michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsIRDFDataSource.idl"
michael@0: 
michael@0: interface nsISimpleEnumerator;
michael@0: 
michael@0: /**
michael@0:  * An nsIRDFCompositeDataSource composes individual data sources, providing
michael@0:  * the illusion of a single, coherent RDF graph.
michael@0:  */
michael@0: [scriptable, uuid(96343820-307C-11D2-BC15-00805F912FE7)]
michael@0: interface nsIRDFCompositeDataSource : nsIRDFDataSource {
michael@0: 
michael@0:     /**
michael@0:      *
michael@0:      * Set this value to <code>true</code> if the composite datasource
michael@0:      * may contains at least one datasource that has <em>negative</em>
michael@0:      * assertions. (This is the default.)
michael@0:      *
michael@0:      * Set this value to <code>false</code> if none of the datasources
michael@0:      * being composed contains a negative assertion. This allows the
michael@0:      * composite datasource to perform some query optimizations.
michael@0:      *
michael@0:      * By default, this value is <code>true</true>.
michael@0:      */
michael@0:     attribute boolean	allowNegativeAssertions;
michael@0: 
michael@0:     /**
michael@0:      * Set to <code>true</code> if the composite datasource should
michael@0:      * take care to coalesce duplicate arcs when returning values from
michael@0:      * queries. (This is the default.)
michael@0:      *
michael@0:      * Set to <code>false</code> if the composite datasource shouldn't
michael@0:      * bother to check for duplicates. This allows the composite
michael@0:      * datasource to more efficiently answer queries.
michael@0:      *
michael@0:      * By default, this value is <code>true</code>.
michael@0:      */
michael@0:     attribute boolean	coalesceDuplicateArcs;
michael@0: 
michael@0:     /**
michael@0:      * Add a datasource the the composite data source.
michael@0:      * @param aDataSource the datasource to add to composite
michael@0:      */
michael@0:     void AddDataSource(in nsIRDFDataSource aDataSource);
michael@0: 
michael@0:     /**
michael@0:      * Remove a datasource from the composite data source.
michael@0:      * @param aDataSource the datasource to remove from the composite
michael@0:      */
michael@0:     void RemoveDataSource(in nsIRDFDataSource aDataSource);
michael@0: 
michael@0:     /**
michael@0:      * Retrieve the datasources in the composite data source.
michael@0:      * @return an nsISimpleEnumerator that will enumerate each
michael@0:      * of the datasources in the composite
michael@0:      */
michael@0:     nsISimpleEnumerator GetDataSources();
michael@0: };
michael@0: 
michael@0: %{C++
michael@0: extern nsresult
michael@0: NS_NewRDFCompositeDataSource(nsIRDFCompositeDataSource** result);
michael@0: %}
michael@0: