com.bigdata.rdf.sparql.ast.service

Interface ServiceCall<E>

Type Parameters:

E - The generic type of the solutions which are exchanged with the service implementation. This will be either IBindingSet or BindingSet. Note that those two interfaces do not have any common ancestor other than Object.

All Known Subinterfaces:

BigdataServiceCall, ExternalServiceCall, MockIVReturningServiceCall, RemoteServiceCall

All Known Implementing Classes:

RemoteServiceCallImpl

public interface ServiceCall<E>

Service invocation interface.

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
ICloseableIterator<E>	call(E[] bindingSets) Invoke an service.
IServiceOptions	getServiceOptions() Return options and metadata for the service end point.

Method Detail

getServiceOptions

IServiceOptions getServiceOptions()

Return options and metadata for the service end point. TODO The options for a ServiceCall instance are shared with all instances for the same factory. This should be appropriate because the factory is specific to the service URI. The only exception would be the ServiceRegistry.getDefaultServiceFactory(). Consider replacing this with a back reference to the ServiceFactory.

call

ICloseableIterator<E> call(E[] bindingSets)
                           throws Exception

Invoke an service. The caller will join the results from the service with the solutions in the context in which the service was invoked (using a solution set hash join pattern).

Parameters:

bindingSets - The binding sets flowing into the service.

Returns:

An iterator from which the solutions can be drained. If the iterator is closed, the service invocation must be cancelled.

Throws:

Exception - TODO RECHUNKING: This should probably return an ICloseableIterator for consistent chunking across our access path abstractions. And maybe it could implement IBindingSetAccessPath.