[PATCH v2 4/4] read-cache perf: add a perf test for refresh_index()

[Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>]

Add a perf test for the refresh_index() function to compliment the
existing read()/discard() in a loop perf test added in
1ecb5ff141f (read-cache: add simple performance test, 2013-06-09).

Since this test is much slower (around 10x) than the previous
read()/discard() test let's run it 100 times instead of the 1000 time
the first one runs.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
 t/helper/test-read-cache-perf.c | 12 ++++++++++++
 t/perf/p0002-read-cache.sh      |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/t/helper/test-read-cache-perf.c b/t/helper/test-read-cache-perf.c
index 301e98797b4..630c126fbf3 100644
--- a/t/helper/test-read-cache-perf.c
+++ b/t/helper/test-read-cache-perf.c
@@ -11,8 +11,11 @@ int cmd__read_cache_perf(int argc, const char **argv)
 {
 	struct repository *r = the_repository;
 	int cnt = -1;
+	int refresh = 0;
 	struct option options[] = {
 		OPT_INTEGER(0, "count", &cnt, "number of passes"),
+		OPT_BOOL(0, "refresh", &refresh,
+			 "call refresh_index() in a loop, not read()/discard()"),
 		OPT_END()
 	};
 
@@ -26,10 +29,19 @@ int cmd__read_cache_perf(int argc, const char **argv)
 			      options);
 
 	setup_git_directory();
+	if (refresh)
+		repo_read_index(r);
 	while (cnt--) {
+		if (refresh) {
+			unsigned int flags = REFRESH_QUIET|REFRESH_PROGRESS;
+			refresh_index(r->index, flags, NULL, NULL, NULL);
+			continue;
+		}
 		repo_read_index(r);
 		discard_index(r->index);
 	}
+	if (refresh)
+		discard_index(r->index);
 
 	return 0;
 }
diff --git a/t/perf/p0002-read-cache.sh b/t/perf/p0002-read-cache.sh
index 1762b648654..cbccc5ace95 100755
--- a/t/perf/p0002-read-cache.sh
+++ b/t/perf/p0002-read-cache.sh
@@ -11,4 +11,9 @@ test_perf "read_cache/discard_cache $count times" "
 	test-tool read-cache-perf --count=$count
 "
 
+count=100
+test_perf "refresh_index() $count times" "
+	test-tool read-cache-perf --count=$count --refresh
+"
+
 test_done
-- 
2.33.0.663.gbaff4edb973