[Gdal-dev] Obect Structure Changes

Frank Warmerdam warmerdam at pobox.com
Thu Mar 20 17:14:21 EST 2003


Folks,

Changes have been made in gdal/core, and gdal/ogr that would require a clean
recompile on updates from CVS.  Please keep this in mind if updating from CVS.

Note that the GDALRasterBand will now give a report on "cache thrashing" if
CPL_DEBUG is enabled.  The report is only made if more block reads are made
against a band then there are block in the band (indicating that some must
have been re-read).  The message (issued when the raster band is destroyed)
looks like this:

Thu Mar 20 17:09:35 2003: GDAL: 5609 block reads on 4356 block band 1 of in.tif.

This is part of work Andrey and I are doing on performance tuning for GDAL.
One important aspect of performance tuning is understanding when cache
thrashing is happening and ensuring that effective use is made of caching
imagery in memory.

Best regards,

-- 
---------------------------------------+--------------------------------------
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 Programmer for Rent





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