bundles/org.simantics.objmap2/src/org/simantics/objmap/graph/rules/domain/MappingUtils.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2013 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.objmap.graph.rules.domain;
  13
  14 import java.util.Arrays;
  15 import java.util.Collection;
  16
  17 import org.apache.log4j.Logger;
  18 import org.simantics.db.Resource;
  19 import org.simantics.db.WriteGraph;
  20 import org.simantics.db.exception.DatabaseException;
  21
  22 /**
  23  * Static utility methods for rule implementations.
  24  * @author Hannu Niemistö
  25  */
  26 public class MappingUtils {
  27
  28     static Logger LOGGER = Logger.getLogger("org.simantics.objmap");
  29
  30     /**
  31      * Adds and removes statements to/from the database so that <code>objects</code>
  32      * will be exactly the objects connected to <code>subject</code> by <code>predicate</code>.
  33      * Returns true if the method made modifications to the database.
  34      */
  35         public static boolean synchronizeStatements(WriteGraph g, Resource subject, Resource predicate, Resource[] objects,
  36                 boolean deleteExtraObjects)
  37                 throws DatabaseException {
  38                 Collection<Resource> currentObjects0 = g.getObjects(subject, predicate);
  39                 Resource[] currentObjects = currentObjects0.toArray(new Resource[currentObjects0.size()]);
  40
  41                 Arrays.sort(objects);
  42                 Arrays.sort(currentObjects);
  43
  44                 boolean modified = false;
  45                 int i=0, j=0;
  46                 if(currentObjects.length > 0 && objects.length > 0)
  47                 while(true) {
  48                         int cmp = currentObjects[i].compareTo(objects[j]);
  49                         if(cmp < 0) {
  50                             LOGGER.info("            remove statement");
  51                             if(deleteExtraObjects)
  52                                 g.deny(currentObjects[i]);
  53                             else
  54                                 g.denyStatement(subject, predicate, currentObjects[i]);
  55                                 modified = true;
  56                                 ++i;
  57                                 if(i >= currentObjects.length)
  58                                         break;
  59                         }
  60                         else if(cmp > 0) {
  61                             LOGGER.info("            add statement");
  62                                 g.claim(subject, predicate, objects[j]);
  63                                 modified = true;
  64                                 ++j;
  65                                 if(j >= objects.length)
  66                                         break;
  67                         }
  68                         else {
  69                                 ++i; ++j;
  70                                 if(i >= currentObjects.length)
  71                                         break;
  72                                 if(j >= objects.length)
  73                                         break;
  74                         }
  75                 }
  76                 while(i < currentObjects.length) {
  77                     if(deleteExtraObjects)
  78                 g.deny(currentObjects[i]);
  79             else
  80                 g.denyStatement(subject, predicate, currentObjects[i]);
  81                         modified = true;
  82                         ++i;
  83                 }
  84                 while(j < objects.length) {
  85                         g.claim(subject, predicate, objects[j]);
  86                         modified = true;
  87                         ++j;
  88                 }
  89                 return modified;
  90         }
  91
  92 }