Added two new functions: nstime_diff() and nstime_subtract().

svn path=/trunk/; revision=34660

1 files changed, 18 insertions, 0 deletions

diff --git a/epan/nstime.c b/epan/nstime.c
index da7fc35e05..7ceaf8e975 100644
--- a/epan/nstime.c
+++ b/epan/nstime.c
@@ -131,6 +131,24 @@ void nstime_sum(nstime_t *sum, const nstime_t *a, const nstime_t *b)
 }
 
 /*
+ * function: nstime_diff
+ * diff = a - b
+ */
+
+void nstime_diff(nstime_t *diff, const nstime_t *a, const nstime_t *b)
+{
+    diff->secs = a->secs - b->secs;
+    diff->nsecs = a->nsecs - b->nsecs;
+    if(diff->nsecs>=NS_PER_S || (diff->nsecs>0 && diff->secs<0)){
+        diff->nsecs-=NS_PER_S;
+        diff->secs++;
+    } else if(diff->nsecs<=-NS_PER_S || (diff->nsecs<0 && diff->secs>0)) {
+        diff->nsecs+=NS_PER_S;
+        diff->secs--;
+    }
+}
+
+/*
  * function: nstime_cmp
  *
  * a > b : > 0