1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
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
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.db.layer0.genericrelation.combinators;
14 import gnu.trove.list.array.TIntArrayList;
16 import java.util.ArrayList;
17 import java.util.List;
19 import org.simantics.db.ReadGraph;
20 import org.simantics.db.exception.DatabaseException;
21 import org.simantics.db.layer0.adapter.GenericRelation;
22 import org.simantics.db.layer0.genericrelation.AbstractRelation;
23 import org.simantics.utils.datastructures.Pair;
26 public class SelectByRelation extends AbstractRelation {
30 String bindingPattern;
32 GenericRelation constraint;
34 public SelectByRelation(GenericRelation base, String bindingPattern, GenericRelation constraint) {
37 this.bindingPattern = bindingPattern;
38 TIntArrayList boundPositionArray = new TIntArrayList();
39 baseLength = bindingPattern.length();
40 for(int i=0;i<baseLength;++i)
41 if(bindingPattern.charAt(i) == 'b')
42 boundPositionArray.add(i);
43 boundPositions = boundPositionArray.toArray();
44 this.constraint = constraint;
47 private Object[] map(Object[] tuple) {
48 Object[] result = new Object[boundPositions.length];
49 for(int i=0;i<result.length;++i)
50 result[i] = tuple[boundPositions[i]];
55 public boolean contains(ReadGraph g, Object[] tuple) throws DatabaseException {
56 assert tuple.length == baseLength;
57 return base.contains(g, tuple) && constraint.contains(g, map(tuple));
60 public Pair<String, String>[] getFields() {
61 return base.getFields();
64 public boolean isRealizable() {
65 return base.isRealizable();
68 public GenericRelation select(String bindingPattern, Object[] constants) {
69 return new SelectByRelation(base.select(bindingPattern, constants), bindingPattern, constraint);
72 public List<Object[]> realize(ReadGraph g) throws DatabaseException {
73 ArrayList<Object[]> result = new ArrayList<Object[]>();
74 for(Object[] tuple : base.realize(g))
75 if(constraint.contains(g, map(tuple)))