001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/io/datastore/sql/transaction/delete/FeatureGraph.java $
002    /*----------------------------------------------------------------------------
003     This file is part of deegree, http://deegree.org/
004     Copyright (C) 2001-2009 by:
005       Department of Geography, University of Bonn
006     and
007       lat/lon GmbH
008    
009     This library is free software; you can redistribute it and/or modify it under
010     the terms of the GNU Lesser General Public License as published by the Free
011     Software Foundation; either version 2.1 of the License, or (at your option)
012     any later version.
013     This library is distributed in the hope that it will be useful, but WITHOUT
014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016     details.
017     You should have received a copy of the GNU Lesser General Public License
018     along with this library; if not, write to the Free Software Foundation, Inc.,
019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020    
021     Contact information:
022    
023     lat/lon GmbH
024     Aennchenstr. 19, 53177 Bonn
025     Germany
026     http://lat-lon.de/
027    
028     Department of Geography, University of Bonn
029     Prof. Dr. Klaus Greve
030     Postfach 1147, 53001 Bonn
031     Germany
032     http://www.geographie.uni-bonn.de/deegree/
033    
034     e-mail: info@deegree.org
035    ----------------------------------------------------------------------------*/
036    package org.deegree.io.datastore.sql.transaction.delete;
037    
038    import java.util.ArrayList;
039    import java.util.HashMap;
040    import java.util.HashSet;
041    import java.util.List;
042    import java.util.Map;
043    import java.util.Set;
044    
045    import org.deegree.framework.log.ILogger;
046    import org.deegree.framework.log.LoggerFactory;
047    import org.deegree.i18n.Messages;
048    import org.deegree.io.datastore.DatastoreException;
049    import org.deegree.io.datastore.FeatureId;
050    import org.deegree.io.datastore.schema.MappedFeaturePropertyType;
051    import org.deegree.io.datastore.sql.AbstractRequestHandler;
052    import org.deegree.io.datastore.sql.LockHandler;
053    import org.deegree.ogcwebservices.wfs.operation.transaction.Delete;
054    
055    /**
056     * Used to determine the structure of features and subfeatures that have to be deleted by a {@link Delete} operation.
057     * <p>
058     * When features are selected for deletion, all of their descendant subfeatures will be deleted as well, except for
059     * those features that have superfeatures which are not descendants of the features to be deleted.
060     *
061     * @see DeleteHandler
062     * @see FeatureNode
063     *
064     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
065     * @author last edited by: $Author: mschneider $
066     *
067     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
068     */
069    public class FeatureGraph {
070    
071        private static final ILogger LOG = LoggerFactory.getLogger( FeatureGraph.class );
072    
073        private AbstractRequestHandler handler;
074    
075        private Set<FeatureId> rootFeatures = new HashSet<FeatureId>();
076    
077        private Map<FeatureId, FeatureNode> fidToNode = new HashMap<FeatureId, FeatureNode>();
078    
079        /**
080         * Creates a new <code>FeatureGraph</code> instance for the given root {@link FeatureId}s and the specified
081         * {@link DeleteHandler}.
082         *
083         * @param rootFids
084         *            ids of the feature instances to be deleted
085         * @param handler
086         *            associated <code>DeleteHandler</code>
087         * @throws DatastoreException
088         */
089        FeatureGraph( List<FeatureId> rootFids, DeleteHandler handler ) throws DatastoreException {
090            this.handler = handler;
091            for ( FeatureId fid : rootFids ) {
092                this.rootFeatures.add( fid );
093                addNode( fid );
094            }
095            markUndeletableFeatures();
096        }
097    
098        /**
099         * Creates a new <code>FeatureGraph</code> instance for the given root {@link FeatureId}s and the specified
100         * {@link LockHandler}.
101         *
102         * @param rootFids
103         *            ids of the feature instances to be locked
104         * @param handler
105         *            associated <code>LockHandler</code>
106         * @throws DatastoreException
107         */
108        public FeatureGraph( Set<FeatureId> rootFids, LockHandler handler ) throws DatastoreException {
109            this.handler = handler;
110            for ( FeatureId fid : rootFids ) {
111                this.rootFeatures.add( fid );
112                addNode( fid );
113            }
114        }
115    
116        /**
117         * Returns the {@link FeatureId}s of all features contained in the graph.
118         *
119         * @return the <code>FeatureId</code>s of all features contained in the graph
120         */
121        public Set<FeatureId> getAllFids() {
122            return this.fidToNode.keySet();
123        }
124    
125        /**
126         * Returns the {@link FeatureNode} that represents the feature with the given {@link FeatureId}.
127         *
128         * @param fid
129         *            id of the feature to look up
130         * @return the corresponding <code>FeatureNode</code> if it exists in the graph, null otherwise
131         */
132        FeatureNode getNode( FeatureId fid ) {
133            return fidToNode.get( fid );
134        }
135    
136        /**
137         * Returns the {@link FeatureNode}s that represent all root features that have been targeted for deletion.
138         *
139         * @return <code>FeatureNode</code> representing all root features
140         */
141        List<FeatureNode> getRootNodes() {
142            List<FeatureNode> rootNodes = new ArrayList<FeatureNode>( this.rootFeatures.size() );
143            for ( FeatureId fid : rootFeatures ) {
144                rootNodes.add( getNode( fid ) );
145            }
146            return rootNodes;
147        }
148    
149        /**
150         * Adds the specified feature (and it's descendants) (as {@link FeatureNode}s).
151         *
152         * @param fid
153         *            the id of the feature to be added
154         * @throws DatastoreException
155         */
156        private void addNode( FeatureId fid )
157                                throws DatastoreException {
158    
159            if ( this.fidToNode.get( fid ) == null ) {
160                // skip determination of super features if feature is not deletable anyway
161                Set<FeatureId> superFeatures = null;
162                if ( fid.getFeatureType().isDeletable() ) {
163                    superFeatures = handler.determineSuperFeatures( fid );
164                } else {
165                    LOG.logDebug( "Skipping super feature lookup for feature: " + fid
166                                  + " -- feature type is not deletable anyway." );
167                    superFeatures = new HashSet<FeatureId>();
168                    superFeatures.add (fid);
169                }
170    
171                Map<MappedFeaturePropertyType, List<FeatureId>> subFeatures = handler.determineSubFeatures( fid );
172                FeatureNode node = new FeatureNode( this, fid, subFeatures, superFeatures );
173                this.fidToNode.put( fid, node );
174    
175                for ( FeatureId subFid : node.getSubFeatureIds() ) {
176                    addNode( subFid );
177                }
178            }
179        }
180    
181        /**
182         * Marks all {@link FeatureNode}s in the graph that cannot be deleted, because they are descendants (subfeatures)
183         * of other undeletable {@link FeatureNode}s.
184         */
185        private void markUndeletableFeatures() {
186    
187            LOG.logDebug( "Determining undeletable features." );
188    
189            int lastVetoCount = -1;
190            int vetoCount = 0;
191    
192            while ( vetoCount != lastVetoCount ) {
193                LOG.logDebug( "vetoCount: " + vetoCount );
194                LOG.logDebug( "lastVetoCount: " + lastVetoCount );
195                lastVetoCount = vetoCount;
196                vetoCount = 0;
197                for ( FeatureNode node : this.fidToNode.values() ) {
198                    if ( node.isDeletable() ) {
199                        boolean deletable = true;
200                        if ( !node.getFid().getFeatureType().isDeletable() ) {
201                            String msg = Messages.getMessage( "DATASTORE_FEATURE_NOT_DELETABLE", node.getFid().toString() );
202                            LOG.logInfo( msg );
203                            deletable = false;
204                        } else {
205                            for ( FeatureId superFid : node.getSuperFeatureIds() ) {
206                                FeatureNode superNode = getNode( superFid );
207                                if ( superNode == null || !superNode.isDeletable() ) {
208                                    deletable = false;
209                                    break;
210                                }
211                            }
212                        }
213                        if ( !deletable ) {
214                            node.markAsUndeletable();
215                            vetoCount++;
216                        }
217                    } else {
218                        vetoCount++;
219                    }
220                }
221            }
222            LOG.logDebug( "Delete vetos: " + lastVetoCount );
223        }
224    
225        @Override
226        public String toString() {
227            StringBuffer sb = new StringBuffer( "FeatureGraph:\n" );
228            for ( FeatureId rootFid : this.rootFeatures ) {
229                sb.append( this.fidToNode.get( rootFid ).toString( "", new HashSet<FeatureNode>() ) );
230            }
231            return sb.toString();
232        }
233    }