diff options
Diffstat (limited to 'libmap/tz.c')
-rw-r--r-- | libmap/tz.c | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/libmap/tz.c b/libmap/tz.c new file mode 100644 index 0000000..b77a8ef --- /dev/null +++ b/libmap/tz.c @@ -0,0 +1,399 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */ +/* Generic timezone utilities. + * + * Copyright (C) 2000-2001 Ximian, Inc. + * + * Authors: Hans Petter Jansson <hpj@ximian.com> + * + * Largely based on Michael Fulbright's work on Anaconda. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. + */ + + +#include <glib.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <time.h> +#include <math.h> +#include <string.h> +#include "tz.h" + + +/* Forward declarations for private functions */ + +static float convert_pos (gchar *pos, int digits); +static int compare_country_names (const void *a, const void *b); +static void sort_locations_by_country (GPtrArray *locations); +static gchar * tz_data_file_get (void); + + +/* ---------------- * + * Public interface * + * ---------------- */ +TzDB * +tz_load_db (void) +{ + gchar *tz_data_file; + TzDB *tz_db; + FILE *tzfile; + char buf[4096]; + + tz_data_file = tz_data_file_get (); + if (!tz_data_file) { + g_warning ("Could not get the TimeZone data file name"); + return NULL; + } + tzfile = fopen (tz_data_file, "r"); + if (!tzfile) { + g_warning ("Could not open *%s*\n", tz_data_file); + g_free (tz_data_file); + return NULL; + } + + tz_db = g_new0 (TzDB, 1); + tz_db->locations = g_ptr_array_new (); + + while (fgets (buf, sizeof(buf), tzfile)) + { + gchar **tmpstrarr; + gchar *latstr, *lngstr, *p; + TzLocation *loc; + + if (*buf == '#') continue; + + g_strchomp(buf); + tmpstrarr = g_strsplit(buf,"\t", 6); + + latstr = g_strdup (tmpstrarr[1]); + p = latstr + 1; + while (*p != '-' && *p != '+') p++; + lngstr = g_strdup (p); + *p = '\0'; + + loc = g_new0 (TzLocation, 1); + loc->country = g_strdup (tmpstrarr[0]); + loc->zone = g_strdup (tmpstrarr[2]); + loc->latitude = convert_pos (latstr, 2); + loc->longitude = convert_pos (lngstr, 3); + +#ifdef __sun + if (tmpstrarr[3] && *tmpstrarr[3] == '-' && tmpstrarr[4]) + loc->comment = g_strdup (tmpstrarr[4]); + + if (tmpstrarr[3] && *tmpstrarr[3] != '-' && !islower(loc->zone)) { + TzLocation *locgrp; + + /* duplicate entry */ + locgrp = g_new0 (TzLocation, 1); + locgrp->country = g_strdup (tmpstrarr[0]); + locgrp->zone = g_strdup (tmpstrarr[3]); + locgrp->latitude = convert_pos (latstr, 2); + locgrp->longitude = convert_pos (lngstr, 3); + locgrp->comment = (tmpstrarr[4]) ? g_strdup (tmpstrarr[4]) : NULL; + + g_ptr_array_add (tz_db->locations, (gpointer) locgrp); + } +#else + loc->comment = (tmpstrarr[3]) ? g_strdup(tmpstrarr[3]) : NULL; +#endif + + g_ptr_array_add (tz_db->locations, (gpointer) loc); + + g_free (latstr); + g_free (lngstr); + g_strfreev (tmpstrarr); + } + + fclose (tzfile); + + /* now sort by country */ + sort_locations_by_country (tz_db->locations); + + g_free (tz_data_file); + + return tz_db; +} + +static void +tz_location_free (TzLocation *loc) +{ + g_free (loc->country); + g_free (loc->zone); + g_free (loc->comment); + + g_free (loc); +} + +void +tz_db_free (TzDB *db) +{ + g_ptr_array_foreach (db->locations, (GFunc) tz_location_free, NULL); + g_ptr_array_free (db->locations, TRUE); + g_free (db); +} + +static gint +sort_locations (TzLocation *a, + TzLocation *b) +{ + if (a->dist > b->dist) + return 1; + + if (a->dist < b->dist) + return -1; + + return 0; +} + +static gdouble +convert_longtitude_to_x (gdouble longitude, gint map_width) +{ + const gdouble xdeg_offset = -6; + gdouble x; + + x = (map_width * (180.0 + longitude) / 360.0) + + (map_width * xdeg_offset / 180.0); + + return x; +} + +static gdouble +radians (gdouble degrees) +{ + return (degrees / 360.0) * G_PI * 2; +} + +static gdouble +convert_latitude_to_y (gdouble latitude, gdouble map_height) +{ + gdouble bottom_lat = -59; + gdouble top_lat = 81; + gdouble top_per, y, full_range, top_offset, map_range; + + top_per = top_lat / 180.0; + y = 1.25 * log (tan (G_PI_4 + 0.4 * radians (latitude))); + full_range = 4.6068250867599998; + top_offset = full_range * top_per; + map_range = fabs (1.25 * log (tan (G_PI_4 + 0.4 * radians (bottom_lat))) - top_offset); + y = fabs (y - top_offset); + y = y / map_range; + y = y * map_height; + return y; +} + +GPtrArray * +tz_get_locations (TzDB *db) +{ + return db->locations; +} + + +gchar * +tz_location_get_country (TzLocation *loc) +{ + return loc->country; +} + + +gchar * +tz_location_get_zone (TzLocation *loc) +{ + return loc->zone; +} + + +gchar * +tz_location_get_comment (TzLocation *loc) +{ + return loc->comment; +} + + +void +tz_location_get_position (TzLocation *loc, double *longitude, double *latitude) +{ + *longitude = loc->longitude; + *latitude = loc->latitude; +} + +glong +tz_location_get_utc_offset (TzLocation *loc) +{ + TzInfo *tz_info; + glong offset; + + tz_info = tz_info_from_location (loc); + offset = tz_info->utc_offset; + tz_info_free (tz_info); + return offset; +} + +gint +tz_location_set_locally (TzLocation *loc) +{ + time_t curtime; + struct tm *curzone; + gboolean is_dst = FALSE; + gint correction = 0; + + g_return_val_if_fail (loc != NULL, 0); + g_return_val_if_fail (loc->zone != NULL, 0); + + curtime = time (NULL); + curzone = localtime (&curtime); + is_dst = curzone->tm_isdst; + + setenv ("TZ", loc->zone, 1); +#if 0 + curtime = time (NULL); + curzone = localtime (&curtime); + + if (!is_dst && curzone->tm_isdst) { + correction = (60 * 60); + } + else if (is_dst && !curzone->tm_isdst) { + correction = 0; + } +#endif + + return correction; +} + +TzInfo * +tz_info_from_location (TzLocation *loc) +{ + TzInfo *tzinfo; + time_t curtime; + struct tm *curzone; + + g_return_val_if_fail (loc != NULL, NULL); + g_return_val_if_fail (loc->zone != NULL, NULL); + + setenv ("TZ", loc->zone, 1); + +#if 0 + tzset (); +#endif + tzinfo = g_new0 (TzInfo, 1); + + curtime = time (NULL); + curzone = localtime (&curtime); + +#ifndef __sun + /* Currently this solution doesnt seem to work - I get that */ + /* America/Phoenix uses daylight savings, which is wrong */ + tzinfo->tzname_normal = g_strdup (curzone->tm_zone); + if (curzone->tm_isdst) + tzinfo->tzname_daylight = + g_strdup (&curzone->tm_zone[curzone->tm_isdst]); + else + tzinfo->tzname_daylight = NULL; + + tzinfo->utc_offset = curzone->tm_gmtoff; +#else + tzinfo->tzname_normal = NULL; + tzinfo->tzname_daylight = NULL; + tzinfo->utc_offset = 0; +#endif + + tzinfo->daylight = curzone->tm_isdst; + + return tzinfo; +} + + +void +tz_info_free (TzInfo *tzinfo) +{ + g_return_if_fail (tzinfo != NULL); + + if (tzinfo->tzname_normal) g_free (tzinfo->tzname_normal); + if (tzinfo->tzname_daylight) g_free (tzinfo->tzname_daylight); + g_free (tzinfo); +} + +/* ----------------- * + * Private functions * + * ----------------- */ + +static gchar * +tz_data_file_get (void) +{ + gchar *file; + + file = g_strdup (TZ_DATA_FILE); + + return file; +} + +static float +convert_pos (gchar *pos, int digits) +{ + gchar whole[10]; + gchar *fraction; + gint i; + float t1, t2; + + if (!pos || strlen(pos) < 4 || digits > 9) return 0.0; + + for (i = 0; i < digits + 1; i++) whole[i] = pos[i]; + whole[i] = '\0'; + fraction = pos + digits + 1; + + t1 = g_strtod (whole, NULL); + t2 = g_strtod (fraction, NULL); + + if (t1 >= 0.0) return t1 + t2/pow (10.0, strlen(fraction)); + else return t1 - t2/pow (10.0, strlen(fraction)); +} + + +#if 0 + +/* Currently not working */ +static void +free_tzdata (TzLocation *tz) +{ + + if (tz->country) + g_free(tz->country); + if (tz->zone) + g_free(tz->zone); + if (tz->comment) + g_free(tz->comment); + + g_free(tz); +} +#endif + + +static int +compare_country_names (const void *a, const void *b) +{ + const TzLocation *tza = * (TzLocation **) a; + const TzLocation *tzb = * (TzLocation **) b; + + return strcmp (tza->zone, tzb->zone); +} + + +static void +sort_locations_by_country (GPtrArray *locations) +{ + qsort (locations->pdata, locations->len, sizeof (gpointer), + compare_country_names); +} |