text: /*-
   * Copyright (c) 2008 Christos Zoulas
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "file.h"
  
  #ifndef lint
  FILE_RCSID("@(#)$File: cdf_time.c,v 1.11 2011/12/13 13:48:41 christos Exp $")
  #endif
  
  #include <time.h>
  #ifdef TEST
  #include <err.h>
  #endif
  #include <string.h>
  
  #include "cdf.h"
  
  #define isleap(y) ((((y) % 4) == 0) && \
      ((((y) % 100) != 0) || (((y) % 400) == 0)))
  
  static const int mdays[] = {
      31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  };
  
  /*
   * Return the number of days between jan 01 1601 and jan 01 of year.
   */
  static int
  cdf_getdays(int year)
  {
  	int days = 0;
  	int y;
  
  	for (y = CDF_BASE_YEAR; y < year; y++)
  		days += isleap(y) + 365;
  		
  	return days;
  }
  
  /*
   * Return the day within the month
   */
  static int
  cdf_getday(int year, int days)
  {
  	size_t m;
  
  	for (m = 0; m < sizeof(mdays) / sizeof(mdays[0]); m++) {
  		int sub = mdays[m] + (m == 1 && isleap(year));
  		if (days < sub)
  			return days;
  		days -= sub;
  	}
  	return days;
  }
  
  /* 
   * Return the 0...11 month number.
   */
  static int
  cdf_getmonth(int year, int days)
  {
  	size_t m;
  
  	for (m = 0; m < sizeof(mdays) / sizeof(mdays[0]); m++) {
  		days -= mdays[m];
  		if (m == 1 && isleap(year))
  			days--;
  		if (days <= 0)
  			return (int)m;
  	}
  	return (int)m;
  }
  
  int
  cdf_timestamp_to_timespec(struct timeval *ts, cdf_timestamp_t t)
  {
  	struct tm tm;
  #ifdef HAVE_STRUCT_TM_TM_ZONE
  	static char UTC[] = "UTC";
  #endif
  	int rdays;
  
  	/* Time interval, in microseconds */
  	ts->tv_usec = (t % CDF_TIME_PREC) * CDF_TIME_PREC;
  
  	t /= CDF_TIME_PREC;
  	tm.tm_sec = (int)(t % 60);
  	t /= 60;
  
  	tm.tm_min = (int)(t % 60);
  	t /= 60;
  
  	tm.tm_hour = (int)(t % 24);
  	t /= 24;
  
  	/* XXX: Approx */
  	tm.tm_year = (int)(CDF_BASE_YEAR + (t / 365));
  
  	rdays = cdf_getdays(tm.tm_year);
  	t -= rdays - 1;
  	tm.tm_mday = cdf_getday(tm.tm_year, (int)t);
  	tm.tm_mon = cdf_getmonth(tm.tm_year, (int)t);
  	tm.tm_wday = 0;
  	tm.tm_yday = 0;
  	tm.tm_isdst = 0;
  #ifdef HAVE_STRUCT_TM_TM_GMTOFF
  	tm.tm_gmtoff = 0;
  #endif
  #ifdef HAVE_STRUCT_TM_TM_ZONE
  	tm.tm_zone = UTC;
  #endif
  	tm.tm_year -= 1900;
  	ts->tv_sec = mktime(&tm);
  	if (ts->tv_sec == -1) {
  		errno = EINVAL;
  		return -1;
  	}
  	return 0;
  }
  
  int
  /*ARGSUSED*/
  cdf_timespec_to_timestamp(cdf_timestamp_t *t, const struct timeval *ts)
  {
  #ifndef __lint__
  	(void)&t;
  	(void)&ts;
  #endif
  #ifdef notyet
  	struct tm tm;
  	if (gmtime_r(&ts->ts_sec, &tm) == NULL) {
  		errno = EINVAL;
  		return -1;
  	}
  	*t = (ts->ts_usec / CDF_TIME_PREC) * CDF_TIME_PREC;
  	*t = tm.tm_sec;
  	*t += tm.tm_min * 60;
  	*t += tm.tm_hour * 60 * 60;
  	*t += tm.tm_mday * 60 * 60 * 24;
  #endif
  	return 0;
  }
  
  char *
  cdf_ctime(const time_t *sec)
  {
  	static char ctbuf[26];
  	char *ptr = ctime(sec);
  	if (ptr != NULL)
  		return ptr;
  	(void)snprintf(ctbuf, sizeof(ctbuf), "*Bad* 0x%16.16llx\n",
  	    (long long)*sec);
  	return ctbuf;
  }
  
  
  #ifdef TEST
  int
  main(int argc, char *argv[])
  {
  	struct timeval ts;
  	static const cdf_timestamp_t tst = 0x01A5E403C2D59C00ULL;
  	static const char *ref = "Sat Apr 23 01:30:00 1977";
  	char *p, *q;
  
  	cdf_timestamp_to_timespec(&ts, tst);
  	p = cdf_ctime(&ts.tv_sec);
  	if ((q = strchr(p, '\n')) != NULL)
  		*q = '\0';
  	if (strcmp(ref, p) != 0)
  		errx(1, "Error date %s != %s\n", ref, p);
  	return 0;
  }
  #endif
  