1 package org.drools.reteoo.impl;
2
3 /*
4 $Id: ReteImpl.java,v 1.2 2002/08/13 04:12:26 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.Rete;
54 import org.drools.reteoo.ObjectTypeNode;
55 import org.drools.spi.ObjectType;
56
57 import java.util.Map;
58 import java.util.HashMap;
59 import java.util.Collection;
60 import java.util.Collections;
61 import java.util.Iterator;
62
63 /*** The Rete-OO network.
64 *
65 * This node accepts an <code>Object</code>, and simply
66 * propagates it to all <code>ObjectTypeNode</code>s for
67 * type testings.
68 *
69 * @see ObjectTypeNodeImpl
70 *
71 * @author <a href="mailto:bob@eng.werken.com">bob mcwhirter</a>
72 */
73 public class ReteImpl implements Rete
74 {
75 // ------------------------------------------------------------
76 // Instance members
77 // ------------------------------------------------------------
78
79 /*** The set of <code>ObjectTypeNodes</code>. */
80 private Map objectTypeNodes;
81
82 // ------------------------------------------------------------
83 // Constructors
84 // ------------------------------------------------------------
85
86 /*** Construct.
87 */
88 public ReteImpl()
89 {
90 this.objectTypeNodes = Collections.EMPTY_MAP;
91 }
92
93 // ------------------------------------------------------------
94 // Instance methods
95 // ------------------------------------------------------------
96
97 /*** Assert a new fact object into this <code>RuleBase</code>
98 * and the specified <code>WorkingMemory</code>.
99 *
100 * @param object The object to assert.
101 * @param workingMemory The working memory session.
102 *
103 * @throws AssertionException if an error occurs during assertion.
104 */
105 public void assertObject(Object object,
106 WorkingMemory workingMemory) throws AssertionException
107 {
108 Iterator nodeIter = getObjectTypeNodeIterator();
109 ObjectTypeNodeImpl eachNode = null;
110
111 while ( nodeIter.hasNext() )
112 {
113 eachNode = (ObjectTypeNodeImpl) nodeIter.next();
114
115 eachNode.assertObject( object,
116 workingMemory );
117 }
118 }
119
120 /*** Retract a fact object from this <code>RuleBase</code>
121 * and the specified <code>WorkingMemory</code>.
122 *
123 * @param object The object to retract.
124 * @param workingMemory The working memory session.
125 *
126 * @throws RetractionException if an error occurs during retraction.
127 */
128 public void retractObject(Object object,
129 WorkingMemory workingMemory) throws RetractionException
130 {
131 Iterator nodeIter = getObjectTypeNodeIterator();
132 ObjectTypeNodeImpl eachNode = null;
133
134 while ( nodeIter.hasNext() )
135 {
136 eachNode = (ObjectTypeNodeImpl) nodeIter.next();
137
138 eachNode.retractObject( object,
139 workingMemory );
140 }
141 }
142
143 /*** Modify a fact object in this <code>RuleBase</code>
144 * and the specified <code>WorkingMemory</code>.
145 *
146 * With the exception of time-based nodes, modification of
147 * a fact object is semantically equivelent to retracting and
148 * re-asserting it.
149 *
150 * @param object The object to modify.
151 * @param workingMemory The working memory session.
152 *
153 * @throws FactException if an error occurs during modification.
154 */
155 public void modifyObject(Object object,
156 WorkingMemory workingMemory) throws FactException
157 {
158 Iterator nodeIter = getObjectTypeNodeIterator();
159 ObjectTypeNodeImpl eachNode = null;
160
161 while ( nodeIter.hasNext() )
162 {
163 eachNode = (ObjectTypeNodeImpl) nodeIter.next();
164
165 eachNode.modifyObject( object,
166 workingMemory );
167 }
168 }
169
170 /*** Add an <code>ObjectTypeNode</code> child to
171 * this <code>Rete</code>.
172 *
173 * @param node The node to add.
174 */
175 void addObjectTypeNode(ObjectTypeNode node)
176 {
177 if ( this.objectTypeNodes == Collections.EMPTY_MAP )
178 {
179 this.objectTypeNodes = new HashMap();
180 }
181
182 this.objectTypeNodes.put( node.getObjectType(),
183 node );
184 }
185
186 /*** Retrieve all <code>ObjectTypeNode</code> children
187 * of this node.
188 *
189 * @return The <code>Set</code> of <code>ObjectTypeNodes</code>.
190 */
191 public Collection getObjectTypeNodes()
192 {
193 return this.objectTypeNodes.values();
194 }
195
196 /*** Retrieve an <code>Iterator</code> over the
197 * <code>ObjectTypeNode</code> children of this
198 * node.
199 *
200 * @return An <code>Iterator</code> over <code>ObjectTypeNodes</code>.
201 */
202 Iterator getObjectTypeNodeIterator()
203 {
204 return this.objectTypeNodes.values().iterator();
205 }
206
207 /*** Retrieve an <code>ObjectTypeNode</code> keyed by <code>ObjectType</code>.
208 *
209 * @param objectType The <code>ObjectType</code> key.
210 *
211 * @return The matching <code>ObjectTypeNode</code> if one has already
212 * been created, else <code>null</code>.
213 */
214 public ObjectTypeNode getObjectTypeNode(ObjectType objectType)
215 {
216 return (ObjectTypeNode) this.objectTypeNodes.get( objectType );
217 }
218
219 /*** Retrieve an <code>ObjectTypeNode</code> keyed by <code>ObjectType</code>,
220 * creating one, if necessary.
221 *
222 * @param objectType The <code>ObjectType</code> key.
223 *
224 * @return The matching <code>ObjectTypeNode</code>.
225 */
226 public ObjectTypeNodeImpl getOrCreateObjectTypeNode(ObjectType objectType)
227 {
228 ObjectTypeNodeImpl node = (ObjectTypeNodeImpl) getObjectTypeNode( objectType );
229
230 if ( node == null )
231 {
232 node = new ObjectTypeNodeImpl( objectType );
233
234 addObjectTypeNode( node );
235 }
236
237 return node;
238 }
239 }
This page was automatically generated by Maven