001 /*
002 // $Id: //open/mondrian/src/main/mondrian/rolap/agg/MinusStarPredicate.java#3 $
003 // This software is subject to the terms of the Common Public License
004 // Agreement, available at the following URL:
005 // http://www.opensource.org/licenses/cpl.html.
006 // Copyright (C) 2006-2007 Julian Hyde
007 // All Rights Reserved.
008 // You must accept the terms of that agreement to use this software.
009 */
010 package mondrian.rolap.agg;
011
012 import mondrian.rolap.StarPredicate;
013 import mondrian.rolap.StarColumnPredicate;
014 import mondrian.rolap.RolapStar;
015
016 import java.util.*;
017
018 /**
019 * A <code>StarPredicate</code> which evaluates to true if its
020 * first child evaluates to true and its second child evaluates to false.
021 *
022 * @author jhyde
023 * @version $Id: //open/mondrian/src/main/mondrian/rolap/agg/MinusStarPredicate.java#3 $
024 * @since Nov 6, 2006
025 */
026 public class MinusStarPredicate extends AbstractColumnPredicate {
027 private final StarColumnPredicate plus;
028 private final StarColumnPredicate minus;
029
030 /**
031 * Creates a MinusStarPredicate.
032 *
033 * @param plus Positive predicate
034 * @param minus Negative predicate
035 * @pre plus != null
036 * @pre minus != null
037 */
038 public MinusStarPredicate(
039 StarColumnPredicate plus,
040 StarColumnPredicate minus)
041 {
042 super(plus.getConstrainedColumn());
043 assert minus != null;
044 this.plus = plus;
045 this.minus = minus;
046 }
047
048
049 public boolean equals(Object obj) {
050 if (obj instanceof MinusStarPredicate) {
051 MinusStarPredicate that = (MinusStarPredicate) obj;
052 return this.plus.equals(that.plus) &&
053 this.minus.equals(that.minus);
054 } else {
055 return false;
056 }
057 }
058
059 public int hashCode() {
060 return plus.hashCode() * 31 +
061 minus.hashCode();
062 }
063
064 public RolapStar.Column getConstrainedColumn() {
065 return plus.getConstrainedColumn();
066 }
067
068 public void values(Collection<Object> collection) {
069 Set<Object> plusValues = new HashSet<Object>();
070 plus.values(plusValues);
071 List<Object> minusValues = new ArrayList<Object>();
072 minus.values(minusValues);
073 plusValues.removeAll(minusValues);
074 collection.addAll(plusValues);
075 }
076
077 public boolean evaluate(Object value) {
078 return plus.evaluate(value) &&
079 !minus.evaluate(value);
080 }
081
082 public void describe(StringBuilder buf) {
083 buf.append("(").append(plus).append(" - ").append(minus).append(")");
084 }
085
086 public Overlap intersect(StarColumnPredicate predicate) {
087 throw new UnsupportedOperationException();
088 }
089
090 public boolean mightIntersect(StarPredicate other) {
091 // Approximately, this constraint might intersect if it intersects
092 // with the 'plus' side. It's possible that the 'minus' side might
093 // wipe out all of those intersections, but we don't consider that.
094 return plus.mightIntersect(other);
095 }
096
097 public StarColumnPredicate minus(StarPredicate predicate) {
098 assert predicate != null;
099 if (predicate instanceof ValueColumnPredicate) {
100 ValueColumnPredicate valuePredicate =
101 (ValueColumnPredicate) predicate;
102 if (!evaluate(valuePredicate.getValue())) {
103 // Case 3: 'minus' is a list, 'constraint' is a value
104 // which is not matched by this
105 return this;
106 }
107 }
108 if (minus instanceof ListColumnPredicate) {
109 ListColumnPredicate minusList = (ListColumnPredicate) minus;
110 RolapStar.Column column = plus.getConstrainedColumn();
111 if (predicate instanceof ListColumnPredicate) {
112 // Case 1: 'minus' and 'constraint' are both lists.
113 ListColumnPredicate list =
114 (ListColumnPredicate) predicate;
115 List<StarColumnPredicate> unionList =
116 new ArrayList<StarColumnPredicate>();
117 unionList.addAll(minusList.getPredicates());
118 unionList.addAll(list.getPredicates());
119 return new MinusStarPredicate(
120 plus,
121 new ListColumnPredicate(
122 column,
123 unionList));
124 }
125 if (predicate instanceof ValueColumnPredicate) {
126 ValueColumnPredicate valuePredicate =
127 (ValueColumnPredicate) predicate;
128 if (!evaluate(valuePredicate.getValue())) {
129 // Case 3: 'minus' is a list, 'constraint' is a value
130 // which is not matched by this
131 return this;
132 }
133 // Case 2: 'minus' is a list, 'constraint' is a value.
134 List<StarColumnPredicate> unionList =
135 new ArrayList<StarColumnPredicate>();
136 unionList.addAll(minusList.getPredicates());
137 unionList.add(
138 new ValueColumnPredicate(column, valuePredicate.getValue()));
139 return new MinusStarPredicate(
140 plus,
141 new ListColumnPredicate(column, unionList));
142 }
143 }
144 return new MinusStarPredicate(
145 this,
146 (StarColumnPredicate) predicate);
147 }
148
149 public StarColumnPredicate cloneWithColumn(RolapStar.Column column) {
150 return new MinusStarPredicate(
151 plus.cloneWithColumn(column),
152 minus.cloneWithColumn(column));
153 }
154 }
155
156 // End MinusStarPredicate.java