[gdal-dev] Call for discussion for "RFC38 - OGR Faster Open"

Frank Warmerdam warmerdam at pobox.com
Sat Apr 14 16:21:53 EDT 2012


Even,

I am generally in favor of this, but I aspire in GDAL 2.0 to migrate
OGR to using GDALDriver mechanisms which would include being based
around GDALOpenInfo.  I am not sure if it is better to make the
GDALOpenInfo change as part of that broader effort or as a distinct
RFC and work item.

Best regards,
Frank

On Sat, Apr 14, 2012 at 1:11 PM, Even Rouault
<even.rouault at mines-paris.org> wrote:
> Hi,
>
> This is a call for discussion for "RFC38 - OGR Faster Open" :
>
> http://trac.osgeo.org/gdal/wiki/rfc38_ogr_faster_open
>
> Summary
> ---------------
>
> It is proposed that the OGR datasource opening mechanism relies on the
> GDALOpenInfo class, already used by GDAL drivers, to speed-up datasource
> opening. The speed-up is due to the fact that the file passed to OGROpen() will
> be opened and stat'ed only once, whereas currently, it is opened and closed as
> many times as there are OGR drivers. This should be particularly beneficial for
> network filesystems, or when trying to open a file that is not a OGR datasource
> at all.
>
> E.g., trying to open a file that is not a OGR datasource currently requires 45
> file opening or stat operations :
>
> $ strace ogrinfo -ro NEWS 2>&1 | grep NEWS | wc -l
> 45
>
> It is expected that if/once all drivers are migrated, it will decrease to 2
> operations only.
>
> Best regards,
>
> Even
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev



-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Software Developer


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