001    /*
002     * CDDL HEADER START
003     *
004     * The contents of this file are subject to the terms of the
005     * Common Development and Distribution License, Version 1.0 only
006     * (the "License").  You may not use this file except in compliance
007     * with the License.
008     *
009     * You can obtain a copy of the license at
010     * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011     * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012     * See the License for the specific language governing permissions
013     * and limitations under the License.
014     *
015     * When distributing Covered Code, include this CDDL HEADER in each
016     * file and include the License file at
017     * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
018     * add the following below this CDDL HEADER, with the fields enclosed
019     * by brackets "[]" replaced with your own identifying information:
020     *      Portions Copyright [yyyy] [name of copyright owner]
021     *
022     * CDDL HEADER END
023     *
024     *
025     *      Copyright 2006-2008 Sun Microsystems, Inc.
026     */
027    package org.opends.server.schema;
028    
029    
030    
031    import org.opends.server.admin.std.server.EqualityMatchingRuleCfg;
032    import org.opends.server.api.EqualityMatchingRule;
033    import org.opends.server.config.ConfigException;
034    import org.opends.server.protocols.asn1.ASN1OctetString;
035    import org.opends.server.types.AttributeValue;
036    import org.opends.server.types.ByteString;
037    import org.opends.server.types.DirectoryException;
038    import org.opends.server.types.InitializationException;
039    
040    import static org.opends.server.schema.SchemaConstants.*;
041    import static org.opends.server.util.StaticUtils.*;
042    
043    
044    
045    /**
046     * This class implements the directoryStringFirstComponentMatch matching rule
047     * defined in X.520 and referenced in RFC 2252.  This rule is intended for use
048     * with attributes whose values contain a set of parentheses enclosing a
049     * space-delimited set of names and/or name-value pairs (like attribute type or
050     * objectclass descriptions) in which the "first component" is the first item
051     * after the opening parenthesis.
052     */
053    public class DirectoryStringFirstComponentEqualityMatchingRule
054           extends EqualityMatchingRule
055    {
056      /**
057       * Creates a new instance of this directoryStringFirstComponentMatch matching
058       * rule.
059       */
060      public DirectoryStringFirstComponentEqualityMatchingRule()
061      {
062        super();
063      }
064    
065    
066    
067      /**
068       * {@inheritDoc}
069       */
070      public void initializeMatchingRule(EqualityMatchingRuleCfg configuration)
071             throws ConfigException, InitializationException
072      {
073        // No initialization is required.
074      }
075    
076    
077    
078      /**
079       * Retrieves the common name for this matching rule.
080       *
081       * @return  The common name for this matching rule, or <CODE>null</CODE> if
082       * it does not have a name.
083       */
084      public String getName()
085      {
086        return EMR_DIRECTORY_STRING_FIRST_COMPONENT_NAME;
087      }
088    
089    
090    
091      /**
092       * Retrieves the OID for this matching rule.
093       *
094       * @return  The OID for this matching rule.
095       */
096      public String getOID()
097      {
098        return EMR_DIRECTORY_STRING_FIRST_COMPONENT_OID;
099      }
100    
101    
102    
103      /**
104       * Retrieves the description for this matching rule.
105       *
106       * @return  The description for this matching rule, or <CODE>null</CODE> if
107       *          there is none.
108       */
109      public String getDescription()
110      {
111        // There is no standard description for this matching rule.
112        return null;
113      }
114    
115    
116    
117      /**
118       * Retrieves the OID of the syntax with which this matching rule is
119       * associated.
120       *
121       * @return  The OID of the syntax with which this matching rule is associated.
122       */
123      public String getSyntaxOID()
124      {
125        return SYNTAX_DIRECTORY_STRING_OID;
126      }
127    
128    
129    
130      /**
131       * Retrieves the normalized form of the provided value, which is best suited
132       * for efficiently performing matching operations on that value.
133       *
134       * @param  value  The value to be normalized.
135       *
136       * @return  The normalized version of the provided value.
137       *
138       * @throws  DirectoryException  If the provided value is invalid according to
139       *                              the associated attribute syntax.
140       */
141      public ByteString normalizeValue(ByteString value)
142             throws DirectoryException
143      {
144        StringBuilder buffer = new StringBuilder();
145        toLowerCase(value.value(), buffer, true);
146    
147        int bufferLength = buffer.length();
148        if (bufferLength == 0)
149        {
150          if (value.value().length > 0)
151          {
152            // This should only happen if the value is composed entirely of spaces.
153            // In that case, the normalized value is a single space.
154            return new ASN1OctetString(" ");
155          }
156          else
157          {
158            // The value is empty, so it is already normalized.
159            return new ASN1OctetString();
160          }
161        }
162    
163    
164        // Replace any consecutive spaces with a single space.
165        for (int pos = bufferLength-1; pos > 0; pos--)
166        {
167          if (buffer.charAt(pos) == ' ')
168          {
169            if (buffer.charAt(pos-1) == ' ')
170            {
171              buffer.delete(pos, pos+1);
172            }
173          }
174        }
175    
176        return new ASN1OctetString(buffer.toString());
177      }
178    
179    
180    
181      /**
182       * Indicates whether the two provided normalized values are equal to each
183       * other.
184       *
185       * @param  value1  The normalized form of the first value to compare.
186       * @param  value2  The normalized form of the second value to compare.
187       *
188       * @return  <CODE>true</CODE> if the provided values are equal, or
189       *          <CODE>false</CODE> if not.
190       */
191      public boolean areEqual(ByteString value1, ByteString value2)
192      {
193        // For this purpose, the first value will be considered the attribute value,
194        // and the second the assertion value.  The attribute value must start with
195        // an open parenthesis, followed by one or more spaces.
196        String value1String = value1.stringValue();
197        int    value1Length = value1String.length();
198    
199        if ((value1Length == 0) || (value1String.charAt(0) != '('))
200        {
201          // They cannot be equal if the attribute value is empty or doesn't start
202          // with an open parenthesis.
203          return false;
204        }
205    
206        char c;
207        int  pos = 1;
208        while ((pos < value1Length) && ((c = value1String.charAt(pos)) == ' '))
209        {
210          pos++;
211        }
212    
213        if (pos >= value1Length)
214        {
215          // We hit the end of the value before finding a non-space character.
216          return false;
217        }
218    
219    
220        // The current position must be the start position for the value.  Keep
221        // reading until we find the next space.
222        int startPos = pos++;
223        while ((pos < value1Length) && ((c = value1String.charAt(pos)) != ' '))
224        {
225          pos++;
226        }
227    
228        if (pos >= value1Length)
229        {
230          // We hit the end of the value before finding the next space.
231          return false;
232        }
233    
234    
235        // Grab the substring between the start pos and the current pos and compare
236        // it with the assertion value.
237        String compareStr   = value1String.substring(startPos, pos);
238        String value2String = value2.stringValue();
239        return value2String.equals(compareStr);
240      }
241    
242    
243    
244      /**
245       * Generates a hash code for the provided attribute value.  This version of
246       * the method will simply create a hash code from the normalized form of the
247       * attribute value.  For matching rules explicitly designed to work in cases
248       * where byte-for-byte comparisons of normalized values is not sufficient for
249       * determining equality (e.g., if the associated attribute syntax is based on
250       * hashed or encrypted values), then this method must be overridden to provide
251       * an appropriate implementation for that case.
252       *
253       * @param  attributeValue  The attribute value for which to generate the hash
254       *                         code.
255       *
256       * @return  The hash code generated for the provided attribute value.*/
257      public int generateHashCode(AttributeValue attributeValue)
258      {
259        // In this case, we'll always return the same value because the matching
260        // isn't based on the entire value.
261        return 1;
262      }
263    }
264