001 /*
002 // $Id: //open/mondrian/src/main/mondrian/olap/fun/TopBottomCountFunDef.java#10 $
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) 2002-2002 Kana Software, Inc.
007 // Copyright (C) 2002-2008 Julian Hyde and others
008 // All Rights Reserved.
009 // You must accept the terms of that agreement to use this software.
010 */
011 package mondrian.olap.fun;
012
013 import mondrian.calc.*;
014 import mondrian.calc.impl.AbstractListCalc;
015 import mondrian.calc.ResultStyle;
016 import mondrian.mdx.ResolvedFunCall;
017 import mondrian.olap.*;
018 import mondrian.olap.type.TupleType;
019
020 import java.util.*;
021
022 /**
023 * Definition of the <code>TopCount</code> and <code>BottomCount</code>
024 * MDX builtin functions.
025 *
026 * @author jhyde
027 * @version $Id: //open/mondrian/src/main/mondrian/olap/fun/TopBottomCountFunDef.java#10 $
028 * @since Mar 23, 2006
029 */
030 class TopBottomCountFunDef extends FunDefBase {
031 boolean top;
032
033 static final MultiResolver TopCountResolver =
034 new MultiResolver(
035 "TopCount",
036 "TopCount(<Set>, <Count>[, <Numeric Expression>])",
037 "Returns a specified number of items from the top of a set, optionally ordering the set first.",
038 new String[]{"fxxnn", "fxxn"})
039 {
040 protected FunDef createFunDef(Exp[] args, FunDef dummyFunDef) {
041 return new TopBottomCountFunDef(dummyFunDef, true);
042 }
043 };
044
045 static final MultiResolver BottomCountResolver =
046 new MultiResolver(
047 "BottomCount",
048 "BottomCount(<Set>, <Count>[, <Numeric Expression>])",
049 "Returns a specified number of items from the bottom of a set, optionally ordering the set first.",
050 new String[]{"fxxnn", "fxxn"})
051 {
052 protected FunDef createFunDef(Exp[] args, FunDef dummyFunDef) {
053 return new TopBottomCountFunDef(dummyFunDef, false);
054 }
055 };
056
057 public TopBottomCountFunDef(FunDef dummyFunDef, final boolean top) {
058 super(dummyFunDef);
059 this.top = top;
060 }
061
062 public Calc compileCall(final ResolvedFunCall call, ExpCompiler compiler) {
063 // Compile the member list expression. Ask for a mutable list, because
064 // we're going to sortMembers it later.
065 final ListCalc listCalc =
066 compiler.compileList(call.getArg(0), true);
067 final IntegerCalc integerCalc =
068 compiler.compileInteger(call.getArg(1));
069 final Calc orderCalc =
070 call.getArgCount() > 2 ?
071 compiler.compileScalar(call.getArg(2), true) :
072 null;
073 final int arity = call.getType() instanceof TupleType ?
074 ((TupleType) call.getType()).elementTypes.length :
075 1;
076 return new AbstractListCalc(call, new Calc[] {listCalc, integerCalc, orderCalc}) {
077 public List evaluateList(Evaluator evaluator) {
078 // Use a native evaluator, if more efficient.
079 // TODO: Figure this out at compile time.
080 SchemaReader schemaReader = evaluator.getSchemaReader();
081 NativeEvaluator nativeEvaluator =
082 schemaReader.getNativeSetEvaluator(
083 call.getFunDef(), call.getArgs(), evaluator, this);
084 if (nativeEvaluator != null) {
085 return (List) nativeEvaluator.execute(ResultStyle.LIST);
086 }
087
088 List list = listCalc.evaluateList(evaluator);
089 int n = integerCalc.evaluateInteger(evaluator);
090
091 if (n == mondrian.olap.fun.FunUtil.IntegerNull) {
092 return new java.util.ArrayList();
093 }
094
095 if (orderCalc != null) {
096 if (list.isEmpty()) {
097 return list;
098 }
099 final Object trial = list.get(0);
100 boolean highCard = false;
101 if (trial instanceof Member) {
102 if (((Member) trial).getHierarchy().getDimension()
103 .isHighCardinality()) {
104 highCard = true;
105 }
106 } else {
107 final Member[] trials = (Member[]) trial;
108 for (int i = 0; i < trials.length; i++) {
109 if (trials[i].getHierarchy().getDimension()
110 .isHighCardinality()) {
111 break;
112 }
113 }
114 }
115
116 if (highCard) {
117 final List l2 = new ArrayList();
118 final Iterator iterator = list.iterator();
119 for (int i = 0; i < n + 1 && iterator.hasNext(); i++) {
120 final Object o = iterator.next();
121 l2.add(o);
122 }
123 final Evaluator eval = evaluator.push();
124 if (arity == 1) {
125 for (;;) {
126 sortMembers(
127 eval,
128 (List<Member>) l2,
129 orderCalc, top, true);
130 l2.remove(l2.size() - 1);
131 if (!iterator.hasNext()) {
132 break;
133 }
134 l2.add(iterator.next());
135 }
136 return l2;
137 } else {
138 for (;;) {
139 sortTuples(
140 eval,
141 (List<mondrian.olap.Member[]>) l2,
142 orderCalc, top, true, arity);
143 l2.remove(l2.size() - 1);
144 if (!iterator.hasNext()) {
145 break;
146 }
147 l2.add(iterator.next());
148 }
149 return l2;
150 }
151 } else {
152 if (arity == 1) {
153 sortMembers(
154 evaluator.push(),
155 (List<Member>) list,
156 orderCalc, top, true);
157 } else {
158 sortTuples(
159 evaluator.push(),
160 (List<mondrian.olap.Member[]>) list,
161 orderCalc, top, true, arity);
162 }
163 if (n < list.size()) {
164 list = list.subList(0, n);
165 }
166 return list;
167 }
168 } else {
169 if (list instanceof AbstractList && list.size() < n) {
170 return list;
171 } else {
172 return list.subList(0, n);
173 }
174 }
175 }
176
177 public boolean dependsOn(Dimension dimension) {
178 return anyDependsButFirst(getCalcs(), dimension);
179 }
180 };
181 }
182 }
183
184 // End TopBottomCountFunDef.java