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1 package org.drools.reteoo.impl; 2 3 /* 4 $Id: ExtractionNodeImpl.java,v 1.4 2002/11/22 03:08:46 bob Exp $ 5 6 Copyright 2002 (C) The Werken Company. All Rights Reserved. 7 8 Redistribution and use of this software and associated documentation 9 ("Software"), with or without modification, are permitted provided 10 that the following conditions are met: 11 12 1. Redistributions of source code must retain copyright 13 statements and notices. Redistributions must also contain a 14 copy of this document. 15 16 2. Redistributions in binary form must reproduce the 17 above copyright notice, this list of conditions and the 18 following disclaimer in the documentation and/or other 19 materials provided with the distribution. 20 21 3. The name "drools" must not be used to endorse or promote 22 products derived from this Software without prior written 23 permission of The Werken Company. For written permission, 24 please contact bob@werken.com. 25 26 4. Products derived from this Software may not be called "drools" 27 nor may "drools" appear in their names without prior written 28 permission of The Werken Company. "drools" is a registered 29 trademark of The Werken Company. 30 31 5. Due credit should be given to The Werken Company. 32 (http://drools.werken.com/). 33 34 THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS 35 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 36 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 37 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 38 THE WERKEN COMPANY OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 39 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 40 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 41 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 42 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 43 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 44 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 45 OF THE POSSIBILITY OF SUCH DAMAGE. 46 47 */ 48 49 import org.drools.WorkingMemory; 50 import org.drools.FactException; 51 import org.drools.AssertionException; 52 import org.drools.RetractionException; 53 import org.drools.reteoo.ExtractionNode; 54 import org.drools.rule.Declaration; 55 import org.drools.spi.Extractor; 56 57 import java.util.Set; 58 import java.util.HashSet; 59 import java.util.Iterator; 60 61 /*** <i> extraction</i> node in the Rete-OO network. 62 * 63 * @see ExtractionNode 64 * 65 * @author <a href="mailto:bob@eng.werken.com">bob mcwhirter</a> 66 */ 67 public class ExtractionNodeImpl extends TupleSourceImpl implements ExtractionNode, TupleSinkImpl 68 { 69 // ------------------------------------------------------------ 70 // Instance members 71 // ------------------------------------------------------------ 72 73 /*** All declarations for this node. */ 74 private Set tupleDeclarations; 75 76 /*** Declaration on LHS. */ 77 private Declaration targetDeclaration; 78 79 /*** extrator. */ 80 private Extractor extractor; 81 82 // ------------------------------------------------------------ 83 // Constructors 84 // ------------------------------------------------------------ 85 86 /*** Construct. 87 * 88 * @param tupleSource Parent tuple source. 89 * @param targetDeclaration Target of extraction. 90 * @param extractor The fact extractor to use. 91 */ 92 public ExtractionNodeImpl(TupleSourceImpl tupleSource, 93 Declaration targetDeclaration, 94 Extractor extractor) 95 { 96 this.extractor = extractor; 97 this.targetDeclaration = targetDeclaration; 98 99 Set sourceDecls = tupleSource.getTupleDeclarations(); 100 101 this.tupleDeclarations = new HashSet( sourceDecls.size() + 1 ); 102 103 this.tupleDeclarations.addAll( sourceDecls ); 104 this.tupleDeclarations.add( targetDeclaration ); 105 106 tupleSource.setTupleSink( this ); 107 } 108 109 // ------------------------------------------------------------ 110 // Instance methods 111 // ------------------------------------------------------------ 112 113 /*** Retrieve the <code>Declaration</code> which is the target of 114 * the extraction. 115 * 116 * @see Declaration 117 * 118 * @return The target <code>Declaration</code>. 119 */ 120 public Declaration getTargetDeclaration() 121 { 122 return this.targetDeclaration; 123 } 124 125 /*** Retrieve the <code>Extractor</code> used to generate the 126 * right-hand-side value for the extraction. 127 * 128 * @see Extractor 129 * 130 * @return The <code>Extrator</code>. 131 */ 132 public Extractor getExtractor() 133 { 134 return this.extractor; 135 } 136 137 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 138 // org.drools.reteoo.impl.TupleSource 139 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 140 141 /*** Retrieve the <code>Set</code> of <code>Declaration</code>s 142 * in the propagated <code>Tuples</code>. 143 * 144 * @see Declaration 145 * 146 * @return The <code>Set</code> of <code>Declarations</code> 147 * in progated <code>Tuples</code>. 148 */ 149 public Set getTupleDeclarations() 150 { 151 return this.tupleDeclarations; 152 } 153 154 /*** Assert a new <code>Tuple</code>. 155 * 156 * @param tuple The <code>Tuple</code> being asserted. 157 * @param workingMemory The working memory seesion. 158 * 159 * @throws AssertionException If an error occurs while asserting. 160 */ 161 public void assertTuple(ReteTuple tuple, 162 WorkingMemory workingMemory) throws AssertionException 163 { 164 Object value = getExtractor().extractFact( tuple ); 165 166 ReteTuple newTuple = new ReteTuple( tuple ); 167 168 newTuple.putOtherColumn( getTargetDeclaration(), 169 value ); 170 171 propagateAssertTuple( newTuple, 172 workingMemory ); 173 } 174 175 /*** Retract tuples. 176 * 177 * @param key The tuple key. 178 * @param workingMemory The working memory seesion. 179 * 180 * @throws RetractionException If an error occurs while retracting. 181 */ 182 public void retractTuples(TupleKey key, 183 WorkingMemory workingMemory) throws RetractionException 184 { 185 propagateRetractTuples( key, 186 workingMemory ); 187 } 188 189 /*** Modify tuples. 190 * 191 * @param trigger The root fact object. 192 * @param newTuples Modification replacement tuples. 193 * @param workingMemory The working memory session. 194 * 195 * @throws FactException If an error occurs while modifying. 196 */ 197 public void modifyTuples(Object trigger, 198 TupleSet newTuples, 199 WorkingMemory workingMemory) throws FactException 200 { 201 Set retractedKeys = new HashSet(); 202 203 Iterator tupleIter = newTuples.iterator(); 204 ReteTuple eachTuple = null; 205 206 while ( tupleIter.hasNext() ) 207 { 208 eachTuple = (ReteTuple) tupleIter.next(); 209 210 retractedKeys.add( eachTuple.getKey() ); 211 } 212 213 Iterator keyIter = retractedKeys.iterator(); 214 TupleKey eachKey = null; 215 216 while ( keyIter.hasNext() ) 217 { 218 eachKey = (TupleKey) keyIter.next(); 219 220 propagateRetractTuples( eachKey, 221 workingMemory ); 222 } 223 224 tupleIter = newTuples.iterator(); 225 226 while ( tupleIter.hasNext() ) 227 { 228 eachTuple = (ReteTuple) tupleIter.next(); 229 230 assertTuple( eachTuple, 231 workingMemory ); 232 } 233 } 234 235 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 236 // java.lang.Object 237 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 238 239 /*** Produce a debug string. 240 * 241 * @return The debug string. 242 */ 243 public String toString() 244 { 245 return "[ExtractionNodeImpl: target=" + getTargetDeclaration() 246 + "; extractor=" + getExtractor() + "]"; 247 } 248 }

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