--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.mapping.constraint.instructions;\r
+\r
+import gnu.trove.set.hash.TIntHashSet;\r
+\r
+import java.util.Collection;\r
+import java.util.Iterator;\r
+\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.exception.DatabaseException;\r
+\r
+public class TripletObjectQuery extends TripletInstruction {\r
+\r
+ public TripletObjectQuery(int variable0, int variable1, int variable2) {\r
+ super(variable0, variable1, variable2); \r
+ }\r
+ \r
+ @Override\r
+ public Object query(ReadGraph g, Object[] bindings) throws DatabaseException {\r
+ Resource r0 = (Resource)bindings[variable0];\r
+ Resource r1 = (Resource)bindings[variable1];\r
+ Collection<Resource> result = g.getObjects(r0, r1);\r
+ if(result.isEmpty())\r
+ return IInstruction.FAILURE;\r
+ Iterator<Resource> it = result.iterator();\r
+ bindings[variable2] = it.next();\r
+ if(it.hasNext())\r
+ return it;\r
+ else\r
+ return null;\r
+ }\r
+ \r
+ @SuppressWarnings("unchecked")\r
+ @Override\r
+ public Object next(ReadGraph g, Object[] bindings, Object continuation) {\r
+ Iterator<Resource> it = (Iterator<Resource>)continuation;\r
+ if(it.hasNext()) {\r
+ bindings[variable2] = it.next();\r
+ if(it.hasNext())\r
+ return it;\r
+ else\r
+ return null;\r
+ }\r
+ else\r
+ return IInstruction.FAILURE;\r
+ } \r
+ \r
+ @Override\r
+ public void collectVariables(TIntHashSet reads, TIntHashSet writes) { \r
+ super.collectVariables(reads, writes);\r
+ writes.add(variable2);\r
+ }\r
+\r
+}\r