001/*
002 * Copyright 2007-2017 UnboundID Corp.
003 * All Rights Reserved.
004 */
005/*
006 * Copyright (C) 2008-2017 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 */
021package com.unboundid.ldap.sdk.controls;
022
023
024
025import java.util.ArrayList;
026import java.util.Collection;
027
028import com.unboundid.asn1.ASN1Element;
029import com.unboundid.asn1.ASN1Exception;
030import com.unboundid.asn1.ASN1OctetString;
031import com.unboundid.asn1.ASN1Sequence;
032import com.unboundid.ldap.sdk.Attribute;
033import com.unboundid.ldap.sdk.Control;
034import com.unboundid.ldap.sdk.DecodeableControl;
035import com.unboundid.ldap.sdk.LDAPException;
036import com.unboundid.ldap.sdk.LDAPResult;
037import com.unboundid.ldap.sdk.ReadOnlyEntry;
038import com.unboundid.ldap.sdk.ResultCode;
039import com.unboundid.util.NotMutable;
040import com.unboundid.util.ThreadSafety;
041import com.unboundid.util.ThreadSafetyLevel;
042
043import static com.unboundid.ldap.sdk.controls.ControlMessages.*;
044import static com.unboundid.util.Debug.*;
045import 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)
064public 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}