merge(3p/git): Merge git subtree at v2.29.2

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

third_party/git/t/perf/README

@@ -84,6 +84,15 @@ You can set the following variables (also in your config.mak):
 	probably be about linux.git size for optimal results.
 	Both default to the git.git you are running from.
 
+    GIT_PERF_EXTRA
+	Boolean to enable additional tests. Most test scripts are
+	written to detect regressions between two versions of Git, and
+	the output will compare timings for individual tests between
+	those versions. Some scripts have additional tests which are not
+	run by default, that show patterns within a single version of
+	Git (e.g., performance of index-pack as the number of threads
+	changes). These can be enabled with GIT_PERF_EXTRA.
+
 You can also pass the options taken by ordinary git tests; the most
 useful one is:
 

third_party/git/t/perf/aggregate.perl

@@ -4,7 +4,6 @@ use lib '../../perl/build/lib';
 use strict;
 use warnings;
 use Getopt::Long;
-use Git;
 use Cwd qw(realpath);
 
 sub get_times {
@@ -85,6 +84,11 @@ sub format_size {
 	return $out;
 }
 
+sub sane_backticks {
+	open(my $fh, '-|', @_);
+	return <$fh>;
+}
+
 my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests,
     $codespeed, $sortby, $subsection, $reponame);
 
@@ -102,7 +106,8 @@ while (scalar @ARGV) {
 	my $prefix = '';
 	last if -f $arg or $arg eq "--";
 	if (! -d $arg) {
-		my $rev = Git::command_oneline(qw(rev-parse --verify), $arg);
+		my $rev = sane_backticks(qw(git rev-parse --verify), $arg);
+		chomp $rev;
 		$dir = "build/".$rev;
 	} elsif ($arg eq '.') {
 		$dir = '.';
@@ -219,13 +224,7 @@ sub print_default_results {
 		for my $i (0..$#dirs) {
 			my $d = $dirs[$i];
 			my $base = "$resultsdir/$prefixes{$d}$t";
-			$times{$prefixes{$d}.$t} = [];
-			foreach my $type (qw(times size)) {
-				if (-e "$base.$type") {
-					$times{$prefixes{$d}.$t} = [get_times("$base.$type")];
-					last;
-				}
-			}
+			$times{$prefixes{$d}.$t} = [get_times("$base.result")];
 			my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
 			my $w = length format_times($r,$u,$s,$firstr);
 			$colwidth[$i] = $w if $w > $colwidth[$i];
@@ -267,7 +266,7 @@ sub print_sorted_results {
 		my ($prevr, $prevu, $prevs, $prevrev);
 		for my $i (0..$#dirs) {
 			my $d = $dirs[$i];
-			my ($r, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.times");
+			my ($r, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.result");
 			if ($i > 0 and defined $r and defined $prevr and $prevr > 0) {
 				my $percent = 100.0 * ($r - $prevr) / $prevr;
 				push @evolutions, { "percent"  => $percent,
@@ -327,7 +326,7 @@ sub print_codespeed_results {
 			my $commitid = $prefixes{$d};
 			$commitid =~ s/^build_//;
 			$commitid =~ s/\.$//;
-			my ($result_value, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.times");
+			my ($result_value, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.result");
 
 			my %vals = (
 				"commitid" => $commitid,

third_party/git/t/perf/bisect_regression

@@ -51,7 +51,7 @@ oldtime=$(echo "$oldtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
 newtime=$(echo "$newtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
 
 test $(echo "$newtime" "$oldtime" | awk '{ print ($1 > $2) }') = 1 ||
-	die "New time '$newtime' shoud be greater than old time '$oldtime'"
+	die "New time '$newtime' should be greater than old time '$oldtime'"
 
 tmpdir=$(mktemp -d -t bisect_regression_XXXXXX) || die "Failed to create temp directory"
 echo "$oldtime" >"$tmpdir/oldtime" || die "Failed to write to '$tmpdir/oldtime'"

third_party/git/t/perf/p1400-update-ref.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+test_description="Tests performance of update-ref"
+
+. ./perf-lib.sh
+
+test_perf_fresh_repo
+
+test_expect_success "setup" '
+	git init --bare target-repo.git &&
+	test_commit PRE &&
+	test_commit POST &&
+	printf "create refs/heads/%d PRE\n" $(test_seq 1000) >create &&
+	printf "update refs/heads/%d POST PRE\n" $(test_seq 1000) >update &&
+	printf "delete refs/heads/%d POST\n" $(test_seq 1000) >delete &&
+	git update-ref --stdin <create
+'
+
+test_perf "update-ref" '
+	for i in $(test_seq 1000)
+	do
+		git update-ref refs/heads/branch PRE &&
+		git update-ref refs/heads/branch POST PRE &&
+		git update-ref -d refs/heads/branch
+	done
+'
+
+test_perf "update-ref --stdin" '
+	git update-ref --stdin <update &&
+	git update-ref --stdin <delete &&
+	git update-ref --stdin <create
+'
+
+test_perf "nonatomic push" '
+	git push ./target-repo.git $(test_seq 1000) &&
+	git push --delete ./target-repo.git $(test_seq 1000)
+'
+
+test_done

third_party/git/t/perf/p5302-pack-index.sh

@@ -13,35 +13,36 @@ test_expect_success 'repack' '
 	export PACK
 '
 
-test_perf 'index-pack 0 threads' '
+# Rather than counting up and doubling each time, count down from the endpoint,
+# halving each time. That ensures that our final test uses as many threads as
+# CPUs, even if it isn't a power of 2.
+test_expect_success 'set up thread-counting tests' '
+	t=$(test-tool online-cpus) &&
+	threads= &&
+	while test $t -gt 0
+	do
+		threads="$t $threads"
+		t=$((t / 2))
+	done
+'
+
+test_perf PERF_EXTRA 'index-pack 0 threads' '
 	rm -rf repo.git &&
 	git init --bare repo.git &&
 	GIT_DIR=repo.git git index-pack --threads=1 --stdin < $PACK
 '
 
-test_perf 'index-pack 1 thread ' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git GIT_FORCE_THREADS=1 git index-pack --threads=1 --stdin < $PACK
-'
-
-test_perf 'index-pack 2 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=2 --stdin < $PACK
-'
-
-test_perf 'index-pack 4 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=4 --stdin < $PACK
-'
-
-test_perf 'index-pack 8 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=8 --stdin < $PACK
-'
+for t in $threads
+do
+	THREADS=$t
+	export THREADS
+	test_perf PERF_EXTRA "index-pack $t threads" '
+		rm -rf repo.git &&
+		git init --bare repo.git &&
+		GIT_DIR=repo.git GIT_FORCE_THREADS=1 \
+		git index-pack --threads=$THREADS --stdin <$PACK
+	'
+done
 
 test_perf 'index-pack default number of threads' '
 	rm -rf repo.git &&

third_party/git/t/perf/p5303-many-packs.sh

@@ -73,10 +73,15 @@ do
 		git rev-list --objects --all >/dev/null
 	'
 
+	test_perf "abbrev-commit ($nr_packs)" '
+		git rev-list --abbrev-commit HEAD >/dev/null
+	'
+
 	# This simulates the interesting part of the repack, which is the
 	# actual pack generation, without smudging the on-disk setup
 	# between trials.
 	test_perf "repack ($nr_packs)" '
+		GIT_TEST_FULL_IN_PACK_ARRAY=1 \
 		git pack-objects --keep-true-parents \
 		  --honor-pack-keep --non-empty --all \
 		  --reflog --indexed-objects --delta-base-offset \
@@ -84,4 +89,22 @@ do
 	'
 done
 
+# Measure pack loading with 10,000 packs.
+test_expect_success 'generate lots of packs' '
+	for i in $(test_seq 10000); do
+		echo "blob"
+		echo "data <<EOF"
+		echo "blob $i"
+		echo "EOF"
+		echo "checkpoint"
+	done |
+	git -c fastimport.unpackLimit=0 fast-import
+'
+
+# The purpose of this test is to evaluate load time for a large number
+# of packs while doing as little other work as possible.
+test_perf "load 10,000 packs" '
+	git rev-parse --verify "HEAD^{commit}"
+'
+
 test_done

third_party/git/t/perf/p5310-pack-bitmaps.sh

@@ -31,14 +31,37 @@ test_perf 'simulated fetch' '
 	} | git pack-objects --revs --stdout >/dev/null
 '
 
-test_perf 'pack to file' '
-	git pack-objects --all pack1 </dev/null >/dev/null
-'
-
 test_perf 'pack to file (bitmap)' '
 	git pack-objects --use-bitmap-index --all pack1b </dev/null >/dev/null
 '
 
+test_perf 'rev-list (commits)' '
+	git rev-list --all --use-bitmap-index >/dev/null
+'
+
+test_perf 'rev-list (objects)' '
+	git rev-list --all --use-bitmap-index --objects >/dev/null
+'
+
+test_perf 'rev-list count with blob:none' '
+	git rev-list --use-bitmap-index --count --objects --all \
+		--filter=blob:none >/dev/null
+'
+
+test_perf 'rev-list count with blob:limit=1k' '
+	git rev-list --use-bitmap-index --count --objects --all \
+		--filter=blob:limit=1k >/dev/null
+'
+
+test_perf 'rev-list count with tree:0' '
+	git rev-list --use-bitmap-index --count --objects --all \
+		--filter=tree:0 >/dev/null
+'
+
+test_perf 'simulated partial clone' '
+	git pack-objects --stdout --all --filter=blob:none </dev/null >/dev/null
+'
+
 test_expect_success 'create partial bitmap state' '
 	# pick a commit to represent the repo tip in the past
 	cutoff=$(git rev-list HEAD~100 -1) &&
@@ -68,4 +91,9 @@ test_perf 'pack to file (partial bitmap)' '
 	git pack-objects --use-bitmap-index --all pack2b </dev/null >/dev/null
 '
 
+test_perf 'rev-list with tree filter (partial bitmap)' '
+	git rev-list --use-bitmap-index --count --objects --all \
+		--filter=tree:0 >/dev/null
+'
+
 test_done

third_party/git/t/perf/p9300-fast-import-export.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+test_description='test fast-import and fast-export performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+# Use --no-data here to produce a vastly smaller export file.
+# This is much cheaper to work with but should still exercise
+# fast-import pretty well (we'll still process all commits and
+# trees, which account for 60% or more of objects in most repos).
+#
+# Use --reencode to avoid the default of aborting on non-utf8 commits,
+# which lets this test run against a wider variety of sample repos.
+test_perf 'export (no-blobs)' '
+	git fast-export --reencode=yes --no-data HEAD >export
+'
+
+test_perf 'import (no-blobs)' '
+	git fast-import --force <export
+'
+
+test_done

third_party/git/t/perf/perf-lib.sh

@@ -214,7 +214,7 @@ test_perf_ () {
 	else
 		test_ok_ "$1"
 	fi
-	"$TEST_DIRECTORY"/perf/min_time.perl test_time.* >"$base".times
+	"$TEST_DIRECTORY"/perf/min_time.perl test_time.* >"$base".result
 }
 
 test_perf () {
@@ -223,7 +223,7 @@ test_perf () {
 
 test_size_ () {
 	say >&3 "running: $2"
-	if test_eval_ "$2" 3>"$base".size; then
+	if test_eval_ "$2" 3>"$base".result; then
 		test_ok_ "$1"
 	else
 		test_failure_ "$@"
@@ -245,3 +245,5 @@ test_at_end_hook_ () {
 test_export () {
 	export "$@"
 }
+
+test_lazy_prereq PERF_EXTRA 'test_bool_env GIT_PERF_EXTRA false'