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From: David Kastrup <dak@gnu.org>
To: Johannes Sixt <j.sixt@eudaptics.com>
Cc: Marius Storm-Olsen <marius@trolltech.com>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Johannes Sixt <johannes.sixt@telecom.at>,
	Git Mailing List <git@vger.kernel.org>
Subject: Re: [PATCH] Add a new lstat and fstat implementation based on Win32 API
Date: Tue, 04 Sep 2007 23:31:28 +0200	[thread overview]
Message-ID: <85hcmajexb.fsf@lola.goethe.zz> (raw)
In-Reply-To: <46DD3943.8040403@eudaptics.com> (Johannes Sixt's message of "Tue\, 04 Sep 2007 12\:53\:55 +0200")

Johannes Sixt <j.sixt@eudaptics.com> writes:

> Marius Storm-Olsen schrieb:
>
>> Ok, I can give it a performance test, but I tend to agree with
>> David Kastrup there. It would be better if we rather fix the places
>> where we check with the local timestamp instead; depending of
>> course on how many places we actually do this.  We'll see how much
>> the timezone conversion in the custom stat functions actually hurt
>> us performance wise.
>
> I'd make the decision on the grounds of a perfomance test. If it
> turns out that the penalty is bearable, we should keep this stuff
> private to the MinGW build. Otherwise, we would need MinGW specific
> code at the call sites (unless we can hide the opposite conversion
> in some other wrapper function).
>
> ... time passes ...
>
> Ok, I just tested FileTimeToLocalFileTime() in a tight loop, and I
> can run it 100,000,000 times per second. So I'm confident that there
> won't be any noticable degradation with my proposed change.

The problem is that it will break in the hour when day light saving
time ends.  Or when you travel between timezones.

Local time is not continuous or unique.  That is why it is a bad idea
to make decisions based on it.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

  parent reply	other threads:[~2007-09-04 21:31 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-02 14:49 Stats in Git Marius Storm-Olsen
2007-09-02 14:51 ` [PATCH] Add a new lstat implementation based on Win32 API, and make stat use that implementation too Marius Storm-Olsen
2007-09-02 14:57   ` Marius Storm-Olsen
2007-09-02 15:32   ` Reece Dunn
2007-09-02 16:09     ` Marius Storm-Olsen
2007-09-02 16:33       ` Reece Dunn
2007-09-02 16:47         ` Brian Gernhardt
2007-09-02 16:53           ` Reece Dunn
2007-09-02 17:05             ` Marius Storm-Olsen
2007-09-02 17:44               ` Johannes Schindelin
2007-09-02 17:58                 ` David Kastrup
2007-09-02 18:18                 ` Marius Storm-Olsen
2007-09-02 18:16   ` Johannes Sixt
2007-09-02 18:44     ` Marius Storm-Olsen
2007-09-02 19:07       ` Johannes Sixt
2007-09-02 19:31       ` Marius Storm-Olsen
2007-09-02 20:27         ` Robin Rosenberg
2007-09-02 21:26           ` Johannes Schindelin
2007-09-02 21:42             ` Robin Rosenberg
2007-09-02 23:02               ` Johannes Schindelin
2007-09-03  7:07               ` Johannes Sixt
2007-09-03 11:21                 ` Miklos Vajna
2007-09-03 11:32                   ` David Kastrup
2007-09-05 16:02                     ` Miklos Vajna
2007-09-05 19:01                       ` David Kastrup
2007-09-06 16:26                         ` Miklos Vajna
2007-09-06 16:33                           ` David Kastrup
2007-09-06 23:31                             ` Douglas Stockwell
2007-09-07  6:36                               ` David Kastrup
2007-09-02 21:38           ` Alex Riesen
2007-09-02 22:04             ` Robin Rosenberg
2007-09-03  6:15           ` Marius Storm-Olsen
2007-09-03 11:39             ` Johannes Schindelin
2007-09-03 11:51               ` David Kastrup
2007-09-03 11:53               ` Marius Storm-Olsen
2007-09-03 12:33                 ` Johannes Schindelin
2007-09-02 21:41         ` Alex Riesen
2007-09-03  6:12           ` Marius Storm-Olsen
2007-09-03  7:47   ` Johannes Sixt
2007-09-03  7:55     ` Marius Storm-Olsen
     [not found]     ` <46DBFA2A.7050003@trolltech.com>
2007-09-03 12:38       ` [PATCH] Add a new lstat and fstat implementation based on Win32 API Marius Storm-Olsen
2007-09-03 13:33       ` Johannes Schindelin
2007-09-03 13:52         ` Marius Storm-Olsen
2007-09-03 14:39           ` Johannes Schindelin
2007-09-03 16:22             ` Marius Storm-Olsen
2007-09-03 16:56               ` Johannes Schindelin
2007-09-03 13:53         ` Johannes Sixt
2007-09-03 14:35           ` Johannes Schindelin
2007-09-03 19:21         ` Marius Storm-Olsen
2007-09-04  2:21           ` Johannes Schindelin
2007-09-04  7:41           ` Johannes Sixt
2007-09-04  8:53             ` David Kastrup
2007-09-04 10:20             ` Marius Storm-Olsen
2007-09-04 10:53               ` Johannes Sixt
2007-09-04 11:21                 ` Marius Storm-Olsen
2007-09-04 11:28                   ` Johannes Sixt
2007-09-04 21:31                 ` David Kastrup [this message]
2007-09-04 10:48             ` Johannes Schindelin
2007-09-04 11:36               ` Johannes Sixt
2007-09-04 11:53                 ` Marius Storm-Olsen
2007-09-04 13:56                   ` Marius Storm-Olsen
2007-09-04 14:07                     ` Johannes Sixt
2007-09-04 14:32                       ` Johannes Schindelin
2007-09-04 14:52                         ` Johannes Sixt
2007-09-04 14:16                     ` Johannes Schindelin
2007-09-04 14:30                     ` Johannes Schindelin
2007-09-04 14:43                       ` Marius Storm-Olsen
2007-09-04 14:48                         ` Johannes Schindelin
2007-09-04 15:05                           ` David Kastrup
2007-09-04 16:32                           ` Marius Storm-Olsen
2007-09-04 12:46                 ` Johannes Schindelin
2007-09-04 12:57                   ` Johannes Schindelin
2007-09-04 21:02                     ` Rutger Nijlunsing
2007-09-04 21:54                       ` Reece Dunn
2007-09-05  6:22                       ` Marius Storm-Olsen
2007-09-05 10:15                         ` Johannes Schindelin
2007-09-04 13:03                   ` Johannes Sixt
2007-09-06 16:18             ` Johannes Sixt
2007-09-06 16:34               ` Marius Storm-Olsen
2007-09-03 13:49       ` Johannes Sixt
2007-09-03 14:38         ` Johannes Schindelin
2007-09-03 16:15           ` Marius Storm-Olsen
2007-09-03 16:55             ` Johannes Schindelin
2007-09-02 20:02 ` Stats in Git Alex Riesen
2007-09-02 20:09   ` Marius Storm-Olsen
2007-09-03  8:19 ` Matthieu Moy

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