summaryrefslogtreecommitdiffstats
path: root/nuttx/sched/mktime.c
blob: 9c849646330194b33d2936e7f83e73d57edbde71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/************************************************************
 * mktime.c
 *
 *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * 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.
 * 3. Neither the name Gregory Nutt nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT OWNER 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.
 *
 ************************************************************/

/************************************************************
 * Included Files
 ************************************************************/

#include <sys/types.h>
#include <time.h>
#include <debug.h>
#include "clock_internal.h"

/************************************************************
 * Definitions
 ************************************************************/

/************************************************************
 * Private Type Declarations
 ************************************************************/

/************************************************************
 * Private Function Prototypes
 ************************************************************/

/**********************************************************
 * Public Constant Data
 **********************************************************/

/************************************************************
 * Public Variables
 ************************************************************/

/**********************************************************
 * Private Variables
 **********************************************************/

/************************************************************
 * Private Functions
 ************************************************************/

/************************************************************
 * Function:  clock_gregorian2utc, clock_julian2utc
 *
 * Description:
 *    UTC conversion routines.  These conversions are based
 *    on algorithms from p. 604 of Seidelman, P. K. 1992.
 *    Explanatory Supplement to the Astronomical Almanac.
 *    University Science Books, Mill Valley. 
 *
 ************************************************************/

static inline time_t clock_gregorian2utc(int year, int month, int day)
{
  int temp;

  /* temp = (month - 14)/12; */

  temp = (month <= 2 ? -1:0);

  return (1461*(year + 4800 + temp))/4
    + (367*(month - 2 - 12*temp))/12
    - (3*((year + 4900 + temp)/100))/4 + day - 32075;
}

#ifdef CONFIG_JULIAN_TIME
static inline time_t clock_julian2utc(int year, int month, int day)
{
  return 367*year
    - (7*(year + 5001 + (month-9)/7))/4
    + (275*month)/9
    + day + 1729777;
}
#endif

/************************************************************
 * Public Functions
 ************************************************************/

/************************************************************
 * Function:  mktime
 *
 * Description:
 *  Time conversion (based on the POSIX API)
 *
 ************************************************************/

time_t mktime(struct tm *tp)
{
  time_t ret;
  time_t jdn;

  /* Get the EPOCH-relative julian date from the calendar year,
   * month, and date
   */

  jdn = clock_calendar2utc(tp->tm_year+1900, tp->tm_mon+1, tp->tm_mday);
  dbg("%s: jdn=%d tm_year=%d tm_mon=%d tm_mday=%d\n",
      __FUNCTION__, (int)jdn, tp->tm_year, tp->tm_mon, tp->tm_mday);

  /* Return the seconds into the julian day. */

  ret = ((jdn*24 + tp->tm_hour)*60 + tp->tm_min)*60 + tp->tm_sec;
  dbg("%s:\tret=%d tm_hour=%d tm_min=%d tm_sec=%d\n",
      __FUNCTION__, (int)ret, tp->tm_hour, tp->tm_min, tp->tm_sec);

  return ret;
}

/************************************************************
 * Function:  clock_calendar2utc
 *
 * Description:
 *    Calendar/UTC conversion based on algorithms from p. 604
 *    of Seidelman, P. K. 1992.  Explanatory Supplement to
 *    the Astronomical Almanac.  University Science Books,
 *    Mill Valley. 
 *
 ************************************************************/

time_t clock_calendar2utc(int year, int month, int day)
{
  int dyear;
#ifdef CONFIG_JULIAN_TIME
  int isgreg;
#endif /* CONFIG_JULIAN_TIME */

  /* Correct year & month ranges.  Shift month into range 1-12 */

  dyear = (month-1) / 12;	
  month -= 12 * dyear;
  year += dyear;

  if (month < 1)
    {
      month += 12;
      year -= 1;
    }

#ifdef CONFIG_JULIAN_TIME
  /* Determine which calendar to use */

  if (year > GREG_YEAR)
    {
      isgreg = TRUE;
    }
  else if (year < GREG_YEAR)
    {
      isgreg = FALSE;
    }
  else if (month > GREG_MONTH)
    {
      isgreg = TRUE;
    }
  else if (month < GREG_MONTH)
    {
      isgreg = FALSE;
    }
  else
    {
      isgreg = (day >= GREG_DAY);
    }

  /* Calculate and return date */

  if (isgreg)
    {
      return clock_gregorian2utc(year, month, day) - JD_OF_EPOCH;
    }
  else
    {
      return clock_julian2utc (year, month, day) - JD_OF_EPOCH;
    }

#else /* CONFIG_JULIAN_TIME */

  return clock_gregorian2utc(year, month, day) - JD_OF_EPOCH;

#endif /* CONFIG_JULIAN_TIME */
}