pgtz.h

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/*-------------------------------------------------------------------------
 *
 * pgtz.h
 *    Timezone Library Integration Functions
 *
 * Note: this file contains only definitions that are private to the
 * timezone library.  Public definitions are in pgtime.h.
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *    src/timezone/pgtz.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef _PGTZ_H
#define _PGTZ_H
 
#include "pgtime.h"
#include "tzfile.h"
 
 
#define SMALLEST(a, b)  (((a) < (b)) ? (a) : (b))
#define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
 
struct ttinfo
{                               /* time type information */
    int32       tt_utoff;       /* UT offset in seconds */
    bool        tt_isdst;       /* used to set tm_isdst */
    int         tt_desigidx;    /* abbreviation list index */
    bool        tt_ttisstd;     /* transition is std time */
    bool        tt_ttisut;      /* transition is UT */
};
 
struct lsinfo
{                               /* leap second information */
    pg_time_t   ls_trans;       /* transition time */
    int64       ls_corr;        /* correction to apply */
};
 
struct state
{
    int         leapcnt;
    int         timecnt;
    int         typecnt;
    int         charcnt;
    bool        goback;
    bool        goahead;
    pg_time_t   ats[TZ_MAX_TIMES];
    unsigned char types[TZ_MAX_TIMES];
    struct ttinfo ttis[TZ_MAX_TYPES];
    char        chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, 4 /* sizeof gmt */ ),
                              (2 * (TZ_STRLEN_MAX + 1)))];
    struct lsinfo lsis[TZ_MAX_LEAPS];
 
    /*
     * The time type to use for early times or if no transitions. It is always
     * zero for recent tzdb releases. It might be nonzero for data from tzdb
     * 2018e or earlier.
     */
    int         defaulttype;
};
 
 
struct pg_tz
{
    /* TZname contains the canonically-cased name of the timezone */
    char        TZname[TZ_STRLEN_MAX + 1];
    struct state state;
};
 
 
/* in pgtz.c */
extern int  pg_open_tzfile(const char *name, char *canonname);
 
/* in localtime.c */
extern int  tzload(const char *name, char *canonname, struct state *sp,
                   bool doextend);
extern bool tzparse(const char *name, struct state *sp, bool lastditch);
 
#endif                          /* _PGTZ_H */