Re-organize sources

[babeltrace.git] / src / compat / utc.h

diff --git a/src/compat/utc.h b/src/compat/utc.h
new file mode 100644 (file)
index 0000000..3660e08
--- /dev/null
+++ b/src/compat/utc.h
@@ -0,0 +1,105 @@
+#ifndef _BABELTRACE_UTC_H
+#define _BABELTRACE_UTC_H
+
+/*
+ * Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <time.h>
+
+/* If set, use GNU or BSD timegm(3) */
+#if defined(_BSD_SOURCE) || defined(_SVID_SOURCE)
+
+static inline
+time_t bt_timegm(struct tm *tm)
+{
+       return timegm(tm);
+}
+
+#elif defined(__MINGW32__)
+
+static inline
+time_t bt_timegm(struct tm *tm)
+{
+       return _mkgmtime(tm);
+}
+
+#else
+
+#include <errno.h>
+
+/*
+ * This is a simple implementation of timegm() it just turns the "struct tm" into
+ * a GMT time_t. It does not normalize any of the fields of the "struct tm", nor
+ * does it set tm_wday or tm_yday.
+ */
+
+static inline
+int bt_leapyear(int year)
+{
+    return ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0));
+}
+
+static inline
+time_t bt_timegm(struct tm *tm)
+{
+       int year, month, total_days;
+
+       int monthlen[2][12] = {
+               /* Days per month for a regular year */
+               { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+               /* Days per month for a leap year */
+               { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+       };
+
+       if ((tm->tm_mon >= 12) ||
+                       (tm->tm_mday >= 32) ||
+                       (tm->tm_hour >= 24) ||
+                       (tm->tm_min >= 60) ||
+                       (tm->tm_sec >= 61)) {
+               errno = EOVERFLOW;
+               return (time_t) -1;
+       }
+
+       /* Add 365 days for each year since 1970 */
+       total_days = 365 * (tm->tm_year - 70);
+
+       /* Add one day for each leap year since 1970 */
+       for (year = 70; year < tm->tm_year; year++) {
+               if (bt_leapyear(1900 + year)) {
+                       total_days++;
+               }
+       }
+
+       /* Add days for each remaining month */
+       for (month = 0; month < tm->tm_mon; month++) {
+               total_days += monthlen[bt_leapyear(1900 + year)][month];
+       }
+
+       /* Add remaining days */
+       total_days += tm->tm_mday - 1;
+
+       return ((((total_days * 24) + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec);
+}
+
+#endif
+
+#endif /* _BABELTRACE_UTC_H */