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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 07:08:06 +02:00
/*-------------------------------------------------------------------------
*
* pgtime.h
* PostgreSQL internal timezone library
*
Update copyright for 2014 Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
2014-01-07 22:05:30 +01:00
* Portions Copyright (c) 1996-2014, 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 07:08:06 +02:00
*
* IDENTIFICATION
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/pgtime.h
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 07:08:06 +02:00
*
*-------------------------------------------------------------------------
*/
#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.
2004-06-03 04:08:07 +02:00
/*
* 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 07:08:06 +02:00
*/
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.
2004-06-03 04:08:07 +02:00
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 07:08:06 +02:00
Pgindent run for 8.0.
2004-08-29 07:07:03 +02:00
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 07:08:06 +02:00
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
2005-04-19 05:13:59 +02:00
typedef struct pg_tz pg_tz;
Rename the recently-added pg_timezonenames view to pg_timezone_abbrevs, and create a new view pg_timezone_names that provides information about the zones known in the 'zic' database. Magnus Hagander, with some additional work by Tom Lane.
2006-09-16 22:14:34 +02:00
typedef struct pg_tzenum pg_tzenum;
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
2005-04-19 05:13:59 +02:00
Simplify handling of the timezone GUC by making initdb choose the default. We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.
2011-09-09 23:59:11 +02:00
/* Maximum length of a timezone name (not including trailing null) */
#define TZ_STRLEN_MAX 255
/* these functions are in localtime.c */
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
2005-04-19 05:13:59 +02:00
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 22:34:44 +01:00
extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
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 07:08:06 +02:00
extern size_t pg_strftime(char *s, size_t max, const char *format,
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
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 22:34:44 +01:00
Fix up timetz input so that a date is required only when the specified timezone actually has a daylight-savings rule. This avoids breaking cases that used to work because they went through the DecodePosixTimezone code path. Per contrib regression failures (mea culpa for not running those yesterday...). Also document the already-applied change to allow GMT offsets up to 14 hours.
2006-10-18 18:43:14 +02:00
extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
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
2005-04-19 05:13:59 +02:00
extern const char *pg_get_timezone_name(pg_tz *tz);
Simplify handling of the timezone GUC by making initdb choose the default. We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.
2011-09-09 23:59:11 +02:00
extern bool pg_tz_acceptable(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 07:08:06 +02:00
Simplify handling of the timezone GUC by making initdb choose the default. We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.
2011-09-09 23:59:11 +02:00
/* these functions and variables are in pgtz.c */
Rename the recently-added pg_timezonenames view to pg_timezone_abbrevs, and create a new view pg_timezone_names that provides information about the zones known in the 'zic' database. Magnus Hagander, with some additional work by Tom Lane.
2006-09-16 22:14:34 +02:00
Switch over to using the src/timezone functions for formatting timestamps displayed in the postmaster log. This avoids Windows-specific problems with localized time zone names that are in the wrong encoding, and generally seems like a good idea to forestall other potential platform-dependent issues. To preserve the existing behavior that all backends will log in the same time zone, create a new GUC variable log_timezone that can only be changed on a system-wide basis, and reference log-related calculations to that zone instead of the TimeZone variable. This fixes the issue reported by Hiroshi Saito that timestamps printed by xlog.c startup could be improperly localized on Windows. We still need a simpler patch for that problem in the back branches, however.
2007-08-04 03:26:54 +02:00
extern pg_tz *session_timezone;
extern pg_tz *log_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
2005-06-15 02:34:11 +02:00
Simplify handling of the timezone GUC by making initdb choose the default. We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.
2011-09-09 23:59:11 +02:00
extern void pg_timezone_initialize(void);
extern pg_tz *pg_tzset(const char *tzname);
Fix some odd behaviors when using a SQL-style simple GMT offset timezone. Formerly, when using a SQL-spec timezone setting with a fixed GMT offset (called a "brute force" timezone in the code), the session_timezone variable was not updated to match the nominal timezone; rather, all code was expected to ignore session_timezone if HasCTZSet was true. This is of course obviously fragile, though a search of the code finds only timeofday() failing to honor the rule. A bigger problem was that DetermineTimeZoneOffset() supposed that if its pg_tz parameter was pointer-equal to session_timezone, then HasCTZSet should override the parameter. This would cause datetime input containing an explicit zone name to be treated as referencing the brute-force zone instead, if the zone name happened to match the session timezone that had prevailed before installing the brute-force zone setting (as reported in bug #8572). The same malady could affect AT TIME ZONE operators. To fix, set up session_timezone so that it matches the brute-force zone specification, which we can do using the POSIX timezone definition syntax "<abbrev>offset", and get rid of the bogus lookaside check in DetermineTimeZoneOffset(). Aside from fixing the erroneous behavior in datetime parsing and AT TIME ZONE, this will cause the timeofday() function to print its result in the user-requested time zone rather than some previously-set zone. It might also affect results in third-party extensions, if there are any that make use of session_timezone without considering HasCTZSet, but in all cases the new behavior should be saner than before. Back-patch to all supported branches.
2013-11-01 17:13:18 +01:00
extern pg_tz *pg_tzset_offset(long gmtoffset);
Simplify handling of the timezone GUC by making initdb choose the default. We were doing some amazingly complicated things in order to avoid running the very expensive identify_system_timezone() procedure during GUC initialization. But there is an obvious fix for that, which is to do it once during initdb and have initdb install the system-specific default into postgresql.conf, as it already does for most other GUC variables that need system-environment-dependent defaults. This means that the timezone (and log_timezone) settings no longer have any magic behavior in the server. Per discussion.
2011-09-09 23:59:11 +02:00
extern pg_tzenum *pg_tzenumerate_start(void);
extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
extern void pg_tzenumerate_end(pg_tzenum *dir);
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
2005-06-15 02:34:11 +02:00
Pgindent run for 8.0.
2004-08-29 07:07:03 +02:00
#endif /* _PGTIME_H */