[gdal-dev] Considering drivers removal ?

[Stephen Woodbridge]

Even,

This makes a lot of sense to me. How would you handle this in Python?
Would it make sense to create a GDAL-removed repository and move stuff 
into it just so it is available if someone wants it. This would not be 
supported or updated by GDAL just making it available if someone 
wants/needs to fork it, something else like this?

-Steve W

On 1/10/2021 6:02 PM, Even Rouault wrote:
> Hi,
>
> It's not spring yet, but I'm in a mood lately of axing useless things, and we
> probably have tons of candidate for that in GDAL, especially in drivers.
> I was going to just axe the DB2 driver
> (https://github.com/OSGeo/gdal/pull/3366) but the issue is more general.
>
> Any idea how we can know what is used and what isn't ? A "call-home"
> functionality where we would track driver usage would only be acceptable if
> people enable it and have network connectivity, so we won't probably get lots
> of feedback. Having a spreadsheet with the driver list and asking people to
> fill it would probably also receive little feedback. So the idea I had was to
> do something like the following in the Open() method of a candidate for
> removal:
>
> GDALDataset* FooDriver::Open( .... )
> {
>     if( !Identify(poOpenInfo) )
>        return nullptr;
>
>     if( !CPLTestBool(CPLGetConfigOption("GDAL_ENABLE_DRIVER_FOO", "NO") )
>     {
>         CPLError(CE_Failure, CPLE_AppDefined,
>      "Driver FOO is considered for removal in GDAL 3.5. You are invited "
>      "to convert any dataset in that format to another more common one ."
>      "If you need this driver in future GDAL versions, create a ticket at "
>      "https://github.com/OSGeo/gdal (look first for an existing one first) to "
>      "explain how critical it is for you (but the GDAL project may still "
>      "remove it), and to enable it now, set the GDAL_ENABLE_DRIVER_FOO "
>      "configuration option / environment variable to YES");
>         return nullptr;
>      }
>      ...
> }
>
> That is, when we detect a file to be handled by the driver, emit the above
> error message and do not open the dataset, unless the user defines the
> environment variable.
> Similarly in the Create()/CreateCopy() methods.
> If we ship this in 3.3, with a 3.5 milestone for removal, this would offer a
> feedback period of one year / 2 feature versions.
>
> Here's my own list of candidates for retirement (probably over-conservative).
> Mostly based on gut feeling. None of them are particularly bad citizens, but I
> have no indication that they are still used, which doesn't mean they aren't.
>
> * Raster side:
> BPG
> DB2Raster
> DOQ1
> DOQ2
> E00GRID
> Epsilon
> FujiBAS
> GS7BG
> GSAG
> IDA
> JDEM
> JPEG2000 (Jasper): JP2OpenJPEG is a better replacement
> JPEGLS
> LAN
> MFF
> MG4Lidar ?
> NDF
> NTv1
> SDTS Raster
> SGI
> XPM
> ZMap
>
> * Vector side:
> AERONAVFAA
> ESRI ArcObjects
> ARCGEN
> BNA
> Cloudant
> CouchDB
> DB2
> DODS
> FMEObjects Gateway
> Geomedia MDB
> GMT ASCII Vectors
> GTM
> HTF
> INGRES
> MongoDB (the old one, superseded by MongoDBv3)
> OpenAIR
> REC
> SDTS
> SUA
> SVG
> TIGER
> WALK
>
>
> Anything you'd add / remove ?
>
> What is not obvious is what would be the criterion for keeping a driver: 1,
> 10, 100 users asking for the driver to be kept ?
> If a GDAL developer contributing to the overall good of the project needs the
> preservation of a driver to be able to justify its continued involvement, I'd
> tend to think it to be enough to keep it.
>
>
> Even
>