001 /*
002 // $Id: //open/mondrian/src/main/mondrian/olap/fun/LastPeriodsFunDef.java#5 $
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) 2006-2008 Julian Hyde
007 // All Rights Reserved.
008 // You must accept the terms of that agreement to use this software.
009 */
010 package mondrian.olap.fun;
011
012 import mondrian.olap.*;
013 import mondrian.olap.type.Type;
014 import mondrian.olap.type.SetType;
015 import mondrian.olap.type.MemberType;
016 import mondrian.olap.type.TypeUtil;
017 import mondrian.resource.MondrianResource;
018 import mondrian.calc.Calc;
019 import mondrian.calc.ExpCompiler;
020 import mondrian.calc.MemberCalc;
021 import mondrian.calc.IntegerCalc;
022 import mondrian.calc.impl.DimensionCurrentMemberCalc;
023 import mondrian.calc.impl.AbstractListCalc;
024 import mondrian.mdx.ResolvedFunCall;
025
026 import java.util.List;
027 import java.util.Collections;
028 import java.util.ArrayList;
029
030 /**
031 * Definition of the <code>LastPeriods</code> MDX function.
032 *
033 * @author jhyde
034 * @version $Id: //open/mondrian/src/main/mondrian/olap/fun/LastPeriodsFunDef.java#5 $
035 * @since Mar 23, 2006
036 */
037 class LastPeriodsFunDef extends FunDefBase {
038 static final ReflectiveMultiResolver Resolver = new ReflectiveMultiResolver(
039 "LastPeriods",
040 "LastPeriods(<Index> [, <Member>])",
041 "Returns a set of members prior to and including a specified member.",
042 new String[] {"fxn", "fxnm"},
043 LastPeriodsFunDef.class);
044
045 public LastPeriodsFunDef(FunDef dummyFunDef) {
046 super(dummyFunDef);
047 }
048
049 public Type getResultType(Validator validator, Exp[] args) {
050 if (args.length == 1) {
051 // If Member is not specified,
052 // it is Time.CurrentMember.
053 Dimension defaultTimeDimension =
054 validator.getQuery().getCube().getTimeDimension();
055 if (defaultTimeDimension == null) {
056 throw MondrianResource.instance().
057 NoTimeDimensionInCube.ex(getName());
058 }
059 Hierarchy hierarchy = defaultTimeDimension.getHierarchy();
060 return new SetType(MemberType.forHierarchy(hierarchy));
061 } else {
062 Type type = args[1].getType();
063 Type memberType =
064 TypeUtil.toMemberOrTupleType(type);
065 return new SetType(memberType);
066 }
067 }
068
069 public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
070 // Member defaults to [Time].currentmember
071 Exp[] args = call.getArgs();
072 final MemberCalc memberCalc;
073 if (args.length == 1) {
074 Dimension timeDimension =
075 compiler.getEvaluator().getCube()
076 .getTimeDimension();
077 if (timeDimension == null) {
078 throw MondrianResource.instance().
079 NoTimeDimensionInCube.ex(getName());
080 }
081 memberCalc = new DimensionCurrentMemberCalc(
082 timeDimension);
083 } else {
084 memberCalc = compiler.compileMember(args[1]);
085 }
086
087 // Numeric Expression.
088 final IntegerCalc indexValueCalc =
089 compiler.compileInteger(args[0]);
090
091 return new AbstractListCalc(call, new Calc[] {memberCalc, indexValueCalc}) {
092 public List evaluateList(Evaluator evaluator) {
093 Member member = memberCalc.evaluateMember(evaluator);
094 int indexValue = indexValueCalc.evaluateInteger(evaluator);
095
096 return lastPeriods(member, evaluator, indexValue);
097 }
098 };
099 }
100
101 /*
102 If Index is positive, returns the set of Index
103 members ending with Member and starting with the
104 member lagging Index - 1 from Member.
105
106 If Index is negative, returns the set of (- Index)
107 members starting with Member and ending with the
108 member leading (- Index - 1) from Member.
109
110 If Index is zero, the empty set is returned.
111 */
112 List<Member> lastPeriods(
113 Member member,
114 Evaluator evaluator,
115 int indexValue) {
116 // empty set
117 if ((indexValue == 0) || member.isNull()) {
118 return Collections.emptyList();
119 }
120 List<Member> list = new ArrayList<Member>();
121
122 // set with just member
123 if ((indexValue == 1) || (indexValue == -1)) {
124 list.add(member);
125 return list;
126 }
127
128 // When null is found, getting the first/last
129 // member at a given level is not particularly
130 // fast.
131 Member startMember;
132 Member endMember;
133 if (indexValue > 0) {
134 startMember = evaluator.getSchemaReader()
135 .getLeadMember(member, - (indexValue - 1));
136 endMember = member;
137 if (startMember.isNull()) {
138 List<Member> members = evaluator.getSchemaReader()
139 .getLevelMembers(member.getLevel(), false);
140 startMember = members.get(0);
141 }
142 } else {
143 startMember = member;
144 endMember = evaluator.getSchemaReader()
145 .getLeadMember(member, -(indexValue + 1));
146 if (endMember.isNull()) {
147 List<Member> members = evaluator.getSchemaReader()
148 .getLevelMembers(member.getLevel(), false);
149 endMember = members.get(members.size() - 1);
150 }
151 }
152
153 evaluator.getSchemaReader().
154 getMemberRange(member.getLevel(),
155 startMember,
156 endMember,
157 list);
158 return list;
159 }
160 }
161
162 // End LastPeriodsFunDef.java