pgtime.h

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/*-------------------------------------------------------------------------
 *
 * pgtime.h
 *    PostgreSQL internal timezone library
 *
 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *    src/include/pgtime.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef _PGTIME_H
#define _PGTIME_H
 
 
/*
 * The API of this library is generally similar to the corresponding
 * C library functions, except that we use pg_time_t which (we hope) is
 * 64 bits wide, and which is most definitely signed not unsigned.
 */
 
typedef int64 pg_time_t;
 
struct pg_tm
{
    int         tm_sec;
    int         tm_min;
    int         tm_hour;
    int         tm_mday;
    int         tm_mon;         /* origin 1, not 0! */
    int         tm_year;        /* relative to 1900 */
    int         tm_wday;
    int         tm_yday;
    int         tm_isdst;
    long int    tm_gmtoff;
    const char *tm_zone;
};
 
typedef struct pg_tz pg_tz;
typedef struct pg_tzenum pg_tzenum;
 
/* Maximum length of a timezone name (not including trailing null) */
#define TZ_STRLEN_MAX 255
 
/* these functions are in localtime.c */
 
extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
extern int  pg_next_dst_boundary(const pg_time_t *timep,
                                 long int *before_gmtoff,
                                 int *before_isdst,
                                 pg_time_t *boundary,
                                 long int *after_gmtoff,
                                 int *after_isdst,
                                 const pg_tz *tz);
extern bool pg_interpret_timezone_abbrev(const char *abbrev,
                                         const pg_time_t *timep,
                                         long int *gmtoff,
                                         int *isdst,
                                         const pg_tz *tz);
extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
extern const char *pg_get_timezone_name(pg_tz *tz);
extern bool pg_tz_acceptable(pg_tz *tz);
 
/* these functions are in strftime.c */
 
extern size_t pg_strftime(char *s, size_t max, const char *format,
                          const struct pg_tm *tm);
 
/* these functions and variables are in pgtz.c */
 
extern pg_tz *session_timezone;
extern pg_tz *log_timezone;
 
extern void pg_timezone_initialize(void);
extern pg_tz *pg_tzset(const char *tzname);
extern pg_tz *pg_tzset_offset(long gmtoffset);
 
extern pg_tzenum *pg_tzenumerate_start(void);
extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
extern void pg_tzenumerate_end(pg_tzenum *dir);
 
#endif                          /* _PGTIME_H */