1 files changed, 203 insertions, 0 deletions
diff --git a/t/t5332-multi-pack-reuse.sh b/t/t5332-multi-pack-reuse.sh
new file mode 100755
index 0000000000..2ba788b042
--- /dev/null
+++ b/t/t5332-multi-pack-reuse.sh
@@ -0,0 +1,203 @@
+#!/bin/sh
+
+test_description='pack-objects multi-pack reuse'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-bitmap.sh
+
+objdir=.git/objects
+packdir=$objdir/pack
+
+test_pack_reused () {
+	test_trace2_data pack-objects pack-reused "$1"
+}
+
+test_packs_reused () {
+	test_trace2_data pack-objects packs-reused "$1"
+}
+
+
+# pack_position <object> </path/to/pack.idx
+pack_position () {
+	git show-index >objects &&
+	grep "$1" objects | cut -d" " -f1
+}
+
+test_expect_success 'preferred pack is reused for single-pack reuse' '
+	test_config pack.allowPackReuse single &&
+
+	for i in A B
+	do
+		test_commit "$i" &&
+		git repack -d || return 1
+	done &&
+
+	git multi-pack-index write --bitmap &&
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --revs --all >/dev/null &&
+
+	test_pack_reused 3 <trace2.txt &&
+	test_packs_reused 1 <trace2.txt
+'
+
+test_expect_success 'enable multi-pack reuse' '
+	git config pack.allowPackReuse multi
+'
+
+test_expect_success 'reuse all objects from subset of bitmapped packs' '
+	test_commit C &&
+	git repack -d &&
+
+	git multi-pack-index write --bitmap &&
+
+	cat >in <<-EOF &&
+	$(git rev-parse C)
+	^$(git rev-parse A)
+	EOF
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --revs <in >/dev/null &&
+
+	test_pack_reused 6 <trace2.txt &&
+	test_packs_reused 2 <trace2.txt
+'
+
+test_expect_success 'reuse all objects from all packs' '
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --revs --all >/dev/null &&
+
+	test_pack_reused 9 <trace2.txt &&
+	test_packs_reused 3 <trace2.txt
+'
+
+test_expect_success 'reuse objects from first pack with middle gap' '
+	for i in D E F
+	do
+		test_commit "$i" || return 1
+	done &&
+
+	# Set "pack.window" to zero to ensure that we do not create any
+	# deltas, which could alter the amount of pack reuse we perform
+	# (if, for e.g., we are not sending one or more bases).
+	D="$(git -c pack.window=0 pack-objects --all --unpacked $packdir/pack)" &&
+
+	d_pos="$(pack_position $(git rev-parse D) <$packdir/pack-$D.idx)" &&
+	e_pos="$(pack_position $(git rev-parse E) <$packdir/pack-$D.idx)" &&
+	f_pos="$(pack_position $(git rev-parse F) <$packdir/pack-$D.idx)" &&
+
+	# commits F, E, and D, should appear in that order at the
+	# beginning of the pack
+	test $f_pos -lt $e_pos &&
+	test $e_pos -lt $d_pos &&
+
+	# Ensure that the pack we are constructing sorts ahead of any
+	# other packs in lexical/bitmap order by choosing it as the
+	# preferred pack.
+	git multi-pack-index write --bitmap --preferred-pack="pack-$D.idx" &&
+
+	cat >in <<-EOF &&
+	$(git rev-parse E)
+	^$(git rev-parse D)
+	EOF
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --delta-base-offset --revs <in >/dev/null &&
+
+	test_pack_reused 3 <trace2.txt &&
+	test_packs_reused 1 <trace2.txt
+'
+
+test_expect_success 'reuse objects from middle pack with middle gap' '
+	rm -fr $packdir/multi-pack-index* &&
+
+	# Ensure that the pack we are constructing sort into any
+	# position *but* the first one, by choosing a different pack as
+	# the preferred one.
+	git multi-pack-index write --bitmap --preferred-pack="pack-$A.idx" &&
+
+	cat >in <<-EOF &&
+	$(git rev-parse E)
+	^$(git rev-parse D)
+	EOF
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --delta-base-offset --revs <in >/dev/null &&
+
+	test_pack_reused 3 <trace2.txt &&
+	test_packs_reused 1 <trace2.txt
+'
+
+test_expect_success 'omit delta with uninteresting base (same pack)' '
+	git repack -adk &&
+
+	test_seq 32 >f &&
+	git add f &&
+	test_tick &&
+	git commit -m "delta" &&
+	delta="$(git rev-parse HEAD)" &&
+
+	test_seq 64 >f &&
+	test_tick &&
+	git commit -a -m "base" &&
+	base="$(git rev-parse HEAD)" &&
+
+	test_commit other &&
+
+	git repack -d &&
+
+	have_delta "$(git rev-parse $delta:f)" "$(git rev-parse $base:f)" &&
+
+	git multi-pack-index write --bitmap &&
+
+	cat >in <<-EOF &&
+	$(git rev-parse other)
+	^$base
+	EOF
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --delta-base-offset --revs <in >/dev/null &&
+
+	# We can only reuse the 3 objects corresponding to "other" from
+	# the latest pack.
+	#
+	# This is because even though we want "delta", we do not want
+	# "base", meaning that we have to inflate the delta/base-pair
+	# corresponding to the blob in commit "delta", which bypasses
+	# the pack-reuse mechanism.
+	#
+	# The remaining objects from the other pack are similarly not
+	# reused because their objects are on the uninteresting side of
+	# the query.
+	test_pack_reused 3 <trace2.txt &&
+	test_packs_reused 1 <trace2.txt
+'
+
+test_expect_success 'omit delta from uninteresting base (cross pack)' '
+	cat >in <<-EOF &&
+	$(git rev-parse $base)
+	^$(git rev-parse $delta)
+	EOF
+
+	P="$(git pack-objects --revs $packdir/pack <in)" &&
+
+	git multi-pack-index write --bitmap --preferred-pack="pack-$P.idx" &&
+
+	: >trace2.txt &&
+	GIT_TRACE2_EVENT="$PWD/trace2.txt" \
+		git pack-objects --stdout --delta-base-offset --all >/dev/null &&
+
+	packs_nr="$(find $packdir -type f -name "pack-*.pack" | wc -l)" &&
+	objects_nr="$(git rev-list --count --all --objects)" &&
+
+	test_pack_reused $(($objects_nr - 1)) <trace2.txt &&
+	test_packs_reused $packs_nr <trace2.txt
+'
+
+test_done