From: Jeff Hostetler <jeffh...@microsoft.com>
Created test to measure read_index() with and without
skip_verify_index set and report performance differences.
Signed-off-by: Jeff Hostetler <jeffh...@microsoft.com>
---
Makefile | 1 +
t/helper/.gitignore | 1 +
t/helper/test-skip-verify-index.c | 73 +++++++++++++++++++++++++++++++++++++++
3 files changed, 75 insertions(+)
create mode 100644 t/helper/test-skip-verify-index.c
diff --git a/Makefile b/Makefile
index 9ec6065..e4932b6 100644
--- a/Makefile
+++ b/Makefile
@@ -631,6 +631,7 @@ TEST_PROGRAMS_NEED_X += test-scrap-cache-tree
TEST_PROGRAMS_NEED_X += test-sha1
TEST_PROGRAMS_NEED_X += test-sha1-array
TEST_PROGRAMS_NEED_X += test-sigchain
+TEST_PROGRAMS_NEED_X += test-skip-verify-index
TEST_PROGRAMS_NEED_X += test-string-list
TEST_PROGRAMS_NEED_X += test-submodule-config
TEST_PROGRAMS_NEED_X += test-subprocess
diff --git a/t/helper/.gitignore b/t/helper/.gitignore
index d6e8b36..4d2ed3c 100644
--- a/t/helper/.gitignore
+++ b/t/helper/.gitignore
@@ -25,6 +25,7 @@
/test-sha1
/test-sha1-array
/test-sigchain
+/test-skip-verify-index
/test-string-list
/test-submodule-config
/test-subprocess
diff --git a/t/helper/test-skip-verify-index.c
b/t/helper/test-skip-verify-index.c
new file mode 100644
index 0000000..ec2db27
--- /dev/null
+++ b/t/helper/test-skip-verify-index.c
@@ -0,0 +1,73 @@
+#include "cache.h"
+#include "parse-options.h"
+
+uint64_t time_runs(int count)
+{
+ uint64_t t0, t1;
+ uint64_t sum = 0;
+ uint64_t avg;
+ int i;
+
+ for (i = 0; i < count; i++) {
+ t0 = getnanotime();
+ read_cache();
+ t1 = getnanotime();
+
+ sum += (t1 - t0);
+
+ printf("%f %d [cache_nr %d]\n",
+ ((double)(t1 - t0))/1000000000,
+ skip_verify_index,
+ the_index.cache_nr);
+ fflush(stdout);
+
+ discard_cache();
+ }
+
+ avg = sum / count;
+ if (count > 1) {
+ printf("%f %d avg\n",
+ (double)avg/1000000000,
+ skip_verify_index);
+ fflush(stdout);
+ }
+
+ return avg;
+}
+
+int cmd_main(int argc, const char **argv)
+{
+ int count = 1;
+ const char *usage[] = {
+ "test-core-verify-index",
+ NULL
+ };
+ struct option options[] = {
+ OPT_INTEGER('c', "count", &count, "number of passes"),
+ OPT_END(),
+ };
+ const char *prefix;
+ uint64_t avg_no_skip, avg_skip;
+
+ prefix = setup_git_directory();
+ argc = parse_options(argc, argv, prefix, options, usage, 0);
+
+ if (count < 1)
+ die("count must greater than zero");
+
+ /* throw away call to get the index in the disk cache */
+ read_cache();
+ discard_cache();
+
+ /* disable index SHA verification */
+ skip_verify_index = 0;
+ avg_no_skip = time_runs(count);
+
+ /* enable index SHA verification */
+ skip_verify_index = 1;
+ avg_skip = time_runs(count);
+
+ if (avg_skip > avg_no_skip)
+ die("skipping index SHA verification did not help");
+ return 0;
+}
--
2.7.4
