src/include/pgtime.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pgtime.h
   4  *        PostgreSQL internal timezone library
   5  *
   6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
   7  *
   8  * IDENTIFICATION
   9  *        src/include/pgtime.h
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef _PGTIME_H
  14 #define _PGTIME_H
  15
  16
  17 /*
  18  * The API of this library is generally similar to the corresponding
  19  * C library functions, except that we use pg_time_t which (we hope) is
  20  * 64 bits wide, and which is most definitely signed not unsigned.
  21  */
  22
  23 typedef int64 pg_time_t;
  24
  25 struct pg_tm
  26 {
  27         int                     tm_sec;
  28         int                     tm_min;
  29         int                     tm_hour;
  30         int                     tm_mday;
  31         int                     tm_mon;                 /* origin 1, not 0! */
  32         int                     tm_year;                /* relative to 1900 */
  33         int                     tm_wday;
  34         int                     tm_yday;
  35         int                     tm_isdst;
  36         long int        tm_gmtoff;
  37         const char *tm_zone;
  38 };
  39
  40 typedef struct pg_tz pg_tz;
  41 typedef struct pg_tzenum pg_tzenum;
  42
  43 /* Maximum length of a timezone name (not including trailing null) */
  44 #define TZ_STRLEN_MAX 255
  45
  46 /* these functions are in localtime.c */
  47
  48 extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
  49 extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
  50 extern int      pg_next_dst_boundary(const pg_time_t *timep,
  51                                                                  long int *before_gmtoff,
  52                                                                  int *before_isdst,
  53                                                                  pg_time_t *boundary,
  54                                                                  long int *after_gmtoff,
  55                                                                  int *after_isdst,
  56                                                                  const pg_tz *tz);
  57 extern bool pg_interpret_timezone_abbrev(const char *abbrev,
  58                                                                                  const pg_time_t *timep,
  59                                                                                  long int *gmtoff,
  60                                                                                  int *isdst,
  61                                                                                  const pg_tz *tz);
  62 extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
  63 extern const char *pg_get_timezone_name(pg_tz *tz);
  64 extern bool pg_tz_acceptable(pg_tz *tz);
  65
  66 /* these functions are in strftime.c */
  67
  68 extern size_t pg_strftime(char *s, size_t max, const char *format,
  69                                                   const struct pg_tm *tm);
  70
  71 /* these functions and variables are in pgtz.c */
  72
  73 extern PGDLLIMPORT pg_tz *session_timezone;
  74 extern pg_tz *log_timezone;
  75
  76 extern void pg_timezone_initialize(void);
  77 extern pg_tz *pg_tzset(const char *tzname);
  78 extern pg_tz *pg_tzset_offset(long gmtoffset);
  79
  80 extern pg_tzenum *pg_tzenumerate_start(void);
  81 extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
  82 extern void pg_tzenumerate_end(pg_tzenum *dir);
  83
  84 #endif                                                  /* _PGTIME_H */