+/**
+ * collectd - src/utils_time.h
+ * Copyright (C) 2010 Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors:
+ * Florian octo Forster <ff at octo.it>
+ **/
+
+#ifndef UTILS_TIME_H
+#define UTILS_TIME_H 1
+
+#include "collectd.h"
+
+/*
+ * "cdtime_t" is a 64bit unsigned integer. The time is stored at a 2^-30 second
+ * resolution, i.e. the most significant 34 bit are used to store the time in
+ * seconds, the least significant bits store the sub-second part in something
+ * very close to nanoseconds. *The* big advantage of storing time in this
+ * manner is that comparing times and calculating differences is as simple as
+ * it is with "time_t", i.e. a simple integer comparison / subtraction works.
+ */
+typedef uint64_t cdtime_t;
+
+/* 2^30 = 1073741824 */
+#define TIME_T_TO_CDTIME_T(t) (((cdtime_t) (t)) * 1073741824)
+#define CDTIME_T_TO_TIME_T(t) ((time_t) ((t) / 1073741824))
+
+#define CDTIME_T_TO_DOUBLE(t) (((double) (t)) / 1073741824.0)
+#define DOUBLE_TO_CDTIME_T(d) ((cdtime_t) ((d) * 1073741824.0))
+
+#define US_TO_CDTIME_T(us) ((cdtime_t) (((double) (us)) * 1073.741824))
+#define NS_TO_CDTIME_T(ns) ((cdtime_t) (((double) (ns)) * 1.073741824))
+
+#define TIMEVAL_TO_CDTIME_T(tv) (TIME_T_TO_CDTIME_T ((tv).tv_sec) \
+ + US_TO_CDTIME_T ((tv).tv_usec))
+#define TIMESPEC_TO_CDTIME_T(ts) (TIME_T_TO_CDTIME_T ((ts).tv_sec) \
+ + NS_TO_CDTIME_T ((ts).tv_nsec))
+
+cdtime_t cdtime (void);
+
+#endif /* UTILS_TIME_H */