Configuring Protocol Processors

Protocol Processors are classes that can process SPARQL Graph Store HTTP Protocol requests and return appropriate responses. Protocol Processors implement the ISparqlHttpProtocolProcessor interface and the library provides 3 concrete implementations of this all of which can be configured using the Configuration API.

Basic Configuration

Basic Configuration for a Protocol Processor looks like the following:

@prefix dnr: <http://www.dotnetrdf.org/configuration#> .

_:proc a dnr:SparqlHttpProtocolProcessor .
  dnr:type "VDS.RDF.Update.Protocol.LeviathanProtocolProcessor" .

Leviathan Protocol Processor

The Leviathan Protocol Processor is used to process protocol requests on in-memory stores using the library's Leviathan SPARQL Engine. It is configured quite simply by adding a dnr:usingStore property to the basic configuration, the object pointed to by this property must be a Triple Store which implements the IInMemoryQueryableStore interface e.g.

@prefix dnr: <http://www.dotnetrdf.org/configuration#> .

_:proc a dnr:SparqlHttpProtocolProcessor .
  dnr:type "VDS.RDF.Update.Protocol.LeviathanProtocolProcessor" ;
  dnr:usingStore _:store .

_:store a dnr:TripleStore ;
  dnr:type "VDS.RDF.TripleStore" .

For information on how to configure Triple Stores see Configuration API - Triple Stores.

Alternatively you may use the dnr:usingDataset property to connect it to a Dataset instead. See Configuration API - Datasets for details. If both dnr:usingDataset and dnr:usingStore are present then dnr:usingDataset has priority and the value of dnr:usingStore is ignored.

Generic Protocol Processor

The Generic Protocol Processor is used to process protocol requests against some arbitrary store where the store you wish to connect to has an implementation of IStorageProvider.

Not all features of the protocol may be supported or behave correctly depending on the capabilities of the IStorageProvider used.

To configure these handlers simply add a dnr:storageProvider property to the basic configuration like so:

@prefix dnr: <http://www.dotnetrdf.org/configuration#> .

_:proc a dnr:SparqlHttpProtocolProcessor .
  dnr:type "VDS.RDF.Update.Protocol.GenericProtocolProcessor" ;
  dnr:storageProvider _:manager .

_:manager a dnr:StorageProvider ;
  dnr:type "VDS.RDF.Storage.VirtuosoManager" ;
  dnr:server "http://virtuoso.example.com" ;
  dnr:user "username" ;
  dnr:password "password" .

The above configures a Generic Protocol Processor which processes requests using a Virtuoso quad store.

Protocol to Update Processor

The Protocol to Update Processor is a processor which operates using the supplied Query and Update processors, see Configuration API - Query Processors and Configuration API - Update Processors for details on configuring these.

@prefix dnr: <http://www.dotnetrdf.org/configuration#> .

_:proc a dnr:SparqlHttpProtocolProcessor .
  dnr:type "VDS.RDF.Update.Protocol.ProtocolToUpdateProcessor" ;
  dnr:queryProcessor _:qProc ;
  dnr:updateProcessor _:uProc .

_:qProc a dnr:SparqlQueryProcessor ;
  dnr:type "VDS.RDF.Query.LeviathanQueryProcessor" ;
  dnr:usingStore _:store .

_:uProc a dnr:SparqlUpdateProcessor ;
  dnr:type "VDS.RDF.Update.LeviathanUpdateProcessor" ;
  dnr:usingStore _:store .

_:store a dnr:TripleStore ;
  dnr:type "VDS.RDF.TripleStore" .

Note that the above is in effect identical to the example given for the Leviathan Protocol Processor but much more complex configurations are possible than with the plain Leviathan processor.