[gdal-dev] GSoC 2014 Weekly Report 11 : GDAL PostGIS Raster driver

[Even Rouault]

Le lundi 04 août 2014 22:38:20, Varun Saraf a écrit :
> Hello,
> 
> Thank you for this information. I will explicitly call Create() using a
> script. Is the IWriteBlock method to be tested in a similar manner? Note
> that pData buffer is passed to this method as an argument, which I will
> have to generate and pass to it. Any suggestions how I should generate this
> pData buffer?

Well, any data might do.
But based on my previous note regarding the generic GDAL core CreateCopy() 
implementation, another possibility for your testing is to temporarily comment 
poDriver->pfnCreateCopy = .... and use gdal_translate.

> 
> Regards,
> Varun Saraf
> 
> 
> On Tue, Aug 5, 2014 at 1:44 AM, Even Rouault <even.rouault at mines-paris.org>
> 
> wrote:
> > Le lundi 04 août 2014 21:38:36, Varun Saraf a écrit :
> > > Hello,
> > > 
> > > Yes, the code on the github repository is the latest state. I was
> > > trying the following input queries :
> > > 
> > > (1) Assuming that my Create() will be called.
> > > gdal_translate --debug ON -of PostGISRaster ~/GSoC/ap_clip5x5.tif
> > > 
> > >  PG:"host=localhost port=5432 user=postgres password=postgres
> > > 
> > > dbname=test123 table=newtable"
> > > 
> > > (2) When that did not work, I tried the following (suggested by my
> > 
> > mentor,
> > 
> > > Jorge Arevalo) which didn't work either.
> > > gdal_translate --debug ON -of PostGISRaster -outsize 50% 50%
> > > ~/GSoC/ap_clip5x5.tif  PG:"host=localhost port=5432 user=postgres
> > > password=postgres dbname=test123 table=newtable"
> > 
> > gdal_translate will never call Create(), but only CreateCopy().
> > 
> > You might want to call Create() directly with a Python script for
> > example, or
> > a sample C/C++ code. gdalwarp will call Create() too, but gdalwarp can
> > potentially rewrite existing tiles, which can complicate your initial
> > coding.
> > 
> > > QuiteDelete() method is called in both cases and the following error
> > > messages are shown
> > > ERROR 1: Couldn't drop the table public.newtable: ERROR:  table
> > 
> > "newtable"
> > 
> > > does not exist
> > > ERROR 6: PostGISRasterDataset::CreateCopy() only works on source
> > > datasets that are PostGISRaster
> > 
> > Yes, as the message implies, the current CreateCopy() implementation only
> > works when the source dataset is a postgisraster dataset itself.
> > As far as the error message "Couldn't drop ...",
> > PostGISRasterDataset::Delete() should probably be more silent in case the
> > dataset doesn't exist.
> > 
> > Note that once you have a full feature Create() implementation (with
> > working
> > IWriteBlock() of course), CreateCopy() is no longer strictly needed,
> > since there is generic implementation in GDAL core that will emulate
> > CreateCopy() with Create() + IWriteBlock()
> > 
> > > I even tried calling the Create() method directly from CreateCopy(),
> > 
> > since
> > 
> > > that is being called, but again the same error message is being
> > > printed.
> > > 
> > > Regards,
> > > Varun Saraf
> > > 
> > > On Mon, Aug 4, 2014 at 11:33 PM, Even Rouault
> > > <even.rouault at mines-paris.org>
> > > 
> > > wrote:
> > > > Le lundi 04 août 2014 14:39:52, Varun Saraf a écrit :
> > > > >  Hi,
> > > > > 
> > > > > Below is my eleventh weekly report.
> > > > > 
> > > > > *What did I do this week?*
> > > > > 
> > > > >    - There are some issues with the calling of different methods.
> > > > >    My
> > > > 
> > > > method
> > > > 
> > > > >    PostGISRasterDataset::Create() is not being called. Tried to
> > 
> > resolve
> > 
> > > > > that.
> > > > 
> > > > Varun,
> > > > 
> > > > If the code at
> > 
> > https://github.com/varunsaraf/postgis_raster/blob/master/postgisrasterdat
> > 
> > > > aset.cpp is the latest state, I don't see any reason why your
> > > > Create() method wouldn't
> > > > be called. Do you try to trigger it directly by calling Create()
> > > > explicetely
> > > > or through other more high level operations ?
> > > > 
> > > > Even
> > > > 
> > > > > - Fixed some small bugs and removed unnecessary variables that were
> > > > > being used.
> > > > > 
> > > > > *What do I plan on doing next week?*
> > > > > 
> > > > >    - Continue with testing and bug fixing.
> > > > > 
> > > > > *Am I blocked on anything?*
> > > > > 
> > > > >    - No.
> > > > > 
> > > > > Link to weekly report :
> > > > > https://github.com/varunsaraf/postgis_raster/wiki/Report-11
> > 
> > > > > Link to code repository :
> > https://github.com/varunsaraf/postgis_raster
> > 
> > > > > More details at :
> > http://trac.osgeo.org/gdal/wiki/PostGIS_raster_driver
> > 
> > > > > Regards,
> > > > > Varun Saraf
> > > > > Lab for Spatial Informatics
> > > > > IIIT Hyderabad, India
> > > > 
> > > > --
> > > > Geospatial professional services
> > > > http://even.rouault.free.fr/services.html
> > 
> > --
> > Geospatial professional services
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