time-util: rename usec_sub() to usec_sub_signed() and add usec_sub_unsigned()

[elogind.git] / src / basic / time-util.h

diff --git a/src/basic/time-util.h b/src/basic/time-util.h
index 2ea7e8b511173c461fe7d3523e442d1356530d0d..a6df932ad2040cbfabe6bd1b2514749d6451a39f 100644 (file)
--- a/src/basic/time-util.h
+++ b/src/basic/time-util.h
@@ -191,19 +191,23 @@ static inline usec_t usec_add(usec_t a, usec_t b) {
         return c;
 }
 
-static inline usec_t usec_sub(usec_t timestamp, int64_t delta) {
-        if (delta < 0)
-                return usec_add(timestamp, (usec_t) (-delta));
+static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
 
         if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
                 return USEC_INFINITY;
-
-        if (timestamp < (usec_t) delta)
+        if (timestamp < delta)
                 return 0;
 
         return timestamp - delta;
 }
 
+static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
+        if (delta < 0)
+                return usec_add(timestamp, (usec_t) (-delta));
+        else
+                return usec_sub_unsigned(timestamp, (usec_t) delta);
+}
+
 #if SIZEOF_TIME_T == 8
 /* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
  * territory. However, since we want to stay away from this in all timezones we take one day off. */