/src/php-src/ext/date/lib/parse_posix.c

Source
/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2021 MongoDB, Inc.
 *
 * 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 "timelib.h"
#include "timelib_private.h"

// This section adds the missing 'strndup' implementation on Windows.
#if TIMELIB_USE_BUILTIN_STRNDUP == 1
# include <stdlib.h>
# include <string.h>

/**
 * char* timelib_strndup(const char* s, size_t n)
 *
 * Returns a pointer to a copy of 's' with at most 'n' characters
 * in memory obtained from 'malloc', or 'NULL' if insufficient
 * memory was available.  The result is always 'NULL' terminated.
 */
static char* timelib_strndup(const char* s, size_t n)
{
  char* result;
  size_t len = strlen(s);

  if (n < len) {
    len = n;
  }

  result = (char*)malloc(len + 1);
  if (!result) {
    return 0;
  }

  result[len] = '\0';
  return (char*)memcpy(result, s, len);
}
#endif

/* Forwards declrations */
static timelib_posix_trans_info *timelib_posix_trans_info_ctor(void);
static void timelib_posix_trans_info_dtor(timelib_posix_trans_info* ts);

/* "<" [+-]? .+? ">" */
static char *read_description_numeric_abbr(char **ptr)
{
  const char *begin = *ptr + 1;

  // skip '<'
  (*ptr)++;

  while (**ptr != '\0' && **ptr != '>') {
    (*ptr)++;
  }

  if (**ptr == '\0') {
    return NULL;
  }

  if (**ptr == '>') {
    (*ptr)++;
  }

  // Abbreviation may not be empty
  if (*ptr - begin - 1 < 1) {
    return NULL;
  }

  return timelib_strndup(begin, *ptr - begin - 1);
}

/* [A-Z]+ */
static char *read_description_abbr(char **ptr)
{
  const char *begin = *ptr;

  // Find the end
  while ((**ptr >= 'A' && **ptr <= 'Z') || (**ptr >= 'a' && **ptr <= 'z')) {
    (*ptr)++;
  }

  // Abbreviation may not be empty
  if (*ptr - begin < 1) {
    return NULL;
  }

  return timelib_strndup(begin, *ptr - begin);
}

/* "<" [+-]? .+? ">" | [A-Z]+ */
static char *read_description(char **ptr)
{
  if (**ptr == '<') {
    return read_description_numeric_abbr(ptr);
  } else {
    return read_description_abbr(ptr);
  }
}

/* [+-]? */
static int read_sign(char **ptr)
{
  int bias = 1;

  if (**ptr == '+') {
    (*ptr)++;
  } else if (**ptr == '-') {
    bias = -1;
    (*ptr)++;
  }

  return bias;
}

/* [0-9]+ */
static timelib_sll read_number(char **ptr)
{
  const char *begin = *ptr;
  int acc = 0;

  // skip leading 0's
  while (**ptr == '0') {
    (*ptr)++;
  }

  while (**ptr >= '0' && **ptr <= '9') {
    acc = acc * 10;
    acc += (**ptr) - '0';
    (*ptr)++;
  }

  if (begin == *ptr) {
    return TIMELIB_UNSET;
  }

  return acc;
}

/* [+-]? [0-9]+ ( ":" [0-9]+ ( ":" [0-9]+ )? )? */
static timelib_sll read_offset(char **ptr)
{
  const char *begin;
  int bias = read_sign(ptr);
  int hours = 0;
  int minutes = 0;
  int seconds = 0;

  begin = *ptr;

  // read through to : or non-digit for hours
  hours = read_number(ptr);
  if (hours == TIMELIB_UNSET) {
    return hours;
  }

  // check for optional minutes
  if (**ptr == ':') {
    (*ptr)++; // skip ':'
    minutes = read_number(ptr);
    if (minutes == TIMELIB_UNSET) {
      return minutes;
    }
  }

  // check for optional seconds
  if (**ptr == ':') {
    (*ptr)++; // skip ':'
    seconds = read_number(ptr);
    if (seconds == TIMELIB_UNSET) {
      return seconds;
    }
  }

  if (begin == *ptr) {
    return TIMELIB_UNSET;
  }

  // multiplication with -1, because the offset in the identifier is the
  // 'wrong' way around as for example EST5 is UTC-5 (and not +5)
  return -1 * bias * (hours * 3600 + minutes * 60 + seconds);
}


// Mw.m.d
static timelib_posix_trans_info* read_trans_spec_mwd(char **ptr)
{
  timelib_posix_trans_info *tmp = timelib_posix_trans_info_ctor();

  tmp->type = TIMELIB_POSIX_TRANS_TYPE_MWD;

  // Skip 'M'
  (*ptr)++;

  tmp->mwd.month = read_number(ptr);
  if (tmp->mwd.month == TIMELIB_UNSET) {
    goto fail;
  }

  // check for '.' and skip it
  if (**ptr != '.') {
    goto fail;
  }
  (*ptr)++;

  tmp->mwd.week = read_number(ptr);
  if (tmp->mwd.week == TIMELIB_UNSET) {
    goto fail;
  }

  // check for '.' and skip it
  if (**ptr != '.') {
    goto fail;
  }
  (*ptr)++;

  tmp->mwd.dow = read_number(ptr);
  if (tmp->mwd.dow == TIMELIB_UNSET) {
    goto fail;
  }

  return tmp;

fail:
  timelib_posix_trans_info_dtor(tmp);
  return NULL;
}

// (Jn | n | Mw.m.d) ( /time )?
static timelib_posix_trans_info* read_transition_spec(char **ptr)
{
  timelib_posix_trans_info *tmp;

  if (**ptr == 'M') {
    tmp = read_trans_spec_mwd(ptr);
    if (!tmp) {
      return NULL;
    }
  } else {
    tmp = timelib_posix_trans_info_ctor();

    if (**ptr == 'J') {
      tmp->type = TIMELIB_POSIX_TRANS_TYPE_JULIAN_NO_FEB29;
      (*ptr)++;
    }

    tmp->days = read_number(ptr);
    if (tmp->days == TIMELIB_UNSET) {
      goto fail;
    }
  }

  // Check for the optional hour
  if (**ptr == '/') {
    (*ptr)++;
    tmp->hour = read_offset(ptr);
    if (tmp->hour == TIMELIB_UNSET) {
      goto fail;
    }
    // as the bias for normal offsets = -1, we need to reverse it here
    tmp->hour = -tmp->hour;
  }

  return tmp;

fail:
  timelib_posix_trans_info_dtor(tmp);
  return NULL;
}

static timelib_posix_trans_info* timelib_posix_trans_info_ctor(void)
{
  timelib_posix_trans_info *tmp;

  tmp = timelib_calloc(1, sizeof(timelib_posix_trans_info));
  tmp->type = TIMELIB_POSIX_TRANS_TYPE_JULIAN_FEB29;
  tmp->hour = 2 * 3600;

  return tmp;
}

static void timelib_posix_trans_info_dtor(timelib_posix_trans_info* ts)
{
  timelib_free(ts);
}

void timelib_posix_str_dtor(timelib_posix_str *ps)
{
  if (ps->std) {
    timelib_free(ps->std);
  }
  if (ps->dst) {
    timelib_free(ps->dst);
  }
  if (ps->dst_begin) {
    timelib_posix_trans_info_dtor(ps->dst_begin);
  }
  if (ps->dst_end) {
    timelib_posix_trans_info_dtor(ps->dst_end);
  }

  timelib_free(ps);
}

timelib_posix_str* timelib_parse_posix_str(const char *posix)
{
  timelib_posix_str *tmp = timelib_calloc(1, sizeof(timelib_posix_str));
  char *ptr = (char*) posix;

  // read standard description (ie. EST or <-03>)
  tmp->std = read_description(&ptr);
  if (!tmp->std) {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  // read required offset
  tmp->std_offset = read_offset(&ptr);
  if (tmp->std_offset == TIMELIB_UNSET) {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  // if we're at the end return, otherwise we'll continue to try to parse
  // the dst abbreviation and spec
  if (*ptr == '\0') {
    return tmp;
  }

  // assume dst is there, and initialise offset
  tmp->dst_offset = tmp->std_offset + 3600;

  tmp->dst = read_description(&ptr);
  if (!tmp->dst) {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  // if we have a "," here, then the dst offset is the standard offset +
  // 3600 seconds, otherwise, try to parse the dst offset
  if (*ptr != ',' && *ptr != '\0') {
    tmp->dst_offset = read_offset(&ptr);
    if (tmp->dst_offset == TIMELIB_UNSET) {
      timelib_posix_str_dtor(tmp);
      return NULL;
    }
  }

  // if we *don't* have a "," here, we're missing the dst transitions
  // ,start[/time],end[/time]
  if (*ptr != ',') {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  ptr++; // skip ','

  // start[/time]
  tmp->dst_begin = read_transition_spec(&ptr);
  if (!tmp->dst_begin) {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  // if we *don't* have a "," here, we're missing the dst end transition
  // ,end[/time]
  if (*ptr != ',') {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  ptr++; // skip ','

  // end[/time]
  tmp->dst_end = read_transition_spec(&ptr);
  if (!tmp->dst_end) {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  // make sure there is no trailing data
  if (*ptr != '\0') {
    timelib_posix_str_dtor(tmp);
    return NULL;
  }

  return tmp;
}

static const int month_lengths[2][MONTHS_PER_YEAR] = {
  { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, // normal year
  { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }  // leap year
};

/* This function is adapted from the 'localtime.c' function 'transtime' as bundled with the 'tzcode' project
 * from IANA, and is public domain licensed. */
static timelib_sll calc_transition(timelib_posix_trans_info *psi, timelib_sll year)
{
  int leap_year = timelib_is_leap(year);

  switch (psi->type) {
    case TIMELIB_POSIX_TRANS_TYPE_JULIAN_NO_FEB29: {
      timelib_sll value = (psi->days - 1);

      if (leap_year && psi->days >= 60) {
        value++;
      }

      return value * SECS_PER_DAY;
    }

    case TIMELIB_POSIX_TRANS_TYPE_JULIAN_FEB29: {
      return psi->days * SECS_PER_DAY;
    }

    case TIMELIB_POSIX_TRANS_TYPE_MWD: {
      /*
       * Mm.n.d - nth "dth day" of month m.
       */

      int i, d, m1, yy0, yy1, yy2, dow;
      timelib_sll value = 0;

      /* Use Zeller's Congruence to get day-of-week of first day of
       * month. */
      m1 = (psi->mwd.month + 9) % 12 + 1;
      yy0 = (psi->mwd.month <= 2) ? (year - 1) : year;
      yy1 = yy0 / 100;
      yy2 = yy0 % 100;
      dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
      if (dow < 0) {
        dow += DAYS_PER_WEEK;
      }

      /* "dow" is the day-of-week of the first day of the month. Get the
       * day-of-month (zero-origin) of the first "dow" day of the month. */
      d = psi->mwd.dow - dow;
      if (d < 0) {
        d += DAYS_PER_WEEK;
      }
      for (i = 1; i < psi->mwd.week; ++i) {
        if (d + DAYS_PER_WEEK >= month_lengths[leap_year][psi->mwd.month - 1]) {
          break;
        }
        d += DAYS_PER_WEEK;
      }

      /* "d" is the day-of-month (zero-origin) of the day we want. */
      value = d * SECS_PER_DAY;
      for (i = 0; i < psi->mwd.month - 1; ++i) {
        value += month_lengths[leap_year][i] * SECS_PER_DAY;
      }

      return value;
    } break;
  }

  return 0;
}

static timelib_sll count_leap_years(timelib_sll y)
{
  /* Because we want this for Jan 1, the leap day hasn't happend yet, so
   * subtract one of year before we calculate */
  y--;

  return (y/4) - (y/100) + (y/400);
}

timelib_sll timelib_ts_at_start_of_year(timelib_sll year)
{
  timelib_sll epoch_leap_years = count_leap_years(1970);
  timelib_sll current_leap_years = count_leap_years(year);

  return SECS_PER_DAY * (
    ((year-1970) * DAYS_PER_YEAR)
    + current_leap_years
    - epoch_leap_years
  );
}

void timelib_get_transitions_for_year(timelib_tzinfo *tz, timelib_sll year, timelib_posix_transitions *transitions)
{
  timelib_sll trans_begin; /* Since start of the year */
  timelib_sll trans_end;
  timelib_sll year_begin_ts = timelib_ts_at_start_of_year(year);

  trans_begin = year_begin_ts;
  trans_begin += calc_transition(tz->posix_info->dst_begin, year);
  trans_begin += tz->posix_info->dst_begin->hour;
  trans_begin -= tz->posix_info->std_offset;

  trans_end = year_begin_ts;
  trans_end += calc_transition(tz->posix_info->dst_end, year);
  trans_end += tz->posix_info->dst_end->hour;
  trans_end -= tz->posix_info->dst_offset;

  if (trans_begin < trans_end) {
    transitions->times[transitions->count  ] = trans_begin;
    transitions->times[transitions->count+1] = trans_end;
    transitions->types[transitions->count  ] = tz->posix_info->type_index_dst_type;
    transitions->types[transitions->count+1] = tz->posix_info->type_index_std_type;
  } else {
    transitions->times[transitions->count+1] = trans_begin;
    transitions->times[transitions->count  ] = trans_end;
    transitions->types[transitions->count+1] = tz->posix_info->type_index_dst_type;
    transitions->types[transitions->count  ] = tz->posix_info->type_index_std_type;
  }

  transitions->count += 2;
}

ttinfo* timelib_fetch_posix_timezone_offset(timelib_tzinfo *tz, timelib_sll ts, timelib_sll *transition_time)
{
  timelib_sll               year;
  timelib_time              dummy;
  timelib_posix_transitions transitions = { 0 };
  size_t            i;

  /* If there is no second (dst_end) information, the UTC offset is valid for the whole year, so no need to
   * do clever logic */
  if (!tz->posix_info->dst_end) {
    if (transition_time) {
      *transition_time = tz->trans[tz->bit64.timecnt - 1];
    }
    return &(tz->type[tz->posix_info->type_index_std_type]);
  }

  /* Find 'year' (UTC) for 'ts' */
  timelib_unixtime2gmt(&dummy, ts);
  year = dummy.y;

  /* Calculate transition times for 'year-1', 'year', and 'year+1' */
  timelib_get_transitions_for_year(tz, year - 1, &transitions);
  timelib_get_transitions_for_year(tz, year,     &transitions);
  timelib_get_transitions_for_year(tz, year + 1, &transitions);

  /* Check where the 'ts' falls in the 4 transitions */
  for (i = 1; i < transitions.count; i++) {
    if (ts < transitions.times[i]) {
      if (transition_time) {
        *transition_time = transitions.times[i - 1];
      }
      return &(tz->type[transitions.types[i - 1]]);
    }
  }

  return NULL;
}

Coverage Report

Created: 2025-09-27 06:26

Line	Count	Source
1		/*
2		* The MIT License (MIT)
3		*
4		* Copyright (c) 2021 MongoDB, Inc.
5		*
6		* Permission is hereby granted, free of charge, to any person obtaining a copy
7		* of this software and associated documentation files (the "Software"), to deal
8		* in the Software without restriction, including without limitation the rights
9		* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10		* copies of the Software, and to permit persons to whom the Software is
11		* furnished to do so, subject to the following conditions:
12		*
13		* The above copyright notice and this permission notice shall be included in
14		* all copies or substantial portions of the Software.
15		*
16		* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17		* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18		* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19		* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20		* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21		* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22		* THE SOFTWARE.
23		*/
24
25		#include "timelib.h"
26		#include "timelib_private.h"
27
28		// This section adds the missing 'strndup' implementation on Windows.
29		#if TIMELIB_USE_BUILTIN_STRNDUP == 1
30		# include <stdlib.h>
31		# include <string.h>
32
33		/**
34		* char* timelib_strndup(const char* s, size_t n)
35		*
36		* Returns a pointer to a copy of 's' with at most 'n' characters
37		* in memory obtained from 'malloc', or 'NULL' if insufficient
38		* memory was available. The result is always 'NULL' terminated.
39		*/
40		static char* timelib_strndup(const char* s, size_t n)
41		{
42		char* result;
43		size_t len = strlen(s);
44
45		if (n < len) {
46		len = n;
47		}
48
49		result = (char*)malloc(len + 1);
50		if (!result) {
51		return 0;
52		}
53
54		result[len] = '\0';
55		return (char*)memcpy(result, s, len);
56		}
57		#endif
58
59		/* Forwards declrations */
60		static timelib_posix_trans_info *timelib_posix_trans_info_ctor(void);
61		static void timelib_posix_trans_info_dtor(timelib_posix_trans_info* ts);
62
63		/* "<" [+-]? .+? ">" */
64		static char read_description_numeric_abbr(char *ptr)
65	4	{
66	4	const char begin = ptr + 1;
67
68		// skip '<'
69	4	(*ptr)++;
70
71	24	while (ptr != '\0' && ptr != '>') {
72	20	(*ptr)++;
73	20	}
74
75	4	if (**ptr == '\0') {
76	0	return NULL;
77	0	}
78
79	4	if (**ptr == '>') {
80	4	(*ptr)++;
81	4	}
82
83		// Abbreviation may not be empty
84	4	if (*ptr - begin - 1 < 1) {
85	0	return NULL;
86	0	}
87
88	4	return timelib_strndup(begin, *ptr - begin - 1);
89	4	}
90
91		/* [A-Z]+ */
92		static char read_description_abbr(char *ptr)
93	6.40k	{
94	6.40k	const char begin = ptr;
95
96		// Find the end
97	25.9k	while ((ptr >= 'A' && ptr <= 'Z') \|\| (ptr >= 'a' && ptr <= 'z')) {
98	19.5k	(*ptr)++;
99	19.5k	}
100
101		// Abbreviation may not be empty
102	6.40k	if (*ptr - begin < 1) {
103	0	return NULL;
104	0	}
105
106	6.40k	return timelib_strndup(begin, *ptr - begin);
107	6.40k	}
108
109		/* "<" [+-]? .+? ">" \| [A-Z]+ */
110		static char read_description(char *ptr)
111	6.41k	{
112	6.41k	if (**ptr == '<') {
113	4	return read_description_numeric_abbr(ptr);
114	6.40k	} else {
115	6.40k	return read_description_abbr(ptr);
116	6.40k	}
117	6.41k	}
118
119		/* [+-]? */
120		static int read_sign(char **ptr)
121	6.41k	{
122	6.41k	int bias = 1;
123
124	6.41k	if (**ptr == '+') {
125	0	(*ptr)++;
126	6.41k	} else if (**ptr == '-') {
127	198	bias = -1;
128	198	(*ptr)++;
129	198	}
130
131	6.41k	return bias;
132	6.41k	}
133
134		/* [0-9]+ */
135		static timelib_sll read_number(char **ptr)
136	11.6k	{
137	11.6k	const char begin = ptr;
138	11.6k	int acc = 0;
139
140		// skip leading 0's
141	18.6k	while (**ptr == '0') {
142	7.08k	(*ptr)++;
143	7.08k	}
144
145	17.0k	while (ptr >= '0' && ptr <= '9') {
146	5.40k	acc = acc * 10;
147	5.40k	acc += (**ptr) - '0';
148	5.40k	(*ptr)++;
149	5.40k	}
150
151	11.6k	if (begin == *ptr) {
152	0	return TIMELIB_UNSET;
153	0	}
154
155	11.6k	return acc;
156	11.6k	}
157
158		/* [+-]? [0-9]+ ( ":" [0-9]+ ( ":" [0-9]+ )? )? */
159		static timelib_sll read_offset(char **ptr)
160	6.41k	{
161	6.41k	const char *begin;
162	6.41k	int bias = read_sign(ptr);
163	6.41k	int hours = 0;
164	6.41k	int minutes = 0;
165	6.41k	int seconds = 0;
166
167	6.41k	begin = *ptr;
168
169		// read through to : or non-digit for hours
170	6.41k	hours = read_number(ptr);
171	6.41k	if (hours == TIMELIB_UNSET) {
172	0	return hours;
173	0	}
174
175		// check for optional minutes
176	6.41k	if (**ptr == ':') {
177	4	(*ptr)++; // skip ':'
178	4	minutes = read_number(ptr);
179	4	if (minutes == TIMELIB_UNSET) {
180	0	return minutes;
181	0	}
182	4	}
183
184		// check for optional seconds
185	6.41k	if (**ptr == ':') {
186	0	(*ptr)++; // skip ':'
187	0	seconds = read_number(ptr);
188	0	if (seconds == TIMELIB_UNSET) {
189	0	return seconds;
190	0	}
191	0	}
192
193	6.41k	if (begin == *ptr) {
194	0	return TIMELIB_UNSET;
195	0	}
196
197		// multiplication with -1, because the offset in the identifier is the
198		// 'wrong' way around as for example EST5 is UTC-5 (and not +5)
199	6.41k	return -1 * bias * (hours * 3600 + minutes * 60 + seconds);
200	6.41k	}
201
202
203		// Mw.m.d
204		static timelib_posix_trans_info* read_trans_spec_mwd(char **ptr)
205	1.73k	{
206	1.73k	timelib_posix_trans_info *tmp = timelib_posix_trans_info_ctor();
207
208	1.73k	tmp->type = TIMELIB_POSIX_TRANS_TYPE_MWD;
209
210		// Skip 'M'
211	1.73k	(*ptr)++;
212
213	1.73k	tmp->mwd.month = read_number(ptr);
214	1.73k	if (tmp->mwd.month == TIMELIB_UNSET) {
215	0	goto fail;
216	0	}
217
218		// check for '.' and skip it
219	1.73k	if (**ptr != '.') {
220	0	goto fail;
221	0	}
222	1.73k	(*ptr)++;
223
224	1.73k	tmp->mwd.week = read_number(ptr);
225	1.73k	if (tmp->mwd.week == TIMELIB_UNSET) {
226	0	goto fail;
227	0	}
228
229		// check for '.' and skip it
230	1.73k	if (**ptr != '.') {
231	0	goto fail;
232	0	}
233	1.73k	(*ptr)++;
234
235	1.73k	tmp->mwd.dow = read_number(ptr);
236	1.73k	if (tmp->mwd.dow == TIMELIB_UNSET) {
237	0	goto fail;
238	0	}
239
240	1.73k	return tmp;
241
242	0	fail:
243	0	timelib_posix_trans_info_dtor(tmp);
244	0	return NULL;
245	1.73k	}
246
247		// (Jn \| n \| Mw.m.d) ( /time )?
248		static timelib_posix_trans_info* read_transition_spec(char **ptr)
249	1.73k	{
250	1.73k	timelib_posix_trans_info *tmp;
251
252	1.73k	if (**ptr == 'M') {
253	1.73k	tmp = read_trans_spec_mwd(ptr);
254	1.73k	if (!tmp) {
255	0	return NULL;
256	0	}
257	1.73k	} else {
258	0	tmp = timelib_posix_trans_info_ctor();
259
260	0	if (**ptr == 'J') {
261	0	tmp->type = TIMELIB_POSIX_TRANS_TYPE_JULIAN_NO_FEB29;
262	0	(*ptr)++;
263	0	}
264
265	0	tmp->days = read_number(ptr);
266	0	if (tmp->days == TIMELIB_UNSET) {
267	0	goto fail;
268	0	}
269	0	}
270
271		// Check for the optional hour
272	1.73k	if (**ptr == '/') {
273	867	(*ptr)++;
274	867	tmp->hour = read_offset(ptr);
275	867	if (tmp->hour == TIMELIB_UNSET) {
276	0	goto fail;
277	0	}
278		// as the bias for normal offsets = -1, we need to reverse it here
279	867	tmp->hour = -tmp->hour;
280	867	}
281
282	1.73k	return tmp;
283
284	0	fail:
285	0	timelib_posix_trans_info_dtor(tmp);
286	0	return NULL;
287	1.73k	}
288
289		static timelib_posix_trans_info* timelib_posix_trans_info_ctor(void)
290	1.73k	{
291	1.73k	timelib_posix_trans_info *tmp;
292
293	1.73k	tmp = timelib_calloc(1, sizeof(timelib_posix_trans_info));
294	1.73k	tmp->type = TIMELIB_POSIX_TRANS_TYPE_JULIAN_FEB29;
295	1.73k	tmp->hour = 2 * 3600;
296
297	1.73k	return tmp;
298	1.73k	}
299
300		static void timelib_posix_trans_info_dtor(timelib_posix_trans_info* ts)
301	1.73k	{
302	1.73k	timelib_free(ts);
303	1.73k	}
304
305		void timelib_posix_str_dtor(timelib_posix_str *ps)
306	5.54k	{
307	5.54k	if (ps->std) {
308	5.54k	timelib_free(ps->std);
309	5.54k	}
310	5.54k	if (ps->dst) {
311	867	timelib_free(ps->dst);
312	867	}
313	5.54k	if (ps->dst_begin) {
314	867	timelib_posix_trans_info_dtor(ps->dst_begin);
315	867	}
316	5.54k	if (ps->dst_end) {
317	867	timelib_posix_trans_info_dtor(ps->dst_end);
318	867	}
319
320	5.54k	timelib_free(ps);
321	5.54k	}
322
323		timelib_posix_str* timelib_parse_posix_str(const char *posix)
324	5.54k	{
325	5.54k	timelib_posix_str *tmp = timelib_calloc(1, sizeof(timelib_posix_str));
326	5.54k	char ptr = (char) posix;
327
328		// read standard description (ie. EST or <-03>)
329	5.54k	tmp->std = read_description(&ptr);
330	5.54k	if (!tmp->std) {
331	0	timelib_posix_str_dtor(tmp);
332	0	return NULL;
333	0	}
334
335		// read required offset
336	5.54k	tmp->std_offset = read_offset(&ptr);
337	5.54k	if (tmp->std_offset == TIMELIB_UNSET) {
338	0	timelib_posix_str_dtor(tmp);
339	0	return NULL;
340	0	}
341
342		// if we're at the end return, otherwise we'll continue to try to parse
343		// the dst abbreviation and spec
344	5.54k	if (*ptr == '\0') {
345	4.67k	return tmp;
346	4.67k	}
347
348		// assume dst is there, and initialise offset
349	867	tmp->dst_offset = tmp->std_offset + 3600;
350
351	867	tmp->dst = read_description(&ptr);
352	867	if (!tmp->dst) {
353	0	timelib_posix_str_dtor(tmp);
354	0	return NULL;
355	0	}
356
357		// if we have a "," here, then the dst offset is the standard offset +
358		// 3600 seconds, otherwise, try to parse the dst offset
359	867	if (ptr != ',' && ptr != '\0') {
360	1	tmp->dst_offset = read_offset(&ptr);
361	1	if (tmp->dst_offset == TIMELIB_UNSET) {
362	0	timelib_posix_str_dtor(tmp);
363	0	return NULL;
364	0	}
365	1	}
366
367		// if we don't have a "," here, we're missing the dst transitions
368		// ,start[/time],end[/time]
369	867	if (*ptr != ',') {
370	0	timelib_posix_str_dtor(tmp);
371	0	return NULL;
372	0	}
373
374	867	ptr++; // skip ','
375
376		// start[/time]
377	867	tmp->dst_begin = read_transition_spec(&ptr);
378	867	if (!tmp->dst_begin) {
379	0	timelib_posix_str_dtor(tmp);
380	0	return NULL;
381	0	}
382
383		// if we don't have a "," here, we're missing the dst end transition
384		// ,end[/time]
385	867	if (*ptr != ',') {
386	0	timelib_posix_str_dtor(tmp);
387	0	return NULL;
388	0	}
389
390	867	ptr++; // skip ','
391
392		// end[/time]
393	867	tmp->dst_end = read_transition_spec(&ptr);
394	867	if (!tmp->dst_end) {
395	0	timelib_posix_str_dtor(tmp);
396	0	return NULL;
397	0	}
398
399		// make sure there is no trailing data
400	867	if (*ptr != '\0') {
401	0	timelib_posix_str_dtor(tmp);
402	0	return NULL;
403	0	}
404
405	867	return tmp;
406	867	}
407
408		static const int month_lengths[2][MONTHS_PER_YEAR] = {
409		{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, // normal year
410		{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } // leap year
411		};
412
413		/* This function is adapted from the 'localtime.c' function 'transtime' as bundled with the 'tzcode' project
414		* from IANA, and is public domain licensed. */
415		static timelib_sll calc_transition(timelib_posix_trans_info *psi, timelib_sll year)
416	36	{
417	36	int leap_year = timelib_is_leap(year);
418
419	36	switch (psi->type) {
420	0	case TIMELIB_POSIX_TRANS_TYPE_JULIAN_NO_FEB29: {
421	0	timelib_sll value = (psi->days - 1);
422
423	0	if (leap_year && psi->days >= 60) {
424	0	value++;
425	0	}
426
427	0	return value * SECS_PER_DAY;
428	0	}
429
430	0	case TIMELIB_POSIX_TRANS_TYPE_JULIAN_FEB29: {
431	0	return psi->days * SECS_PER_DAY;
432	0	}
433
434	36	case TIMELIB_POSIX_TRANS_TYPE_MWD: {
435		/*
436		* Mm.n.d - nth "dth day" of month m.
437		*/
438
439	36	int i, d, m1, yy0, yy1, yy2, dow;
440	36	timelib_sll value = 0;
441
442		/* Use Zeller's Congruence to get day-of-week of first day of
443		* month. */
444	36	m1 = (psi->mwd.month + 9) % 12 + 1;
445	36	yy0 = (psi->mwd.month <= 2) ? (year - 1) : year;
446	36	yy1 = yy0 / 100;
447	36	yy2 = yy0 % 100;
448	36	dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
449	36	if (dow < 0) {
450	0	dow += DAYS_PER_WEEK;
451	0	}
452
453		/* "dow" is the day-of-week of the first day of the month. Get the
454		* day-of-month (zero-origin) of the first "dow" day of the month. */
455	36	d = psi->mwd.dow - dow;
456	36	if (d < 0) {
457	30	d += DAYS_PER_WEEK;
458	30	}
459	96	for (i = 1; i < psi->mwd.week; ++i) {
460	72	if (d + DAYS_PER_WEEK >= month_lengths[leap_year][psi->mwd.month - 1]) {
461	12	break;
462	12	}
463	60	d += DAYS_PER_WEEK;
464	60	}
465
466		/* "d" is the day-of-month (zero-origin) of the day we want. */
467	36	value = d * SECS_PER_DAY;
468	234	for (i = 0; i < psi->mwd.month - 1; ++i) {
469	198	value += month_lengths[leap_year][i] * SECS_PER_DAY;
470	198	}
471
472	36	return value;
473	0	} break;
474	36	}
475
476	0	return 0;
477	36	}
478
479		static timelib_sll count_leap_years(timelib_sll y)
480	36	{
481		/* Because we want this for Jan 1, the leap day hasn't happend yet, so
482		* subtract one of year before we calculate */
483	36	y--;
484
485	36	return (y/4) - (y/100) + (y/400);
486	36	}
487
488		timelib_sll timelib_ts_at_start_of_year(timelib_sll year)
489	18	{
490	18	timelib_sll epoch_leap_years = count_leap_years(1970);
491	18	timelib_sll current_leap_years = count_leap_years(year);
492
493	18	return SECS_PER_DAY * (
494	18	((year-1970) * DAYS_PER_YEAR)
495	18	+ current_leap_years
496	18	- epoch_leap_years
497	18	);
498	18	}
499
500		void timelib_get_transitions_for_year(timelib_tzinfo tz, timelib_sll year, timelib_posix_transitions transitions)
501	18	{
502	18	timelib_sll trans_begin; /* Since start of the year */
503	18	timelib_sll trans_end;
504	18	timelib_sll year_begin_ts = timelib_ts_at_start_of_year(year);
505
506	18	trans_begin = year_begin_ts;
507	18	trans_begin += calc_transition(tz->posix_info->dst_begin, year);
508	18	trans_begin += tz->posix_info->dst_begin->hour;
509	18	trans_begin -= tz->posix_info->std_offset;
510
511	18	trans_end = year_begin_ts;
512	18	trans_end += calc_transition(tz->posix_info->dst_end, year);
513	18	trans_end += tz->posix_info->dst_end->hour;
514	18	trans_end -= tz->posix_info->dst_offset;
515
516	18	if (trans_begin < trans_end) {
517	0	transitions->times[transitions->count ] = trans_begin;
518	0	transitions->times[transitions->count+1] = trans_end;
519	0	transitions->types[transitions->count ] = tz->posix_info->type_index_dst_type;
520	0	transitions->types[transitions->count+1] = tz->posix_info->type_index_std_type;
521	18	} else {
522	18	transitions->times[transitions->count+1] = trans_begin;
523	18	transitions->times[transitions->count ] = trans_end;
524	18	transitions->types[transitions->count+1] = tz->posix_info->type_index_dst_type;
525	18	transitions->types[transitions->count ] = tz->posix_info->type_index_std_type;
526	18	}
527
528	18	transitions->count += 2;
529	18	}
530
531		ttinfo* timelib_fetch_posix_timezone_offset(timelib_tzinfo tz, timelib_sll ts, timelib_sll transition_time)
532	5.34k	{
533	5.34k	timelib_sll year;
534	5.34k	timelib_time dummy;
535	5.34k	timelib_posix_transitions transitions = { 0 };
536	5.34k	size_t i;
537
538		/* If there is no second (dst_end) information, the UTC offset is valid for the whole year, so no need to
539		* do clever logic */
540	5.34k	if (!tz->posix_info->dst_end) {
541	5.33k	if (transition_time) {
542	0	*transition_time = tz->trans[tz->bit64.timecnt - 1];
543	0	}
544	5.33k	return &(tz->type[tz->posix_info->type_index_std_type]);
545	5.33k	}
546
547		/* Find 'year' (UTC) for 'ts' */
548	6	timelib_unixtime2gmt(&dummy, ts);
549	6	year = dummy.y;
550
551		/* Calculate transition times for 'year-1', 'year', and 'year+1' */
552	6	timelib_get_transitions_for_year(tz, year - 1, &transitions);
553	6	timelib_get_transitions_for_year(tz, year, &transitions);
554	6	timelib_get_transitions_for_year(tz, year + 1, &transitions);
555
556		/* Check where the 'ts' falls in the 4 transitions */
557	18	for (i = 1; i < transitions.count; i++) {
558	18	if (ts < transitions.times[i]) {
559	6	if (transition_time) {
560	6	*transition_time = transitions.times[i - 1];
561	6	}
562	6	return &(tz->type[transitions.types[i - 1]]);
563	6	}
564	18	}
565
566	0	return NULL;
567	6	}