Moved time functions into a shared file.

[greproxy] / timeutil.cpp

diff --git a/timeutil.cpp b/timeutil.cpp
new file mode 100644 (file)
index 0000000..b3d58a7
--- /dev/null
+++ b/timeutil.cpp
@@ -0,0 +1,48 @@
+#include <sys/time.h>
+
+#include <algorithm>
+
+#include "timeutil.h"
+
+using namespace std;
+
+double tdiff(const timeval& a, const timeval& b)
+{
+       return b.tv_sec - a.tv_sec +
+               1e-6 * (b.tv_usec - a.tv_usec);
+}
+
+bool less_than(const timeval &a, const timeval &b)
+{
+       return make_pair(a.tv_sec, a.tv_usec) < make_pair(b.tv_sec, b.tv_usec);
+}
+
+timeval subtract_timeval_saturate(const timeval &a, const timeval &b)
+{      
+       timeval ret;
+       if (less_than(a, b)) {
+               ret.tv_sec = ret.tv_usec = 0;
+               return ret;
+       }
+       ret.tv_sec = b.tv_sec - a.tv_sec;
+       ret.tv_usec = b.tv_usec - a.tv_usec;
+       if (ret.tv_usec < 0) {
+               ret.tv_usec += 1000000;
+               --ret.tv_sec;
+       }
+       return ret;
+}
+
+timeval offset_timeval_seconds(const timeval &a, double s)
+{
+       int usec_to_add = lrint(1e6 * s);
+       int sec_to_add = usec_to_add / 1000000;
+       usec_to_add %= 1000000;
+
+       timeval ret = a;
+       ret.tv_usec += usec_to_add;
+       ret.tv_sec += sec_to_add;
+       ret.tv_sec += ret.tv_usec / 1000000;
+       ret.tv_usec %= 1000000;
+       return ret;
+}