001    /*
002     * Copyright 2007-2016 UnboundID Corp.
003     * All Rights Reserved.
004     */
005    /*
006     * Copyright (C) 2008-2016 UnboundID Corp.
007     *
008     * This program is free software; you can redistribute it and/or modify
009     * it under the terms of the GNU General Public License (GPLv2 only)
010     * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
011     * as published by the Free Software Foundation.
012     *
013     * This program is distributed in the hope that it will be useful,
014     * but WITHOUT ANY WARRANTY; without even the implied warranty of
015     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016     * GNU General Public License for more details.
017     *
018     * You should have received a copy of the GNU General Public License
019     * along with this program; if not, see <http://www.gnu.org/licenses>.
020     */
021    package com.unboundid.ldap.sdk.controls;
022    
023    
024    
025    import java.util.ArrayList;
026    import java.util.Collection;
027    
028    import com.unboundid.asn1.ASN1Element;
029    import com.unboundid.asn1.ASN1Exception;
030    import com.unboundid.asn1.ASN1OctetString;
031    import com.unboundid.asn1.ASN1Sequence;
032    import com.unboundid.ldap.sdk.Attribute;
033    import com.unboundid.ldap.sdk.Control;
034    import com.unboundid.ldap.sdk.DecodeableControl;
035    import com.unboundid.ldap.sdk.LDAPException;
036    import com.unboundid.ldap.sdk.LDAPResult;
037    import com.unboundid.ldap.sdk.ReadOnlyEntry;
038    import com.unboundid.ldap.sdk.ResultCode;
039    import com.unboundid.util.NotMutable;
040    import com.unboundid.util.ThreadSafety;
041    import com.unboundid.util.ThreadSafetyLevel;
042    
043    import static com.unboundid.ldap.sdk.controls.ControlMessages.*;
044    import static com.unboundid.util.Debug.*;
045    import static com.unboundid.util.Validator.*;
046    
047    
048    
049    /**
050     * This class provides an implementation of the LDAP pre-read response control
051     * as defined in <A HREF="http://www.ietf.org/rfc/rfc4527.txt">RFC 4527</A>.  It
052     * may be used to return a copy of the target entry immediately before
053     * processing a delete, modify, or modify DN operation.
054     * <BR><BR>
055     * If the corresponding delete, modify, or modify DN request included the
056     * {@link PreReadRequestControl} and the operation was successful, then the
057     * response for that operation should include the pre-read response control with
058     * a read-only copy of the entry as it appeared immediately before processing
059     * the request.  If the operation was not successful, then the pre-read response
060     * control will not be returned.
061     */
062    @NotMutable()
063    @ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
064    public final class PreReadResponseControl
065           extends Control
066           implements DecodeableControl
067    {
068      /**
069       * The OID (1.3.6.1.1.13.1) for the pre-read response control.
070       */
071      public static final String PRE_READ_RESPONSE_OID = "1.3.6.1.1.13.1";
072    
073    
074    
075      /**
076       * The serial version UID for this serializable class.
077       */
078      private static final long serialVersionUID = -4719875382095056686L;
079    
080    
081    
082      // The entry returned in the response control.
083      private final ReadOnlyEntry entry;
084    
085    
086    
087      /**
088       * Creates a new empty control instance that is intended to be used only for
089       * decoding controls via the {@code DecodeableControl} interface.
090       */
091      PreReadResponseControl()
092      {
093        entry = null;
094      }
095    
096    
097    
098      /**
099       * Creates a new pre-read response control including the provided entry.
100       *
101       * @param  entry  The entry to include in this pre-read response control.  It
102       *                must not be {@code null}.
103       */
104      public PreReadResponseControl(final ReadOnlyEntry entry)
105      {
106        super(PRE_READ_RESPONSE_OID, false, encodeValue(entry));
107    
108        this.entry = entry;
109      }
110    
111    
112    
113      /**
114       * Creates a new pre-read response control with the provided information.
115       *
116       * @param  oid         The OID for the control.
117       * @param  isCritical  Indicates whether the control should be marked
118       *                     critical.
119       * @param  value       The encoded value for the control.  This may be
120       *                     {@code null} if no value was provided.
121       *
122       * @throws  LDAPException  If the provided control cannot be decoded as a
123       *                         pre-read response control.
124       */
125      public PreReadResponseControl(final String oid, final boolean isCritical,
126                                    final ASN1OctetString value)
127             throws LDAPException
128      {
129        super(oid, isCritical, value);
130    
131        if (value == null)
132        {
133          throw new LDAPException(ResultCode.DECODING_ERROR,
134                                  ERR_PRE_READ_RESPONSE_NO_VALUE.get());
135        }
136    
137        final ASN1Sequence entrySequence;
138        try
139        {
140          final ASN1Element entryElement = ASN1Element.decode(value.getValue());
141          entrySequence = ASN1Sequence.decodeAsSequence(entryElement);
142        }
143        catch (final ASN1Exception ae)
144        {
145          debugException(ae);
146          throw new LDAPException(ResultCode.DECODING_ERROR,
147                                  ERR_PRE_READ_RESPONSE_VALUE_NOT_SEQUENCE.get(ae),
148                                  ae);
149        }
150    
151        final ASN1Element[] entryElements = entrySequence.elements();
152        if (entryElements.length != 2)
153        {
154          throw new LDAPException(ResultCode.DECODING_ERROR,
155                                  ERR_PRE_READ_RESPONSE_INVALID_ELEMENT_COUNT.get(
156                                       entryElements.length));
157        }
158    
159        final String dn =
160             ASN1OctetString.decodeAsOctetString(entryElements[0]).stringValue();
161    
162        final ASN1Sequence attrSequence;
163        try
164        {
165          attrSequence = ASN1Sequence.decodeAsSequence(entryElements[1]);
166        }
167        catch (final ASN1Exception ae)
168        {
169          debugException(ae);
170          throw new LDAPException(ResultCode.DECODING_ERROR,
171                         ERR_PRE_READ_RESPONSE_ATTRIBUTES_NOT_SEQUENCE.get(ae), ae);
172        }
173    
174        final ASN1Element[] attrElements = attrSequence.elements();
175        final Attribute[] attrs = new Attribute[attrElements.length];
176        for (int i=0; i < attrElements.length; i++)
177        {
178          try
179          {
180            attrs[i] =
181                 Attribute.decode(ASN1Sequence.decodeAsSequence(attrElements[i]));
182          }
183          catch (final ASN1Exception ae)
184          {
185            debugException(ae);
186            throw new LDAPException(ResultCode.DECODING_ERROR,
187                           ERR_PRE_READ_RESPONSE_ATTR_NOT_SEQUENCE.get(ae), ae);
188          }
189        }
190    
191        entry = new ReadOnlyEntry(dn, attrs);
192      }
193    
194    
195    
196      /**
197       * {@inheritDoc}
198       */
199      public PreReadResponseControl
200                  decodeControl(final String oid, final boolean isCritical,
201                                final ASN1OctetString value)
202             throws LDAPException
203      {
204        return new PreReadResponseControl(oid, isCritical, value);
205      }
206    
207    
208    
209      /**
210       * Extracts a pre-read response control from the provided result.
211       *
212       * @param  result  The result from which to retrieve the pre-read response
213       *                 control.
214       *
215       * @return  The pre-read response control contained in the provided result, or
216       *          {@code null} if the result did not contain a pre-read response
217       *          control.
218       *
219       * @throws  LDAPException  If a problem is encountered while attempting to
220       *                         decode the pre-read response control contained in
221       *                         the provided result.
222       */
223      public static PreReadResponseControl get(final LDAPResult result)
224             throws LDAPException
225      {
226        final Control c = result.getResponseControl(PRE_READ_RESPONSE_OID);
227        if (c == null)
228        {
229          return null;
230        }
231    
232        if (c instanceof PreReadResponseControl)
233        {
234          return (PreReadResponseControl) c;
235        }
236        else
237        {
238          return new PreReadResponseControl(c.getOID(), c.isCritical(),
239               c.getValue());
240        }
241      }
242    
243    
244    
245      /**
246       * Encodes the provided information into an octet string that can be used as
247       * the value for this control.
248       *
249       * @param  entry  The entry to include in this pre-read response control.  It
250       *                must not be {@code null}.
251       *
252       * @return  An ASN.1 octet string that can be used as the value for this
253       *          control.
254       */
255      private static ASN1OctetString encodeValue(final ReadOnlyEntry entry)
256      {
257        ensureNotNull(entry);
258    
259        final Collection<Attribute> attrs = entry.getAttributes();
260        final ArrayList<ASN1Element> attrElements =
261             new ArrayList<ASN1Element>(attrs.size());
262        for (final Attribute a : attrs)
263        {
264          attrElements.add(a.encode());
265        }
266    
267        final ASN1Element[] entryElements =
268        {
269          new ASN1OctetString(entry.getDN()),
270          new ASN1Sequence(attrElements)
271        };
272    
273        return new ASN1OctetString(new ASN1Sequence(entryElements).encode());
274      }
275    
276    
277    
278      /**
279       * Retrieves a read-only copy of the entry returned by this post-read response
280       * control.
281       *
282       * @return  A read-only copy of the entry returned by this post-read response
283       *          control.
284       */
285      public ReadOnlyEntry getEntry()
286      {
287        return entry;
288      }
289    
290    
291    
292      /**
293       * {@inheritDoc}
294       */
295      @Override()
296      public String getControlName()
297      {
298        return INFO_CONTROL_NAME_PRE_READ_RESPONSE.get();
299      }
300    
301    
302    
303      /**
304       * {@inheritDoc}
305       */
306      @Override()
307      public void toString(final StringBuilder buffer)
308      {
309        buffer.append("PreReadResponseControl(entry=");
310        entry.toString(buffer);
311        buffer.append(", isCritical=");
312        buffer.append(isCritical());
313        buffer.append(')');
314      }
315    }