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17 package org.apache.ldap.server.partition.impl.btree;
18
19
20 import java.math.BigInteger;
21 import java.util.Map;
22
23 import javax.naming.Name;
24 import javax.naming.NamingEnumeration;
25 import javax.naming.NamingException;
26 import javax.naming.directory.SearchControls;
27
28 import org.apache.ldap.common.filter.AbstractExprNode;
29 import org.apache.ldap.common.filter.BranchNode;
30 import org.apache.ldap.common.filter.ExprNode;
31 import org.apache.ldap.common.filter.ScopeNode;
32 import org.apache.ldap.common.message.DerefAliasesEnum;
33 import org.apache.ldap.common.name.LdapName;
34
35
36 /***
37 * Given a search filter and a scope the search engine identifies valid
38 * candidate entries returning their ids.
39 *
40 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
41 * @version $Rev: 264732 $
42 */
43 public class DefaultSearchEngine implements SearchEngine
44 {
45 /*** the Optimizer used by this DefaultSearchEngine */
46 private final Optimizer optimizer;
47 /*** the Database this DefaultSearchEngine operates on */
48 private BTreeContextPartition db;
49 /*** Evaluator flyweight used for filter expression assertions */
50 private ExpressionEvaluator evaluator;
51 /*** Enumerator flyweight that creates enumerations on filter expressions */
52 private ExpressionEnumerator enumerator;
53
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58
59
60 /***
61 * Creates a DefaultSearchEngine for searching a Database without setting
62 * up the database.
63 */
64 public DefaultSearchEngine( BTreeContextPartition db,
65 ExpressionEvaluator evaluator,
66 ExpressionEnumerator enumerator )
67 {
68 this.db = db;
69 this.evaluator = evaluator;
70 this.enumerator = enumerator;
71 optimizer = new DefaultOptimizer( db );
72 }
73
74
75 /***
76 * Gets the optimizer for this DefaultSearchEngine.
77 *
78 * @return the optimizer
79 */
80 public Optimizer getOptimizer()
81 {
82 return optimizer;
83 }
84
85
86 /***
87 * @see SearchEngine#search(Name, Map, ExprNode,SearchControls)
88 */
89 public NamingEnumeration search( Name base, Map env, ExprNode filter,
90 SearchControls searchCtls )
91 throws NamingException
92 {
93 Name effectiveBase = null;
94 BigInteger baseId = db.getEntryId( base.toString() );
95 String aliasedBase = ( String ) db.getAliasIndex().reverseLookup( baseId );
96 DerefAliasesEnum mode = DerefAliasesEnum.getEnum( env );
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109 if ( null == aliasedBase || ! mode.derefFindingBase() )
110 {
111 effectiveBase = base;
112 }
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118 else if ( null != aliasedBase )
119 {
120 effectiveBase = new LdapName( aliasedBase );
121 }
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125 else
126 {
127 effectiveBase = base;
128 }
129
130
131 BranchNode root = new BranchNode( AbstractExprNode.AND );
132 ExprNode node = new ScopeNode( env, effectiveBase.toString(),
133 searchCtls.getSearchScope() );
134 root.getChildren().add( node );
135 root.getChildren().add( filter );
136
137
138 optimizer.annotate( root );
139 return enumerator.enumerate( root );
140 }
141
142
143 /***
144 * @see SearchEngine#evaluate(ExprNode, BigInteger)
145 */
146 public boolean evaluate( ExprNode ilter, BigInteger id ) throws NamingException
147 {
148 IndexRecord rec = new IndexRecord();
149 rec.setEntryId( id );
150 return evaluator.evaluate( ilter, rec );
151 }
152 }