Add timespec_to_micros in time-util

The function timespec_to_micros converts the time stored in a struct
timespec into microseconds (uint64_t type).

Signed-off-by: Joonyoung Shim <[email protected]>

src/libbluechi/common/time-util.c

@@ -15,19 +15,15 @@ uint64_t get_time_micros() {
         if (clock_gettime(CLOCK_REALTIME, &now) < 0) {
                 return 0;
         }
-        uint64_t now_micros = now.tv_sec * sec_to_microsec_multiplier +
-                        (uint64_t) ((double) now.tv_nsec * nanosec_to_microsec_multiplier);
-        return now_micros;
+        return timespec_to_micros(now);
 }
 
 uint64_t get_time_micros_monotonic() {
         struct timespec now;
         if (clock_gettime(CLOCK_MONOTONIC, &now) < 0) {
                 return 0;
         }
-        uint64_t now_micros = now.tv_sec * sec_to_microsec_multiplier +
-                        (uint64_t) ((double) now.tv_nsec * nanosec_to_microsec_multiplier);
-        return now_micros;
+        return timespec_to_micros(now);
 }
 
 uint64_t finalize_time_interval_micros(int64_t start_time_micros) {
@@ -38,6 +34,23 @@ double micros_to_millis(uint64_t time_micros) {
         return (double) time_micros * microsec_to_millisec_multiplier;
 }
 
+uint64_t timespec_to_micros(struct timespec time) {
+        uint64_t sec_micros = 0;
+        uint64_t nsec_micros = 0;
+
+        if ((uint64_t) time.tv_sec > UINT64_MAX / sec_to_microsec_multiplier) {
+                return 0;
+        }
+
+        sec_micros = time.tv_sec * sec_to_microsec_multiplier;
+        nsec_micros = (uint64_t) ((double) time.tv_nsec * nanosec_to_microsec_multiplier);
+        if (sec_micros > UINT64_MAX - nsec_micros) {
+                return 0;
+        }
+
+        return sec_micros + nsec_micros;
+}
+
 char *get_formatted_log_timestamp() {
         struct timespec now;
         int r = 0;

src/libbluechi/common/time-util.h

@@ -19,5 +19,6 @@ uint64_t get_time_micros();
 uint64_t get_time_micros_monotonic();
 uint64_t finalize_time_interval_micros(int64_t start_time_micros);
 double micros_to_millis(uint64_t time_micros);
+uint64_t timespec_to_micros(struct timespec time);
 char *get_formatted_log_timestamp();
 char *get_formatted_log_timestamp_for_timespec(struct timespec time, bool is_gmt);

src/libbluechi/test/common/time-util/meson.build

@@ -6,6 +6,7 @@
 network_src = [
   'get_log_timestamp',
   'micros_to_millis_test',
+  'timespec_to_micros_test',
 ]
 
 foreach src : network_src

src/libbluechi/test/common/time-util/timespec_to_micros_test.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright Contributors to the Eclipse BlueChi project
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include "libbluechi/common/time-util.h"
+
+int main() {
+        struct timespec time = { 0, 0 };
+
+        assert(timespec_to_micros(time) == 0);
+
+        time.tv_sec = 0;
+        time.tv_nsec = 1234;
+        assert(timespec_to_micros(time) == 1);
+
+        time.tv_sec = 5678;
+        time.tv_nsec = 0;
+        assert(timespec_to_micros(time) == 5678000000);
+
+        time.tv_sec = 123;
+        time.tv_nsec = 4567890;
+        assert(timespec_to_micros(time) == 123004567);
+
+        if (LONG_MAX < UINT64_MAX / sec_to_microsec_multiplier) {
+                time.tv_sec = LONG_MAX;
+                time.tv_nsec = 999999999;
+                assert(timespec_to_micros(time) == LONG_MAX * sec_to_microsec_multiplier + 999999);
+        }
+
+#if defined(__x86_64__) || defined(__aarch64__)
+        time.tv_sec = LONG_MAX;
+        time.tv_nsec = 0;
+        assert(timespec_to_micros(time) == 0);
+
+        time.tv_sec = UINT64_MAX / sec_to_microsec_multiplier;
+        time.tv_nsec = 0;
+        assert(timespec_to_micros(time) == 18446744073709000000ULL);
+
+        time.tv_sec = UINT64_MAX / sec_to_microsec_multiplier;
+        time.tv_nsec = 551615000;
+        assert(timespec_to_micros(time) == UINT64_MAX);
+
+        time.tv_sec = UINT64_MAX / sec_to_microsec_multiplier;
+        time.tv_nsec = 551616000;
+        assert(timespec_to_micros(time) == 0);
+
+        time.tv_sec = UINT64_MAX / sec_to_microsec_multiplier + 1;
+        time.tv_nsec = 0;
+        assert(timespec_to_micros(time) == 0);
+#endif
+
+        return EXIT_SUCCESS;
+}