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pgtime.h
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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 /*
26  * CAUTION: the IANA timezone library (src/timezone/) follows the POSIX
27  * convention that tm_mon counts from 0 and tm_year is relative to 1900.
28  * However, Postgres' datetime functions generally treat tm_mon as counting
29  * from 1 and tm_year as relative to 1 BC. Be sure to make the appropriate
30  * adjustments when moving from one code domain to the other.
31  */
32 struct pg_tm
33 {
34  int tm_sec;
35  int tm_min;
36  int tm_hour;
37  int tm_mday;
38  int tm_mon; /* see above */
39  int tm_year; /* see above */
40  int tm_wday;
41  int tm_yday;
42  int tm_isdst;
43  long int tm_gmtoff;
44  const char *tm_zone;
45 };
46 
47 typedef struct pg_tz pg_tz;
48 typedef struct pg_tzenum pg_tzenum;
49 
50 /* Maximum length of a timezone name (not including trailing null) */
51 #define TZ_STRLEN_MAX 255
52 
53 /* these functions are in localtime.c */
54 
55 extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
56 extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
57 extern int pg_next_dst_boundary(const pg_time_t *timep,
58  long int *before_gmtoff,
59  int *before_isdst,
60  pg_time_t *boundary,
61  long int *after_gmtoff,
62  int *after_isdst,
63  const pg_tz *tz);
64 extern bool pg_interpret_timezone_abbrev(const char *abbrev,
65  const pg_time_t *timep,
66  long int *gmtoff,
67  int *isdst,
68  const pg_tz *tz);
69 extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
70 extern const char *pg_get_timezone_name(pg_tz *tz);
71 extern bool pg_tz_acceptable(pg_tz *tz);
72 
73 /* these functions are in strftime.c */
74 
75 extern size_t pg_strftime(char *s, size_t max, const char *format,
76  const struct pg_tm *tm);
77 
78 /* these functions and variables are in pgtz.c */
79 
81 extern pg_tz *log_timezone;
82 
83 extern void pg_timezone_initialize(void);
84 extern pg_tz *pg_tzset(const char *tzname);
85 extern pg_tz *pg_tzset_offset(long gmtoffset);
86 
87 extern pg_tzenum *pg_tzenumerate_start(void);
88 extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
89 extern void pg_tzenumerate_end(pg_tzenum *dir);
90 
91 #endif /* _PGTIME_H */
size_t pg_strftime(char *s, size_t max, const char *format, const struct pg_tm *tm)
Definition: strftime.c:128
int64 pg_time_t
Definition: pgtime.h:23
int tm_wday
Definition: pgtime.h:40
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)
Definition: localtime.c:1608
PGDLLIMPORT pg_tz * session_timezone
Definition: pgtz.c:28
struct pg_tm * pg_gmtime(const pg_time_t *timep)
Definition: localtime.c:1387
int tm_isdst
Definition: pgtime.h:42
int tm_hour
Definition: pgtime.h:36
void pg_tzenumerate_end(pg_tzenum *dir)
Definition: pgtz.c:414
long int tm_gmtoff
Definition: pgtime.h:43
Definition: pgtime.h:32
#define PGDLLIMPORT
Definition: c.h:1317
static struct pg_tm tm
Definition: localtime.c:102
pg_tz * log_timezone
Definition: pgtz.c:31
pg_tz * pg_tzset(const char *tzname)
Definition: pgtz.c:234
void pg_timezone_initialize(void)
Definition: pgtz.c:361
bool pg_interpret_timezone_abbrev(const char *abbrev, const pg_time_t *timep, long int *gmtoff, int *isdst, const pg_tz *tz)
Definition: localtime.c:1755
const char * pg_get_timezone_name(pg_tz *tz)
Definition: localtime.c:1873
int tm_mday
Definition: pgtime.h:37
int tm_mon
Definition: pgtime.h:38
const char * tm_zone
Definition: pgtime.h:44
pg_tz * pg_tzset_offset(long gmtoffset)
Definition: pgtz.c:320
bool pg_tz_acceptable(pg_tz *tz)
Definition: localtime.c:1888
Definition: pgtz.h:65
pg_tzenum * pg_tzenumerate_start(void)
Definition: pgtz.c:397
struct pg_tm * pg_localtime(const pg_time_t *timep, const pg_tz *tz)
Definition: localtime.c:1342
pg_tz * pg_tzenumerate_next(pg_tzenum *dir)
Definition: pgtz.c:426
int tm_year
Definition: pgtime.h:39
int tm_yday
Definition: pgtime.h:41
static char format
bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff)
Definition: localtime.c:1849
int tm_sec
Definition: pgtime.h:34
int tm_min
Definition: pgtime.h:35