util: make time formatting a bit smarter

Instead of outputting "5h 55s 50ms 3us" we'll now output "5h
55.050003s". Also, while outputting the accuracy is configurable.

Basically we now try use "dot notation" for all time values > 1min. For
>= 1s we use 's' as unit, otherwise for >= 1ms we use 'ms' as unit, and
finally 'us'.

This should give reasonably values in most cases.

2 files changed, 52 insertions, 2 deletions

diff --git a/src/test/test-efivars.c b/src/test/test-efivars.c
index e54a83665a..43ea5917b6 100644
--- a/src/test/test-efivars.c
+++ b/src/test/test-efivars.c
@@ -36,8 +36,8 @@ int main(int argc, char* argv[]) {
                 return 1;
         }
 
-        log_info("Firmware began %s before kernel.", format_timespan(s, sizeof(s), fw.monotonic));
-        log_info("Loader began %s before kernel.", format_timespan(s, sizeof(s), l.monotonic));
+        log_info("Firmware began %s before kernel.", format_timespan(s, sizeof(s), fw.monotonic, 0));
+        log_info("Loader began %s before kernel.", format_timespan(s, sizeof(s), l.monotonic, 0));
 
         log_info("Firmware began %s.", format_timestamp(s, sizeof(s), fw.realtime));
         log_info("Loader began %s.", format_timestamp(s, sizeof(s), l.realtime));
diff --git a/src/test/test-time.c b/src/test/test-time.c
index e9d188fced..36a33046a2 100644
--- a/src/test/test-time.c
+++ b/src/test/test-time.c
@@ -79,8 +79,58 @@ static void test_parse_nsec(void) {
         assert_se(parse_nsec(".s ", &u) < 0);
 }
 
+static void test_format_timespan_one(usec_t x, usec_t accuracy) {
+        char *r;
+        char l[FORMAT_TIMESPAN_MAX];
+        usec_t y;
+
+        log_info("%llu     (at accuracy %llu)", (unsigned long long) x, (unsigned long long) accuracy);
+
+        r = format_timespan(l, sizeof(l), x, accuracy);
+        assert_se(r);
+
+        log_info(" = <%s>", l);
+
+        assert_se(parse_sec(l, &y) >= 0);
+
+        log_info(" = %llu", (unsigned long long) y);
+
+        if (accuracy <= 0)
+                accuracy = 1;
+
+        assert_se(x / accuracy == y / accuracy);
+}
+
+static void test_format_timespan(usec_t accuracy) {
+        test_format_timespan_one(0, accuracy);
+        test_format_timespan_one(1, accuracy);
+        test_format_timespan_one(1*USEC_PER_SEC, accuracy);
+        test_format_timespan_one(999*USEC_PER_MSEC, accuracy);
+        test_format_timespan_one(1234567, accuracy);
+        test_format_timespan_one(12, accuracy);
+        test_format_timespan_one(123, accuracy);
+        test_format_timespan_one(1234, accuracy);
+        test_format_timespan_one(12345, accuracy);
+        test_format_timespan_one(123456, accuracy);
+        test_format_timespan_one(1234567, accuracy);
+        test_format_timespan_one(12345678, accuracy);
+        test_format_timespan_one(1200000, accuracy);
+        test_format_timespan_one(1230000, accuracy);
+        test_format_timespan_one(1230000, accuracy);
+        test_format_timespan_one(1234000, accuracy);
+        test_format_timespan_one(1234500, accuracy);
+        test_format_timespan_one(1234560, accuracy);
+        test_format_timespan_one(1234567, accuracy);
+        test_format_timespan_one(986087, accuracy);
+        test_format_timespan_one(500 * USEC_PER_MSEC, accuracy);
+        test_format_timespan_one(9*USEC_PER_YEAR/5 - 23, accuracy);
+}
+
 int main(int argc, char *argv[]) {
         test_parse_sec();
         test_parse_nsec();
+        test_format_timespan(1);
+        test_format_timespan(USEC_PER_MSEC);
+        test_format_timespan(USEC_PER_SEC);
         return 0;
 }