1 /*******************************************************************************
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2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
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3 * in Industry THTH ry.
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4 * All rights reserved. This program and the accompanying materials
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5 * are made available under the terms of the Eclipse Public License v1.0
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6 * which accompanies this distribution, and is available at
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7 * http://www.eclipse.org/legal/epl-v10.html
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10 * VTT Technical Research Centre of Finland - initial API and implementation
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11 *******************************************************************************/
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12 package org.simantics.db.layer0.genericrelation.combinators;
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14 import gnu.trove.list.array.TIntArrayList;
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16 import java.util.ArrayList;
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17 import java.util.List;
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19 import org.simantics.db.ReadGraph;
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20 import org.simantics.db.exception.DatabaseException;
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21 import org.simantics.db.layer0.adapter.GenericRelation;
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22 import org.simantics.db.layer0.genericrelation.AbstractRelation;
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23 import org.simantics.utils.datastructures.Pair;
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26 public class SelectByRelation extends AbstractRelation {
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28 GenericRelation base;
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30 String bindingPattern;
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31 int[] boundPositions;
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32 GenericRelation constraint;
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34 public SelectByRelation(GenericRelation base, String bindingPattern, GenericRelation constraint) {
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37 this.bindingPattern = bindingPattern;
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38 TIntArrayList boundPositionArray = new TIntArrayList();
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39 baseLength = bindingPattern.length();
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40 for(int i=0;i<baseLength;++i)
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41 if(bindingPattern.charAt(i) == 'b')
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42 boundPositionArray.add(i);
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43 boundPositions = boundPositionArray.toArray();
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44 this.constraint = constraint;
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47 private Object[] map(Object[] tuple) {
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48 Object[] result = new Object[boundPositions.length];
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49 for(int i=0;i<result.length;++i)
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50 result[i] = tuple[boundPositions[i]];
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55 public boolean contains(ReadGraph g, Object[] tuple) throws DatabaseException {
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56 assert tuple.length == baseLength;
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57 return base.contains(g, tuple) && constraint.contains(g, map(tuple));
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60 public Pair<String, String>[] getFields() {
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61 return base.getFields();
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64 public boolean isRealizable() {
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65 return base.isRealizable();
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68 public GenericRelation select(String bindingPattern, Object[] constants) {
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69 return new SelectByRelation(base.select(bindingPattern, constants), bindingPattern, constraint);
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72 public List<Object[]> realize(ReadGraph g) throws DatabaseException {
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73 ArrayList<Object[]> result = new ArrayList<Object[]>();
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74 for(Object[] tuple : base.realize(g))
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75 if(constraint.contains(g, map(tuple)))
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