Timezone classes

[Nicolas Goutte]

On Saturday 17 September 2005 21:59, Nicolas Goutte wrote:
> On Saturday 17 September 2005 20:27, Shaheed wrote:
> > On Thursday 15 September 2005 19:06, Nicolas Goutte wrote:
> > > On Thursday 15 September 2005 19:50, David Jarvie wrote:
> > > (...)
> > >
> > > > KTimezones::local() doesn't allow for the possibility of
> > > > /etc/localtime being a link to a file in /use/share/zoneinfo/ (or
> > > > wherever). This is quite
> > >
> > > If I remember well, the problem about /etc/localtime being a link, had
> > > been reported immediately in kde-commits (but apparently the code was
> > > not changed).
> >
> > I don't understand either comment (from David or Nicolas). The code in
> > question is trying to find the name of the file in /use/share/zoneinfo/
> > (or wherever) with the link or copy of the file that is in
> > /etc/localtime.
> >
> > AFAICS, it should work in both the link or copy case (I am not able to
> > test right now, but I thought I had done so).
> >
> > Does that make more sense? Maybe I need to make the comment there a bit
> > more verbose...
>
> As far as I understand the critic, the wish is to find that the file is a
> link and to use that link instead of guessing it with some MD5 handling.

Therefore you could use code like (Qt3):

QString zoneInfoFileName;
QFileInfo fi ( f );
if ( fi.isSymLink() )
{
  const QString ref ( fi.readLink() );
  QFileInfo fi2 ( ref );
  if ( ref.exists() && ref.isReadable() )
  {
	zoneInfoFileName = ref;
  }
}
if ( zoneInfoFileName.isEmpty() )
{
   // Find the zoneinfo file by the current method using the size and the MD5 
   ...
   zoneInfoFileName = somename;
}

if ( zoneInfoFileName.isEmpty() )
{
	return m_UTC;
}
else
{
	// Process zoneInfoName, assuming the file name is not empty.
}

>
> Sure the current code should work but it is quite an overhead in such a
> case, as MD5-ing thousand of files uses much computing power. (Counting
> quickly&dirty the SuSE 9.0 on my system has 1611 files in the /usr/share/
> zoneinfo and its subdirectories. However here it is not a link.)

Sorry, i wtote a little too fast. Sure not so many MD5 sums are calcualted but 
as many files a read, having potential drawbacks like purging buffers.

>
> > Thanks, Shaheed
>
> Have a nice day!