bundles/org.simantics.db.common/src/org/simantics/db/common/request/IndexRoot.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 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.db.common.request;
  13
  14 import java.util.Collection;
  15 import java.util.HashSet;
  16
  17 import org.simantics.db.ReadGraph;
  18 import org.simantics.db.Resource;
  19 import org.simantics.db.common.utils.NameUtils;
  20 import org.simantics.db.exception.DatabaseException;
  21 import org.simantics.layer0.Layer0;
  22
  23 public class IndexRoot extends ResourceRead<Resource> {
  24
  25     public IndexRoot(Resource resource) {
  26         super(resource);
  27     }
  28
  29     @Override
  30     public Resource perform(ReadGraph graph) throws DatabaseException {
  31
  32         Layer0 L0 = Layer0.getInstance(graph);
  33
  34         if (graph.isInstanceOf(resource, L0.IndexRoot))
  35             return resource;
  36
  37         Collection<Resource> parents = new HashSet<Resource>(graph.getObjects(resource, L0.IsOwnedBy));
  38         Resource parent = parents.size() == 1 ? parents.iterator().next() : null;
  39
  40         // What is this?
  41         if(resource.equals(parent))
  42                 parent = null;
  43
  44         if (parent == null) {
  45
  46                 if(parents.size() > 1) {
  47                         // Maybe we have a case where there is ConsistsOf and HasProperty that is incorrectly classified as IsComposedOf
  48                         parent = graph.getPossibleObject(resource, L0.PartOf);
  49                 }
  50
  51                 // Assertion object?
  52                 if(parent == null)
  53                         parent = graph.getPossibleObject(resource, L0.HasObjectInverse);
  54
  55                 if(parent == null)
  56                         throw new DatabaseException("Index root was not found for " + NameUtils.getSafeName(graph, resource, true));
  57
  58         }
  59
  60         try {
  61                 return graph.syncRequest(new IndexRoot(parent));
  62         } catch (DatabaseException e) {
  63                 throw new DatabaseException("Index root was not found for " + NameUtils.getSafeName(graph, resource, true));
  64         }
  65
  66     }
  67
  68 }