git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
 			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 || return 1
 		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 (ewah)' '
 		test_config pack.writebitmaphashcache false &&
 		test_config pack.writebitmaplookuptable false &&
 		git repack -ad &&
 		git rev-list --use-bitmap-index --count --all >expect &&
 		bitmap=$(ls .git/objects/pack/*.bitmap) &&
 		test_when_finished "rm -f $bitmap" &&
 		test_copy_bytes 256 <$bitmap >$bitmap.tmp &&
 		mv -f $bitmap.tmp $bitmap &&
 		git rev-list --use-bitmap-index --count --all >actual 2>stderr &&
 		test_cmp expect actual &&
 		test_grep corrupt.ewah.bitmap stderr
 	'

 	test_expect_success 'truncated bitmap fails gracefully (cache)' '
 		git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
 		git repack -ad &&
 		git rev-list --use-bitmap-index --count --all >expect &&
 		bitmap=$(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_grep corrupted.bitmap.index stderr
 	'

 	# 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_expect_success 'pack.preferBitmapTips' '
 		git init repo &&
 		test_when_finished "rm -fr repo" &&
 		(
 			cd repo &&
 			git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&

 			# create enough commits that not all are receive bitmap
 			# coverage even if they are all at the tip of some reference.
 			test_commit_bulk --message="%s" 103 &&

 			git rev-list HEAD >commits.raw &&
 			sort <commits.raw >commits &&

 			git log --format="create refs/tags/%s %H" HEAD >refs &&
 			git update-ref --stdin <refs &&

 			git repack -adb &&
 			test-tool bitmap list-commits | sort >bitmaps &&

 			# remember which commits did not receive bitmaps
 			comm -13 bitmaps commits >before &&
 			test_file_not_empty before &&

 			# mark the commits which did not receive bitmaps as preferred,
 			# and generate the bitmap again
 			perl -pe "s{^}{create refs/tags/include/$. }" <before |
 				git update-ref --stdin &&
 			git -c pack.preferBitmapTips=refs/tags/include repack -adb &&

 			# finally, check that the commit(s) without bitmap coverage
 			# are not the same ones as before
 			test-tool bitmap list-commits | sort >bitmaps &&
 			comm -13 bitmaps commits >after &&

 			! test_cmp before after
 		)
 	'

 	test_expect_success 'pack.preferBitmapTips' '
 		git init repo &&
 		test_when_finished "rm -rf repo" &&
 		(
 			cd repo &&
 			git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
 			test_commit_bulk --message="%s" 103 &&

 			cat >>.git/config <<-\EOF &&
 			[pack]
 				preferBitmapTips
 			EOF
 			cat >expect <<-\EOF &&
 			error: missing value for '\''pack.preferbitmaptips'\''
 			EOF
 			git repack -adb 2>actual &&
 			test_cmp expect actual
 		)
 	'

 	test_expect_success 'complains about multiple pack bitmaps' '
 		rm -fr repo &&
 		git init repo &&
 		test_when_finished "rm -fr repo" &&
 		(
 			cd repo &&
 			git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&

 			test_commit base &&

 			git repack -adb &&
 			bitmap="$(ls .git/objects/pack/pack-*.bitmap)" &&
 			mv "$bitmap" "$bitmap.bak" &&

 			test_commit other &&
 			git repack -ab &&

 			mv "$bitmap.bak" "$bitmap" &&

 			find .git/objects/pack -type f -name "*.pack" >packs &&
 			find .git/objects/pack -type f -name "*.bitmap" >bitmaps &&
 			test_line_count = 2 packs &&
 			test_line_count = 2 bitmaps &&

 			GIT_TRACE2_EVENT=$(pwd)/trace2.txt git rev-list --use-bitmap-index HEAD &&
 			grep "opened bitmap" trace2.txt &&
 			grep "ignoring extra bitmap" trace2.txt
 		)
 	'
 }

 test_bitmap_cases

 GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=1
 export GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

 test_bitmap_cases

 sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

 test_expect_success 'incremental repack fails when bitmaps are requested' '
 	test_commit more-1 &&
 	test_must_fail git repack -d 2>err &&
 	test_grep "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 'boundary-based traversal is used when requested' '
 	git repack -a -d --write-bitmap-index &&

 	for argv in \
 		"git -c pack.useBitmapBoundaryTraversal=true" \
 		"git -c feature.experimental=true" \
 		"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=1 git"
 	do
 		eval "GIT_TRACE2_EVENT=1 $argv rev-list --objects \
 			--use-bitmap-index second..other 2>perf" &&
 		grep "\"region_enter\".*\"label\":\"haves/boundary\"" perf ||
 			return 1
 	done &&

 	for argv in \
 		"git -c pack.useBitmapBoundaryTraversal=false" \
 		"git -c feature.experimental=true -c pack.useBitmapBoundaryTraversal=false" \
 		"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=0 git -c pack.useBitmapBoundaryTraversal=true" \
 		"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=0 git -c feature.experimental=true"
 	do
 		eval "GIT_TRACE2_EVENT=1 $argv rev-list --objects \
 			--use-bitmap-index second..other 2>perf" &&
 		grep "\"region_enter\".*\"label\":\"haves/classic\"" perf ||
 			return 1
 	done
 '

 test_bitmap_cases "pack.writeBitmapLookupTable"

 test_expect_success 'verify writing bitmap lookup table when enabled' '
 	GIT_TRACE2_EVENT="$(pwd)/trace2" \
 		git repack -ad &&
 	grep "\"label\":\"writing_lookup_table\"" trace2
 '

 test_expect_success 'truncated bitmap fails gracefully (lookup table)' '
 	test_config pack.writebitmaphashcache false &&
 	git repack -adb &&
 	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_grep corrupted.bitmap.index stderr
 '

 test_done
	#!/bin/sh

	test_description='exercise basic bitmap functionality'

	. ./test-lib.sh
	. "$TEST_DIRECTORY"/lib-bitmap.sh

	# t5310 deals only with single-pack bitmaps, so don't write MIDX bitmaps in
	# their place.
	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0

	# Likewise, allow individual tests to control whether or not they use
	# the boundary-based traversal.
	sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

	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_bitmap_cases () {
	writeLookupTable=false
	for i in "$@"
	do
	case "$i" in
	"pack.writeBitmapLookupTable") writeLookupTable=true;;
	esac
	done

	test_expect_success 'setup test repository' '
	rm -fr * .git &&
	git init &&
	git config pack.writeBitmapLookupTable '"$writeLookupTable"'
	'
	setup_bitmap_history

	test_expect_success 'setup writing bitmaps during repack' '
	git config repack.writeBitmaps true
	'

	test_expect_success 'full repack creates bitmaps' '
	GIT_TRACE2_EVENT="$(pwd)/trace" \
	git repack -ad &&
	ls .git/objects/pack/ \| grep bitmap >output &&
	test_line_count = 1 output &&
	grep "\"key\":\"num_selected_commits\",\"value\":\"106\"" trace &&
	grep "\"key\":\"num_maximal_commits\",\"value\":\"107\"" trace
	'

	basic_bitmap_tests

	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 second:second &&
	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,SHA1 '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,SHA1 'jgit can read our bitmaps' '
	git clone --bare . compat-us.git &&
	(
	cd compat-us.git &&
	git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
	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 \|\| return 1
	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 (ewah)' '
	test_config pack.writebitmaphashcache false &&
	test_config pack.writebitmaplookuptable false &&
	git repack -ad &&
	git rev-list --use-bitmap-index --count --all >expect &&
	bitmap=$(ls .git/objects/pack/*.bitmap) &&
	test_when_finished "rm -f $bitmap" &&
	test_copy_bytes 256 <$bitmap >$bitmap.tmp &&
	mv -f $bitmap.tmp $bitmap &&
	git rev-list --use-bitmap-index --count --all >actual 2>stderr &&
	test_cmp expect actual &&
	test_grep corrupt.ewah.bitmap stderr
	'

	test_expect_success 'truncated bitmap fails gracefully (cache)' '
	git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
	git repack -ad &&
	git rev-list --use-bitmap-index --count --all >expect &&
	bitmap=$(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_grep corrupted.bitmap.index stderr
	'

	# 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_expect_success 'pack.preferBitmapTips' '
	git init repo &&
	test_when_finished "rm -fr repo" &&
	(
	cd repo &&
	git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&

	# create enough commits that not all are receive bitmap
	# coverage even if they are all at the tip of some reference.
	test_commit_bulk --message="%s" 103 &&

	git rev-list HEAD >commits.raw &&
	sort <commits.raw >commits &&

	git log --format="create refs/tags/%s %H" HEAD >refs &&
	git update-ref --stdin <refs &&

	git repack -adb &&
	test-tool bitmap list-commits \| sort >bitmaps &&

	# remember which commits did not receive bitmaps
	comm -13 bitmaps commits >before &&
	test_file_not_empty before &&

	# mark the commits which did not receive bitmaps as preferred,
	# and generate the bitmap again
	perl -pe "s{^}{create refs/tags/include/$. }" <before \|
	git update-ref --stdin &&
	git -c pack.preferBitmapTips=refs/tags/include repack -adb &&

	# finally, check that the commit(s) without bitmap coverage
	# are not the same ones as before
	test-tool bitmap list-commits \| sort >bitmaps &&
	comm -13 bitmaps commits >after &&

	! test_cmp before after
	)
	'

	test_expect_success 'pack.preferBitmapTips' '
	git init repo &&
	test_when_finished "rm -rf repo" &&
	(
	cd repo &&
	git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
	test_commit_bulk --message="%s" 103 &&

	cat >>.git/config <<-\EOF &&
	[pack]
	preferBitmapTips
	EOF
	cat >expect <<-\EOF &&
	error: missing value for '\''pack.preferbitmaptips'\''
	EOF
	git repack -adb 2>actual &&
	test_cmp expect actual
	)
	'

	test_expect_success 'complains about multiple pack bitmaps' '
	rm -fr repo &&
	git init repo &&
	test_when_finished "rm -fr repo" &&
	(
	cd repo &&
	git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&

	test_commit base &&

	git repack -adb &&
	bitmap="$(ls .git/objects/pack/pack-*.bitmap)" &&
	mv "$bitmap" "$bitmap.bak" &&

	test_commit other &&
	git repack -ab &&

	mv "$bitmap.bak" "$bitmap" &&

	find .git/objects/pack -type f -name "*.pack" >packs &&
	find .git/objects/pack -type f -name "*.bitmap" >bitmaps &&
	test_line_count = 2 packs &&
	test_line_count = 2 bitmaps &&

	GIT_TRACE2_EVENT=$(pwd)/trace2.txt git rev-list --use-bitmap-index HEAD &&
	grep "opened bitmap" trace2.txt &&
	grep "ignoring extra bitmap" trace2.txt
	)
	'
	}

	test_bitmap_cases

	GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=1
	export GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

	test_bitmap_cases

	sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL

	test_expect_success 'incremental repack fails when bitmaps are requested' '
	test_commit more-1 &&
	test_must_fail git repack -d 2>err &&
	test_grep "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 'boundary-based traversal is used when requested' '
	git repack -a -d --write-bitmap-index &&

	for argv in \
	"git -c pack.useBitmapBoundaryTraversal=true" \
	"git -c feature.experimental=true" \
	"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=1 git"
	do
	eval "GIT_TRACE2_EVENT=1 $argv rev-list --objects \
	--use-bitmap-index second..other 2>perf" &&
	grep "\"region_enter\".*\"label\":\"haves/boundary\"" perf \|\|
	return 1
	done &&

	for argv in \
	"git -c pack.useBitmapBoundaryTraversal=false" \
	"git -c feature.experimental=true -c pack.useBitmapBoundaryTraversal=false" \
	"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=0 git -c pack.useBitmapBoundaryTraversal=true" \
	"GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=0 git -c feature.experimental=true"
	do
	eval "GIT_TRACE2_EVENT=1 $argv rev-list --objects \
	--use-bitmap-index second..other 2>perf" &&
	grep "\"region_enter\".*\"label\":\"haves/classic\"" perf \|\|
	return 1
	done
	'

	test_bitmap_cases "pack.writeBitmapLookupTable"

	test_expect_success 'verify writing bitmap lookup table when enabled' '
	GIT_TRACE2_EVENT="$(pwd)/trace2" \
	git repack -ad &&
	grep "\"label\":\"writing_lookup_table\"" trace2
	'

	test_expect_success 'truncated bitmap fails gracefully (lookup table)' '
	test_config pack.writebitmaphashcache false &&
	git repack -adb &&
	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_grep corrupted.bitmap.index stderr
	'

	test_done