/*
* timestamp.c
+ *
+ * Conversion between Windows NT timestamps and UNIX timestamps.
*/
/*
- * Copyright (C) 2012, 2013 Eric Biggers
- *
- * This file is part of wimlib, a library for working with WIM files.
+ * Copyright (C) 2012, 2013, 2014 Eric Biggers
*
- * wimlib 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; either version 3 of the License, or (at your option)
- * any later version.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
*
- * wimlib 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
+ * This file 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 Lesser General Public License for more
* details.
*
- * You should have received a copy of the GNU General Public License
- * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
-#include "wimlib/types.h"
#include "wimlib/timestamp.h"
-#include <time.h>
-#include <sys/time.h>
+/*
+ * Timestamps in WIM files are Windows NT timestamps, or FILETIMEs: 64-bit
+ * values storing the number of 100-nanosecond ticks since January 1, 1601.
+ */
+
+#define NANOSECONDS_PER_TICK 100
+#define TICKS_PER_SECOND (1000000000 / NANOSECONDS_PER_TICK)
+#define TICKS_PER_MICROSECOND (TICKS_PER_SECOND / 1000000)
+
+/*
+ * EPOCH_DISTANCE is the number of 100-nanosecond ticks separating the
+ * Windows NT and UNIX epochs. This is equal to ((1970-1601)*365+89)*
+ * 24*60*60*10000000. 89 is the number of leap years between 1970 and 1601.
+ */
+#define EPOCH_DISTANCE 116444736000000000
+
+#define TO_WINNT_EPOCH(timestamp) ((timestamp) + EPOCH_DISTANCE)
+#define TO_UNIX_EPOCH(timestamp) ((timestamp) - EPOCH_DISTANCE)
+
+/* Windows NT timestamps to UNIX timestamps */
+
+time_t
+wim_timestamp_to_time_t(u64 timestamp)
+{
+ timestamp = TO_UNIX_EPOCH(timestamp);
+
+ return timestamp / TICKS_PER_SECOND;
+}
+
+struct timeval
+wim_timestamp_to_timeval(u64 timestamp)
+{
+ timestamp = TO_UNIX_EPOCH(timestamp);
+
+ return (struct timeval) {
+ .tv_sec = timestamp / TICKS_PER_SECOND,
+ .tv_usec = (timestamp % TICKS_PER_SECOND) / TICKS_PER_MICROSECOND,
+ };
+}
+
+struct timespec
+wim_timestamp_to_timespec(u64 timestamp)
+{
+ timestamp = TO_UNIX_EPOCH(timestamp);
+
+ return (struct timespec) {
+ .tv_sec = timestamp / TICKS_PER_SECOND,
+ .tv_nsec = (timestamp % TICKS_PER_SECOND) * NANOSECONDS_PER_TICK,
+ };
+}
+
+/* UNIX timestamps to Windows NT timestamps */
+
+u64
+time_t_to_wim_timestamp(time_t t)
+{
+ u64 timestamp = (u64)t * TICKS_PER_SECOND;
+
+ return TO_WINNT_EPOCH(timestamp);
+}
+
+u64
+timeval_to_wim_timestamp(const struct timeval *tv)
+{
+ u64 timestamp = (u64)tv->tv_sec * TICKS_PER_SECOND +
+ (u64)tv->tv_usec * TICKS_PER_MICROSECOND;
+
+ return TO_WINNT_EPOCH(timestamp);
+}
+
+u64
+timespec_to_wim_timestamp(const struct timespec *ts)
+{
+ u64 timestamp = (u64)ts->tv_sec * TICKS_PER_SECOND +
+ (u64)ts->tv_nsec / NANOSECONDS_PER_TICK;
+
+ return TO_WINNT_EPOCH(timestamp);
+}
+/* Retrieve the current time as a WIM timestamp. */
u64
-get_wim_timestamp(void)
+now_as_wim_timestamp(void)
{
struct timeval tv;
+
+ /* On Windows we rely on MinGW providing gettimeofday() for us. This
+ * could be changed to calling GetSystemTimeAsFileTime() directly, but
+ * now_as_wim_timestamp() isn't called much and it's simpler to keep the
+ * code for all platforms the same. */
gettimeofday(&tv, NULL);
- return timeval_to_wim_timestamp(tv);
+ return timeval_to_wim_timestamp(&tv);
}
+/* Translate a WIM timestamp into a human-readable string. */
void
wim_timestamp_to_str(u64 timestamp, tchar *buf, size_t len)
{
struct tm tm;
- time_t t = wim_timestamp_to_unix(timestamp);
+ time_t t = wim_timestamp_to_time_t(timestamp);
gmtime_r(&t, &tm);
tstrftime(buf, len, T("%a %b %d %H:%M:%S %Y UTC"), &tm);
}
-