Merge branch 'tb/pack-bitmap-lookup-tables' into jch

Enable lookup tables extension in pack bitmap (and midx bitmap) by
default.

Comments?

* tb/pack-bitmap-lookup-tables:
  t/perf/lib-bitmap.sh: avoid test_perf during setup
  t/perf: avoid testing bitmaps without lookup table
  p5312: removed duplicate performance test script
  pack-bitmap: write lookup table extension by default

Documentation/config/pack.adoc

@@ -199,7 +199,7 @@ pack.writeBitmapLookupTable::
 	bitmap index (if one is written). This table is used to defer
 	loading individual bitmaps as late as possible. This can be
 	beneficial in repositories that have relatively large bitmap
-	indexes. Defaults to false.
+	indexes. Defaults to true.
 
 pack.readReverseIndex::
 	When true, git will read any .rev file(s) that may be available

builtin/multi-pack-index.c

@@ -142,6 +142,7 @@ static int cmd_multi_pack_index_write(int argc, const char **argv,
 	int ret;
 
 	opts.flags |= MIDX_WRITE_BITMAP_HASH_CACHE;
+	opts.flags |= MIDX_WRITE_BITMAP_LOOKUP_TABLE;
 
 	git_config(git_multi_pack_index_write_config, NULL);
 

builtin/pack-objects.c

@@ -250,7 +250,7 @@ static enum {
 	WRITE_BITMAP_QUIET,
 	WRITE_BITMAP_TRUE,
 } write_bitmap_index;
-static uint16_t write_bitmap_options = BITMAP_OPT_HASH_CACHE;
+static uint16_t write_bitmap_options = BITMAP_OPT_HASH_CACHE | BITMAP_OPT_LOOKUP_TABLE;
 
 static int exclude_promisor_objects;
 static int exclude_promisor_objects_best_effort;

t/meson.build

@@ -1131,7 +1131,6 @@ benchmarks = [
   'perf/p5304-prune.sh',
   'perf/p5310-pack-bitmaps.sh',
   'perf/p5311-pack-bitmaps-fetch.sh',
-  'perf/p5312-pack-bitmaps-revs.sh',
   'perf/p5313-pack-objects.sh',
   'perf/p5314-name-hash.sh',
   'perf/p5326-multi-pack-bitmaps.sh',

t/perf/lib-bitmap.sh

@@ -69,7 +69,7 @@ test_partial_bitmap () {
 }
 
 test_pack_bitmap () {
-	test_perf "repack to disk" '
+	test_expect_success "repack to disk" '
 		git repack -ad
 	'
 

t/perf/p5310-pack-bitmaps.sh

@@ -4,37 +4,28 @@ test_description='Tests pack performance using bitmaps'
 . ./perf-lib.sh
 . "${TEST_DIRECTORY}/perf/lib-bitmap.sh"
 
-test_lookup_pack_bitmap () {
+test_expect_success 'start the test from scratch' '
-	test_expect_success 'start the test from scratch' '
+	rm -rf * .git
-		rm -rf * .git
+'
-	'
 
-	test_perf_large_repo
+test_perf_large_repo
 
-	# note that we do everything through config,
+# note that we do everything through config,
-	# since we want to be able to compare bitmap-aware
+# since we want to be able to compare bitmap-aware
-	# git versus non-bitmap git
+# git versus non-bitmap git
-	#
+#
-	# We intentionally use the deprecated pack.writebitmaps
+# We intentionally use the deprecated pack.writebitmaps
-	# config so that we can test against older versions of git.
+# config so that we can test against older versions of git.
-	test_expect_success 'setup bitmap config' '
+test_expect_success 'setup bitmap config' '
-		git config pack.writebitmaps true
+	git config pack.writebitmaps true
-	'
+'
 
-	# we need to create the tag up front such that it is covered by the repack and
+# we need to create the tag up front such that it is covered by the repack and
-	# thus by generated bitmaps.
+# thus by generated bitmaps.
-	test_expect_success 'create tags' '
+test_expect_success 'create tags' '
-		git tag --message="tag pointing to HEAD" perf-tag HEAD
+	git tag --message="tag pointing to HEAD" perf-tag HEAD
-	'
+'
 
-	test_perf "enable lookup table: $1" '
+test_pack_bitmap
-		git config pack.writeBitmapLookupTable '"$1"'
-	'
-
-	test_pack_bitmap
-}
-
-test_lookup_pack_bitmap false
-test_lookup_pack_bitmap true
 
 test_done

t/perf/p5311-pack-bitmaps-fetch.sh

@@ -3,52 +3,46 @@
 test_description='performance of fetches from bitmapped packs'
 . ./perf-lib.sh
 
-test_fetch_bitmaps () {
+test_expect_success 'setup test directory' '
-	test_expect_success 'setup test directory' '
+	rm -fr * .git
-		rm -fr * .git
+'
+
+test_perf_default_repo
+
+test_expect_success 'create bitmapped server repo' '
+	git config pack.writebitmaps true &&
+	git repack -ad
+'
+
+# simulate a fetch from a repository that last fetched N days ago, for
+# various values of N. We do so by following the first-parent chain,
+# and assume the first entry in the chain that is N days older than the current
+# HEAD is where the HEAD would have been then.
+for days in 1 2 4 8 16 32 64 128; do
+	title=$(printf '%10s' "($days days)")
+	test_expect_success "setup revs from $days days ago" '
+		now=$(git log -1 --format=%ct HEAD) &&
+		then=$(($now - ($days * 86400))) &&
+		tip=$(git rev-list -1 --first-parent --until=$then HEAD) &&
+		{
+			echo HEAD &&
+			echo ^$tip
+		} >revs
 	'
 
-	test_perf_default_repo
+	test_perf "server $title" '
-
+		git pack-objects --stdout --revs \
-	test_expect_success 'create bitmapped server repo' '
+				--thin --delta-base-offset \
-		git config pack.writebitmaps true &&
+				<revs >tmp.pack
-		git config pack.writeBitmapLookupTable '"$1"' &&
-		git repack -ad
 	'
 
-	# simulate a fetch from a repository that last fetched N days ago, for
+	test_size "size   $title" '
-	# various values of N. We do so by following the first-parent chain,
+		test_file_size tmp.pack
-	# and assume the first entry in the chain that is N days older than the current
+	'
-	# HEAD is where the HEAD would have been then.
-	for days in 1 2 4 8 16 32 64 128; do
-		title=$(printf '%10s' "($days days)")
-		test_expect_success "setup revs from $days days ago" '
-			now=$(git log -1 --format=%ct HEAD) &&
-			then=$(($now - ($days * 86400))) &&
-			tip=$(git rev-list -1 --first-parent --until=$then HEAD) &&
-			{
-				echo HEAD &&
-				echo ^$tip
-			} >revs
-		'
 
-		test_perf "server $title (lookup=$1)" '
+	test_perf "client $title" '
-			git pack-objects --stdout --revs \
+		git index-pack --stdin --fix-thin <tmp.pack
-					--thin --delta-base-offset \
+	'
-					<revs >tmp.pack
+done
-		'
-
-		test_size "size   $title" '
-			test_file_size tmp.pack
-		'
-
-		test_perf "client $title (lookup=$1)" '
-			git index-pack --stdin --fix-thin <tmp.pack
-		'
-	done
-}
-
-test_fetch_bitmaps true
-test_fetch_bitmaps false
 
 test_done

t/perf/p5312-pack-bitmaps-revs.sh

@@ -1,34 +0,0 @@
-#!/bin/sh
-
-test_description='Tests pack performance using bitmaps (rev index enabled)'
-. ./perf-lib.sh
-. "${TEST_DIRECTORY}/perf/lib-bitmap.sh"
-
-test_lookup_pack_bitmap () {
-	test_expect_success 'start the test from scratch' '
-		rm -rf * .git
-	'
-
-	test_perf_large_repo
-
-	test_expect_success 'setup bitmap config' '
-		git config pack.writebitmaps true
-	'
-
-	# we need to create the tag up front such that it is covered by the repack and
-	# thus by generated bitmaps.
-	test_expect_success 'create tags' '
-		git tag --message="tag pointing to HEAD" perf-tag HEAD
-	'
-
-	test_perf "enable lookup table: $1" '
-		git config pack.writeBitmapLookupTable '"$1"'
-	'
-
-	test_pack_bitmap
-}
-
-test_lookup_pack_bitmap false
-test_lookup_pack_bitmap true
-
-test_done

t/perf/p5326-multi-pack-bitmaps.sh

@@ -4,64 +4,53 @@ test_description='Tests performance using midx bitmaps'
 . ./perf-lib.sh
 . "${TEST_DIRECTORY}/perf/lib-bitmap.sh"
 
-test_bitmap () {
+test_expect_success "remove existing repo" '
-	local enabled="$1"
+	rm -fr * .git
+'
 
-	test_expect_success "remove existing repo (lookup=$enabled)" '
+test_perf_large_repo
-		rm -fr * .git
-	'
 
-	test_perf_large_repo
+# we need to create the tag up front such that it is covered by the repack and
+# thus by generated bitmaps.
+test_expect_success 'create tags' '
+	git tag --message="tag pointing to HEAD" perf-tag HEAD
+'
 
-	# we need to create the tag up front such that it is covered by the repack and
+test_expect_success "start with bitmapped pack" '
-	# thus by generated bitmaps.
+	git repack -adb
-	test_expect_success 'create tags' '
+'
-		git tag --message="tag pointing to HEAD" perf-tag HEAD
-	'
 
-	test_expect_success "use lookup table: $enabled" '
+test_perf "setup multi-pack index" '
-		git config pack.writeBitmapLookupTable '"$enabled"'
+	git multi-pack-index write --bitmap
-	'
+'
 
-	test_expect_success "start with bitmapped pack (lookup=$enabled)" '
+test_expect_success "drop pack bitmap" '
-		git repack -adb
+	rm -f .git/objects/pack/pack-*.bitmap
-	'
+'
 
-	test_perf "setup multi-pack index (lookup=$enabled)" '
+test_full_bitmap
-		git multi-pack-index write --bitmap
-	'
 
-	test_expect_success "drop pack bitmap (lookup=$enabled)" '
+test_expect_success "create partial bitmap state" '
-		rm -f .git/objects/pack/pack-*.bitmap
+	# pick a commit to represent the repo tip in the past
-	'
+	cutoff=$(git rev-list HEAD~100 -1) &&
+	orig_tip=$(git rev-parse HEAD) &&
 
-	test_full_bitmap
+	# now pretend we have just one tip
+	rm -rf .git/logs .git/refs/* .git/packed-refs &&
+	git update-ref HEAD $cutoff &&
 
-	test_expect_success "create partial bitmap state (lookup=$enabled)" '
+	# and then repack, which will leave us with a nice
-		# pick a commit to represent the repo tip in the past
+	# big bitmap pack of the "old" history, and all of
-		cutoff=$(git rev-list HEAD~100 -1) &&
+	# the new history will be loose, as if it had been pushed
-		orig_tip=$(git rev-parse HEAD) &&
+	# up incrementally and exploded via unpack-objects
+	git repack -Ad &&
+	git multi-pack-index write --bitmap &&
 
-		# now pretend we have just one tip
+	# and now restore our original tip, as if the pushes
-		rm -rf .git/logs .git/refs/* .git/packed-refs &&
+	# had happened
-		git update-ref HEAD $cutoff &&
+	git update-ref HEAD $orig_tip
+'
 
-		# and then repack, which will leave us with a nice
+test_partial_bitmap
-		# big bitmap pack of the "old" history, and all of
-		# the new history will be loose, as if it had been pushed
-		# up incrementally and exploded via unpack-objects
-		git repack -Ad &&
-		git multi-pack-index write --bitmap &&
-
-		# and now restore our original tip, as if the pushes
-		# had happened
-		git update-ref HEAD $orig_tip
-	'
-
-	test_partial_bitmap
-}
-
-test_bitmap false
-test_bitmap true
 
 test_done

t/perf/p5333-pseudo-merge-bitmaps.sh

@@ -11,7 +11,6 @@ test_expect_success 'setup' '
 		-c bitmapPseudoMerge.all.threshold=now \
 		-c bitmapPseudoMerge.all.stableThreshold=never \
 		-c bitmapPseudoMerge.all.maxMerges=64 \
-		-c pack.writeBitmapLookupTable=true \
 		repack -adb
 '