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1
23
24 package org.objectweb.medor.eval.lib;
25
26 import org.objectweb.medor.api.MedorException;
27 import org.objectweb.medor.api.TupleStructure;
28 import org.objectweb.medor.eval.api.BinaryEvaluatedTC;
29 import org.objectweb.medor.eval.api.NodeEvaluator;
30 import org.objectweb.medor.eval.prefetch.api.PrefetchBuffer;
31 import org.objectweb.medor.eval.prefetch.api.PrefetchBufferHolder;
32 import org.objectweb.medor.expression.api.ParameterOperand;
33 import org.objectweb.medor.expression.api.VariableOperand;
34 import org.objectweb.medor.expression.api.ExpressionException;
35 import org.objectweb.medor.expression.lib.BasicVariableOperand;
36 import org.objectweb.medor.query.api.QueryNode;
37 import org.objectweb.medor.tuple.api.Tuple;
38 import org.objectweb.medor.tuple.api.TupleCollection;
39 import org.objectweb.medor.tuple.lib.MemoryTuple;
40 import org.objectweb.util.monolog.api.BasicLevel;
41
42
43
47 public class ProjectEvaluatedTC
48 extends BasicBinaryEvalutedTC
49 implements BinaryEvaluatedTC, PrefetchBufferHolder {
50
51 private QueryNode query;
52 private TupleCollection subResultTC;
53 private ParameterOperand[] parameters;
54 private Tuple currentBuffer;
55 private VariableOperand[] currentAttBuffers;
56 private int cursor,size;
57 private boolean empty;
58 private boolean userHasClosed = false;
60 private PrefetchBuffer prefetchBuffer;
61
62 public ProjectEvaluatedTC(QueryNode query,
63 NodeEvaluator subNodeEvaluator,
64 ParameterOperand[] parameters,
65 PrefetchBuffer pb) throws MedorException {
66 super();
67 this.parameters = parameters;
68 this.query = query;
69 this.prefetchBuffer = pb;
70 if (prefetchBuffer != null) {
71 pb.setTupleCollection(this);
72 }
73 size = query.getTupleStructure().getSize();
75 currentAttBuffers = new BasicVariableOperand[size];
76 for (int cpt = 0; (cpt < query.getTupleStructure().getSize()); cpt++) {
77 currentAttBuffers[cpt] = new BasicVariableOperand(
78 query.getTupleStructure().getField(cpt + 1).getType());
79 }
80 currentBuffer = new MemoryTuple(currentAttBuffers);
82 subResultTC = subNodeEvaluator.fetchData(parameters);
83 empty = (subResultTC.isEmpty());
84 if (empty) {
85 cursor = 0;
86 } else {
87 init();
88 }
89 }
90
91 public void invalidatePrefetchBuffer() throws MedorException {
92 if (debug) {
93 log.log(BasicLevel.DEBUG, "Invalidating PrefetchBuffer " + prefetchBuffer + " for " + this);
94 }
95 prefetchBuffer = null;
96 if (userHasClosed) {
97 if (debug) {
98 log.log(BasicLevel.DEBUG, "The tupleCollection was closed earlier: closing it for real");
99 }
100 this.close();
101 }
102 }
103
104 public void close() throws MedorException {
105 if (debug) {
106 log.log(BasicLevel.DEBUG, "Closing TupleCollection " + this);
107 }
108 userHasClosed = true;
109 if (prefetchBuffer == null || prefetchBuffer.isClosed()) {
111 if (debug) {
112 log.log(BasicLevel.DEBUG, "PrefetchBuffer " + prefetchBuffer + " is null or was closed previously: real close of the TupleCollection");
113 }
114 prefetchBuffer = null;
115 super.close();
116 if (subResultTC != null) {
117 subResultTC.close();
118 }
119 }
120 }
121
122 public TupleStructure getMetaData() throws MedorException {
123 return query.getTupleStructure();
124 }
125
126 public boolean isLast() throws MedorException {
127 return subResultTC.isLast();
128 }
129
130 public int card() throws MedorException {
131 return cursor;
132 }
133
134 public boolean next() throws MedorException {
135 boolean moved;
136 if (subResultTC.isLast()) {
137 cursor = -2;
139 moved = false;
140 } else {
141 cursor++;
142 subResultTC.next();
143 getNextResult();
145 if (prefetchBuffer != null) {
146 prefetchBuffer.addPrefetchTuple();
147 }
148 moved = true;
149 }
150 return moved;
151 }
152
153 private void init() throws MedorException {
154 subResultTC.first();
155 getNextResult();
156 cursor = 1;
157 if (prefetchBuffer != null) {
158 prefetchBuffer.addPrefetchTuple();
159 }
160 }
161
162 public void first() throws MedorException {
163 init();
165 }
166
167 public int getRow() throws MedorException {
168 return cursor;
169 }
170
171 public Tuple getTuple() throws MedorException {
172 if (!isEmpty() && (getRow() >= 1))
173 return currentBuffer;
174 else
175 throw new MedorException(" No elements fetched in this TupleCollection " + getRow());
176 }
177
178 public synchronized Tuple getTuple(int numTuple) throws MedorException {
179 row(numTuple);
180 return getTuple();
181 }
182
183 public boolean isEmpty() throws MedorException {
184 return (subResultTC.isEmpty());
185 }
186
187 public boolean row(int numTuple) throws MedorException {
188 boolean go = subResultTC.row(numTuple);
189 if (!go) {
190 return false;
191 } else {
192 getNextResult();
193 cursor = numTuple;
194 return true;
195 }
196 }
197
198 public int getLeftTCCursor() throws MedorException {
199 return subResultTC.getRow();
200 }
201
202 public int getRightTCCursor() throws MedorException {
203 return -1;
204 }
205
206 private void getNextResult() throws MedorException {
207 try {
208 query.getTupleLoader().loadTuple(
209 subResultTC.getTuple(), currentAttBuffers, parameters);
210 }
211 catch (ExpressionException e) {
212 throw new MedorException(e);
213 }
214 }
215 }
216 |
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