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Diffstat (limited to 'libkcal/libical/src/libical/icaltimezone.c')
| -rw-r--r-- | libkcal/libical/src/libical/icaltimezone.c | 1670 |
1 files changed, 1670 insertions, 0 deletions
diff --git a/libkcal/libical/src/libical/icaltimezone.c b/libkcal/libical/src/libical/icaltimezone.c new file mode 100644 index 00000000..fab228ef --- /dev/null +++ b/libkcal/libical/src/libical/icaltimezone.c @@ -0,0 +1,1670 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/*====================================================================== + FILE: icaltimezone.c + CREATOR: Damon Chaplin 15 March 2001 + + + (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/ + + +======================================================================*/ + +/** @file icaltimezone.c + * @brief implementation of timezone handling routines + **/ + +#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" + +#ifdef WIN32 +#define snprintf _snprintf +#define PACKAGE_DATA_DIR "/Projects/libical" +#endif + +/** 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 { + char *tzid; + /**< 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 *location; + /**< 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 *tznames; + /**< 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. */ + + double latitude; + double longitude; + /**< The coordinates of the city, in degrees. */ + + icalcomponent *component; + /**< The toplevel VTIMEZONE component loaded from the .ics file for this + timezone. If we need to regenerate the changes data we need this. */ + + icaltimezone *builtin_timezone; + /**< 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. */ + + int end_year; + /**< 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. */ + + icalarray *changes; + /**< 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. */ +}; + +typedef struct _icaltimezonechange icaltimezonechange; + +struct _icaltimezonechange { + int utc_offset; + /**< The offset to add to UTC to get local time, in seconds. */ + + int prev_utc_offset; + /**< The offset to add to UTC, before this change, in seconds. */ + + int year; /**< Actual year, e.g. 2001. */ + int month; /**< 1 (Jan) to 12 (Dec). */ + int day; + int hour; + int minute; + int second; + /**< 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 is_daylight; + /**< Whether this is STANDARD or DAYLIGHT time. */ +}; + + +/** An array of icaltimezones for the builtin timezones. */ +static icalarray *builtin_timezones = NULL; + +/** This is the special UTC timezone, which isn't in builtin_timezones. */ +static icaltimezone utc_timezone = { 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + +static char* zone_files_directory = NULL; + +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); + +static const char* get_zone_directory(void); + + +/** Creates a new icaltimezone. */ +icaltimezone* +icaltimezone_new (void) +{ + icaltimezone *zone; + + zone = (icaltimezone*) malloc (sizeof (icaltimezone)); + if (!zone) { + icalerror_set_errno (ICAL_NEWFAILED_ERROR); + return NULL; + } + + 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 ((void *)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; + + 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; + if ( zone->location != 0 ) free ( zone->location ); + 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; + const char *name; + + 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 && !strcasecmp (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; + + standard_max_date = icaltime_null_time(); + daylight_max_date = icaltime_null_time(); + + /* 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); + } + + /* Outlook (2000) places "Standard Time" and "Daylight Time" in the TZNAME + strings, which is totally useless. So we return NULL in that case. */ + if (standard_tzname && !strcmp (standard_tzname, "Standard Time")) + return NULL; + + /* 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) { + unsigned 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 icaltimetype today = icaltime_today(); + icaltimezone_minimum_expansion_year = today.year; + } + + 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 (icaltime_is_date(rdate.time)) { + 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 (!icaltime_is_utc(rdate.time)) + 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) +{ + icaltimezonechange *change1, *change2; + int retval; + + change1 = (icaltimezonechange *)elem1; + change2 = (icaltimezonechange *)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 (icaltime_is_date(*tt) || 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); +} + + + + +/** @deprecated This API wasn't updated when we changed icaltimetype to contain its own + timezone. Also, this takes a pointer instead of the struct. */ +/* 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; + int want_daylight; + + if (tt == NULL) + return 0; + + 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 ((unsigned int)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; +} + + +/** @deprecated This API wasn't updated when we changed icaltimetype to contain its own + timezone. Also, this takes a pointer instead of the struct. */ +/** 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 ((unsigned int)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) / 2; + 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; +} + + +const char* +icaltimezone_get_tzid (icaltimezone *zone) +{ + /* If this is a floating time, without a timezone, return NULL. */ + if (!zone) + return NULL; + + if (!zone->tzid) + icaltimezone_load_builtin_timezone (zone); + + return zone->tzid; +} + + +const 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; +} + + +const 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; + + if ( timezones ) + { + for (i = 0; (unsigned int)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; +} + +/** Release builtin timezone memory */ +void +icaltimezone_free_builtin_timezones(void) +{ + icaltimezone_array_free(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; + const 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) / 2; + 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) +{ + if (!builtin_timezones) + icaltimezone_init_builtin_timezones (); + + 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 = (char *)"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. */ + unsigned 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 (get_zone_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", get_zone_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; + unsigned 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 (get_zone_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", get_zone_directory(), + zone->location); + + fp = fopen (filename, "r"); + free (filename); + if (!fp) { + icalerror_set_errno(ICAL_FILE_ERROR); + return; + } + + + /* ##### B.# Sun, 11 Nov 2001 04:04:29 +1100 + this is where the MALFORMEDDATA error is being set, after the call to 'icalparser_parse' + fprintf(stderr, "** WARNING ** %s: %d %s\n", __FILE__, __LINE__, icalerror_strerror(icalerrno)); + */ + + 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); + + icalcomponent_remove_component(comp,subcomp); + + icalcomponent_free(comp); + +} + + +/** Callback used from icalparser_parse() */ +static char * +icaltimezone_load_get_line_fn (char *s, + size_t size, + void *data) +{ + return fgets (s, (int)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 const 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; (unsigned int)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"); + } + return 1; +} + + +/** 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) +{ + const 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) + snprintf (buffer, sizeof(buffer), "%s%02i%02i", sign, hours, minutes); + else + snprintf (buffer, sizeof(buffer), "%s%02i%02i%02i", sign, hours, minutes, seconds); +} + +static const char* get_zone_directory(void) +{ + return zone_files_directory == NULL ? ZONEINFO_DIRECTORY : zone_files_directory; +} + +void set_zone_directory(char *path) +{ + zone_files_directory = malloc(strlen(path)+1); + if ( zone_files_directory != NULL ) + { + strcpy(zone_files_directory,path); + } +} + +void free_zone_directory(void) +{ + if ( zone_files_directory != NULL ) + { + free(zone_files_directory); + } +} |