Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.layer0 / src / org / simantics / db / layer0 / genericrelation / combinators / Union.java

diff --git a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/genericrelation/combinators/Union.java b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/genericrelation/combinators/Union.java
new file mode 100644 (file)
index 0000000..5ff96a1
--- /dev/null
+++ b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/genericrelation/combinators/Union.java
@@ -0,0 +1,88 @@
+/*******************************************************************************\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.db.layer0.genericrelation.combinators;\r
+\r
+import java.util.ArrayList;\r
+import java.util.Collection;\r
+import java.util.List;\r
+\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.layer0.adapter.GenericRelation;\r
+import org.simantics.db.layer0.genericrelation.AbstractRelation;\r
+import org.simantics.utils.datastructures.Pair;\r
+\r
+/**\r
+ * Takes the union of multiple relations. Does not remove duplicates.\r
+ */\r
+public class Union extends AbstractRelation {\r
+\r
+       Collection<GenericRelation> relations;\r
+       \r
+       public Union(Collection<GenericRelation> relations) {\r
+               this.relations = relations;\r
+       }\r
+\r
+       @Override\r
+       public boolean contains(ReadGraph g, Object[] tuple) throws DatabaseException {\r
+               for(GenericRelation relation : relations)\r
+                       if(relation.contains(g, tuple))\r
+                               return true;\r
+               return false;\r
+       }\r
+\r
+       @Override\r
+       public boolean isRealizable() {\r
+               for(GenericRelation relation : relations)\r
+                       if(!relation.isRealizable())\r
+                               return false;\r
+               return true;\r
+       }\r
+\r
+       @Override\r
+       public List<Object[]> realize(ReadGraph g) throws DatabaseException {\r
+               ArrayList<List<Object[]>> results = new ArrayList<List<Object[]>>(relations.size());            \r
+               for(GenericRelation relation : relations)\r
+                       results.add(relation.realize(g));\r
+               int size = 0;\r
+               for(List<Object[]> part : results)\r
+                       size += part.size();\r
+               ArrayList<Object[]> result = new ArrayList<Object[]>(size);\r
+               for(List<Object[]> part : results)\r
+                       result.addAll(part);\r
+               return result;\r
+       }\r
+       \r
+       @Override\r
+       public GenericRelation selectByRelation(String bindingPattern, GenericRelation constraint) {\r
+               ArrayList<GenericRelation> semijoinRelations = new ArrayList<GenericRelation>(relations.size()); \r
+               for(GenericRelation relation : relations)\r
+                       semijoinRelations.add(relation.selectByRelation(bindingPattern, constraint));\r
+               return new Union(semijoinRelations);\r
+       }\r
+       \r
+       @Override\r
+       public GenericRelation select(String bindingPattern, Object[] constants) {\r
+               ArrayList<GenericRelation> selectedRelations = new ArrayList<GenericRelation>(relations.size()); \r
+               for(GenericRelation relation : relations)\r
+                       selectedRelations.add(relation.select(bindingPattern, constants));\r
+               return new Union(selectedRelations);\r
+       }\r
+\r
+       @Override\r
+       public Pair<String, String>[] getFields() {\r
+               for(GenericRelation relation : relations)\r
+                       return relation.getFields();\r
+               return null;\r
+       }\r
+\r
+}\r