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.slf4j.Logger;
  18 import org.slf4j.LoggerFactory;
  19 import org.simantics.db.Resource;
  20 import org.simantics.db.WriteGraph;
  21 import org.simantics.db.exception.DatabaseException;
  22
  23 /**
  24  * Static utility methods for rule implementations.
  25  * @author Hannu Niemistö
  26  */
  27 public class MappingUtils {
  28
  29     static final Logger LOGGER = LoggerFactory.getLogger(MappingUtils.class);
  30
  31     /**
  32      * Adds and removes statements to/from the database so that <code>objects</code>
  33      * will be exactly the objects connected to <code>subject</code> by <code>predicate</code>.
  34      * Returns true if the method made modifications to the database.
  35      */
  36         public static boolean synchronizeStatements(WriteGraph g, Resource subject, Resource predicate, Resource[] objects,
  37                 boolean deleteExtraObjects)
  38                 throws DatabaseException {
  39                 Collection<Resource> currentObjects0 = g.getObjects(subject, predicate);
  40                 Resource[] currentObjects = currentObjects0.toArray(new Resource[currentObjects0.size()]);
  41
  42                 Arrays.sort(objects);
  43                 Arrays.sort(currentObjects);
  44
  45                 boolean modified = false;
  46                 int i=0, j=0;
  47                 if(currentObjects.length > 0 && objects.length > 0)
  48                 while(true) {
  49                         int cmp = currentObjects[i].compareTo(objects[j]);
  50                         if(cmp < 0) {
  51                             LOGGER.info("            remove statement");
  52                             if(deleteExtraObjects)
  53                                 g.deny(currentObjects[i]);
  54                             else
  55                                 g.denyStatement(subject, predicate, currentObjects[i]);
  56                                 modified = true;
  57                                 ++i;
  58                                 if(i >= currentObjects.length)
  59                                         break;
  60                         }
  61                         else if(cmp > 0) {
  62                             LOGGER.info("            add statement");
  63                                 g.claim(subject, predicate, objects[j]);
  64                                 modified = true;
  65                                 ++j;
  66                                 if(j >= objects.length)
  67                                         break;
  68                         }
  69                         else {
  70                                 ++i; ++j;
  71                                 if(i >= currentObjects.length)
  72                                         break;
  73                                 if(j >= objects.length)
  74                                         break;
  75                         }
  76                 }
  77                 while(i < currentObjects.length) {
  78                     if(deleteExtraObjects)
  79                 g.deny(currentObjects[i]);
  80             else
  81                 g.denyStatement(subject, predicate, currentObjects[i]);
  82                         modified = true;
  83                         ++i;
  84                 }
  85                 while(j < objects.length) {
  86                         g.claim(subject, predicate, objects[j]);
  87                         modified = true;
  88                         ++j;
  89                 }
  90                 return modified;
  91         }
  92
  93 }