001 /*
002 // $Id: //open/mondrian/src/main/mondrian/olap/ParameterImpl.java#7 $
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) 2000-2002 Kana Software, Inc.
007 // Copyright (C) 2001-2007 Julian Hyde and others
008 // All Rights Reserved.
009 // You must accept the terms of that agreement to use this software.
010 //
011 // leonardk, 10 January, 2000
012 */
013
014 package mondrian.olap;
015 import mondrian.olap.type.Type;
016 import mondrian.olap.type.NumericType;
017 import mondrian.olap.type.StringType;
018 import mondrian.olap.type.MemberType;
019 import mondrian.mdx.MemberExpr;
020 import mondrian.calc.*;
021 import mondrian.calc.impl.GenericCalc;
022
023 /**
024 * Implementation of {@link Parameter}.
025 *
026 * @author jhyde
027 * @version $Id: //open/mondrian/src/main/mondrian/olap/ParameterImpl.java#7 $
028 * @since Jul 22, 2006
029 */
030 public class ParameterImpl
031 implements Parameter, ParameterCompilable {
032
033 private final String name;
034 private String description;
035 private Exp defaultExp;
036 private Type type;
037 private ParameterSlot slot = new ParameterSlot() {
038 Object value;
039 public Object getCachedDefaultValue() {
040 throw new UnsupportedOperationException();
041 }
042
043 public Calc getDefaultValueCalc() {
044 throw new UnsupportedOperationException();
045 }
046
047 public int getIndex() {
048 throw new UnsupportedOperationException();
049 }
050
051 public Parameter getParameter() {
052 return ParameterImpl.this;
053 }
054
055 public Object getParameterValue() {
056 return value;
057 }
058
059 public void setCachedDefaultValue(Object value) {
060 throw new UnsupportedOperationException();
061 }
062
063 public void setParameterValue(Object value) {
064 this.value = value;
065 }
066
067 };
068
069 public ParameterImpl(
070 String name,
071 Exp defaultExp,
072 String description,
073 Type type)
074 {
075 this.name = name;
076 this.defaultExp = defaultExp;
077 this.description = description;
078 this.type = type;
079 assert defaultExp != null;
080 assert type instanceof StringType ||
081 type instanceof NumericType ||
082 type instanceof MemberType;
083 }
084
085 public Scope getScope() {
086 return Scope.Statement;
087 }
088
089 public Type getType() {
090 return type;
091 }
092
093 public Exp getDefaultExp() {
094 return defaultExp;
095 }
096
097 public String getName() {
098 return name;
099 }
100
101 public Object getValue() {
102 if (slot == null) {
103 // query has not been resolved yet, so it's not possible for the
104 // parameter to have a value
105 return null;
106 } else {
107 return slot.getParameterValue();
108 }
109 }
110
111 public void setValue(Object value) {
112 if (value instanceof MemberExpr) {
113 slot.setParameterValue(((MemberExpr) value).getMember());
114 } else if (value instanceof Literal) {
115 slot.setParameterValue(((Literal) value).getValue());
116 } else {
117 slot.setParameterValue(value);
118 }
119 }
120
121 public String getDescription() {
122 return description;
123 }
124
125 // For the purposes of type inference and expression substitution, a
126 // parameter is atomic; therefore, we ignore the child member, if any.
127 public Object[] getChildren() {
128 return null;
129 }
130
131 /**
132 * Returns whether this parameter is equal to another, based upon name,
133 * type and value
134 */
135 public boolean equals(Object other) {
136 if (!(other instanceof ParameterImpl)) {
137 return false;
138 }
139 ParameterImpl that = (ParameterImpl) other;
140 return that.getName().equals(this.getName()) &&
141 that.defaultExp.equals(this.defaultExp);
142 }
143
144 public int hashCode() {
145 return Util.hash(getName().hashCode(), defaultExp.hashCode());
146 }
147
148 /**
149 * Returns whether the parameter can be modified.
150 */
151 public boolean isModifiable() {
152 return true;
153 }
154
155 public void setDescription(String description) {
156 this.description = description;
157 }
158
159 public void setType(Type type) {
160 assert type instanceof StringType ||
161 type instanceof NumericType ||
162 type instanceof MemberType;
163 this.type = type;
164 }
165
166 public void setDefaultExp(Exp defaultExp) {
167 assert defaultExp != null;
168 this.defaultExp = defaultExp;
169 }
170
171 public Calc compile(ExpCompiler compiler) {
172 final ParameterSlot slot = compiler.registerParameter(this);
173 if (this.slot != null) {
174 // save previous value
175 slot.setParameterValue(this.slot.getParameterValue());
176 }
177 this.slot = slot;
178 return new ParameterCalc(slot);
179 }
180
181 /**
182 * Compiled expression which yields the value of a parameter.
183 * It uses a slot which has a unique id within the execution environment.
184 */
185 private static class ParameterCalc
186 extends GenericCalc {
187 private final ParameterSlot slot;
188
189 public ParameterCalc(ParameterSlot slot) {
190 super(new DummyExp(slot.getParameter().getType()));
191 this.slot = slot;
192 }
193
194 public Calc[] getCalcs() {
195 return new Calc[0];
196 }
197
198 public Object evaluate(Evaluator evaluator) {
199 Object value = evaluator.getParameterValue(slot);
200 if (slot.getParameterValue() == null) {
201 // save value if not set (setting the default value)
202 slot.setParameterValue(value);
203 }
204 return value;
205 }
206 }
207 }
208
209 // End ParameterImpl.java
210