glib/gdate.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-or-later
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #ifndef __G_DATE_H__
  28 #define __G_DATE_H__
  29
  30 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  31 #error "Only <glib.h> can be included directly."
  32 #endif
  33
  34 #include <time.h>
  35
  36 #include <glib/gtypes.h>
  37 #include <glib/gquark.h>
  38
  39 G_BEGIN_DECLS
  40
  41 /* GDate
  42  *
  43  * Date calculations (not time for now, to be resolved). These are a
  44  * mutant combination of Steffen Beyer's DateCalc routines
  45  * (http://www.perl.com/CPAN/authors/id/STBEY/) and Jon Trowbridge's
  46  * date routines (written for in-house software).  Written by Havoc
  47  * Pennington <hp@pobox.com>
  48  */
  49
  50 typedef gint32  GTime GLIB_DEPRECATED_TYPE_IN_2_62_FOR(GDateTime);
  51 typedef guint16 GDateYear;
  52 typedef guint8  GDateDay;   /* day of the month */
  53 typedef struct _GDate GDate;
  54
  55 /* enum used to specify order of appearance in parsed date strings */
  56 typedef enum
  57 {
  58   G_DATE_DAY   = 0,
  59   G_DATE_MONTH = 1,
  60   G_DATE_YEAR  = 2
  61 } GDateDMY;
  62
  63 /* actual week and month values */
  64 typedef enum
  65 {
  66   G_DATE_BAD_WEEKDAY  = 0,
  67   G_DATE_MONDAY       = 1,
  68   G_DATE_TUESDAY      = 2,
  69   G_DATE_WEDNESDAY    = 3,
  70   G_DATE_THURSDAY     = 4,
  71   G_DATE_FRIDAY       = 5,
  72   G_DATE_SATURDAY     = 6,
  73   G_DATE_SUNDAY       = 7
  74 } GDateWeekday;
  75 typedef enum
  76 {
  77   G_DATE_BAD_MONTH = 0,
  78   G_DATE_JANUARY   = 1,
  79   G_DATE_FEBRUARY  = 2,
  80   G_DATE_MARCH     = 3,
  81   G_DATE_APRIL     = 4,
  82   G_DATE_MAY       = 5,
  83   G_DATE_JUNE      = 6,
  84   G_DATE_JULY      = 7,
  85   G_DATE_AUGUST    = 8,
  86   G_DATE_SEPTEMBER = 9,
  87   G_DATE_OCTOBER   = 10,
  88   G_DATE_NOVEMBER  = 11,
  89   G_DATE_DECEMBER  = 12
  90 } GDateMonth;
  91
  92 #define G_DATE_BAD_JULIAN 0U
  93 #define G_DATE_BAD_DAY    0U
  94 #define G_DATE_BAD_YEAR   0U
  95
  96 /* Note: directly manipulating structs is generally a bad idea, but
  97  * in this case it's an *incredibly* bad idea, because all or part
  98  * of this struct can be invalid at any given time. Use the functions,
  99  * or you will get hosed, I promise.
 100  */
 101 struct _GDate
 102 {
 103   guint julian_days : 32; /* julian days representation - we use a
 104                            *  bitfield hoping that 64 bit platforms
 105                            *  will pack this whole struct in one big
 106                            *  int
 107                            */
 108
 109   guint julian : 1;    /* julian is valid */
 110   guint dmy    : 1;    /* dmy is valid */
 111
 112   /* DMY representation */
 113   guint day    : 6;
 114   guint month  : 4;
 115   guint year   : 16;
 116 };
 117
 118 /* g_date_new() returns an invalid date, you then have to _set() stuff
 119  * to get a usable object. You can also allocate a GDate statically,
 120  * then call g_date_clear() to initialize.
 121  */
 122 GLIB_AVAILABLE_IN_ALL
 123 GDate*       g_date_new                   (void);
 124 GLIB_AVAILABLE_IN_ALL
 125 GDate*       g_date_new_dmy               (GDateDay     day,
 126                                            GDateMonth   month,
 127                                            GDateYear    year);
 128 GLIB_AVAILABLE_IN_ALL
 129 GDate*       g_date_new_julian            (guint32      julian_day);
 130 GLIB_AVAILABLE_IN_ALL
 131 void         g_date_free                  (GDate       *date);
 132 GLIB_AVAILABLE_IN_2_56
 133 GDate*       g_date_copy                  (const GDate *date);
 134
 135 /* check g_date_valid() after doing an operation that might fail, like
 136  * _parse.  Almost all g_date operations are undefined on invalid
 137  * dates (the exceptions are the mutators, since you need those to
 138  * return to validity).
 139  */
 140 GLIB_AVAILABLE_IN_ALL
 141 gboolean     g_date_valid                 (const GDate *date);
 142 GLIB_AVAILABLE_IN_ALL
 143 gboolean     g_date_valid_day             (GDateDay     day) G_GNUC_CONST;
 144 GLIB_AVAILABLE_IN_ALL
 145 gboolean     g_date_valid_month           (GDateMonth month) G_GNUC_CONST;
 146 GLIB_AVAILABLE_IN_ALL
 147 gboolean     g_date_valid_year            (GDateYear  year) G_GNUC_CONST;
 148 GLIB_AVAILABLE_IN_ALL
 149 gboolean     g_date_valid_weekday         (GDateWeekday weekday) G_GNUC_CONST;
 150 GLIB_AVAILABLE_IN_ALL
 151 gboolean     g_date_valid_julian          (guint32 julian_date) G_GNUC_CONST;
 152 GLIB_AVAILABLE_IN_ALL
 153 gboolean     g_date_valid_dmy             (GDateDay     day,
 154                                            GDateMonth   month,
 155                                            GDateYear    year) G_GNUC_CONST;
 156
 157 GLIB_AVAILABLE_IN_ALL
 158 GDateWeekday g_date_get_weekday           (const GDate *date);
 159 GLIB_AVAILABLE_IN_ALL
 160 GDateMonth   g_date_get_month             (const GDate *date);
 161 GLIB_AVAILABLE_IN_ALL
 162 GDateYear    g_date_get_year              (const GDate *date);
 163 GLIB_AVAILABLE_IN_ALL
 164 GDateDay     g_date_get_day               (const GDate *date);
 165 GLIB_AVAILABLE_IN_ALL
 166 guint32      g_date_get_julian            (const GDate *date);
 167 GLIB_AVAILABLE_IN_ALL
 168 guint        g_date_get_day_of_year       (const GDate *date);
 169 /* First monday/sunday is the start of week 1; if we haven't reached
 170  * that day, return 0. These are not ISO weeks of the year; that
 171  * routine needs to be added.
 172  * these functions return the number of weeks, starting on the
 173  * corresponding day
 174  */
 175 GLIB_AVAILABLE_IN_ALL
 176 guint        g_date_get_monday_week_of_year (const GDate *date);
 177 GLIB_AVAILABLE_IN_ALL
 178 guint        g_date_get_sunday_week_of_year (const GDate *date);
 179 GLIB_AVAILABLE_IN_ALL
 180 guint        g_date_get_iso8601_week_of_year (const GDate *date);
 181
 182 /* If you create a static date struct you need to clear it to get it
 183  * in a safe state before use. You can clear a whole array at
 184  * once with the ndates argument.
 185  */
 186 GLIB_AVAILABLE_IN_ALL
 187 void         g_date_clear                 (GDate       *date,
 188                                            guint        n_dates);
 189
 190 /* The parse routine is meant for dates typed in by a user, so it
 191  * permits many formats but tries to catch common typos. If your data
 192  * needs to be strictly validated, it is not an appropriate function.
 193  */
 194 GLIB_AVAILABLE_IN_ALL
 195 void         g_date_set_parse             (GDate       *date,
 196                                            const gchar *str);
 197 GLIB_AVAILABLE_IN_ALL
 198 void         g_date_set_time_t            (GDate       *date,
 199                                            time_t       timet);
 200 G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 201 GLIB_DEPRECATED_IN_2_62_FOR(g_date_set_time_t)
 202 void         g_date_set_time_val          (GDate       *date,
 203                                            GTimeVal    *timeval);
 204 GLIB_DEPRECATED_FOR(g_date_set_time_t)
 205 void         g_date_set_time              (GDate       *date,
 206                                            GTime        time_);
 207 G_GNUC_END_IGNORE_DEPRECATIONS
 208 GLIB_AVAILABLE_IN_ALL
 209 void         g_date_set_month             (GDate       *date,
 210                                            GDateMonth   month);
 211 GLIB_AVAILABLE_IN_ALL
 212 void         g_date_set_day               (GDate       *date,
 213                                            GDateDay     day);
 214 GLIB_AVAILABLE_IN_ALL
 215 void         g_date_set_year              (GDate       *date,
 216                                            GDateYear    year);
 217 GLIB_AVAILABLE_IN_ALL
 218 void         g_date_set_dmy               (GDate       *date,
 219                                            GDateDay     day,
 220                                            GDateMonth   month,
 221                                            GDateYear    y);
 222 GLIB_AVAILABLE_IN_ALL
 223 void         g_date_set_julian            (GDate       *date,
 224                                            guint32      julian_date);
 225 GLIB_AVAILABLE_IN_ALL
 226 gboolean     g_date_is_first_of_month     (const GDate *date);
 227 GLIB_AVAILABLE_IN_ALL
 228 gboolean     g_date_is_last_of_month      (const GDate *date);
 229
 230 /* To go forward by some number of weeks just go forward weeks*7 days */
 231 GLIB_AVAILABLE_IN_ALL
 232 void         g_date_add_days              (GDate       *date,
 233                                            guint        n_days);
 234 GLIB_AVAILABLE_IN_ALL
 235 void         g_date_subtract_days         (GDate       *date,
 236                                            guint        n_days);
 237
 238 /* If you add/sub months while day > 28, the day might change */
 239 GLIB_AVAILABLE_IN_ALL
 240 void         g_date_add_months            (GDate       *date,
 241                                            guint        n_months);
 242 GLIB_AVAILABLE_IN_ALL
 243 void         g_date_subtract_months       (GDate       *date,
 244                                            guint        n_months);
 245
 246 /* If it's feb 29, changing years can move you to the 28th */
 247 GLIB_AVAILABLE_IN_ALL
 248 void         g_date_add_years             (GDate       *date,
 249                                            guint        n_years);
 250 GLIB_AVAILABLE_IN_ALL
 251 void         g_date_subtract_years        (GDate       *date,
 252                                            guint        n_years);
 253 GLIB_AVAILABLE_IN_ALL
 254 gboolean     g_date_is_leap_year          (GDateYear    year) G_GNUC_CONST;
 255 GLIB_AVAILABLE_IN_ALL
 256 guint8       g_date_get_days_in_month     (GDateMonth   month,
 257                                            GDateYear    year) G_GNUC_CONST;
 258 GLIB_AVAILABLE_IN_ALL
 259 guint8       g_date_get_monday_weeks_in_year  (GDateYear    year) G_GNUC_CONST;
 260 GLIB_AVAILABLE_IN_ALL
 261 guint8       g_date_get_sunday_weeks_in_year  (GDateYear    year) G_GNUC_CONST;
 262
 263 /* Returns the number of days between the two dates.  If date2 comes
 264    before date1, a negative value is return. */
 265 GLIB_AVAILABLE_IN_ALL
 266 gint         g_date_days_between          (const GDate *date1,
 267                                            const GDate *date2);
 268
 269 /* qsort-friendly (with a cast...) */
 270 GLIB_AVAILABLE_IN_ALL
 271 gint         g_date_compare               (const GDate *lhs,
 272                                            const GDate *rhs);
 273 GLIB_AVAILABLE_IN_ALL
 274 void         g_date_to_struct_tm          (const GDate *date,
 275                                            struct tm   *tm);
 276
 277 GLIB_AVAILABLE_IN_ALL
 278 void         g_date_clamp                 (GDate *date,
 279                                            const GDate *min_date,
 280                                            const GDate *max_date);
 281
 282 /* Swap date1 and date2's values if date1 > date2. */
 283 GLIB_AVAILABLE_IN_ALL
 284 void         g_date_order                 (GDate *date1, GDate *date2);
 285
 286 /* Just like strftime() except you can only use date-related formats.
 287  *   Using a time format is undefined.
 288  */
 289 GLIB_AVAILABLE_IN_ALL
 290 gsize        g_date_strftime              (gchar       *s,
 291                                            gsize        slen,
 292                                            const gchar *format,
 293                                            const GDate *date);
 294
 295 #define g_date_weekday                  g_date_get_weekday GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_weekday)
 296 #define g_date_month                    g_date_get_month GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_month)
 297 #define g_date_year                     g_date_get_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_year)
 298 #define g_date_day                      g_date_get_day GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_day)
 299 #define g_date_julian                   g_date_get_julian GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_julian)
 300 #define g_date_day_of_year              g_date_get_day_of_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_day_of_year)
 301 #define g_date_monday_week_of_year      g_date_get_monday_week_of_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_monday_week_of_year)
 302 #define g_date_sunday_week_of_year      g_date_get_sunday_week_of_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_sunday_week_of_year)
 303 #define g_date_days_in_month            g_date_get_days_in_month GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_days_in_month)
 304 #define g_date_monday_weeks_in_year     g_date_get_monday_weeks_in_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_monday_weeks_in_year)
 305 #define g_date_sunday_weeks_in_year     g_date_get_sunday_weeks_in_year GLIB_DEPRECATED_MACRO_IN_2_26_FOR(g_date_get_sunday_weeks_in_year)
 306
 307 G_END_DECLS
 308
 309 #endif /* __G_DATE_H__ */