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Diffstat (limited to 'libical/src/libical/icaltimezone.c')
| -rw-r--r-- | libical/src/libical/icaltimezone.c | 1597 |
1 files changed, 0 insertions, 1597 deletions
diff --git a/libical/src/libical/icaltimezone.c b/libical/src/libical/icaltimezone.c deleted file mode 100644 index fcb12c378b..0000000000 --- a/libical/src/libical/icaltimezone.c +++ /dev/null @@ -1,1597 +0,0 @@ -/* -*- 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 "icalproperty.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" - -/* The prefix we use to uniquely identify TZIDs. */ -#define TZID_PREFIX "/softwarestudio.org/" -#define TZID_PREFIX_LEN 20 - -/* 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 2035 - - -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_reset (icaltimezone *zone); -static char* icaltimezone_get_location_from_vtimezone (icalcomponent *component); -static char* icaltimezone_get_tznames_from_vtimezone (icalcomponent *component); -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); - -/* Gets the TZID, LOCATION/X-LIC-LOCATION, and TZNAME properties from the - VTIMEZONE component and places them in the icaltimezone. It returns 1 on - success, or 0 if the TZID can't be found. */ -static int icaltimezone_get_vtimezone_properties (icaltimezone *zone, - icalcomponent *component); - - -static void icaltimezone_load_builtin_timezone (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); - - -/* Creates a new icaltimezone. */ -icaltimezone* -icaltimezone_new (void) -{ - icaltimezone *zone; - - zone = (icaltimezone*) malloc (sizeof (icaltimezone)); - if (!zone) { - icalerror_set_errno (ICAL_NEWFAILED_ERROR); - return; - } - - icaltimezone_init (zone); - - return zone; -} - - -/* Frees all memory used for the icaltimezone. */ -void -icaltimezone_free (icaltimezone *zone, - int free_struct) -{ - icaltimezone_reset (zone); - if (free_struct) - free (zone); -} - - -/* Resets the icaltimezone to the initial state, freeing most of the fields. */ -static void -icaltimezone_reset (icaltimezone *zone) -{ - if (zone->tzid) - free (zone->tzid); - if (zone->location) - free (zone->location); - if (zone->tznames) - free (zone->tznames); - if (zone->component) - icalcomponent_free (zone->component); - if (zone->changes) - icalarray_free (zone->changes); - - icaltimezone_init (zone); -} - - -/* Initializes an icaltimezone. */ -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; -} - - -/* Gets the TZID, LOCATION/X-LIC-LOCATION and TZNAME properties of the - VTIMEZONE component and stores them in the icaltimezone. - It returns 1 on success, or 0 if the TZID can't be found. - Note that it expects the zone to be initialized or reset - it doesn't free - any old values. */ -static int -icaltimezone_get_vtimezone_properties (icaltimezone *zone, - icalcomponent *component) -{ - icalproperty *prop; - const char *tzid, *location; - - prop = icalcomponent_get_first_property (component, ICAL_TZID_PROPERTY); - if (!prop) - return 0; - - /* A VTIMEZONE MUST have a TZID, or a lot of our code won't work. */ - tzid = icalproperty_get_tzid (prop); - if (!tzid) - return 0; - - zone->tzid = strdup (tzid); - zone->component = component; - zone->location = icaltimezone_get_location_from_vtimezone (component); - zone->tznames = icaltimezone_get_tznames_from_vtimezone (component); - - return 1; -} - -/* Gets the LOCATION or X-LIC-LOCATION property from a VTIMEZONE. */ -static char* -icaltimezone_get_location_from_vtimezone (icalcomponent *component) -{ - icalproperty *prop; - const char *location; - char *name; - int found_location = 0; - - prop = icalcomponent_get_first_property (component, - ICAL_LOCATION_PROPERTY); - if (prop) { - location = icalproperty_get_location (prop); - if (location) - return strdup (location); - } - - prop = icalcomponent_get_first_property (component, ICAL_X_PROPERTY); - while (prop) { - name = icalproperty_get_x_name (prop); - if (name && !strcmp (name, "X-LIC-LOCATION")) { - location = icalproperty_get_x (prop); - if (location) - return strdup (location); - } - prop = icalcomponent_get_next_property (component, - ICAL_X_PROPERTY); - } - - return NULL; -} - - -/* Gets the TZNAMEs used for the last STANDARD & DAYLIGHT components in a - VTIMEZONE. If both STANDARD and DAYLIGHT components use the same TZNAME, - it returns that. If they use different TZNAMEs, it formats them like - "EST/EDT". The returned string should be freed by the caller. */ -static char* -icaltimezone_get_tznames_from_vtimezone (icalcomponent *component) -{ - icalcomponent *comp; - icalcomponent_kind type; - icalproperty *prop; - struct icaltimetype dtstart; - struct icaldatetimeperiodtype rdate; - const char *current_tzname; - const char *standard_tzname = NULL, *daylight_tzname = NULL; - struct icaltimetype standard_max_date, daylight_max_date; - struct icaltimetype current_max_date; - - /* Step through the STANDARD & DAYLIGHT subcomponents. */ - comp = icalcomponent_get_first_component (component, ICAL_ANY_COMPONENT); - while (comp) { - type = icalcomponent_isa (comp); - if (type == ICAL_XSTANDARD_COMPONENT - || type == ICAL_XDAYLIGHT_COMPONENT) { - current_max_date = icaltime_null_time (); - current_tzname = NULL; - - /* Step through the properties. We want to find the TZNAME, and - the largest DTSTART or RDATE. */ - prop = icalcomponent_get_first_property (comp, ICAL_ANY_PROPERTY); - while (prop) { - switch (icalproperty_isa (prop)) { - case ICAL_TZNAME_PROPERTY: - current_tzname = icalproperty_get_tzname (prop); - break; - - case ICAL_DTSTART_PROPERTY: - dtstart = icalproperty_get_dtstart (prop); - if (icaltime_compare (dtstart, current_max_date) > 0) - current_max_date = dtstart; - - break; - - case ICAL_RDATE_PROPERTY: - rdate = icalproperty_get_rdate (prop); - if (icaltime_compare (rdate.time, current_max_date) > 0) - current_max_date = rdate.time; - - break; - - default: - break; - } - - prop = icalcomponent_get_next_property (comp, - ICAL_ANY_PROPERTY); - } - - if (current_tzname) { - if (type == ICAL_XSTANDARD_COMPONENT) { - if (!standard_tzname - || icaltime_compare (current_max_date, - standard_max_date) > 0) { - standard_max_date = current_max_date; - standard_tzname = current_tzname; - } - } else { - if (!daylight_tzname - || icaltime_compare (current_max_date, - daylight_max_date) > 0) { - daylight_max_date = current_max_date; - daylight_tzname = current_tzname; - } - } - } - } - - comp = icalcomponent_get_next_component (component, - ICAL_ANY_COMPONENT); - } - - /* If both standard and daylight TZNAMEs were found, if they are the same - we return just one, else we format them like "EST/EDT". */ - if (standard_tzname && daylight_tzname) { - int standard_len, daylight_len; - char *tznames; - - if (!strcmp (standard_tzname, daylight_tzname)) - return strdup (standard_tzname); - - standard_len = strlen (standard_tzname); - daylight_len = strlen (daylight_tzname); - tznames = malloc (standard_len + daylight_len + 2); - strcpy (tznames, standard_tzname); - tznames[standard_len] = '/'; - strcpy (tznames + standard_len + 1, daylight_tzname); - return tznames; - } else { - const char *tznames; - - /* If either of the TZNAMEs was found just return that, else NULL. */ - tznames = standard_tzname ? standard_tzname : daylight_tzname; - return tznames ? strdup (tznames) : NULL; - } -} - - -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_builtin_timezone (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; - - /* If the time is a DATE value or both timezones are the same, or we are - converting a floating time, we don't need to do anything. */ - if (tt->is_date || from_zone == to_zone || from_zone == NULL) - return; - - /* 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 0 - if (zone_change->is_daylight == prev_zone_change->is_daylight) - printf (" **** Same is_daylight setting\n"); -#endif - - 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; - - 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 and adjust it to UTC. */ - tmp_change = *zone_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 (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; - - 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; -} - - -char* -icaltimezone_get_tzid (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return NULL. */ - if (!zone) - return NULL; - - if (!zone->component) - icaltimezone_load_builtin_timezone (zone); - - return zone->tzid; -} - - -char* -icaltimezone_get_location (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return NULL. */ - if (!zone) - return NULL; - - /* Note that for builtin timezones this comes from zones.tab so we don't - need to check the timezone is loaded here. */ - return zone->location; -} - - -char* -icaltimezone_get_tznames (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return NULL. */ - if (!zone) - return NULL; - - if (!zone->component) - icaltimezone_load_builtin_timezone (zone); - - return zone->tznames; -} - - -/* Returns the latitude of a builtin timezone. */ -double -icaltimezone_get_latitude (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return 0. */ - if (!zone) - return 0.0; - - /* Note that for builtin timezones this comes from zones.tab so we don't - need to check the timezone is loaded here. */ - return zone->latitude; -} - - -/* Returns the longitude of a builtin timezone. */ -double -icaltimezone_get_longitude (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return 0. */ - if (!zone) - return 0.0; - - /* Note that for builtin timezones this comes from zones.tab so we don't - need to check the timezone is loaded here. */ - return zone->longitude; -} - - -/* Returns the VTIMEZONE component of a timezone. */ -icalcomponent* -icaltimezone_get_component (icaltimezone *zone) -{ - /* If this is a floating time, without a timezone, return NULL. */ - if (!zone) - return NULL; - - if (!zone->component) - icaltimezone_load_builtin_timezone (zone); - - return zone->component; -} - - -/* Sets the VTIMEZONE component of an icaltimezone, initializing the tzid, - location & tzname fields. It returns 1 on success or 0 on failure, i.e. - no TZID was found. */ -int -icaltimezone_set_component (icaltimezone *zone, - icalcomponent *comp) -{ - icaltimezone_reset (zone); - return icaltimezone_get_vtimezone_properties (zone, comp); -} - - -icalarray* -icaltimezone_array_new (void) -{ - return icalarray_new (sizeof (icaltimezone), 16); -} - - -void -icaltimezone_array_append_from_vtimezone (icalarray *timezones, - icalcomponent *child) -{ - icaltimezone zone; - - icaltimezone_init (&zone); - if (icaltimezone_get_vtimezone_properties (&zone, child)) - icalarray_append (timezones, &zone); -} - - -void -icaltimezone_array_free (icalarray *timezones) -{ - icaltimezone *zone; - int i; - - for (i = 0; i < timezones->num_elements; i++) { - zone = icalarray_element_at (timezones, i); - icaltimezone_free (zone, 0); - } - - icalarray_free (timezones); -} - - -/* - * 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 a single builtin timezone, given its Olson city name. */ -icaltimezone* -icaltimezone_get_builtin_timezone (const char *location) -{ - icaltimezone *zone; - int lower, upper, middle, cmp; - char *zone_location; - - if (!location || !location[0]) - return NULL; - - if (!strcmp (location, "UTC")) - return &utc_timezone; - - if (!builtin_timezones) - icaltimezone_init_builtin_timezones (); - - /* Do a simple binary search. */ - lower = middle = 0; - upper = builtin_timezones->num_elements; - - while (lower < upper) { - middle = (lower + upper) >> 1; - zone = icalarray_element_at (builtin_timezones, middle); - zone_location = icaltimezone_get_location (zone); - cmp = strcmp (location, zone_location); - if (cmp == 0) - return zone; - else if (cmp < 0) - upper = middle; - else - lower = middle + 1; - } - - return NULL; -} - - -/* Returns a single builtin timezone, given its TZID. */ -icaltimezone* -icaltimezone_get_builtin_timezone_from_tzid (const char *tzid) -{ - int num_slashes = 0; - const char *p, *zone_tzid; - icaltimezone *zone; - - if (!tzid || !tzid[0]) - return NULL; - - /* Check that the TZID starts with our unique prefix. */ - if (strncmp (tzid, TZID_PREFIX, TZID_PREFIX_LEN)) - return NULL; - - /* Get the location, which is after the 3rd '/' character. */ - p = tzid; - for (p = tzid; *p; p++) { - if (*p == '/') { - num_slashes++; - if (num_slashes == 3) - break; - } - } - - if (num_slashes != 3) - return NULL; - - p++; - - /* Now we can use the function to get the builtin timezone from the - location string. */ - zone = icaltimezone_get_builtin_timezone (p); - if (!zone) - return NULL; - - /* Check that the builtin TZID matches exactly. We don't want to return - a different version of the VTIMEZONE. */ - zone_tzid = icaltimezone_get_tzid (zone); - if (!strcmp (zone_tzid, tzid)) - return zone; - else - return NULL; -} - - -/* Returns the special UTC timezone. */ -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"); - - builtin_timezones = icalarray_new (sizeof (icaltimezone), 32); - - 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; - } - - 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_builtin_timezone (icaltimezone *zone) -{ - char *filename; - int filename_len; - FILE *fp; - icalparser *parser; - icalcomponent *comp, *subcomp; - - /* If the location isn't set, it isn't a builtin timezone. */ - if (!zone->location || !zone->location[0]) - return; - - 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. */ - subcomp = icalcomponent_get_first_component (comp, - ICAL_VTIMEZONE_COMPONENT); - if (!subcomp) { - icalerror_set_errno(ICAL_PARSE_ERROR); - return; - } - - icaltimezone_get_vtimezone_properties (zone, subcomp); -} - - -/* 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); -} |