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authorDamon Chaplin <damon@ximian.com>2001-06-14 10:17:40 +0800
committerDamon Chaplin <damon@src.gnome.org>2001-06-14 10:17:40 +0800
commit71c06920584e2e3c3953c2624e65085b705ceef6 (patch)
treee55da2f7e6e17efbc0b6c5d1812277c10d6f884e /libical/src
parent9913eeda8c544747343e563617feef1d420a02f4 (diff)
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new files to contain support for timezones.
2001-06-13 Damon Chaplin <damon@ximian.com> * src/libical/icaltimezone.[hc]: new files to contain support for timezones. * src/libical/icalarray.[hc]: new files to provide a simple expanding array datatype. svn path=/trunk/; revision=10215
Diffstat (limited to 'libical/src')
-rw-r--r--libical/src/libical/icalarray.c147
-rw-r--r--libical/src/libical/icalarray.h61
-rw-r--r--libical/src/libical/icaltimezone.c1300
-rw-r--r--libical/src/libical/icaltimezone.h124
4 files changed, 1632 insertions, 0 deletions
diff --git a/libical/src/libical/icalarray.c b/libical/src/libical/icalarray.c
new file mode 100644
index 0000000000..9aea671b64
--- /dev/null
+++ b/libical/src/libical/icalarray.c
@@ -0,0 +1,147 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*-
+ ======================================================================
+ FILE: icalarray.c
+ CREATOR: Damon Chaplin 07 March 2001
+
+ $Id$
+ $Locker$
+
+ (C) COPYRIGHT 2001, Ximian, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of either:
+
+ The LGPL as published by the Free Software Foundation, version
+ 2.1, available at: http://www.fsf.org/copyleft/lesser.html
+
+ Or:
+
+ The Mozilla Public License Version 1.0. You may obtain a copy of
+ the License at http://www.mozilla.org/MPL/
+
+
+ ======================================================================*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "icalarray.h"
+#include "icalerror.h"
+
+
+static void icalarray_expand (icalarray *array,
+ int space_needed);
+
+
+icalarray*
+icalarray_new (int element_size,
+ int increment_size)
+{
+ icalarray *array;
+
+ array = (icalarray*) malloc (sizeof (icalarray));
+ if (!array) {
+ icalerror_set_errno(ICAL_NEWFAILED_ERROR);
+ return NULL;
+ }
+
+ array->element_size = element_size;
+ array->increment_size = increment_size;
+ array->num_elements = 0;
+ array->space_allocated = 0;
+ array->data = NULL;
+
+ return array;
+}
+
+
+void
+icalarray_free (icalarray *array)
+{
+ if (array->data)
+ free (array->data);
+ free (array);
+}
+
+
+void
+icalarray_append (icalarray *array,
+ void *element)
+{
+ if (array->num_elements >= array->space_allocated)
+ icalarray_expand (array, 1);
+
+ memcpy (array->data + array->num_elements * array->element_size, element,
+ array->element_size);
+ array->num_elements++;
+}
+
+
+void*
+icalarray_element_at (icalarray *array,
+ int position)
+{
+ assert (position >= 0);
+ assert (position < array->num_elements);
+
+ return array->data + position * array->element_size;
+}
+
+
+void
+icalarray_remove_element_at (icalarray *array,
+ int position)
+{
+ void *dest;
+ int elements_to_move;
+
+ assert (position >= 0);
+ assert (position < array->num_elements);
+
+ dest = array->data + position * array->element_size;
+ elements_to_move = array->num_elements - position - 1;
+
+ if (elements_to_move > 0)
+ memmove (dest, dest + array->element_size,
+ elements_to_move * array->element_size);
+
+ array->num_elements--;
+}
+
+
+void
+icalarray_sort (icalarray *array,
+ int (*compare) (const void *,
+ const void *))
+{
+ qsort (array->data, array->num_elements, array->element_size, compare);
+}
+
+
+static void
+icalarray_expand (icalarray *array,
+ int space_needed)
+{
+ int new_space_allocated;
+ void *new_data;
+
+ new_space_allocated = array->space_allocated + array->increment_size;
+
+ if (space_needed > array->increment_size)
+ new_space_allocated += space_needed;
+
+ new_data = realloc (array->data,
+ new_space_allocated * array->element_size);
+ if (new_data) {
+ array->data = new_data;
+ array->space_allocated = new_space_allocated;
+ } else {
+ icalerror_set_errno(ICAL_ALLOCATION_ERROR);
+ }
+}
+
+
diff --git a/libical/src/libical/icalarray.h b/libical/src/libical/icalarray.h
new file mode 100644
index 0000000000..cbf72688da
--- /dev/null
+++ b/libical/src/libical/icalarray.h
@@ -0,0 +1,61 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/*======================================================================
+ FILE: icalarray.h
+ CREATOR: Damon Chaplin 07 March 2001
+
+
+ $Id$
+ $Locker$
+
+ (C) COPYRIGHT 2001, Ximian, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of either:
+
+ The LGPL as published by the Free Software Foundation, version
+ 2.1, available at: http://www.fsf.org/copyleft/lesser.html
+
+ Or:
+
+ The Mozilla Public License Version 1.0. You may obtain a copy of
+ the License at http://www.mozilla.org/MPL/
+
+
+======================================================================*/
+
+
+#ifndef ICALARRAY_H
+#define ICALARRAY_H
+
+/* An array of arbitrarily-sized elements which grows dynamically as elements
+ are added. */
+
+
+typedef struct _icalarray icalarray;
+struct _icalarray {
+ int element_size;
+ int increment_size;
+ int num_elements;
+ int space_allocated;
+ void *data;
+};
+
+
+
+icalarray *icalarray_new (int element_size,
+ int increment_size);
+void icalarray_free (icalarray *array);
+
+void icalarray_append (icalarray *array,
+ void *element);
+void icalarray_remove_element_at (icalarray *array,
+ int position);
+
+void *icalarray_element_at (icalarray *array,
+ int position);
+
+void icalarray_sort (icalarray *array,
+ int (*compare) (const void *, const void *));
+
+
+#endif /* ICALARRAY_H */
diff --git a/libical/src/libical/icaltimezone.c b/libical/src/libical/icaltimezone.c
new file mode 100644
index 0000000000..ced5a98e7e
--- /dev/null
+++ b/libical/src/libical/icaltimezone.c
@@ -0,0 +1,1300 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/*======================================================================
+ FILE: icaltimezone.h
+ CREATOR: Damon Chaplin 15 March 2001
+
+
+ $Id$
+ $Locker$
+
+ (C) COPYRIGHT 2001, Damon Chaplin
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of either:
+
+ The LGPL as published by the Free Software Foundation, version
+ 2.1, available at: http://www.fsf.org/copyleft/lesser.html
+
+ Or:
+
+ The Mozilla Public License Version 1.0. You may obtain a copy of
+ the License at http://www.mozilla.org/MPL/
+
+
+======================================================================*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "icalarray.h"
+#include "icalerror.h"
+#include "icalparser.h"
+#include "icaltimezone.h"
+
+
+/* This is the toplevel directory where the timezone data is installed in. */
+#define ZONEINFO_DIRECTORY PACKAGE_DATA_DIR "/zoneinfo"
+
+/* This is the filename of the file containing the city names and coordinates
+ of all the builtin timezones. */
+#define ZONES_TAB_FILENAME "zones.tab"
+
+/* This is the number of years of extra coverage we do when expanding the
+ timezone changes. */
+#define ICALTIMEZONE_EXTRA_COVERAGE 5
+
+/* This is the maximum year we will expand to. time_t values only go up to
+ somewhere around 2037. */
+#define ICALTIMEZONE_MAX_YEAR 2032
+
+
+struct _icaltimezone {
+ /* The unique ID of this timezone,
+ e.g. "/softwarestudio.org/Olson_20010601_1/Africa/Banjul".
+ This should only be used to identify a VTIMEZONE. It is not meant to
+ be displayed to the user in any form. */
+ char *tzid;
+
+ /* The location for the timezone, e.g. "Africa/Accra" for the Olson
+ database. We look for this in the "LOCATION" or "X-LIC-LOCATION"
+ properties of the VTIMEZONE component. It isn't a standard property
+ yet. This will be NULL if no location is found in the VTIMEZONE. */
+ char *location;
+
+ /* This will be set to a combination of the TZNAME properties from the last
+ STANDARD and DAYLIGHT components in the VTIMEZONE, e.g. "EST/EDT".
+ If they both use the same TZNAME, or only one type of component is
+ found, then only one TZNAME will appear, e.g. "AZOT". If no TZNAME
+ is found this will be NULL. */
+ char *tznames;
+
+ /* The coordinates of the city, in degrees. */
+ double latitude;
+ double longitude;
+
+ /* The toplevel VTIMEZONE component loaded from the .ics file for this
+ timezone. If we need to regenerate the changes data we need this. */
+ icalcomponent *component;
+
+ /* If this is not NULL it points to the builtin icaltimezone that the
+ above TZID refers to. This icaltimezone should be used instead when
+ accessing the timezone changes data, so that the expanded timezone
+ changes data is shared between calendar components. */
+ icaltimezone *builtin_timezone;
+
+ /* This is the last year for which we have expanded the data to.
+ If we need to calculate a date past this we need to expand the
+ timezone component data from scratch. */
+ int end_year;
+
+ /* A dynamically-allocated array of time zone changes, sorted by the
+ time of the change in local time. So we can do fast binary-searches
+ to convert from local time to UTC. */
+ icalarray *changes;
+};
+
+
+typedef struct _icaltimezonechange icaltimezonechange;
+
+struct _icaltimezonechange {
+ /* The offset to add to UTC to get local time, in seconds. */
+ int utc_offset;
+
+ /* The offset to add to UTC, before this change, in seconds. */
+ int prev_utc_offset;
+
+ /* The time that the change came into effect, in UTC.
+ Note that the prev_utc_offset applies to this local time,
+ since we haven't changed to the new offset yet. */
+ int year; /* Actual year, e.g. 2001. */
+ char month; /* 1 (Jan) to 12 (Dec). */
+ char day;
+ char hour;
+ char minute;
+ char second;
+
+ /* Whether this is STANDARD or DAYLIGHT time. */
+ char is_daylight;
+};
+
+
+/* An array of icaltimezones for the builtin timezones. */
+icalarray *builtin_timezones = NULL;
+
+/* This is the special UTC timezone, which isn't in builtin_timezones. */
+icaltimezone utc_timezone = { 0 };
+
+
+
+static void icaltimezone_expand_changes (icaltimezone *zone,
+ int end_year);
+static void icaltimezone_expand_vtimezone (icalcomponent *comp,
+ int end_year,
+ icalarray *changes);
+static int icaltimezone_compare_change_fn (const void *elem1,
+ const void *elem2);
+
+static int icaltimezone_find_nearby_change (icaltimezone *zone,
+ icaltimezonechange *change);
+
+static void icaltimezone_adjust_change (icaltimezonechange *tt,
+ int days,
+ int hours,
+ int minutes,
+ int seconds);
+
+static void icaltimezone_init (icaltimezone *zone);
+
+/* Initializes an icaltimezone from the given VTIMEZONE component. It gets
+ the TZID from the VTIMEZONE component. It returns 1 on success, or 0 if
+ the TZID can't be found. */
+static int icaltimezone_init_from_vtimezone (icaltimezone *zone,
+ icalcomponent *component);
+
+
+static void icaltimezone_load (icaltimezone *zone);
+
+static void icaltimezone_ensure_coverage (icaltimezone *zone,
+ int end_year);
+
+
+static void icaltimezone_init_builtin_timezones(void);
+
+static void icaltimezone_parse_zone_tab (void);
+
+static char* icaltimezone_load_get_line_fn (char *s,
+ size_t size,
+ void *data);
+
+static void format_utc_offset (int utc_offset,
+ char *buffer);
+
+
+
+/* Initializes an icaltimezone with the given TZID. */
+static void
+icaltimezone_init (icaltimezone *zone)
+{
+ zone->tzid = NULL;
+ zone->location = NULL;
+ zone->tznames = NULL;
+ zone->latitude = 0.0;
+ zone->longitude = 0.0;
+ zone->component = NULL;
+ zone->builtin_timezone = NULL;
+ zone->end_year = 0;
+ zone->changes = NULL;
+}
+
+
+/* Initializes an icaltimezone from the given VTIMEZONE component. It gets
+ the TZID from the VTIMEZONE component. It returns 1 on success, or 0 if
+ the TZID can't be found. */
+static int
+icaltimezone_init_from_vtimezone (icaltimezone *zone,
+ icalcomponent *component)
+{
+ icalproperty *prop;
+ const char *tzid;
+
+ prop = icalcomponent_get_first_property (component, ICAL_TZID_PROPERTY);
+ if (!prop)
+ return 0;
+
+ tzid = icalproperty_get_tzid (prop);
+ if (!tzid)
+ return 0;
+
+ icaltimezone_init (zone);
+ zone->tzid = strdup (tzid);
+ zone->component = component;
+
+ return 1;
+}
+
+
+static void
+icaltimezone_ensure_coverage (icaltimezone *zone,
+ int end_year)
+{
+ /* When we expand timezone changes we always expand at least up to this
+ year, plus ICALTIMEZONE_EXTRA_COVERAGE. */
+ static int icaltimezone_minimum_expansion_year = -1;
+
+ int changes_end_year;
+
+ if (!zone->component)
+ icaltimezone_load (zone);
+
+ if (icaltimezone_minimum_expansion_year == -1) {
+ struct tm *tmp_tm;
+ time_t t;
+
+ t = time (NULL);
+ tmp_tm = localtime (&t);
+ icaltimezone_minimum_expansion_year = tmp_tm->tm_year + 1900;
+ }
+
+ changes_end_year = end_year;
+ if (changes_end_year < icaltimezone_minimum_expansion_year)
+ changes_end_year = icaltimezone_minimum_expansion_year;
+
+ changes_end_year += ICALTIMEZONE_EXTRA_COVERAGE;
+
+ if (changes_end_year > ICALTIMEZONE_MAX_YEAR)
+ changes_end_year = ICALTIMEZONE_MAX_YEAR;
+
+ if (!zone->changes || zone->end_year < end_year)
+ icaltimezone_expand_changes (zone, changes_end_year);
+}
+
+
+static void
+icaltimezone_expand_changes (icaltimezone *zone,
+ int end_year)
+{
+ icalarray *changes;
+ icalcomponent *comp;
+
+#if 0
+ printf ("\nExpanding changes for: %s to year: %i\n", zone->tzid, end_year);
+#endif
+
+ changes = icalarray_new (sizeof (icaltimezonechange), 32);
+ if (!changes)
+ return;
+
+ /* Scan the STANDARD and DAYLIGHT subcomponents. */
+ comp = icalcomponent_get_first_component (zone->component,
+ ICAL_ANY_COMPONENT);
+ while (comp) {
+ icaltimezone_expand_vtimezone (comp, end_year, changes);
+ comp = icalcomponent_get_next_component (zone->component,
+ ICAL_ANY_COMPONENT);
+ }
+
+ /* Sort the changes. We may have duplicates but I don't think it will
+ matter. */
+ icalarray_sort (changes, icaltimezone_compare_change_fn);
+
+ if (zone->changes)
+ icalarray_free (zone->changes);
+
+ zone->changes = changes;
+ zone->end_year = end_year;
+}
+
+
+static void
+icaltimezone_expand_vtimezone (icalcomponent *comp,
+ int end_year,
+ icalarray *changes)
+{
+ icaltimezonechange change;
+ icalproperty *prop;
+ struct icaltimetype dtstart, occ;
+ struct icalrecurrencetype rrule;
+ icalrecur_iterator* rrule_iterator;
+ struct icaldatetimeperiodtype rdate;
+ int found_dtstart = 0, found_tzoffsetto = 0, found_tzoffsetfrom = 0;
+ int has_recurrence = 0;
+
+ /* First we check if it is a STANDARD or DAYLIGHT component, and
+ just return if it isn't. */
+ if (icalcomponent_isa (comp) == ICAL_XSTANDARD_COMPONENT)
+ change.is_daylight = 0;
+ else if (icalcomponent_isa (comp) == ICAL_XDAYLIGHT_COMPONENT)
+ change.is_daylight = 1;
+ else
+ return;
+
+ /* Step through each of the properties to find the DTSTART,
+ TZOFFSETFROM and TZOFFSETTO. We can't expand recurrences here
+ since we need these properties before we can do that. */
+ prop = icalcomponent_get_first_property (comp, ICAL_ANY_PROPERTY);
+ while (prop) {
+ switch (icalproperty_isa (prop)) {
+ case ICAL_DTSTART_PROPERTY:
+ dtstart = icalproperty_get_dtstart (prop);
+ found_dtstart = 1;
+ break;
+ case ICAL_TZOFFSETTO_PROPERTY:
+ change.utc_offset = icalproperty_get_tzoffsetto (prop);
+ /*printf ("Found TZOFFSETTO: %i\n", change.utc_offset);*/
+ found_tzoffsetto = 1;
+ break;
+ case ICAL_TZOFFSETFROM_PROPERTY:
+ change.prev_utc_offset = icalproperty_get_tzoffsetfrom (prop);
+ /*printf ("Found TZOFFSETFROM: %i\n", change.prev_utc_offset);*/
+ found_tzoffsetfrom = 1;
+ break;
+ case ICAL_RDATE_PROPERTY:
+ case ICAL_RRULE_PROPERTY:
+ has_recurrence = 1;
+ break;
+ default:
+ /* Just ignore any other properties. */
+ break;
+ }
+
+ prop = icalcomponent_get_next_property (comp, ICAL_ANY_PROPERTY);
+ }
+
+ /* If we didn't find a DTSTART, TZOFFSETTO and TZOFFSETFROM we have to
+ ignore the component. FIXME: Add an error property? */
+ if (!found_dtstart || !found_tzoffsetto || !found_tzoffsetfrom)
+ return;
+
+#if 0
+ printf ("\n Expanding component DTSTART (Y/M/D): %i/%i/%i %i:%02i:%02i\n",
+ dtstart.year, dtstart.month, dtstart.day,
+ dtstart.hour, dtstart.minute, dtstart.second);
+#endif
+
+ /* If the STANDARD/DAYLIGHT component has no recurrence data, we just add
+ a single change for the DTSTART. */
+ if (!has_recurrence) {
+ change.year = dtstart.year;
+ change.month = dtstart.month;
+ change.day = dtstart.day;
+ change.hour = dtstart.hour;
+ change.minute = dtstart.minute;
+ change.second = dtstart.second;
+
+ /* Convert to UTC. */
+ icaltimezone_adjust_change (&change, 0, 0, 0, -change.prev_utc_offset);
+
+#if 0
+ printf (" Appending single DTSTART (Y/M/D): %i/%02i/%02i %i:%02i:%02i\n",
+ change.year, change.month, change.day,
+ change.hour, change.minute, change.second);
+#endif
+
+ /* Add the change to the array. */
+ icalarray_append (changes, &change);
+ return;
+ }
+
+ /* The component has recurrence data, so we expand that now. */
+ prop = icalcomponent_get_first_property (comp, ICAL_ANY_PROPERTY);
+ while (prop) {
+#if 0
+ printf ("Expanding property...\n");
+#endif
+ switch (icalproperty_isa (prop)) {
+ case ICAL_RDATE_PROPERTY:
+ rdate = icalproperty_get_rdate (prop);
+ change.year = rdate.time.year;
+ change.month = rdate.time.month;
+ change.day = rdate.time.day;
+ /* RDATEs with a DATE value inherit the time from
+ the DTSTART. */
+ if (rdate.time.is_date) {
+ change.hour = dtstart.hour;
+ change.minute = dtstart.minute;
+ change.second = dtstart.second;
+ } else {
+ change.hour = rdate.time.hour;
+ change.minute = rdate.time.minute;
+ change.second = rdate.time.second;
+
+ /* The spec was a bit vague about whether RDATEs were in local
+ time or UTC so we support both to be safe. So if it is in
+ UTC we have to add the UTC offset to get a local time. */
+ if (!rdate.time.is_utc)
+ icaltimezone_adjust_change (&change, 0, 0, 0,
+ -change.prev_utc_offset);
+ }
+
+#if 0
+ printf (" Appending RDATE element (Y/M/D): %i/%02i/%02i %i:%02i:%02i\n",
+ change.year, change.month, change.day,
+ change.hour, change.minute, change.second);
+#endif
+
+ icalarray_append (changes, &change);
+ break;
+ case ICAL_RRULE_PROPERTY:
+ rrule = icalproperty_get_rrule (prop);
+
+ /* If the rrule UNTIL value is set and is in UTC, we convert it to
+ a local time, since the recurrence code has no way to convert
+ it itself. */
+ if (!icaltime_is_null_time (rrule.until) && rrule.until.is_utc) {
+#if 0
+ printf (" Found RRULE UNTIL in UTC.\n");
+#endif
+
+ /* To convert from UTC to a local time, we use the TZOFFSETFROM
+ since that is the offset from UTC that will be in effect
+ when each of the RRULE occurrences happens. */
+ icaltime_adjust (&rrule.until, 0, 0, 0,
+ change.prev_utc_offset);
+ rrule.until.is_utc = 0;
+ }
+
+ rrule_iterator = icalrecur_iterator_new (rrule, dtstart);
+ for (;;) {
+ occ = icalrecur_iterator_next (rrule_iterator);
+ if (occ.year > end_year || icaltime_is_null_time (occ))
+ break;
+
+ change.year = occ.year;
+ change.month = occ.month;
+ change.day = occ.day;
+ change.hour = occ.hour;
+ change.minute = occ.minute;
+ change.second = occ.second;
+
+#if 0
+ printf (" Appending RRULE element (Y/M/D): %i/%02i/%02i %i:%02i:%02i\n",
+ change.year, change.month, change.day,
+ change.hour, change.minute, change.second);
+#endif
+
+ icaltimezone_adjust_change (&change, 0, 0, 0,
+ -change.prev_utc_offset);
+
+ icalarray_append (changes, &change);
+ }
+
+ icalrecur_iterator_free (rrule_iterator);
+ break;
+ default:
+ break;
+ }
+
+ prop = icalcomponent_get_next_property (comp, ICAL_ANY_PROPERTY);
+ }
+}
+
+
+/* A function to compare 2 icaltimezonechange elements, used for qsort(). */
+static int
+icaltimezone_compare_change_fn (const void *elem1,
+ const void *elem2)
+{
+ const icaltimezonechange *change1, *change2;
+ int retval;
+
+ change1 = elem1;
+ change2 = elem2;
+
+ if (change1->year < change2->year)
+ retval = -1;
+ else if (change1->year > change2->year)
+ retval = 1;
+
+ else if (change1->month < change2->month)
+ retval = -1;
+ else if (change1->month > change2->month)
+ retval = 1;
+
+ else if (change1->day < change2->day)
+ retval = -1;
+ else if (change1->day > change2->day)
+ retval = 1;
+
+ else if (change1->hour < change2->hour)
+ retval = -1;
+ else if (change1->hour > change2->hour)
+ retval = 1;
+
+ else if (change1->minute < change2->minute)
+ retval = -1;
+ else if (change1->minute > change2->minute)
+ retval = 1;
+
+ else if (change1->second < change2->second)
+ retval = -1;
+ else if (change1->second > change2->second)
+ retval = 1;
+
+ else
+ retval = 0;
+
+ return retval;
+}
+
+
+
+void
+icaltimezone_convert_time (struct icaltimetype *tt,
+ icaltimezone *from_zone,
+ icaltimezone *to_zone)
+{
+ int utc_offset, is_daylight;
+
+ /* First we convert the time to UTC by getting the UTC offset and
+ subtracting it. */
+ utc_offset = icaltimezone_get_utc_offset (from_zone, tt, NULL);
+ icaltime_adjust (tt, 0, 0, 0, -utc_offset);
+
+ /* Now we convert the time to the new timezone by getting the UTC offset
+ of our UTC time and adding it. */
+ utc_offset = icaltimezone_get_utc_offset_of_utc_time (to_zone, tt,
+ &is_daylight);
+ tt->is_daylight = is_daylight;
+ icaltime_adjust (tt, 0, 0, 0, utc_offset);
+}
+
+
+
+
+
+/* Calculates the UTC offset of a given local time in the given timezone.
+ It is the number of seconds to add to UTC to get local time.
+ The is_daylight flag is set to 1 if the time is in daylight-savings time. */
+int
+icaltimezone_get_utc_offset (icaltimezone *zone,
+ struct icaltimetype *tt,
+ int *is_daylight)
+{
+ icaltimezonechange *zone_change, *prev_zone_change, tt_change, tmp_change;
+ int change_num, step, utc_offset_change, cmp;
+ int change_num_to_use;
+ char want_daylight;
+
+ if (is_daylight)
+ *is_daylight = 0;
+
+ /* For local times and UTC return 0. */
+ if (zone == NULL || zone == &utc_timezone)
+ return 0;
+
+ /* Use the builtin icaltimezone if possible. */
+ if (zone->builtin_timezone)
+ zone = zone->builtin_timezone;
+
+ /* Make sure the changes array is expanded up to the given time. */
+ icaltimezone_ensure_coverage (zone, tt->year);
+
+ if (!zone->changes || zone->changes->num_elements == 0)
+ return 0;
+
+ /* Copy the time parts of the icaltimetype to an icaltimezonechange so we
+ can use our comparison function on it. */
+ tt_change.year = tt->year;
+ tt_change.month = tt->month;
+ tt_change.day = tt->day;
+ tt_change.hour = tt->hour;
+ tt_change.minute = tt->minute;
+ tt_change.second = tt->second;
+
+ /* This should find a change close to the time, either the change before
+ it or the change after it. */
+ change_num = icaltimezone_find_nearby_change (zone, &tt_change);
+
+ /* Sanity check. */
+ icalerror_assert (change_num >= 0,
+ "Negative timezone change index");
+ icalerror_assert (change_num < zone->changes->num_elements,
+ "Timezone change index out of bounds");
+
+ /* Now move backwards or forwards to find the timezone change that applies
+ to tt. It should only have to do 1 or 2 steps. */
+ zone_change = icalarray_element_at (zone->changes, change_num);
+ step = 1;
+ change_num_to_use = -1;
+ for (;;) {
+ /* Copy the change, so we can adjust it. */
+ tmp_change = *zone_change;
+
+ /* If the clock is going backward, check if it is in the region of time
+ that is used twice. If it is, use the change with the daylight
+ setting which matches tt, or use standard if we don't know. */
+ if (tmp_change.utc_offset < tmp_change.prev_utc_offset) {
+ /* If the time change is at 2:00AM local time and the clock is
+ going back to 1:00AM we adjust the change to 1:00AM. We may
+ have the wrong change but we'll figure that out later. */
+ icaltimezone_adjust_change (&tmp_change, 0, 0, 0,
+ tmp_change.utc_offset);
+ } else {
+ icaltimezone_adjust_change (&tmp_change, 0, 0, 0,
+ tmp_change.prev_utc_offset);
+ }
+
+ cmp = icaltimezone_compare_change_fn (&tt_change, &tmp_change);
+
+ /* If the given time is on or after this change, then this change may
+ apply, but we continue as a later change may be the right one.
+ If the given time is before this change, then if we have already
+ found a change which applies we can use that, else we need to step
+ backwards. */
+ if (cmp >= 0)
+ change_num_to_use = change_num;
+ else
+ step = -1;
+
+ /* If we are stepping backwards through the changes and we have found
+ a change that applies, then we know this is the change to use so
+ we exit the loop. */
+ if (step == -1 && change_num_to_use != -1)
+ break;
+
+ change_num += step;
+
+ /* If we go past the start of the changes array, then we have no data
+ for this time so we return a UTC offset of 0. */
+ if (change_num < 0)
+ return 0;
+
+ if (change_num >= zone->changes->num_elements)
+ break;
+
+ zone_change = icalarray_element_at (zone->changes, change_num);
+ }
+
+ /* If we didn't find a change to use, then we have a bug! */
+ icalerror_assert (change_num_to_use != -1,
+ "No applicable timezone change found");
+
+ /* Now we just need to check if the time is in the overlapped region of
+ time when clocks go back. */
+ zone_change = icalarray_element_at (zone->changes, change_num_to_use);
+
+ utc_offset_change = zone_change->utc_offset - zone_change->prev_utc_offset;
+ if (utc_offset_change < 0 && change_num_to_use > 0) {
+ tmp_change = *zone_change;
+ icaltimezone_adjust_change (&tmp_change, 0, 0, 0,
+ tmp_change.prev_utc_offset);
+
+ if (icaltimezone_compare_change_fn (&tt_change, &tmp_change) < 0) {
+ /* The time is in the overlapped region, so we may need to use
+ either the current zone_change or the previous one. If the
+ time has the is_daylight field set we use the matching change,
+ else we use the change with standard time. */
+ prev_zone_change = icalarray_element_at (zone->changes,
+ change_num_to_use - 1);
+
+ /* I was going to add an is_daylight flag to struct icaltimetype,
+ but iCalendar doesn't let us distinguish between standard and
+ daylight time anyway, so there's no point. So we just use the
+ standard time instead. */
+ want_daylight = (tt->is_daylight == 1) ? 1 : 0;
+
+ if (zone_change->is_daylight == prev_zone_change->is_daylight)
+ printf (" **** Same is_daylight setting\n");
+
+ if (zone_change->is_daylight != want_daylight
+ && prev_zone_change->is_daylight == want_daylight)
+ zone_change = prev_zone_change;
+ }
+ }
+
+ /* Now we know exactly which timezone change applies to the time, so
+ we can return the UTC offset and whether it is a daylight time. */
+ if (is_daylight)
+ *is_daylight = zone_change->is_daylight;
+ return zone_change->utc_offset;
+}
+
+
+/* Calculates the UTC offset of a given UTC time in the given timezone.
+ It is the number of seconds to add to UTC to get local time.
+ The is_daylight flag is set to 1 if the time is in daylight-savings time. */
+int
+icaltimezone_get_utc_offset_of_utc_time (icaltimezone *zone,
+ struct icaltimetype *tt,
+ int *is_daylight)
+{
+ icaltimezonechange *zone_change, tt_change, tmp_change;
+ int change_num, step, change_num_to_use;
+ int debug = 0;
+
+ if (is_daylight)
+ *is_daylight = 0;
+
+#if 0
+ if (tt->day == 30 && tt->month == 3 && tt->year == 2000
+ && tt->hour == 22 && tt->minute == 0 && tt->second == 0) {
+ printf ("Getting UTC offset of %i/%i/%i %i:%02i:%02i\n",
+ tt->day, tt->month, tt->year,
+ tt->hour, tt->minute, tt->second);
+ debug = 1;
+ }
+#endif
+
+ /* For local times and UTC return 0. */
+ if (zone == NULL || zone == &utc_timezone)
+ return 0;
+
+ /* Use the builtin icaltimezone if possible. */
+ if (zone->builtin_timezone)
+ zone = zone->builtin_timezone;
+
+ /* Make sure the changes array is expanded up to the given time. */
+ icaltimezone_ensure_coverage (zone, tt->year);
+
+ if (!zone->changes || zone->changes->num_elements == 0)
+ return 0;
+
+ /* Copy the time parts of the icaltimetype to an icaltimezonechange so we
+ can use our comparison function on it. */
+ tt_change.year = tt->year;
+ tt_change.month = tt->month;
+ tt_change.day = tt->day;
+ tt_change.hour = tt->hour;
+ tt_change.minute = tt->minute;
+ tt_change.second = tt->second;
+
+ /* This should find a change close to the time, either the change before
+ it or the change after it. */
+ change_num = icaltimezone_find_nearby_change (zone, &tt_change);
+
+ /* Sanity check. */
+ icalerror_assert (change_num >= 0,
+ "Negative timezone change index");
+ icalerror_assert (change_num < zone->changes->num_elements,
+ "Timezone change index out of bounds");
+
+ /* Now move backwards or forwards to find the timezone change that applies
+ to tt. It should only have to do 1 or 2 steps. */
+ zone_change = icalarray_element_at (zone->changes, change_num);
+ step = 1;
+ change_num_to_use = -1;
+ for (;;) {
+ /* Copy the change and adjust it to UTC. */
+ tmp_change = *zone_change;
+
+ if (debug) {
+ printf (" Change: %i/%i/%i %i:%02i:%02i\n",
+ zone_change->day, zone_change->month, zone_change->year,
+ zone_change->hour, zone_change->minute, zone_change->second);
+ }
+
+
+ /* If the given time is on or after this change, then this change may
+ apply, but we continue as a later change may be the right one.
+ If the given time is before this change, then if we have already
+ found a change which applies we can use that, else we need to step
+ backwards. */
+ if (icaltimezone_compare_change_fn (&tt_change, &tmp_change) >= 0)
+ change_num_to_use = change_num;
+ else
+ step = -1;
+
+ /* If we are stepping backwards through the changes and we have found
+ a change that applies, then we know this is the change to use so
+ we exit the loop. */
+ if (step == -1 && change_num_to_use != -1)
+ break;
+
+ change_num += step;
+
+ /* If we go past the start of the changes array, then we have no data
+ for this time so we return a UTC offset of 0. */
+ if (change_num < 0)
+ return 0;
+
+ if (change_num >= zone->changes->num_elements)
+ break;
+
+ zone_change = icalarray_element_at (zone->changes, change_num);
+ }
+
+ /* If we didn't find a change to use, then we have a bug! */
+ icalerror_assert (change_num_to_use != -1,
+ "No applicable timezone change found");
+
+ /* Now we know exactly which timezone change applies to the time, so
+ we can return the UTC offset and whether it is a daylight time. */
+ zone_change = icalarray_element_at (zone->changes, change_num_to_use);
+ if (is_daylight)
+ *is_daylight = zone_change->is_daylight;
+
+ if (debug) {
+ printf (" Change: %i/%i/%i %i:%02i:%02i\n",
+ zone_change->day, zone_change->month, zone_change->year,
+ zone_change->hour, zone_change->minute, zone_change->second);
+ printf (" -> %i\n", zone_change->utc_offset);
+ }
+
+ return zone_change->utc_offset;
+}
+
+
+/* Returns the index of a timezone change which is close to the time given
+ in change. */
+static int
+icaltimezone_find_nearby_change (icaltimezone *zone,
+ icaltimezonechange *change)
+{
+ icaltimezonechange *zone_change;
+ int lower, upper, middle, cmp;
+
+ /* Do a simple binary search. */
+ lower = middle = 0;
+ upper = zone->changes->num_elements;
+
+ while (lower < upper) {
+ middle = (lower + upper) >> 1;
+ zone_change = icalarray_element_at (zone->changes, middle);
+ cmp = icaltimezone_compare_change_fn (change, zone_change);
+ if (cmp == 0)
+ break;
+ else if (cmp < 0)
+ upper = middle;
+ else
+ lower = middle + 1;
+ }
+
+ return middle;
+}
+
+
+
+
+/* Adds (or subtracts) a time from a icaltimezonechange.
+ NOTE: This function is exactly the same as icaltime_adjust()
+ except for the type of the first parameter. */
+static void
+icaltimezone_adjust_change (icaltimezonechange *tt,
+ int days,
+ int hours,
+ int minutes,
+ int seconds)
+{
+ int second, minute, hour, day;
+ int minutes_overflow, hours_overflow, days_overflow;
+ int days_in_month;
+
+ /* Add on the seconds. */
+ second = tt->second + seconds;
+ tt->second = second % 60;
+ minutes_overflow = second / 60;
+ if (tt->second < 0) {
+ tt->second += 60;
+ minutes_overflow--;
+ }
+
+ /* Add on the minutes. */
+ minute = tt->minute + minutes + minutes_overflow;
+ tt->minute = minute % 60;
+ hours_overflow = minute / 60;
+ if (tt->minute < 0) {
+ tt->minute += 60;
+ hours_overflow--;
+ }
+
+ /* Add on the hours. */
+ hour = tt->hour + hours + hours_overflow;
+ tt->hour = hour % 24;
+ days_overflow = hour / 24;
+ if (tt->hour < 0) {
+ tt->hour += 24;
+ days_overflow--;
+ }
+
+ /* Add on the days. */
+ day = tt->day + days + days_overflow;
+ if (day > 0) {
+ for (;;) {
+ days_in_month = icaltime_days_in_month (tt->month, tt->year);
+ if (day <= days_in_month)
+ break;
+
+ tt->month++;
+ if (tt->month >= 13) {
+ tt->year++;
+ tt->month = 1;
+ }
+
+ day -= days_in_month;
+ }
+ } else {
+ while (day <= 0) {
+ if (tt->month == 1) {
+ tt->year--;
+ tt->month = 12;
+ } else {
+ tt->month--;
+ }
+
+ day += icaltime_days_in_month (tt->month, tt->year);
+ }
+ }
+ tt->day = day;
+}
+
+
+
+/* Compares 2 VTIMEZONE components to see if they match, ignoring their TZIDs.
+ It returns 1 if they match, 0 if they don't, or -1 on error. */
+int
+icaltimezone_compare_vtimezone (icalcomponent *vtimezone1,
+ icalcomponent *vtimezone2)
+{
+ icalproperty *prop1, *prop2;
+ const char *tzid1, *tzid2;
+ char *tzid2_copy, *string1, *string2;
+ int cmp;
+
+ /* Get the TZID property of the first VTIMEZONE. */
+ prop1 = icalcomponent_get_first_property (vtimezone1, ICAL_TZID_PROPERTY);
+ if (!prop1)
+ return -1;
+
+ tzid1 = icalproperty_get_tzid (prop1);
+ if (!tzid1)
+ return -1;
+
+ /* Get the TZID property of the second VTIMEZONE. */
+ prop2 = icalcomponent_get_first_property (vtimezone1, ICAL_TZID_PROPERTY);
+ if (!prop2)
+ return -1;
+
+ tzid2 = icalproperty_get_tzid (prop2);
+ if (!tzid2)
+ return -1;
+
+ /* Copy the second TZID, and set the property to the same as the first
+ TZID, since we don't care if these match of not. */
+ tzid2_copy = strdup (tzid2);
+ icalproperty_set_tzid (prop2, tzid1);
+
+ /* Now convert both VTIMEZONEs to strings and compare them. */
+ string1 = icalcomponent_as_ical_string (vtimezone1);
+ if (!string1) {
+ free (tzid2_copy);
+ return -1;
+ }
+
+ string2 = icalcomponent_as_ical_string (vtimezone2);
+ if (!string2) {
+ free (string1);
+ free (tzid2_copy);
+ return -1;
+ }
+
+ cmp = strcmp (string1, string2);
+
+ free (string1);
+ free (string2);
+
+ /* Now reset the second TZID. */
+ icalproperty_set_tzid (prop2, tzid2_copy);
+ free (tzid2_copy);
+
+ return (cmp == 0) ? 1 : 0;
+}
+
+
+
+char*
+icaltimezone_get_tzid (icaltimezone *zone)
+{
+ return zone->tzid;
+}
+
+
+char*
+icaltimezone_get_location (icaltimezone *zone)
+{
+ return zone->location;
+}
+
+
+/* Returns the VTIMEZONE component of a timezone. */
+icalcomponent*
+icaltimezone_get_component (icaltimezone *zone)
+{
+ return zone->component;
+
+}
+
+
+icalarray*
+icaltimezone_array_new (void)
+{
+ return icalarray_new (sizeof (icaltimezone), 16);
+}
+
+
+void
+icaltimezone_array_append_from_vtimezone (icalarray *timezones,
+ icalcomponent *child)
+{
+ icaltimezone zone;
+
+ if (icaltimezone_init_from_vtimezone (&zone, child))
+ icalarray_append (timezones, &zone);
+}
+
+
+
+/*
+ * BUILTIN TIMEZONE HANDLING
+ */
+
+
+/* Returns an icalarray of icaltimezone structs, one for each builtin timezone.
+ This will load and parse the zones.tab file to get the timezone names and
+ their coordinates. It will not load the VTIMEZONE data for any timezones. */
+icalarray*
+icaltimezone_get_builtin_timezones (void)
+{
+ if (!builtin_timezones)
+ icaltimezone_init_builtin_timezones ();
+
+ return builtin_timezones;
+}
+
+
+/* Returns an icaltimezone corresponding to the given location. */
+icaltimezone*
+icaltimezone_get_utc_timezone (void)
+{
+ return &utc_timezone;
+}
+
+
+
+/* This initializes the builtin timezone data, i.e. the builtin_timezones
+ array and the special UTC timezone. It should be called before any
+ code that uses the timezone functions. */
+static void
+icaltimezone_init_builtin_timezones (void)
+{
+ /* Initialize the special UTC timezone. */
+ utc_timezone.tzid = "UTC";
+
+ icaltimezone_parse_zone_tab ();
+}
+
+
+/* This parses the zones.tab file containing the names and locations of the
+ builtin timezones. It creates the builtin_timezones array which is an
+ icalarray of icaltimezone structs. It only fills in the location, latitude
+ and longtude fields; the rest are left blank. The VTIMEZONE component is
+ loaded later if it is needed. The timezones in the zones.tab file are
+ sorted by their name, which is useful for binary searches. */
+static void
+icaltimezone_parse_zone_tab (void)
+{
+ char *filename;
+ FILE *fp;
+ char buf[1024]; /* Used to store each line of zones.tab as it is read. */
+ char location[1024]; /* Stores the city name when parsing buf. */
+ int filename_len;
+ int latitude_degrees, latitude_minutes, latitude_seconds;
+ int longitude_degrees, longitude_minutes, longitude_seconds;
+ icaltimezone zone;
+
+ icalerror_assert (builtin_timezones == NULL,
+ "Parsing zones.tab file multiple times");
+
+ filename_len = strlen (ZONEINFO_DIRECTORY) + strlen (ZONES_TAB_FILENAME)
+ + 2;
+
+ filename = (char*) malloc (filename_len);
+ if (!filename) {
+ icalerror_set_errno(ICAL_NEWFAILED_ERROR);
+ return;
+ }
+
+ snprintf (filename, filename_len, "%s/%s", ZONEINFO_DIRECTORY,
+ ZONES_TAB_FILENAME);
+
+ fp = fopen (filename, "r");
+ free (filename);
+ if (!fp) {
+ icalerror_set_errno(ICAL_FILE_ERROR);
+ return;
+ }
+
+ builtin_timezones = icalarray_new (sizeof (icaltimezone), 32);
+
+ while (fgets (buf, sizeof(buf), fp)) {
+ if (*buf == '#') continue;
+
+ /* The format of each line is: "latitude longitude location". */
+ if (sscanf (buf, "%4d%2d%2d %4d%2d%2d %s",
+ &latitude_degrees, &latitude_minutes,
+ &latitude_seconds,
+ &longitude_degrees, &longitude_minutes,
+ &longitude_seconds,
+ &location) != 7) {
+ fprintf (stderr, "Invalid timezone description line: %s\n", buf);
+ continue;
+ }
+
+ icaltimezone_init (&zone);
+ zone.location = strdup (location);
+
+ if (latitude_degrees >= 0)
+ zone.latitude = (double) latitude_degrees
+ + (double) latitude_minutes / 60
+ + (double) latitude_seconds / 3600;
+ else
+ zone.latitude = (double) latitude_degrees
+ - (double) latitude_minutes / 60
+ - (double) latitude_seconds / 3600;
+
+ if (longitude_degrees >= 0)
+ zone.longitude = (double) longitude_degrees
+ + (double) longitude_minutes / 60
+ + (double) longitude_seconds / 3600;
+ else
+ zone.longitude = (double) longitude_degrees
+ - (double) longitude_minutes / 60
+ - (double) longitude_seconds / 3600;
+
+ icalarray_append (builtin_timezones, &zone);
+
+#if 0
+ printf ("Found zone: %s %f %f\n",
+ location, zone.latitude, zone.longitude);
+#endif
+ }
+
+ fclose (fp);
+}
+
+
+/* Loads the builtin VTIMEZONE data for the given timezone. */
+static void
+icaltimezone_load (icaltimezone *zone)
+{
+ char *filename;
+ int filename_len;
+ FILE *fp;
+ icalparser *parser;
+ icalcomponent *comp;
+
+ filename_len = strlen (ZONEINFO_DIRECTORY) + strlen (zone->location) + 6;
+
+ filename = (char*) malloc (filename_len);
+ if (!filename) {
+ icalerror_set_errno(ICAL_NEWFAILED_ERROR);
+ return;
+ }
+
+ snprintf (filename, filename_len, "%s/%s.ics", ZONEINFO_DIRECTORY,
+ zone->location);
+
+ fp = fopen (filename, "r");
+ free (filename);
+ if (!fp) {
+ icalerror_set_errno(ICAL_FILE_ERROR);
+ return;
+ }
+
+ parser = icalparser_new ();
+ icalparser_set_gen_data (parser, fp);
+ comp = icalparser_parse (parser, icaltimezone_load_get_line_fn);
+ icalparser_free (parser);
+ fclose (fp);
+
+ /* Find the VTIMEZONE component inside the VCALENDAR. There should be 1. */
+ zone->component = icalcomponent_get_first_component (comp, ICAL_VTIMEZONE_COMPONENT);
+}
+
+
+/* Callback used from icalparser_parse() */
+static char *
+icaltimezone_load_get_line_fn (char *s,
+ size_t size,
+ void *data)
+{
+ return fgets (s, size, (FILE*) data);
+}
+
+
+
+
+/*
+ * DEBUGGING
+ */
+
+/*
+ * This outputs a list of timezone changes for the given timezone to the
+ * given file, up to the maximum year given. We compare this output with the
+ * output from 'vzic --dump-changes' to make sure that we are consistent.
+ * (vzic is the Olson timezone database to VTIMEZONE converter.)
+ *
+ * The output format is:
+ *
+ * Zone-Name [tab] Date [tab] Time [tab] UTC-Offset
+ *
+ * The Date and Time fields specify the time change in UTC.
+ *
+ * The UTC Offset is for local (wall-clock) time. It is the amount of time
+ * to add to UTC to get local time.
+ */
+int
+icaltimezone_dump_changes (icaltimezone *zone,
+ int max_year,
+ FILE *fp)
+{
+ static char *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
+ icaltimezonechange *zone_change;
+ int change_num;
+ char buffer[8];
+
+ /* Make sure the changes array is expanded up to the given time. */
+ icaltimezone_ensure_coverage (zone, max_year);
+
+#if 0
+ printf ("Num changes: %i\n", zone->changes->num_elements);
+#endif
+
+ change_num = 0;
+ for (change_num = 0; change_num < zone->changes->num_elements; change_num++) {
+ zone_change = icalarray_element_at (zone->changes, change_num);
+
+ if (zone_change->year > max_year)
+ break;
+
+ fprintf (fp, "%s\t%2i %s %04i\t%2i:%02i:%02i",
+ zone->location,
+ zone_change->day, months[zone_change->month - 1],
+ zone_change->year,
+ zone_change->hour, zone_change->minute, zone_change->second);
+
+ /* Wall Clock Time offset from UTC. */
+ format_utc_offset (zone_change->utc_offset, buffer);
+ fprintf (fp, "\t%s", buffer);
+
+ fprintf (fp, "\n");
+ }
+}
+
+
+/* This formats a UTC offset as "+HHMM" or "+HHMMSS".
+ buffer should have space for 8 characters. */
+static void
+format_utc_offset (int utc_offset,
+ char *buffer)
+{
+ char *sign = "+";
+ int hours, minutes, seconds;
+
+ if (utc_offset < 0) {
+ utc_offset = -utc_offset;
+ sign = "-";
+ }
+
+ hours = utc_offset / 3600;
+ minutes = (utc_offset % 3600) / 60;
+ seconds = utc_offset % 60;
+
+ /* Sanity check. Standard timezone offsets shouldn't be much more than 12
+ hours, and daylight saving shouldn't change it by more than a few hours.
+ (The maximum offset is 15 hours 56 minutes at present.) */
+ if (hours < 0 || hours >= 24 || minutes < 0 || minutes >= 60
+ || seconds < 0 || seconds >= 60) {
+ fprintf (stderr, "Warning: Strange timezone offset: H:%i M:%i S:%i\n",
+ hours, minutes, seconds);
+ }
+
+ if (seconds == 0)
+ sprintf (buffer, "%s%02i%02i", sign, hours, minutes);
+ else
+ sprintf (buffer, "%s%02i%02i%02i", sign, hours, minutes, seconds);
+}
diff --git a/libical/src/libical/icaltimezone.h b/libical/src/libical/icaltimezone.h
new file mode 100644
index 0000000000..028fd8c10a
--- /dev/null
+++ b/libical/src/libical/icaltimezone.h
@@ -0,0 +1,124 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/*======================================================================
+ FILE: icaltimezone.h
+ CREATOR: Damon Chaplin 15 March 2001
+
+
+ $Id$
+ $Locker$
+
+ (C) COPYRIGHT 2001, Damon Chaplin
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of either:
+
+ The LGPL as published by the Free Software Foundation, version
+ 2.1, available at: http://www.fsf.org/copyleft/lesser.html
+
+ Or:
+
+ The Mozilla Public License Version 1.0. You may obtain a copy of
+ the License at http://www.mozilla.org/MPL/
+
+
+======================================================================*/
+
+
+#ifndef ICALTIMEZONE_H
+#define ICALTIMEZONE_H
+
+#include <stdio.h> /* For FILE* */
+#include "icaltime.h"
+
+
+/* An opaque struct representing a timezone. */
+typedef struct _icaltimezone icaltimezone;
+
+
+
+/*
+ * Accessing timezones.
+ */
+
+/* Returns the array of builtin icaltimezones. */
+icalarray* icaltimezone_get_builtin_timezones (void);
+
+/* Returns a single builtin timezone, given its Olson city name. */
+icaltimezone* icaltimezone_get_builtin_timezone (const char *location);
+
+/* Returns the UTC timezone. */
+icaltimezone* icaltimezone_get_utc_timezone (void);
+
+/* Returns the TZID of a timezone. */
+char* icaltimezone_get_tzid (icaltimezone *zone);
+
+/* Returns the city name of a timezone. */
+char* icaltimezone_get_location (icaltimezone *zone);
+
+/* Returns the VTIMEZONE component of a timezone. */
+icalcomponent* icaltimezone_get_component (icaltimezone *zone);
+
+
+/*
+ * Converting times between timezones.
+ */
+
+void icaltimezone_convert_time (struct icaltimetype *tt,
+ icaltimezone *from_zone,
+ icaltimezone *to_zone);
+
+
+/*
+ * Getting offsets from UTC.
+ */
+
+/* Calculates the UTC offset of a given local time in the given timezone.
+ It is the number of seconds to add to UTC to get local time.
+ The is_daylight flag is set to 1 if the time is in daylight-savings time. */
+int icaltimezone_get_utc_offset (icaltimezone *zone,
+ struct icaltimetype *tt,
+ int *is_daylight);
+
+/* Calculates the UTC offset of a given UTC time in the given timezone.
+ It is the number of seconds to add to UTC to get local time.
+ The is_daylight flag is set to 1 if the time is in daylight-savings time. */
+int icaltimezone_get_utc_offset_of_utc_time (icaltimezone *zone,
+ struct icaltimetype *tt,
+ int *is_daylight);
+
+
+
+
+/*
+ * Comparing VTIMEZONE components.
+ */
+
+/* Compares 2 VTIMEZONE components to see if they match, ignoring their TZIDs.
+ It returns 1 if they match, 0 if they don't, or -1 on error. */
+int icaltimezone_compare_vtimezone (icalcomponent *vtimezone1,
+ icalcomponent *vtimezone2);
+
+
+
+
+/*
+ * Handling arrays of timezones.
+ */
+icalarray* icaltimezone_array_new (void);
+
+void icaltimezone_array_append_from_vtimezone (icalarray *timezones,
+ icalcomponent *child);
+
+
+
+/*
+ * Debugging Output.
+ */
+
+/* Dumps information about changes in the timezone up to and including
+ max_year. */
+int icaltimezone_dump_changes (icaltimezone *zone,
+ int max_year,
+ FILE *fp);
+
+#endif /* ICALTIMEZONE_H */