bundles/org.simantics.mapping/src/org/simantics/mapping/constraint/instructions/TripletPredicateObjectQuery.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.mapping.constraint.instructions;\r
  13 \r
  14 import gnu.trove.set.hash.TIntHashSet;\r
  15 \r
  16 import java.util.Collection;\r
  17 import java.util.Iterator;\r
  18 \r
  19 import org.simantics.db.ReadGraph;\r
  20 import org.simantics.db.Resource;\r
  21 import org.simantics.db.Statement;\r
  22 import org.simantics.db.exception.DatabaseException;\r
  23 import org.simantics.layer0.Layer0;\r
  24 \r
  25 public class TripletPredicateObjectQuery extends TripletInstruction {\r
  26 \r
  27         Resource predicate;\r
  28         \r
  29         public TripletPredicateObjectQuery(int variable0, int variable1, int variable2,\r
  30                         Resource predicate) {\r
  31                 super(variable0, variable1, variable2);\r
  32                 this.predicate = predicate;\r
  33         }\r
  34         \r
  35         public TripletPredicateObjectQuery(int variable0, int variable1, int variable2) {\r
  36                 this(variable0, variable1, variable2, null);\r
  37         }\r
  38         \r
  39         @Override\r
  40         public Object query(ReadGraph g, Object[] bindings) throws DatabaseException {\r
  41                 Resource r0 = (Resource)bindings[variable0];\r
  42 //              ITask task = ThreadLogger.getInstance().begin("g");\r
  43                 Collection<Statement> result =\r
  44                         predicate == null \r
  45                         ? g.getStatements(r0, Layer0.getInstance(g).IsWeaklyRelatedTo)\r
  46                                 : g.getStatements(r0, predicate);\r
  47 //              task.finish();\r
  48                 if(result.isEmpty())\r
  49                         return IInstruction.FAILURE;\r
  50                 Iterator<Statement> it = result.iterator();\r
  51                 Statement stat = it.next();\r
  52                 bindings[variable1] = stat.getPredicate();\r
  53                 bindings[variable2] = stat.getObject();\r
  54                 if(it.hasNext())\r
  55                         return it;\r
  56                 else\r
  57                         return null;\r
  58         }\r
  59         \r
  60         @SuppressWarnings("unchecked")\r
  61         @Override\r
  62         public Object next(ReadGraph g, Object[] bindings, Object continuation) {\r
  63                 Iterator<Statement> it = (Iterator<Statement>)continuation;\r
  64                 if(it.hasNext()) {\r
  65                         Statement stat = it.next();\r
  66                         bindings[variable1] = stat.getPredicate();\r
  67                         bindings[variable2] = stat.getObject();\r
  68                         if(it.hasNext())\r
  69                                 return it;\r
  70                         else\r
  71                                 return null;\r
  72                 }\r
  73                 else\r
  74                         return IInstruction.FAILURE;\r
  75         }       \r
  76         \r
  77         @Override\r
  78         public void collectVariables(TIntHashSet reads, TIntHashSet writes) {           \r
  79                 super.collectVariables(reads, writes);\r
  80                 writes.add(variable1);\r
  81                 writes.add(variable2);\r
  82         }\r
  83 \r
  84 }\r