Application: gvSIG desktop

/* gvSIG. Geographic Information System of the Valencian Government

*

* Copyright (C) 2007-2008 Infrastructures and Transports Department

* of the Valencian Government (CIT)

* 

* This program is free software; you can redistribute it and/or

* modify it under the terms of the GNU General Public License

* as published by the Free Software Foundation; either version 2

* of the License, or (at your option) any later version.

* 

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU General Public License for more details.

* 

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 

* MA  02110-1301, USA.

* 

*/

/*

* AUTHORS (In addition to CIT):

* 2009 {Iver T.I.}   {Task}

*/

package org.gvsig.fmap.dal.feature;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.geom.primitive.Envelope;

/**

 * This class represents a vectorial cache that is used to save and retrieve

 * {@link FeatureSet}s. First time that a {@link FeatureStore} have to retrieve

 * data from a {@link FeatureStoreProvider} can save the {@link FeatureSet} in

 * the cache with its envelope. Next time that the store has to access to a envelope

 * contained in the previous envelope can retrieve the features directly 

 * from the cache and it is not necessary to retrieve data from the provider.

 * 

 * The cache supports different scales and creates

 *  

 * @author <a href="mailto:jpiera@gvsig.org">Jorge Piera</a>

 */

public interface FeatureCache {

        /**

         * Delete all the features for a concrete scale.

         * @param scale

         * The scale.

         * @throws DataException

         */

        public void delete(double scale) throws DataException;

        /**

         * Delete all the features for all the scales in the cache system.

         * @throws DataException

         */

        public void deleteAll() throws DataException;

        /**

         * Add a set of features contained in a envelope for a concrete scale.

         * @param featureSet

         * The feature set retrieved from the server.

         * @throws DataException

         */

        public void addFeatures(FeatureSet featureSet, FeatureStore featureStore) throws DataException;

        /**

         * Return a feature set form a concrete envelope and a scale.

         * @param envelope

         * The envelope.

         * @param scale

         * The scale.

         * @return

         * A feature set contained in the evelope.

         * @throws DataException

         */

        public FeatureSet getFeatureSet(Envelope envelope, double scale) throws DataException;

}