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postgresql/src/include/pgtime.h

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Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
/*-------------------------------------------------------------------------
*
* pgtime.h
* PostgreSQL internal timezone library
*
Tag appropriate files for rc3 Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-12-31 17:04:05 -05:00
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
*
* IDENTIFICATION
Standard pgindent run for 8.1.
2005-10-14 22:49:52 -04:00
* $PostgreSQL: pgsql/src/include/pgtime.h,v 1.11 2005/10/15 02:49:41 momjian Exp $
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
*
*-------------------------------------------------------------------------
*/
#ifndef _PGTIME_H
#define _PGTIME_H
Adjust our timezone library to use pg_time_t (typedef'd as int64) in place of time_t, as per prior discussion. The behavior does not change on machines without a 64-bit-int type, but on machines with one, which is most, we are rid of the bizarre boundary behavior at the edges of the 32-bit-time_t range (1901 and 2038). The system will now treat times over the full supported timestamp range as being in your local time zone. It may seem a little bizarre to consider that times in 4000 BC are PST or EST, but this is surely at least as reasonable as propagating Gregorian calendar rules back that far. I did not modify the format of the zic timezone database files, which means that for the moment the system will not know about daylight-savings periods outside the range 1901-2038. Given the way the files are set up, it's not a simple decision like 'widen to 64 bits'; we have to actually think about the range of years that need to be supported. We should probably inquire what the plans of the upstream zic people are before making any decisions of our own.
2004-06-02 22:08:07 -04:00
/*
* 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.
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
*/
Adjust our timezone library to use pg_time_t (typedef'd as int64) in place of time_t, as per prior discussion. The behavior does not change on machines without a 64-bit-int type, but on machines with one, which is most, we are rid of the bizarre boundary behavior at the edges of the 32-bit-time_t range (1901 and 2038). The system will now treat times over the full supported timestamp range as being in your local time zone. It may seem a little bizarre to consider that times in 4000 BC are PST or EST, but this is surely at least as reasonable as propagating Gregorian calendar rules back that far. I did not modify the format of the zic timezone database files, which means that for the moment the system will not know about daylight-savings periods outside the range 1901-2038. Given the way the files are set up, it's not a simple decision like 'widen to 64 bits'; we have to actually think about the range of years that need to be supported. We should probably inquire what the plans of the upstream zic people are before making any decisions of our own.
2004-06-02 22:08:07 -04:00
typedef int64 pg_time_t;
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
Pgindent run for 8.0.
2004-08-29 01:07:03 -04:00
struct pg_tm
{
int tm_sec;
int tm_min;
int tm_hour;
int tm_mday;
int tm_mon; /* origin 0, not 1 */
int tm_year; /* relative to 1900 */
int tm_wday;
int tm_yday;
int tm_isdst;
long int tm_gmtoff;
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
const char *tm_zone;
};
Attached patch gets rid of the global timezone in the following steps: * Changes the APIs to the timezone functions to take a pg_tz pointer as an argument, representing the timezone to use for the selected operation. * Adds a global_timezone variable that represents the current timezone in the backend as set by SET TIMEZONE (or guc, or env, etc). * Implements a hash-table cache of loaded tables, so we don't have to read and parse the TZ file everytime we change a timezone. While not necesasry now (we don't change timezones very often), I beleive this will be necessary (or at least good) when "multiple timezones in the same query" is eventually implemented. And code-wise, this was the time to do it. There are no user-visible changes at this time. Implementing the "multiple zones in one query" is a later step... This also gets rid of some of the cruft needed to "back out a timezone change", since we previously couldn't check a timezone unless it was activated first. Passes regression tests on win32, linux (slackware 10) and solaris x86. Magnus Hagander
2005-04-18 23:13:59 -04:00
typedef struct pg_tz pg_tz;
extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
Invent pg_next_dst_boundary() and rewrite DetermineLocalTimeZone() to use it, as per my proposal of yesterday. This gives us a means of determining the zone offset to impute to an unlabeled timestamp that is both efficient and reliable, unlike all our previous tries involving mktime() and localtime(). The behavior for invalid or ambiguous times at a DST transition is fixed to be really and truly "assume standard time", fixing a bug that has come and gone repeatedly but was back again in 7.4. (There is some ongoing discussion about whether we should raise an error instead, but for the moment I'll make it do what it was previously intended to do.)
2004-11-01 16:34:44 -05:00
extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
Standard pgindent run for 8.1.
2005-10-14 22:49:52 -04:00
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);
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
extern size_t pg_strftime(char *s, size_t max, const char *format,
Standard pgindent run for 8.1.
2005-10-14 22:49:52 -04:00
const struct pg_tm * tm);
Invent pg_next_dst_boundary() and rewrite DetermineLocalTimeZone() to use it, as per my proposal of yesterday. This gives us a means of determining the zone offset to impute to an unlabeled timestamp that is both efficient and reliable, unlike all our previous tries involving mktime() and localtime(). The behavior for invalid or ambiguous times at a DST transition is fixed to be really and truly "assume standard time", fixing a bug that has come and gone repeatedly but was back again in 7.4. (There is some ongoing discussion about whether we should raise an error instead, but for the moment I'll make it do what it was previously intended to do.)
2004-11-01 16:34:44 -05:00
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
extern void pg_timezone_initialize(void);
Attached patch gets rid of the global timezone in the following steps: * Changes the APIs to the timezone functions to take a pg_tz pointer as an argument, representing the timezone to use for the selected operation. * Adds a global_timezone variable that represents the current timezone in the backend as set by SET TIMEZONE (or guc, or env, etc). * Implements a hash-table cache of loaded tables, so we don't have to read and parse the TZ file everytime we change a timezone. While not necesasry now (we don't change timezones very often), I beleive this will be necessary (or at least good) when "multiple timezones in the same query" is eventually implemented. And code-wise, this was the time to do it. There are no user-visible changes at this time. Implementing the "multiple zones in one query" is a later step... This also gets rid of some of the cruft needed to "back out a timezone change", since we previously couldn't check a timezone unless it was activated first. Passes regression tests on win32, linux (slackware 10) and solaris x86. Magnus Hagander
2005-04-18 23:13:59 -04:00
extern pg_tz *pg_tzset(const char *tzname);
extern bool tz_acceptable(pg_tz *tz);
extern const char *pg_get_timezone_name(pg_tz *tz);
Integrate src/timezone library for all platforms. There is more we can and should do now that we control our own destiny for timezone handling, but this commit gets the bulk of the picayune diffs in place. Magnus Hagander and Tom Lane.
2004-05-21 01:08:06 -04:00
Attached patch gets rid of the global timezone in the following steps: * Changes the APIs to the timezone functions to take a pg_tz pointer as an argument, representing the timezone to use for the selected operation. * Adds a global_timezone variable that represents the current timezone in the backend as set by SET TIMEZONE (or guc, or env, etc). * Implements a hash-table cache of loaded tables, so we don't have to read and parse the TZ file everytime we change a timezone. While not necesasry now (we don't change timezones very often), I beleive this will be necessary (or at least good) when "multiple timezones in the same query" is eventually implemented. And code-wise, this was the time to do it. There are no user-visible changes at this time. Implementing the "multiple zones in one query" is a later step... This also gets rid of some of the cruft needed to "back out a timezone change", since we previously couldn't check a timezone unless it was activated first. Passes regression tests on win32, linux (slackware 10) and solaris x86. Magnus Hagander
2005-04-18 23:13:59 -04:00
extern pg_tz *global_timezone;
This patch makes it possible to use the full set of timezones when doing "AT TIME ZONE", and not just the shorlist previously available. For example: SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London'; works fine now. It will also obey whatever DST rules were in effect at just that date, which the previous implementation did not. It also supports the AT TIME ZONE on the timetz datatype. The whole handling of DST is a bit bogus there, so I chose to make it use whatever DST rules are in effect at the time of executig the query. not sure if anybody is actuallyi *using* timetz though, it seems pretty unpredictable just because of this... Magnus Hagander
2005-06-14 20:34:11 -04:00
Fix the various forms of AT TIME ZONE to accept either timezones found in the zic database or zone names found in the date token table. This preserves the old ability to do AT TIME ZONE 'PST' along with the new ability to do AT TIME ZONE 'PST8PDT'. Per gripe from Bricklen Anderson. Also, fix some inconsistencies in usage of TZ_STRLEN_MAX --- the old code had the potential for one-byte buffer overruns, though given alignment considerations it's unlikely there was any real risk.
2005-09-08 22:31:50 -04:00
/* Maximum length of a timezone name (not including trailing null) */
This patch makes it possible to use the full set of timezones when doing "AT TIME ZONE", and not just the shorlist previously available. For example: SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London'; works fine now. It will also obey whatever DST rules were in effect at just that date, which the previous implementation did not. It also supports the AT TIME ZONE on the timetz datatype. The whole handling of DST is a bit bogus there, so I chose to make it use whatever DST rules are in effect at the time of executig the query. not sure if anybody is actuallyi *using* timetz though, it seems pretty unpredictable just because of this... Magnus Hagander
2005-06-14 20:34:11 -04:00
#define TZ_STRLEN_MAX 255
Pgindent run for 8.0.
2004-08-29 01:07:03 -04:00
#endif /* _PGTIME_H */
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