time/era.c

   1 /* Helper functions used by strftime/strptime to handle locale-specific "eras".
   2    Copyright (C) 1995-2002, 2008, 2010 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "../locale/localeinfo.h"
  20 #include <bits/libc-lock.h>
  21 #include <stdlib.h>
  22 #include <wchar.h>
  23 #include <string.h>
  24
  25 /* Some of the functions here must not be used while setlocale is called.  */
  26 __libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
  27
  28 #define CURRENT(item)           (current->values[_NL_ITEM_INDEX (item)].string)
  29 #define CURRENT_WORD(item)      (current->values[_NL_ITEM_INDEX (item)].word)
  30
  31 #define ERA_DATE_CMP(a, b) \
  32   (a[0] < b[0] || (a[0] == b[0] && (a[1] < b[1]                               \
  33                                     || (a[1] == b[1] && a[2] <= b[2]))))
  34
  35 /* Look up the era information in CURRENT's locale strings and
  36    cache it in CURRENT->private.  */
  37 static void internal_function
  38 _nl_init_era_entries (struct __locale_data *current)
  39 {
  40   size_t cnt;
  41   struct lc_time_data *data;
  42
  43   /* Avoid touching CURRENT if there is no data at all, for _nl_C_LC_TIME.  */
  44   if (CURRENT_WORD (_NL_TIME_ERA_NUM_ENTRIES) == 0)
  45     return;
  46
  47   __libc_rwlock_wrlock (__libc_setlocale_lock);
  48
  49   if (current->private.time == NULL)
  50     {
  51       current->private.time = malloc (sizeof *current->private.time);
  52       if (current->private.time == NULL)
  53         goto out;
  54       memset (current->private.time, 0, sizeof *current->private.time);
  55       current->private.cleanup = &_nl_cleanup_time;
  56     }
  57   data = current->private.time;
  58
  59   if (! data->era_initialized)
  60     {
  61       size_t new_num_eras = CURRENT_WORD (_NL_TIME_ERA_NUM_ENTRIES);
  62       if (new_num_eras == 0)
  63         {
  64           if (data->eras != NULL)
  65             {
  66               free (data->eras);
  67               data->eras = NULL;
  68             }
  69         }
  70       else
  71         {
  72           struct era_entry *new_eras = data->eras;
  73
  74           if (data->num_eras != new_num_eras)
  75             new_eras =
  76               (struct era_entry *) realloc (data->eras,
  77                                             new_num_eras
  78                                             * sizeof (struct era_entry));
  79           if (new_eras == NULL)
  80             {
  81               free (data->eras);
  82               data->num_eras = 0;
  83               data->eras = NULL;
  84             }
  85           else
  86             {
  87               const char *ptr = CURRENT (_NL_TIME_ERA_ENTRIES);
  88               data->num_eras = new_num_eras;
  89               data->eras = new_eras;
  90
  91               for (cnt = 0; cnt < new_num_eras; ++cnt)
  92                 {
  93                   const char *base_ptr = ptr;
  94                   memcpy ((void *) (new_eras + cnt), (const void *) ptr,
  95                           sizeof (uint32_t) * 8);
  96
  97                   if (ERA_DATE_CMP(new_eras[cnt].start_date,
  98                                    new_eras[cnt].stop_date))
  99                     if (new_eras[cnt].direction == (uint32_t) '+')
 100                       new_eras[cnt].absolute_direction = 1;
 101                     else
 102                       new_eras[cnt].absolute_direction = -1;
 103                   else
 104                     if (new_eras[cnt].direction == (uint32_t) '+')
 105                       new_eras[cnt].absolute_direction = -1;
 106                     else
 107                       new_eras[cnt].absolute_direction = 1;
 108
 109                   /* Skip numeric values.  */
 110                   ptr += sizeof (uint32_t) * 8;
 111
 112                   /* Set and skip era name.  */
 113                   new_eras[cnt].era_name = ptr;
 114                   ptr = strchr (ptr, '\0') + 1;
 115
 116                   /* Set and skip era format.  */
 117                   new_eras[cnt].era_format = ptr;
 118                   ptr = strchr (ptr, '\0') + 1;
 119
 120                   ptr += 3 - (((ptr - (const char *) base_ptr) + 3) & 3);
 121
 122                   /* Set and skip wide era name.  */
 123                   new_eras[cnt].era_wname = (wchar_t *) ptr;
 124                   ptr = (char *) (wcschr ((wchar_t *) ptr, L'\0') + 1);
 125
 126                   /* Set and skip wide era format.  */
 127                   new_eras[cnt].era_wformat = (wchar_t *) ptr;
 128                   ptr = (char *) (wcschr ((wchar_t *) ptr, L'\0') + 1);
 129                 }
 130             }
 131         }
 132
 133       data->era_initialized = 1;
 134     }
 135
 136  out:
 137   __libc_rwlock_unlock (__libc_setlocale_lock);
 138 }
 139
 140 struct era_entry *
 141 internal_function
 142 _nl_get_era_entry (const struct tm *tp, struct __locale_data *current)
 143 {
 144   if (current->private.time == NULL || !current->private.time->era_initialized)
 145     _nl_init_era_entries (current);
 146
 147   if (current->private.time != NULL)
 148     {
 149       /* Now compare date with the available eras.  */
 150       const int32_t tdate[3] = { tp->tm_year, tp->tm_mon, tp->tm_mday };
 151       size_t cnt;
 152       for (cnt = 0; cnt < current->private.time->num_eras; ++cnt)
 153         if ((ERA_DATE_CMP (current->private.time->eras[cnt].start_date, tdate)
 154              && ERA_DATE_CMP (tdate,
 155                               current->private.time->eras[cnt].stop_date))
 156             || (ERA_DATE_CMP (current->private.time->eras[cnt].stop_date,
 157                               tdate)
 158                 && ERA_DATE_CMP (tdate,
 159                                  current->private.time->eras[cnt].start_date)))
 160           return &current->private.time->eras[cnt];
 161     }
 162
 163   return NULL;
 164 }
 165
 166
 167 struct era_entry *
 168 internal_function
 169 _nl_select_era_entry (int cnt, struct __locale_data *current)
 170 {
 171   if (current->private.time == NULL || !current->private.time->era_initialized)
 172     _nl_init_era_entries (current);
 173
 174   return (current->private.time == NULL
 175           ? NULL : &current->private.time->eras[cnt]);
 176 }