Frank, thank you for your suggestion. I added a GDALProgressFunc as you suggested. In order to prevent blocking in the rasterio now I check a state variable indicating when I have to stop the reading. Since I call rasterio foreach line of the destination bitmap I have added a simple check of the state variable (eg.: if (terminate) then return). Very simple!! I should have think about it by myself. Now my app can browse without blocking the openstreetmap dataset.
Best regards. Stefano - Dr.Eng. Stefano Moratto stefano.mora...@gmail.com stefano.mora...@csiat.it http://www.csiat.it - Traffic Optimization Software On Mon, Jan 31, 2011 at 5:39 PM, Frank Warmerdam <warmer...@pobox.com>wrote: > On 11-01-31 04:26 AM, Stefano Moratto wrote: > >> Hello, >> I need to interrupt a RasterIO and warp calls before they have >> been >> ended. >> The call is invoked in a background thread and It may happen that the >> user >> changes the requested area in the main thread (GUI) (eg. a pan/scroll >> operation). >> > > Stefano, > > Algorithms which take a GDALProgressFunc are likely to be interruptable. > Each time the progress function is invoked it has the opportunity to > return an indicate that the operation has been cancelled by the user. > > So the warper can be canceled if you provide a customized progress > function. But RasterIO cannot since it has no progress function. > > If you want IO to be interruptible you would normally do it in modest > sized chunks, though this can interfere with optimization of the IO in > some cases. > > Best regards, > -- > > ---------------------------------------+-------------------------------------- > I set the clouds in motion - turn up | Frank Warmerdam, > warmer...@pobox.com > light and sound - activate the windows | > http://pobox.com/~warmerdam<http://pobox.com/%7Ewarmerdam> > and watch the world go round - Rush | Geospatial Programmer for Rent > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -
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