glib/gdatetime-private.c - third_party/glib - Git at Google

 /*
  * Copyright 2023 GNOME Foundation Inc.
  *
  * SPDX-License-Identifier: LGPL-2.1-or-later
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  *
  * Authors:
  *  - Philip Withnall <pwithnall@gnome.org>
  */

 #include "glib.h"
 #include "gdatetime-private.h"

 /**
  * _g_era_date_compare:
  * @date1: first date
  * @date2: second date
  *
  * Compare two #GEraDates for ordering, taking into account negative and
  * positive infinity.
  *
  * Returns: strcmp()-style integer, `<0` indicates `date1 < date2`, `0`
  *   indicates `date1 == date2`, `>0` indicates `date1 > date2`
  * Since: 2.80
  */
 int
 _g_era_date_compare (const GEraDate *date1,
                      const GEraDate *date2)
 {
   if (date1->type == G_ERA_DATE_SET &&
       date2->type == G_ERA_DATE_SET)
     {
       if (date1->year != date2->year)
         return date1->year - date2->year;
       if (date1->month != date2->month)
         return date1->month - date2->month;
       return date1->day - date2->day;
     }

   if (date1->type == date2->type)
     return 0;

   if (date1->type == G_ERA_DATE_MINUS_INFINITY || date2->type == G_ERA_DATE_PLUS_INFINITY)
     return -1;
   if (date1->type == G_ERA_DATE_PLUS_INFINITY || date2->type == G_ERA_DATE_MINUS_INFINITY)
     return 1;

   g_assert_not_reached ();
 }

 static gboolean
 parse_era_date (const char *str,
                 const char *endptr,
                 GEraDate   *out_date)
 {
   const char *str_endptr = NULL;
   int year_multiplier;
   guint64 year, month, day;

   year_multiplier = (str[0] == '-') ? -1 : 1;
   if (str[0] == '-' || str[0] == '+')
     str++;

   year = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
   g_assert (str_endptr <= endptr);
   if (str_endptr == endptr || *str_endptr != '/' || year > G_MAXINT)
     return FALSE;
   str = str_endptr + 1;

   month = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
   g_assert (str_endptr <= endptr);
   if (str_endptr == endptr || *str_endptr != '/' || month < 1 || month > 12)
     return FALSE;
   str = str_endptr + 1;

   day = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
   g_assert (str_endptr <= endptr);
   if (str_endptr != endptr || day < 1 || day > 31)
     return FALSE;

   /* Success */
   out_date->type = G_ERA_DATE_SET;
   out_date->year = year_multiplier * year;
   out_date->month = month;
   out_date->day = day;

   return TRUE;
 }

 /**
  * _g_era_description_segment_ref:
  * @segment: a #GEraDescriptionSegment
  *
  * Increase the ref count of @segment.
  *
  * Returns: (transfer full): @segment
  * Since: 2.80
  */
 GEraDescriptionSegment *
 _g_era_description_segment_ref (GEraDescriptionSegment *segment)
 {
   g_atomic_ref_count_inc (&segment->ref_count);
   return segment;
 }

 /**
  * _g_era_description_segment_unref:
  * @segment: (transfer full): a #GEraDescriptionSegment to unref
  *
  * Decreases the ref count of @segment.
  *
  * Since: 2.80
  */
 void
 _g_era_description_segment_unref (GEraDescriptionSegment *segment)
 {
   if (g_atomic_ref_count_dec (&segment->ref_count))
     {
       g_free (segment->era_format);
       g_free (segment->era_name);
       g_free (segment);
     }
 }

 /**
  * _g_era_description_parse:
  * @desc: an `ERA` description string from `nl_langinfo()`
  *
  * Parse an ERA description string. See [`nl_langinfo(3)`](man:nl_langinfo(3)).
  *
  * Example description string for th_TH.UTF-8:
  * ```
  * +:1:-543/01/01:+*:พ.ศ.:%EC %Ey
  * ```
  *
  * @desc must be in UTF-8, so all conversion from the locale encoding must
  * happen before this function is called. The resulting `era_name` and
  * `era_format` in the returned segments will be in UTF-8.
  *
  * Returns: (transfer full) (nullable) (element-type GEraDescriptionSegment):
  *   array of one or more parsed era segments, or %NULL if parsing failed
  * Since: 2.80
  */
 GPtrArray *
 _g_era_description_parse (const char *desc)
 {
   GPtrArray *segments = g_ptr_array_new_with_free_func ((GDestroyNotify) _g_era_description_segment_unref);

   for (const char *p = desc; *p != '\0';)
     {
       const char *next_colon, *endptr = NULL;
       GEraDescriptionSegment *segment = NULL;
       char direction;
       guint64 offset;
       GEraDate start_date, end_date;
       char *era_name = NULL, *era_format = NULL;

       /* direction */
       direction = *p++;
       if (direction != '+' && direction != '-')
         goto error;

       if (*p++ != ':')
         goto error;

       /* offset */
       next_colon = strchr (p, ':');
       if (next_colon == NULL)
         goto error;

       offset = g_ascii_strtoull (p, (gchar **) &endptr, 10);
       if (endptr != next_colon)
         goto error;
       p = next_colon + 1;

       /* start_date */
       next_colon = strchr (p, ':');
       if (next_colon == NULL)
         goto error;

       if (!parse_era_date (p, next_colon, &start_date))
         goto error;
       p = next_colon + 1;

       /* end_date */
       next_colon = strchr (p, ':');
       if (next_colon == NULL)
         goto error;

       if (strncmp (p, "-*", 2) == 0)
         end_date.type = G_ERA_DATE_MINUS_INFINITY;
       else if (strncmp (p, "+*", 2) == 0)
         end_date.type = G_ERA_DATE_PLUS_INFINITY;
       else if (!parse_era_date (p, next_colon, &end_date))
         goto error;
       p = next_colon + 1;

       /* era_name */
       next_colon = strchr (p, ':');
       if (next_colon == NULL)
         goto error;

       if (next_colon - p == 0)
         goto error;
       era_name = g_strndup (p, next_colon - p);
       p = next_colon + 1;

       /* era_format; either the final field in the segment (followed by a
        * semicolon) or the description (followed by nul) */
       next_colon = strchr (p, ';');
       if (next_colon == NULL)
         next_colon = p + strlen (p);

       if (next_colon - p == 0)
         {
           g_free (era_name);
           goto error;
         }
       era_format = g_strndup (p, next_colon - p);
       if (*next_colon == ';')
         p = next_colon + 1;
       else
         p = next_colon;

       /* Successfully parsed that segment. */
       segment = g_new0 (GEraDescriptionSegment, 1);
       g_atomic_ref_count_init (&segment->ref_count);
       segment->offset = offset;
       segment->start_date = start_date;
       segment->end_date = end_date;
       segment->direction_multiplier =
           ((_g_era_date_compare (&segment->start_date, &segment->end_date) <= 0) ? 1 : -1) *
           ((direction == '-') ? -1 : 1);
       segment->era_name = g_steal_pointer (&era_name);
       segment->era_format = g_steal_pointer (&era_format);

       g_ptr_array_add (segments, g_steal_pointer (&segment));
     }

   return g_steal_pointer (&segments);

 error:
   g_ptr_array_unref (segments);
   return NULL;
 }
	/*
	* Copyright 2023 GNOME Foundation Inc.
	*
	* SPDX-License-Identifier: LGPL-2.1-or-later
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
	*
	* Authors:
	* - Philip Withnall <pwithnall@gnome.org>
	*/

	#include "glib.h"
	#include "gdatetime-private.h"

	/**
	* _g_era_date_compare:
	* @date1: first date
	* @date2: second date
	*
	* Compare two #GEraDates for ordering, taking into account negative and
	* positive infinity.
	*
	* Returns: strcmp()-style integer, `<0` indicates `date1 < date2`, `0`
	* indicates `date1 == date2`, `>0` indicates `date1 > date2`
	* Since: 2.80
	*/
	int
	_g_era_date_compare (const GEraDate *date1,
	const GEraDate *date2)
	{
	if (date1->type == G_ERA_DATE_SET &&
	date2->type == G_ERA_DATE_SET)
	{
	if (date1->year != date2->year)
	return date1->year - date2->year;
	if (date1->month != date2->month)
	return date1->month - date2->month;
	return date1->day - date2->day;
	}

	if (date1->type == date2->type)
	return 0;

	if (date1->type == G_ERA_DATE_MINUS_INFINITY \|\| date2->type == G_ERA_DATE_PLUS_INFINITY)
	return -1;
	if (date1->type == G_ERA_DATE_PLUS_INFINITY \|\| date2->type == G_ERA_DATE_MINUS_INFINITY)
	return 1;

	g_assert_not_reached ();
	}

	static gboolean
	parse_era_date (const char *str,
	const char *endptr,
	GEraDate *out_date)
	{
	const char *str_endptr = NULL;
	int year_multiplier;
	guint64 year, month, day;

	year_multiplier = (str[0] == '-') ? -1 : 1;
	if (str[0] == '-' \|\| str[0] == '+')
	str++;

	year = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
	g_assert (str_endptr <= endptr);
	if (str_endptr == endptr \|\| *str_endptr != '/' \|\| year > G_MAXINT)
	return FALSE;
	str = str_endptr + 1;

	month = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
	g_assert (str_endptr <= endptr);
	if (str_endptr == endptr \|\| *str_endptr != '/' \|\| month < 1 \|\| month > 12)
	return FALSE;
	str = str_endptr + 1;

	day = g_ascii_strtoull (str, (gchar **) &str_endptr, 10);
	g_assert (str_endptr <= endptr);
	if (str_endptr != endptr \|\| day < 1 \|\| day > 31)
	return FALSE;

	/* Success */
	out_date->type = G_ERA_DATE_SET;
	out_date->year = year_multiplier * year;
	out_date->month = month;
	out_date->day = day;

	return TRUE;
	}

	/**
	* _g_era_description_segment_ref:
	* @segment: a #GEraDescriptionSegment
	*
	* Increase the ref count of @segment.
	*
	* Returns: (transfer full): @segment
	* Since: 2.80
	*/
	GEraDescriptionSegment *
	_g_era_description_segment_ref (GEraDescriptionSegment *segment)
	{
	g_atomic_ref_count_inc (&segment->ref_count);
	return segment;
	}

	/**
	* _g_era_description_segment_unref:
	* @segment: (transfer full): a #GEraDescriptionSegment to unref
	*
	* Decreases the ref count of @segment.
	*
	* Since: 2.80
	*/
	void
	_g_era_description_segment_unref (GEraDescriptionSegment *segment)
	{
	if (g_atomic_ref_count_dec (&segment->ref_count))
	{
	g_free (segment->era_format);
	g_free (segment->era_name);
	g_free (segment);
	}
	}

	/**
	* _g_era_description_parse:
	* @desc: an `ERA` description string from `nl_langinfo()`
	*
	* Parse an ERA description string. See [`nl_langinfo(3)`](man:nl_langinfo(3)).
	*
	* Example description string for th_TH.UTF-8:
	* ```
	* +:1:-543/01/01:+*:พ.ศ.:%EC %Ey
	* ```
	*
	* @desc must be in UTF-8, so all conversion from the locale encoding must
	* happen before this function is called. The resulting `era_name` and
	* `era_format` in the returned segments will be in UTF-8.
	*
	* Returns: (transfer full) (nullable) (element-type GEraDescriptionSegment):
	* array of one or more parsed era segments, or %NULL if parsing failed
	* Since: 2.80
	*/
	GPtrArray *
	_g_era_description_parse (const char *desc)
	{
	GPtrArray *segments = g_ptr_array_new_with_free_func ((GDestroyNotify) _g_era_description_segment_unref);

	for (const char p = desc; p != '\0';)
	{
	const char next_colon, endptr = NULL;
	GEraDescriptionSegment *segment = NULL;
	char direction;
	guint64 offset;
	GEraDate start_date, end_date;
	char era_name = NULL, era_format = NULL;

	/* direction */
	direction = *p++;
	if (direction != '+' && direction != '-')
	goto error;

	if (*p++ != ':')
	goto error;

	/* offset */
	next_colon = strchr (p, ':');
	if (next_colon == NULL)
	goto error;

	offset = g_ascii_strtoull (p, (gchar **) &endptr, 10);
	if (endptr != next_colon)
	goto error;
	p = next_colon + 1;

	/* start_date */
	next_colon = strchr (p, ':');
	if (next_colon == NULL)
	goto error;

	if (!parse_era_date (p, next_colon, &start_date))
	goto error;
	p = next_colon + 1;

	/* end_date */
	next_colon = strchr (p, ':');
	if (next_colon == NULL)
	goto error;

	if (strncmp (p, "-*", 2) == 0)
	end_date.type = G_ERA_DATE_MINUS_INFINITY;
	else if (strncmp (p, "+*", 2) == 0)
	end_date.type = G_ERA_DATE_PLUS_INFINITY;
	else if (!parse_era_date (p, next_colon, &end_date))
	goto error;
	p = next_colon + 1;

	/* era_name */
	next_colon = strchr (p, ':');
	if (next_colon == NULL)
	goto error;

	if (next_colon - p == 0)
	goto error;
	era_name = g_strndup (p, next_colon - p);
	p = next_colon + 1;

	/* era_format; either the final field in the segment (followed by a
	* semicolon) or the description (followed by nul) */
	next_colon = strchr (p, ';');
	if (next_colon == NULL)
	next_colon = p + strlen (p);

	if (next_colon - p == 0)
	{
	g_free (era_name);
	goto error;
	}
	era_format = g_strndup (p, next_colon - p);
	if (*next_colon == ';')
	p = next_colon + 1;
	else
	p = next_colon;

	/* Successfully parsed that segment. */
	segment = g_new0 (GEraDescriptionSegment, 1);
	g_atomic_ref_count_init (&segment->ref_count);
	segment->offset = offset;
	segment->start_date = start_date;
	segment->end_date = end_date;
	segment->direction_multiplier =
	((_g_era_date_compare (&segment->start_date, &segment->end_date) <= 0) ? 1 : -1) *
	((direction == '-') ? -1 : 1);
	segment->era_name = g_steal_pointer (&era_name);
	segment->era_format = g_steal_pointer (&era_format);

	g_ptr_array_add (segments, g_steal_pointer (&segment));
	}

	return g_steal_pointer (&segments);

	error:
	g_ptr_array_unref (segments);
	return NULL;
	}