[gdal-dev] Can OGR WFS driver take advantage of WFS Server streaming?

[Yingqi Tang]

Thanks a lot, Even. I will give it a try.

On Thu, May 17, 2012 at 9:47 AM, Even Rouault
<even.rouault at mines-paris.org>wrote:

>
> > > 2. Does the GML driver take url pointing to a GML?
> >
> > It can work with /vsicurl/http://something, provided that the server
> allows
> > partial downloading of arbitrary ranges of bytes within the file, which
> is
> > rarely the case with GetFeature() requests.
> >
> > In theory the WFS driver could be improved to use the capability of the
> GML
> > driver to read chunk by chunk, but there is some work to make that
> happen.
> > This would probably require a /vsicurl_streaming/ virtual file system
> where
> > basically only Read() requests would be available, thus not requiring the
> > server to have download range capabilities.
>
> Before considering the effort of implementing /vsicurl_streaming/ , I've
> improved a few things in the GML driver in trunk that allows to parse a GML
> stream that is a WFS GetFeature response document.
>
> So you can now try the following command on Linux :
>
> wget -O - "http://testing.deegree.org/deegree-
>
> wfs/services?SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=app:Springs"
> | ogrinfo -ro -al -q /vsistdin/
>
> or
>
> wget -O - "http://testing.deegree.org/deegree-
>
> wfs/services?SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=app:Springs"
> | ogr2ogr springs.shp /vsistdin/
>
> (or instead of "wget -O -", you can use "curl" depending on what is
> installed
> on your machine)
>
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