Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.mapping / src / org / simantics / mapping / constraint / instructions / TripletObjectQuery.java

diff --git a/bundles/org.simantics.mapping/src/org/simantics/mapping/constraint/instructions/TripletObjectQuery.java b/bundles/org.simantics.mapping/src/org/simantics/mapping/constraint/instructions/TripletObjectQuery.java
new file mode 100644 (file)
index 0000000..51fb9b1
--- /dev/null
+++ b/bundles/org.simantics.mapping/src/org/simantics/mapping/constraint/instructions/TripletObjectQuery.java
@@ -0,0 +1,65 @@
+/*******************************************************************************\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