Hi, I was wondering if these preview jobs are enabled in QGIS Server context, when requesting a GetMap from any client. I am pretty sure the context of the preview jobs execution is related to Desktop, but I would like to be sure. Any hint on this ?
Regards, Michaël 2017-11-16 11:15 GMT+01:00 Matthias Kuhn <[email protected]>: > Hi Patrick, > > Would be interesting to do this test with previews enabled and disabled. > Then we'll see if it's actually the previews or some other mechanism that > is causing this. > > IIRC only a composite image is saved in the preview jobs and not each > layer separately, but that's just what I remember and not evidence based. > > You can enable them in the python console with > > iface.mapCanvas().setPreviewJobsEnabled(True) > > and disable with > > iface.mapCanvas().setPreviewJobsEnabled(False) > > Thanks for a feedback > > Matthias > > On 11/16/2017 08:42 AM, Patrick Dunford wrote: > > In my current project using Qgis 2.99, turning off the rasters uses 16 GB, > turning them on uses 52 GB > > I do not believe it is independent from the number of layers that are > being displayed. > > Previous versions of the software did not cache every single raster (the > number of rasters actually being displayed on the canvas at any one time is > a small fraction of the total number in the project) > On 16/11/17 20:11, Matthias Kuhn wrote: > > Hi Patrick, > > This uses some memory (~ canvas width pixels * canvas height pixels * 8 > preview images * 32 bit RGBA), so let's assume 50 MB to 100 MB. > > This consumption is independent from the number or type of layers. > > Matthias > > On 11/16/2017 08:02 AM, Patrick Dunford wrote: > > So to put it another way this is the reason why Qgis wants to use a huge > amount of memory (40 GB) when I have a lot of raster images loaded in the > background. > > On 16/11/17 18:56, Tim Sutton wrote: > > Hi > > On 16 Nov 2017, at 04:35, Patrick Dunford <[email protected]> wrote: > > What is this "preview job" function? > > > Its application logic to prefetch / pre-render offscreen content in > anticipation of user panning the map. > > Regards > > Tim > > > _______________________________________________ > QGIS-Developer mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > — > > > > > > > *Tim Sutton* > > *Co-founder:* Kartoza > *Project chair:* QGIS.org > > Visit http://kartoza.com to find out about open source: > > Desktop GIS programming services > Geospatial web development > GIS Training > Consulting Services > > *Skype*: timlinux > *IRC:* timlinux on #qgis at freenode.net > > > > > _______________________________________________ > QGIS-Developer mailing [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > > _______________________________________________ > QGIS-Developer mailing [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > > _______________________________________________ > QGIS-Developer mailing [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > _______________________________________________ > QGIS-Developer mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer >
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