From: Johannes Schindelin <johannes.schindelin@xxxxxx>
In the next commit, we want to teach Git's test suite to optionally
output test results in JUnit-style .xml files. These files contain
information about the time spent. So we need a way to measure time.
While we could use `date +%s` for that, this will give us only seconds,
i.e. very coarse-grained timings.
GNU `date` supports `date +%s.%N` (i.e. nanosecond-precision output),
but there is no equivalent in BSD `date` (read: on macOS, we would not
be able to obtain precise timings).
So let's introduce `test-tool date getnanos`, with an optional start
time, that outputs preciser values.
Granted, it is a bit pointless to try measuring times accurately in
shell scripts, certainly to nanosecond precision. But it is better than
second-granularity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
t/helper/test-date.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/t/helper/test-date.c b/t/helper/test-date.c
index a0837371ab..792a805374 100644
--- a/t/helper/test-date.c
+++ b/t/helper/test-date.c
@@ -7,6 +7,7 @@ static const char *usage_msg = "\n"
" test-tool date parse [date]...\n"
" test-tool date approxidate [date]...\n"
" test-tool date timestamp [date]...\n"
+" test-tool date getnanos [start-nanos]\n"
" test-tool date is64bit\n"
" test-tool date time_t-is64bit\n";
@@ -82,6 +83,15 @@ static void parse_approx_timestamp(const char **argv, struct timeval *now)
}
}
+static void getnanos(const char **argv, struct timeval *now)
+{
+ double seconds = getnanotime() / 1.0e9;
+
+ if (*argv)
+ seconds -= strtod(*argv, NULL);
+ printf("%lf\n", seconds);
+}
+
int cmd__date(int argc, const char **argv)
{
struct timeval now;
@@ -108,6 +118,8 @@ int cmd__date(int argc, const char **argv)
parse_approxidate(argv+1, &now);
else if (!strcmp(*argv, "timestamp"))
parse_approx_timestamp(argv+1, &now);
+ else if (!strcmp(*argv, "getnanos"))
+ getnanos(argv+1, &now);
else if (!strcmp(*argv, "is64bit"))
return sizeof(timestamp_t) == 8 ? 0 : 1;
else if (!strcmp(*argv, "time_t-is64bit"))
--
gitgitgadget
