Обсуждение: USECS_* constants undefined with float8 timestamps?

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USECS_* constants undefined with float8 timestamps?

От
"Johann 'Myrkraverk' Oskarsson"
Дата:
Hi all,

I just noticed that the USECS_* constants are not defined when the server
is compiled without integer dates and timestamps.

Explicitly, timestamp.h is

#ifdef HAVE_INT64_TIMESTAMP
#define USECS_PER_DAY    INT64CONST(86400000000)
#define USECS_PER_HOUR    INT64CONST(3600000000)
#define USECS_PER_MINUTE INT64CONST(60000000)
#define USECS_PER_SEC    INT64CONST(1000000)
#endif

Is there a particular reason for this?  Even with float8 timestamps
there are uses for these constants in extensions.


--   Johann Oskarsson                http://www.2ndquadrant.com/    |[]  PostgreSQL Development, 24x7 Support, Training
andServices  --+--                                                                 |  Blog:
http://my.opera.com/myrkraverk/blog/



Re: USECS_* constants undefined with float8 timestamps?

От
Robert Haas
Дата:
On Fri, Jul 29, 2011 at 11:18 AM, Johann 'Myrkraverk' Oskarsson
<johann@2ndquadrant.com> wrote:
> Hi all,
>
> I just noticed that the USECS_* constants are not defined when the server
> is compiled without integer dates and timestamps.
>
> Explicitly, timestamp.h is
>
> #ifdef HAVE_INT64_TIMESTAMP
> #define USECS_PER_DAY   INT64CONST(86400000000)
> #define USECS_PER_HOUR  INT64CONST(3600000000)
> #define USECS_PER_MINUTE INT64CONST(60000000)
> #define USECS_PER_SEC   INT64CONST(1000000)
> #endif
>
> Is there a particular reason for this?  Even with float8 timestamps
> there are uses for these constants in extensions.

I don't see any particular reason not define them unconditionally.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


Re: USECS_* constants undefined with float8 timestamps?

От
Bruce Momjian
Дата:
Robert Haas wrote:
> On Fri, Jul 29, 2011 at 11:18 AM, Johann 'Myrkraverk' Oskarsson
> <johann@2ndquadrant.com> wrote:
> > Hi all,
> >
> > I just noticed that the USECS_* constants are not defined when the server
> > is compiled without integer dates and timestamps.
> >
> > Explicitly, timestamp.h is
> >
> > #ifdef HAVE_INT64_TIMESTAMP
> > #define USECS_PER_DAY   INT64CONST(86400000000)
> > #define USECS_PER_HOUR  INT64CONST(3600000000)
> > #define USECS_PER_MINUTE INT64CONST(60000000)
> > #define USECS_PER_SEC   INT64CONST(1000000)
> > #endif
> >
> > Is there a particular reason for this? ?Even with float8 timestamps
> > there are uses for these constants in extensions.
> 
> I don't see any particular reason not define them unconditionally.

Well, they are only used by integer dates, so why expand their
visibility?  The define does make it clear how they are used.  I suppose
if someone wanted to use them outside that case, we could open them up. 
It is true that with integer dates now the default, we might find that
someone introduces compile problems by using them outside the integer
dates scope.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +


Re: USECS_* constants undefined with float8 timestamps?

От
"Johann 'Myrkraverk' Oskarsson"
Дата:
Bruce Momjian <bruce@momjian.us> writes:

> Robert Haas wrote:
>> On Fri, Jul 29, 2011 at 11:18 AM, Johann 'Myrkraverk' Oskarsson
>> <johann@2ndquadrant.com> wrote:
>> >
>> > I just noticed that the USECS_* constants are not defined when
>> > the server is compiled without integer dates and timestamps.
[snip]
>> I don't see any particular reason not define them unconditionally.
>
> Well, they are only used by integer dates, so why expand their
> visibility?  The define does make it clear how they are used.  I
> suppose if someone wanted to use them outside that case, we could
> open them up. It is true that with integer dates now the default, we
> might find that someone introduces compile problems by using them
> outside the integer dates scope.

I found a use for them in PL/Java which detects at run-time whether
the server is using floating point or integer dates.  The simplest way
was just to use magic numbers instead on the off chance it's compiled
with a server using float dates.


--   Johann Oskarsson                http://www.2ndquadrant.com/    |[]  PostgreSQL Development, 24x7 Support, Training
andServices  --+--                                                                 |  Blog:
http://my.opera.com/myrkraverk/blog/



Re: USECS_* constants undefined with float8 timestamps?

От
Bruce Momjian
Дата:
Johann 'Myrkraverk' Oskarsson wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> 
> > Robert Haas wrote:
> >> On Fri, Jul 29, 2011 at 11:18 AM, Johann 'Myrkraverk' Oskarsson
> >> <johann@2ndquadrant.com> wrote:
> >> >
> >> > I just noticed that the USECS_* constants are not defined when
> >> > the server is compiled without integer dates and timestamps.
> [snip]
> >> I don't see any particular reason not define them unconditionally.
> >
> > Well, they are only used by integer dates, so why expand their
> > visibility?  The define does make it clear how they are used.  I
> > suppose if someone wanted to use them outside that case, we could
> > open them up. It is true that with integer dates now the default, we
> > might find that someone introduces compile problems by using them
> > outside the integer dates scope.
> 
> I found a use for them in PL/Java which detects at run-time whether
> the server is using floating point or integer dates.  The simplest way
> was just to use magic numbers instead on the off chance it's compiled
> with a server using float dates.

OK, that is a good reason.  Done for PG 9.2.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +