root/ext/date/lib/parse_tz.c

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DEFINITIONS

This source file includes following definitions.
  1. read_preamble
  2. read_header
  3. skip_64bit_transistions
  4. read_transistions
  5. skip_64bit_types
  6. read_types
  7. skip_posix_string
  8. read_location
  9. timelib_dump_tzinfo
  10. seek_to_tz_position
  11. timelib_builtin_db
  12. timelib_timezone_builtin_identifiers_list
  13. timelib_timezone_id_is_valid
  14. skip_64bit_preamble
  15. read_64bit_header
  16. timelib_parse_tzfile
  17. fetch_timezone_offset
  18. fetch_leaptime_offset
  19. timelib_timestamp_is_in_dst
  20. timelib_get_time_zone_info
  21. timelib_get_current_offset

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2015 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Derick Rethans <derick@derickrethans.nl>                    |
   +----------------------------------------------------------------------+
 */

/* $Id$ */

#include "timelib.h"

#include <stdio.h>

#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#include "timezonedb.h"

#if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))
# if defined(__LITTLE_ENDIAN__)
#  undef WORDS_BIGENDIAN
# else
#  if defined(__BIG_ENDIAN__)
#   define WORDS_BIGENDIAN
#  endif
# endif
#endif

#ifdef WORDS_BIGENDIAN
#define timelib_conv_int(l) (l)
#else
#define timelib_conv_int(l) ((l & 0x000000ff) << 24) + ((l & 0x0000ff00) << 8) + ((l & 0x00ff0000) >> 8) + ((l & 0xff000000) >> 24)
#endif

static int read_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
{
        uint32_t version;

        /* read ID */
        version = (*tzf)[3] - '0';
        *tzf += 4;

        /* read BC flag */
        tz->bc = (**tzf == '\1');
        *tzf += 1;

        /* read country code */
        memcpy(tz->location.country_code, *tzf, 2);
        tz->location.country_code[2] = '\0';
        *tzf += 2;

        /* skip rest of preamble */
        *tzf += 13;

        return version;
}

static void read_header(const unsigned char **tzf, timelib_tzinfo *tz)
{
        uint32_t buffer[6];

        memcpy(&buffer, *tzf, sizeof(buffer));
        tz->bit32.ttisgmtcnt = timelib_conv_int(buffer[0]);
        tz->bit32.ttisstdcnt = timelib_conv_int(buffer[1]);
        tz->bit32.leapcnt    = timelib_conv_int(buffer[2]);
        tz->bit32.timecnt    = timelib_conv_int(buffer[3]);
        tz->bit32.typecnt    = timelib_conv_int(buffer[4]);
        tz->bit32.charcnt    = timelib_conv_int(buffer[5]);
        *tzf += sizeof(buffer);
}

static void skip_64bit_transistions(const unsigned char **tzf, timelib_tzinfo *tz)
{
        if (tz->bit64.timecnt) {
                *tzf += (sizeof(int64_t) * tz->bit64.timecnt);
                *tzf += (sizeof(unsigned char) * tz->bit64.timecnt);
        }
}

static void read_transistions(const unsigned char **tzf, timelib_tzinfo *tz)
{
        int32_t *buffer = NULL;
        uint32_t i;
        unsigned char *cbuffer = NULL;

        if (tz->bit32.timecnt) {
                buffer = (int32_t*) malloc(tz->bit32.timecnt * sizeof(int32_t));
                if (!buffer) {
                        return;
                }
                memcpy(buffer, *tzf, sizeof(int32_t) * tz->bit32.timecnt);
                *tzf += (sizeof(int32_t) * tz->bit32.timecnt);
                for (i = 0; i < tz->bit32.timecnt; i++) {
                        buffer[i] = timelib_conv_int(buffer[i]);
                }

                cbuffer = (unsigned char*) malloc(tz->bit32.timecnt * sizeof(unsigned char));
                if (!cbuffer) {
                        free(buffer);
                        return;
                }
                memcpy(cbuffer, *tzf, sizeof(unsigned char) * tz->bit32.timecnt);
                *tzf += sizeof(unsigned char) * tz->bit32.timecnt;
        }

        tz->trans = buffer;
        tz->trans_idx = cbuffer;
}

static void skip_64bit_types(const unsigned char **tzf, timelib_tzinfo *tz)
{
        *tzf += sizeof(unsigned char) * 6 * tz->bit64.typecnt;
        *tzf += sizeof(char) * tz->bit64.charcnt;
        if (tz->bit64.leapcnt) {
                *tzf += sizeof(int64_t) * tz->bit64.leapcnt * 2;
        }
        if (tz->bit64.ttisstdcnt) {
                *tzf += sizeof(unsigned char) * tz->bit64.ttisstdcnt;
        }
        if (tz->bit64.ttisgmtcnt) {
                *tzf += sizeof(unsigned char) * tz->bit64.ttisgmtcnt;
        }
}

static void read_types(const unsigned char **tzf, timelib_tzinfo *tz)
{
        unsigned char *buffer;
        int32_t *leap_buffer;
        unsigned int i, j;

        buffer = (unsigned char*) malloc(tz->bit32.typecnt * sizeof(unsigned char) * 6);
        if (!buffer) {
                return;
        }
        memcpy(buffer, *tzf, sizeof(unsigned char) * 6 * tz->bit32.typecnt);
        *tzf += sizeof(unsigned char) * 6 * tz->bit32.typecnt;

        tz->type = (ttinfo*) malloc(tz->bit32.typecnt * sizeof(struct ttinfo));
        if (!tz->type) {
                free(buffer);
                return;
        }

        for (i = 0; i < tz->bit32.typecnt; i++) {
                j = i * 6;
                tz->type[i].offset = (buffer[j] * 16777216) + (buffer[j + 1] * 65536) + (buffer[j + 2] * 256) + buffer[j + 3];
                tz->type[i].isdst = buffer[j + 4];
                tz->type[i].abbr_idx = buffer[j + 5];
        }
        free(buffer);

        tz->timezone_abbr = (char*) malloc(tz->bit32.charcnt);
        if (!tz->timezone_abbr) {
                return;
        }
        memcpy(tz->timezone_abbr, *tzf, sizeof(char) * tz->bit32.charcnt);
        *tzf += sizeof(char) * tz->bit32.charcnt;

        if (tz->bit32.leapcnt) {
                leap_buffer = (int32_t *) malloc(tz->bit32.leapcnt * 2 * sizeof(int32_t));
                if (!leap_buffer) {
                        return;
                }
                memcpy(leap_buffer, *tzf, sizeof(int32_t) * tz->bit32.leapcnt * 2);
                *tzf += sizeof(int32_t) * tz->bit32.leapcnt * 2;

                tz->leap_times = (tlinfo*) malloc(tz->bit32.leapcnt * sizeof(tlinfo));
                if (!tz->leap_times) {
                        free(leap_buffer);
                        return;
                }
                for (i = 0; i < tz->bit32.leapcnt; i++) {
                        tz->leap_times[i].trans = timelib_conv_int(leap_buffer[i * 2]);
                        tz->leap_times[i].offset = timelib_conv_int(leap_buffer[i * 2 + 1]);
                }
                free(leap_buffer);
        }

        if (tz->bit32.ttisstdcnt) {
                buffer = (unsigned char*) malloc(tz->bit32.ttisstdcnt * sizeof(unsigned char));
                if (!buffer) {
                        return;
                }
                memcpy(buffer, *tzf, sizeof(unsigned char) * tz->bit32.ttisstdcnt);
                *tzf += sizeof(unsigned char) * tz->bit32.ttisstdcnt;

                for (i = 0; i < tz->bit32.ttisstdcnt; i++) {
                        tz->type[i].isstdcnt = buffer[i];
                }
                free(buffer);
        }

        if (tz->bit32.ttisgmtcnt) {
                buffer = (unsigned char*) malloc(tz->bit32.ttisgmtcnt * sizeof(unsigned char));
                if (!buffer) {
                        return;
                }
                memcpy(buffer, *tzf, sizeof(unsigned char) * tz->bit32.ttisgmtcnt);
                *tzf += sizeof(unsigned char) * tz->bit32.ttisgmtcnt;

                for (i = 0; i < tz->bit32.ttisgmtcnt; i++) {
                        tz->type[i].isgmtcnt = buffer[i];
                }
                free(buffer);
        }
}

static void skip_posix_string(const unsigned char **tzf, timelib_tzinfo *tz)
{
        int n_count = 0;

        do {
                if (*tzf[0] == '\n') {
                        n_count++;
                }
                (*tzf)++;
        } while (n_count < 2);
}

static void read_location(const unsigned char **tzf, timelib_tzinfo *tz)
{
        uint32_t buffer[3];
        uint32_t comments_len;

        memcpy(&buffer, *tzf, sizeof(buffer));
        tz->location.latitude = timelib_conv_int(buffer[0]);
        tz->location.latitude = (tz->location.latitude / 100000) - 90;
        tz->location.longitude = timelib_conv_int(buffer[1]);
        tz->location.longitude = (tz->location.longitude / 100000) - 180;
        comments_len = timelib_conv_int(buffer[2]);
        *tzf += sizeof(buffer);

        tz->location.comments = malloc(comments_len + 1);
        memcpy(tz->location.comments, *tzf, comments_len);
        tz->location.comments[comments_len] = '\0';
        *tzf += comments_len;
}

void timelib_dump_tzinfo(timelib_tzinfo *tz)
{
        uint32_t i;

        printf("Country Code:      %s\n", tz->location.country_code);
        printf("Geo Location:      %f,%f\n", tz->location.latitude, tz->location.longitude);
        printf("Comments:\n%s\n",          tz->location.comments);
        printf("BC:                %s\n",  tz->bc ? "" : "yes");
        printf("UTC/Local count:   %lu\n", (unsigned long) tz->bit32.ttisgmtcnt);
        printf("Std/Wall count:    %lu\n", (unsigned long) tz->bit32.ttisstdcnt);
        printf("Leap.sec. count:   %lu\n", (unsigned long) tz->bit32.leapcnt);
        printf("Trans. count:      %lu\n", (unsigned long) tz->bit32.timecnt);
        printf("Local types count: %lu\n", (unsigned long) tz->bit32.typecnt);
        printf("Zone Abbr. count:  %lu\n", (unsigned long) tz->bit32.charcnt);

        printf ("%8s (%12s) = %3d [%5ld %1d %3d '%s' (%d,%d)]\n",
                "", "", 0,
                (long int) tz->type[0].offset,
                tz->type[0].isdst,
                tz->type[0].abbr_idx,
                &tz->timezone_abbr[tz->type[0].abbr_idx],
                tz->type[0].isstdcnt,
                tz->type[0].isgmtcnt
                );
        for (i = 0; i < tz->bit32.timecnt; i++) {
                printf ("%08X (%12d) = %3d [%5ld %1d %3d '%s' (%d,%d)]\n",
                        tz->trans[i], tz->trans[i], tz->trans_idx[i],
                        (long int) tz->type[tz->trans_idx[i]].offset,
                        tz->type[tz->trans_idx[i]].isdst,
                        tz->type[tz->trans_idx[i]].abbr_idx,
                        &tz->timezone_abbr[tz->type[tz->trans_idx[i]].abbr_idx],
                        tz->type[tz->trans_idx[i]].isstdcnt,
                        tz->type[tz->trans_idx[i]].isgmtcnt
                        );
        }
        for (i = 0; i < tz->bit32.leapcnt; i++) {
                printf ("%08X (%12ld) = %d\n",
                        tz->leap_times[i].trans,
                        (long) tz->leap_times[i].trans,
                        tz->leap_times[i].offset);
        }
}

static int seek_to_tz_position(const unsigned char **tzf, char *timezone, const timelib_tzdb *tzdb)
{
        int left = 0, right = tzdb->index_size - 1;
#ifdef HAVE_SETLOCALE
        char *cur_locale = NULL, *tmp;

        tmp = setlocale(LC_CTYPE, NULL);
        if (tmp) {
                cur_locale = strdup(tmp);
        }
        setlocale(LC_CTYPE, "C");
#endif

        do {
                int mid = ((unsigned)left + right) >> 1;
                int cmp = strcasecmp(timezone, tzdb->index[mid].id);

                if (cmp < 0) {
                        right = mid - 1;
                } else if (cmp > 0) {
                        left = mid + 1;
                } else { /* (cmp == 0) */
                        (*tzf) = &(tzdb->data[tzdb->index[mid].pos]);
#ifdef HAVE_SETLOCALE
                        setlocale(LC_CTYPE, cur_locale);
                        if (cur_locale) free(cur_locale);
#endif
                        return 1;
                }

        } while (left <= right);

#ifdef HAVE_SETLOCALE
        setlocale(LC_CTYPE, cur_locale);
        if (cur_locale) free(cur_locale);
#endif
        return 0;
}

const timelib_tzdb *timelib_builtin_db(void)
{
        return &timezonedb_builtin;
}

const timelib_tzdb_index_entry *timelib_timezone_builtin_identifiers_list(int *count)
{
        *count = sizeof(timezonedb_idx_builtin) / sizeof(*timezonedb_idx_builtin);
        return timezonedb_idx_builtin;
}

int timelib_timezone_id_is_valid(char *timezone, const timelib_tzdb *tzdb)
{
        const unsigned char *tzf;
        return (seek_to_tz_position(&tzf, timezone, tzdb));
}

static void skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
{
        *tzf += 20;
}

static void read_64bit_header(const unsigned char **tzf, timelib_tzinfo *tz)
{
        uint32_t buffer[6];

        memcpy(&buffer, *tzf, sizeof(buffer));
        tz->bit64.ttisgmtcnt = timelib_conv_int(buffer[0]);
        tz->bit64.ttisstdcnt = timelib_conv_int(buffer[1]);
        tz->bit64.leapcnt    = timelib_conv_int(buffer[2]);
        tz->bit64.timecnt    = timelib_conv_int(buffer[3]);
        tz->bit64.typecnt    = timelib_conv_int(buffer[4]);
        tz->bit64.charcnt    = timelib_conv_int(buffer[5]);
        *tzf += sizeof(buffer);
}

timelib_tzinfo *timelib_parse_tzfile(char *timezone, const timelib_tzdb *tzdb)
{
        const unsigned char *tzf;
        timelib_tzinfo *tmp;
        int version;

        if (seek_to_tz_position(&tzf, timezone, tzdb)) {
                tmp = timelib_tzinfo_ctor(timezone);

                version = read_preamble(&tzf, tmp);
                read_header(&tzf, tmp);
                read_transistions(&tzf, tmp);
                read_types(&tzf, tmp);
                if (version == 2) {
                        skip_64bit_preamble(&tzf, tmp);
                        read_64bit_header(&tzf, tmp);
                        skip_64bit_transistions(&tzf, tmp);
                        skip_64bit_types(&tzf, tmp);
                        skip_posix_string(&tzf, tmp);
                }
                read_location(&tzf, tmp);
        } else {
                tmp = NULL;
        }

        return tmp;
}

static ttinfo* fetch_timezone_offset(timelib_tzinfo *tz, timelib_sll ts, timelib_sll *transition_time)
{
        uint32_t i;

        /* If there is no transition time, we pick the first one, if that doesn't
         * exist we return NULL */
        if (!tz->bit32.timecnt || !tz->trans) {
                *transition_time = 0;
                if (tz->bit32.typecnt == 1) {
                        return &(tz->type[0]);
                }
                return NULL;
        }

        /* If the TS is lower than the first transition time, then we scan over
         * all the transition times to find the first non-DST one, or the first
         * one in case there are only DST entries. Not sure which smartass came up
         * with this idea in the first though :) */
        if (ts < tz->trans[0]) {
                uint32_t j;

                *transition_time = 0;
                j = 0;
                while (j < tz->bit32.timecnt && tz->type[j].isdst) {
                        ++j;
                }
                if (j == tz->bit32.timecnt) {
                        j = 0;
                }
                return &(tz->type[j]);
        }

        /* In all other cases we loop through the available transtion times to find
         * the correct entry */
        for (i = 0; i < tz->bit32.timecnt; i++) {
                if (ts < tz->trans[i]) {
                        *transition_time = tz->trans[i - 1];
                        return &(tz->type[tz->trans_idx[i - 1]]);
                }
        }
        *transition_time = tz->trans[tz->bit32.timecnt - 1];
        return &(tz->type[tz->trans_idx[tz->bit32.timecnt - 1]]);
}

static tlinfo* fetch_leaptime_offset(timelib_tzinfo *tz, timelib_sll ts)
{
        int i;

        if (!tz->bit32.leapcnt || !tz->leap_times) {
                return NULL;
        }

        for (i = tz->bit32.leapcnt - 1; i > 0; i--) {
                if (ts > tz->leap_times[i].trans) {
                        return &(tz->leap_times[i]);
                }
        }
        return NULL;
}

int timelib_timestamp_is_in_dst(timelib_sll ts, timelib_tzinfo *tz)
{
        ttinfo *to;
        timelib_sll dummy;

        if ((to = fetch_timezone_offset(tz, ts, &dummy))) {
                return to->isdst;
        }
        return -1;
}

timelib_time_offset *timelib_get_time_zone_info(timelib_sll ts, timelib_tzinfo *tz)
{
        ttinfo *to;
        tlinfo *tl;
        int32_t offset = 0, leap_secs = 0;
        char *abbr;
        timelib_time_offset *tmp = timelib_time_offset_ctor();
        timelib_sll                transistion_time;

        if ((to = fetch_timezone_offset(tz, ts, &transistion_time))) {
                offset = to->offset;
                abbr = &(tz->timezone_abbr[to->abbr_idx]);
                tmp->is_dst = to->isdst;
                tmp->transistion_time = transistion_time;
        } else {
                offset = 0;
                abbr = tz->timezone_abbr;
                tmp->is_dst = 0;
                tmp->transistion_time = 0;
        }

        if ((tl = fetch_leaptime_offset(tz, ts))) {
                leap_secs = -tl->offset;
        }

        tmp->offset = offset;
        tmp->leap_secs = leap_secs;
        tmp->abbr = abbr ? strdup(abbr) : strdup("GMT");

        return tmp;
}

timelib_sll timelib_get_current_offset(timelib_time *t)
{
        timelib_time_offset *gmt_offset;
        timelib_sll retval;

        switch (t->zone_type) {
                case TIMELIB_ZONETYPE_ABBR:
                case TIMELIB_ZONETYPE_OFFSET:
                        return (t->z + t->dst) * -60;

                case TIMELIB_ZONETYPE_ID:
                        gmt_offset = timelib_get_time_zone_info(t->sse, t->tz_info);
                        retval = gmt_offset->offset;
                        timelib_time_offset_dtor(gmt_offset);
                        return retval;

                default:
                        return 0;
        }
}

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