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e39f990467
DecodeInterval (interval input) was careless about integer-overflow hazards, allowing bogus results to be obtained for sufficiently large input values. Also, since it initially converted the input to a "struct tm", it was impossible to produce the full range of representable interval values. Meanwhile, EncodeInterval (interval output) and a few other functions could suffer failures if asked to process sufficiently large interval values, because they also relied on being able to represent an interval in "struct tm" which is not designed to handle that. Fix all this stuff by introducing new struct types that are more fit for purpose. While this is clearly a bug fix, it's also an API break for any code that's calling these functions directly. So back-patching doesn't seem wise, especially in view of the lack of field complaints. Joe Koshakow, editorialized a bit by me Discussion: https://postgr.es/m/CAAvxfHff0JLYHwyBrtMx_=6wr=k2Xp+D+-X3vEhHjJYMj+mQcg@mail.gmail.com
94 lines
2.8 KiB
C
94 lines
2.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* pgtime.h
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* PostgreSQL internal timezone library
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*
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* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* src/include/pgtime.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef _PGTIME_H
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#define _PGTIME_H
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/*
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* The API of this library is generally similar to the corresponding
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* C library functions, except that we use pg_time_t which (we hope) is
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* 64 bits wide, and which is most definitely signed not unsigned.
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*/
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typedef int64 pg_time_t;
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/*
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* Data structure representing a broken-down timestamp.
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*
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* CAUTION: the IANA timezone library (src/timezone/) follows the POSIX
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* convention that tm_mon counts from 0 and tm_year is relative to 1900.
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* However, Postgres' datetime functions generally treat tm_mon as counting
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* from 1 and tm_year as relative to 1 BC. Be sure to make the appropriate
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* adjustments when moving from one code domain to the other.
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*/
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struct pg_tm
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{
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int tm_sec;
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int tm_min;
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int tm_hour;
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int tm_mday;
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int tm_mon; /* see above */
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int tm_year; /* see above */
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int tm_wday;
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int tm_yday;
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int tm_isdst;
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long int tm_gmtoff;
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const char *tm_zone;
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};
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/* These structs are opaque outside the timezone library */
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typedef struct pg_tz pg_tz;
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typedef struct pg_tzenum pg_tzenum;
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/* Maximum length of a timezone name (not including trailing null) */
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#define TZ_STRLEN_MAX 255
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/* these functions are in localtime.c */
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extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
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extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
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extern int pg_next_dst_boundary(const pg_time_t *timep,
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long int *before_gmtoff,
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int *before_isdst,
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pg_time_t *boundary,
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long int *after_gmtoff,
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int *after_isdst,
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const pg_tz *tz);
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extern bool pg_interpret_timezone_abbrev(const char *abbrev,
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const pg_time_t *timep,
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long int *gmtoff,
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int *isdst,
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const pg_tz *tz);
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extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
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extern const char *pg_get_timezone_name(pg_tz *tz);
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extern bool pg_tz_acceptable(pg_tz *tz);
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/* these functions are in strftime.c */
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extern size_t pg_strftime(char *s, size_t max, const char *format,
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const struct pg_tm *tm);
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/* these functions and variables are in pgtz.c */
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extern PGDLLIMPORT pg_tz *session_timezone;
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extern pg_tz *log_timezone;
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extern void pg_timezone_initialize(void);
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extern pg_tz *pg_tzset(const char *tzname);
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extern pg_tz *pg_tzset_offset(long gmtoffset);
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extern pg_tzenum *pg_tzenumerate_start(void);
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extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
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extern void pg_tzenumerate_end(pg_tzenum *dir);
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#endif /* _PGTIME_H */
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