[PATCH 1/3] perf: add test for writing the index

[Kevin Willford <kewillf@microsoft.com>]

A performance test for writing the index to be able to
determine if changes to allocating ondisk structure help.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
---
 Makefile                    |  1 +
 t/helper/test-write-cache.c | 23 +++++++++++++++++++++++
 t/perf/p0007-write-cache.sh | 29 +++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)
 create mode 100644 t/helper/test-write-cache.c
 create mode 100755 t/perf/p0007-write-cache.sh

diff --git a/Makefile b/Makefile
index 86ec29202b..c6b061086f 100644
--- a/Makefile
+++ b/Makefile
@@ -655,6 +655,7 @@ TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-path-utils
 TEST_PROGRAMS_NEED_X += test-prio-queue
 TEST_PROGRAMS_NEED_X += test-read-cache
+TEST_PROGRAMS_NEED_X += test-write-cache
 TEST_PROGRAMS_NEED_X += test-ref-store
 TEST_PROGRAMS_NEED_X += test-regex
 TEST_PROGRAMS_NEED_X += test-revision-walking
diff --git a/t/helper/test-write-cache.c b/t/helper/test-write-cache.c
new file mode 100644
index 0000000000..b7ee039669
--- /dev/null
+++ b/t/helper/test-write-cache.c
@@ -0,0 +1,23 @@
+#include "cache.h"
+#include "lockfile.h"
+
+static struct lock_file index_lock;
+
+int cmd_main(int argc, const char **argv)
+{
+	int i, cnt = 1, lockfd;
+	if (argc == 2)
+		cnt = strtol(argv[1], NULL, 0);
+	setup_git_directory();
+	read_cache();
+	for (i = 0; i < cnt; i++) {
+		lockfd = hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
+		if (0 <= lockfd) {
+			write_locked_index(&the_index, &index_lock, COMMIT_LOCK);
+		} else {
+			rollback_lock_file(&index_lock);
+		}
+	}
+
+	return 0;
+}
diff --git a/t/perf/p0007-write-cache.sh b/t/perf/p0007-write-cache.sh
new file mode 100755
index 0000000000..261fe92fd9
--- /dev/null
+++ b/t/perf/p0007-write-cache.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+test_description="Tests performance of writing the index"
+
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+test_expect_success "setup repo" '
+	if git rev-parse --verify refs/heads/p0006-ballast^{commit}
+	then
+		echo Assuming synthetic repo from many-files.sh
+		git config --local core.sparsecheckout 1
+		cat >.git/info/sparse-checkout <<-EOF
+		/*
+		!ballast/*
+		EOF
+	else
+		echo Assuming non-synthetic repo...
+	fi &&
+	nr_files=$(git ls-files | wc -l)
+'
+
+count=3
+test_perf "write_locked_index $count times ($nr_files files)" "
+	test-write-cache $count
+"
+
+test_done
-- 
2.14.1.205.g2812f3410d