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1
22
23 package org.xquark.extractor.algebra;
24
25 import java.util.*;
26
27 import org.xquark.extractor.common.SqlWrapperException;
28 import org.xquark.extractor.xfunctions.XFunction;
29
30
36 public final class BuildReferredAttributes extends DefaultCompleteVisitor {
37
38 private static final String  RCSRevision = "$Revision: 1.5 $";
39 private static final String RCSName = "$Name: $";
40
41
42 private Stack _returnStack = new Stack();
43
44 public BuildReferredAttributes() {
45 }
46
47 public void visit(Expression arg) throws SqlWrapperException {
48 _returnStack.push(null);
49 }
50
51 public void visit(BinaryAlgebra arg) throws SqlWrapperException {
52 Set tmpCol = new HashSet();
53
54 arg.getLeftOperand().accept(this);
55 Set popped = (Set)_returnStack.pop();
56 if ( null != popped ) {
57 tmpCol.addAll(popped);
58 }
59
60 arg.getRightOperand().accept(this);
61 popped = (Set)_returnStack.pop();
62 if ( null != popped ) {
63 tmpCol.addAll(popped);
64 }
65
66 arg.setReferredAttributes(tmpCol);
67 _returnStack.push(tmpCol);
68 }
69
70 public void visit(Join arg) throws SqlWrapperException {
71 Set retVal = new HashSet();
72 Set tmpSet = null;
73 List list = arg.getOperandList();
74 Expression expr = null;
75 if (null != list) {
76 for (int i = 0; i < list.size(); i++) {
77 expr = (Expression)list.get(i);
78 expr.accept(this);
79 tmpSet = (Set)_returnStack.pop();
80 if (null != tmpSet) {
81 retVal.addAll(tmpSet);
82 }
83 }
84 }
85
86 list = arg.getPredicateList();
87 if (null != list) {
88 for (int i = 0; i < list.size(); i++) {
89 expr = (Expression)list.get(i);
90 expr.accept(this);
91 tmpSet = (Set)_returnStack.pop();
92 if (null != tmpSet) {
93 retVal.addAll(tmpSet);
94 }
95 }
96 }
97
98 List localAttributeList = new ArrayList();
99 Set localTableInstance = ((Relation)arg).visibleTableInstances();
100 AttributeExpression attr = null;
101 for (Iterator i = retVal.iterator(); i.hasNext(); ) {
102 attr = (AttributeExpression)i.next();
103 if (localTableInstance.contains(attr.getTableInstance())) {
104 localAttributeList.add(attr);
105 }
106 }
107
108 retVal.removeAll(localAttributeList);
109
110 if (retVal.isEmpty()) {
111 retVal = null;
112 }
113
114 _returnStack.push(retVal);
115 }
116
117
118 public void visit(BinOpOuterJoin arg) throws SqlWrapperException {
119 Set retVal = new HashSet();
120 Set tmpSet = null;
121
122 arg.getLeftOperand().accept(this);
123 tmpSet = (Set)_returnStack.pop();
124 if (null != tmpSet) {
125 retVal.addAll(tmpSet);
126 }
127
128 arg.getRightOperand().accept(this);
129 tmpSet = (Set)_returnStack.pop();
130 if (null != tmpSet) {
131 retVal.addAll(tmpSet);
132 }
133
134
135 List list = arg.getPredicateList();
136 Expression expr = null;
137 if (null != list) {
138 for (int i = 0; i < list.size(); i++) {
139 expr = (Expression)list.get(i);
140 expr.accept(this);
141 tmpSet = (Set) _returnStack.pop();
142 if (null != tmpSet) {
143 retVal.addAll(tmpSet);
144 }
145 }
146 }
147
148 List localAttributeList = new ArrayList();
149 Set localTableInstance = ((Relation)arg).visibleTableInstances();
150 AttributeExpression attr = null;
151 for (Iterator i = retVal.iterator(); i.hasNext(); ) {
152 attr = (AttributeExpression)i.next();
153 if (localTableInstance.contains(attr.getTableInstance())) {
154 localAttributeList.add(attr);
155 }
156 }
157
158 retVal.removeAll(localAttributeList);
159
160 if (retVal.isEmpty()) {
161 retVal = null;
162 }
163
164 _returnStack.push(retVal);
165 }
166
167 public void visit(UnaryAlgebra arg) throws SqlWrapperException {
168 arg.getOperand().accept(this);
169 Set retVal = (Set)_returnStack.pop();
170
171 if (null == retVal) {
172 retVal = new HashSet();
173 }
174
175 List list = arg.getParameterList();
176 Expression expr = null;
177 if (null != list) {
178 for (int i = 0; i < list.size(); i++) {
179 expr = (Expression)list.get(i);
180 expr.accept(this);
181 Set tmpSet = (Set) _returnStack.pop();
182 if (null != tmpSet) {
183 retVal.addAll(tmpSet);
184 }
185 }
186 }
187
188 List localAttributeList = new ArrayList();
189 Set localTableInstance = ((Relation)arg).visibleTableInstances();
190 AttributeExpression attr = null;
191 for (Iterator i = retVal.iterator(); i.hasNext(); ) {
192 attr = (AttributeExpression)i.next();
193 if (localTableInstance.contains(attr.getTableInstance()) ||
194 attr.getTableInstance() == null ) {
195 localAttributeList.add(attr);
196 }
197 }
198
199 retVal.removeAll(localAttributeList);
200
201 _returnStack.push(retVal);
202 }
203
204 public void visit(AttributeExpression arg) throws SqlWrapperException {
205 Set tmpCol = new HashSet();
206 tmpCol.add(arg);
207 arg.setReferredAttributes(tmpCol);
208
209 _returnStack.push(tmpCol);
210 }
211
212 public void visit(BinaryAtomicOp arg) throws SqlWrapperException {
213 Set tmpCol = new HashSet();
214
215 arg.getLeftOperand().accept(this);
216 Set popped = (Set)_returnStack.pop();
217 if ( null != popped ) {
218 tmpCol.addAll(popped);
219 }
220
221 arg.getRightOperand().accept(this);
222 popped = (Set)_returnStack.pop();
223 if ( null != popped ) {
224 tmpCol.addAll(popped);
225 }
226
227 arg.setReferredAttributes(tmpCol);
228 _returnStack.push(tmpCol);
229 }
230
231 public void visit(OuterJoinPredicate arg) throws SqlWrapperException {
232 arg.getPredicate().accept(this);
233
234 Set tmpCol = (Set)_returnStack.peek();
235 arg.setReferredAttributes(tmpCol);
236 }
237
238 public void visit(UnaryAtomicOp arg) throws SqlWrapperException {
239 arg.getOperand().accept(this);
240
241 Set tmpCol = (Set)_returnStack.peek();
242 arg.setReferredAttributes(tmpCol);
243 }
244
245 public void visit(XFunction arg) throws SqlWrapperException
246 {
247 Set retVal = null;
248 List argList = arg.getArguments();
249 if (null != argList){
250 retVal= new HashSet();
251 Object aArg = null;
252 for (int i = 0; i < argList.size(); i++) {
253
254 aArg = argList.get(i);
255 if (aArg instanceof Expression) {
256 ((Expression)aArg).accept(this);
257 Set popped = (Set)_returnStack.pop();
258 if ( null != popped ) {
259 retVal.addAll(popped);
260 }
261 }
262 }
263 if (retVal.isEmpty()) {
264 retVal = null;
265 }
266 }
267
268 arg.setReferredAttributes(retVal);
269 _returnStack.push(retVal);
270 }
271 }
272 |
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