001/*
002 * Copyright 2018-2020 Ping Identity Corporation
003 * All Rights Reserved.
004 */
005/*
006 * Copyright 2018-2020 Ping Identity Corporation
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *    http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020/*
021 * Copyright (C) 2018-2020 Ping Identity Corporation
022 *
023 * This program is free software; you can redistribute it and/or modify
024 * it under the terms of the GNU General Public License (GPLv2 only)
025 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
026 * as published by the Free Software Foundation.
027 *
028 * This program is distributed in the hope that it will be useful,
029 * but WITHOUT ANY WARRANTY; without even the implied warranty of
030 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
031 * GNU General Public License for more details.
032 *
033 * You should have received a copy of the GNU General Public License
034 * along with this program; if not, see <http://www.gnu.org/licenses>.
035 */
036package com.unboundid.ldap.sdk.unboundidds.logs;
037
038
039
040import java.io.BufferedReader;
041import java.io.Closeable;
042import java.io.File;
043import java.io.FileReader;
044import java.io.InputStream;
045import java.io.IOException;
046import java.io.InputStreamReader;
047import java.io.Reader;
048import java.util.ArrayList;
049import java.util.List;
050
051import com.unboundid.ldif.LDIFAddChangeRecord;
052import com.unboundid.ldif.LDIFChangeRecord;
053import com.unboundid.ldif.LDIFDeleteChangeRecord;
054import com.unboundid.ldif.LDIFModifyChangeRecord;
055import com.unboundid.ldif.LDIFModifyDNChangeRecord;
056import com.unboundid.ldif.LDIFReader;
057import com.unboundid.util.Debug;
058import com.unboundid.util.NotMutable;
059import com.unboundid.util.StaticUtils;
060import com.unboundid.util.ThreadSafety;
061import com.unboundid.util.ThreadSafetyLevel;
062
063import static com.unboundid.ldap.sdk.unboundidds.logs.LogMessages.*;
064
065
066
067/**
068 * This class provides a mechanism for reading messages from a Directory Server
069 * audit log.
070 * <BR>
071 * <BLOCKQUOTE>
072 *   <B>NOTE:</B>  This class, and other classes within the
073 *   {@code com.unboundid.ldap.sdk.unboundidds} package structure, are only
074 *   supported for use against Ping Identity, UnboundID, and
075 *   Nokia/Alcatel-Lucent 8661 server products.  These classes provide support
076 *   for proprietary functionality or for external specifications that are not
077 *   considered stable or mature enough to be guaranteed to work in an
078 *   interoperable way with other types of LDAP servers.
079 * </BLOCKQUOTE>
080 */
081@NotMutable()
082@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
083public final class AuditLogReader
084       implements Closeable
085{
086  // The reader used to read the contents of the log file.
087  private final BufferedReader reader;
088
089
090
091  /**
092   * Creates a new audit log reader that will read messages from the specified
093   * log file.
094   *
095   * @param  path  The path of the log file to read.
096   *
097   * @throws  IOException  If a problem occurs while opening the file for
098   *                       reading.
099   */
100  public AuditLogReader(final String path)
101         throws IOException
102  {
103    reader = new BufferedReader(new FileReader(path));
104  }
105
106
107
108  /**
109   * Creates a new audit log reader that will read messages from the specified
110   * log file.
111   *
112   * @param  file  The log file to read.
113   *
114   * @throws  IOException  If a problem occurs while opening the file for
115   *                       reading.
116   */
117  public AuditLogReader(final File file)
118         throws IOException
119  {
120    reader = new BufferedReader(new FileReader(file));
121  }
122
123
124
125  /**
126   * Creates a new audit log reader that will read messages using the provided
127   * {@code Reader} object.
128   *
129   * @param  reader  The reader to use to read log messages.
130   */
131  public AuditLogReader(final Reader reader)
132  {
133    if (reader instanceof BufferedReader)
134    {
135      this.reader = (BufferedReader) reader;
136    }
137    else
138    {
139      this.reader = new BufferedReader(reader);
140    }
141  }
142
143
144
145  /**
146   * Creates a new audit log reader that will read messages from the provided
147   * input stream.
148   *
149   * @param  inputStream  The input stream from which to read log messages.
150   */
151  public AuditLogReader(final InputStream inputStream)
152  {
153    reader = new BufferedReader(new InputStreamReader(inputStream));
154  }
155
156
157
158  /**
159   * Reads the next audit log message from the log file.
160   *
161   * @return  The audit log message read from the log file, or {@code null} if
162   *          there are no more messages to be read.
163   *
164   * @throws  IOException  If an error occurs while trying to read from the
165   *                       file.
166   *
167   * @throws  AuditLogException  If an error occurs while trying to parse the
168   *                             log message.
169   */
170  public AuditLogMessage read()
171         throws IOException, AuditLogException
172  {
173    // Read a list of lines until we find the end of the file or a blank line
174    // after a series of non-blank lines.
175    final List<String> fullMessageLines = new ArrayList<>(20);
176    final List<String> nonCommentLines = new ArrayList<>(20);
177    while (true)
178    {
179      final String line = reader.readLine();
180      if (line == null)
181      {
182        // We hit the end of the audit log file.  We obviously can't read any
183        // more.
184        break;
185      }
186
187      if (line.isEmpty())
188      {
189        if (nonCommentLines.isEmpty())
190        {
191          // This means that we encountered consecutive blank lines, or blank
192          // lines with only comments between them.  This is okay.  We'll just
193          // clear the list of full message lines and keep reading.
194          fullMessageLines.clear();
195          continue;
196        }
197        else
198        {
199          // We found a blank line after some non-blank lines that included at
200          // least one non-comment line.  Break out of the loop and process what
201          // we read as an audit log message.
202          break;
203        }
204      }
205      else
206      {
207        // We read a non-empty line.  Add it to the list of full message lines,
208        // and if it's not a comment, then add it to the list of non-comment
209        // lines.
210        fullMessageLines.add(line);
211        if (! line.startsWith("#"))
212        {
213          nonCommentLines.add(line);
214        }
215      }
216    }
217
218
219    // If we've gotten here and the list of non-comment lines is empty, then
220    // that must mean that we hit the end of the audit log without finding any
221    // more messages.  In that case, return null to indicate that we've hit the
222    // end of the file.
223    if (nonCommentLines.isEmpty())
224    {
225      return null;
226    }
227
228
229    // Try to parse the set of non-comment lines as an LDIF change record.  If
230    // that fails, then throw a log exception.
231    final LDIFChangeRecord changeRecord;
232    try
233    {
234      final String[] ldifLines =
235           StaticUtils.toArray(nonCommentLines, String.class);
236      changeRecord = LDIFReader.decodeChangeRecord(ldifLines);
237    }
238    catch (final Exception e)
239    {
240      Debug.debugException(e);
241
242      final String concatenatedLogLines = StaticUtils.concatenateStrings(
243           "[ ", "\"", ", ", "\"", " ]", fullMessageLines);
244      throw new AuditLogException(fullMessageLines,
245           ERR_AUDIT_LOG_READER_CANNOT_PARSE_CHANGE_RECORD.get(
246                concatenatedLogLines, StaticUtils.getExceptionMessage(e)),
247           e);
248    }
249
250
251    // Create the appropriate type of audit log message based on the change
252    // record.
253    if (changeRecord instanceof LDIFAddChangeRecord)
254    {
255      return new AddAuditLogMessage(fullMessageLines,
256           (LDIFAddChangeRecord) changeRecord);
257    }
258    else if (changeRecord instanceof LDIFDeleteChangeRecord)
259    {
260      return new DeleteAuditLogMessage(fullMessageLines,
261           (LDIFDeleteChangeRecord) changeRecord);
262    }
263    else if (changeRecord instanceof LDIFModifyChangeRecord)
264    {
265      return new ModifyAuditLogMessage(fullMessageLines,
266           (LDIFModifyChangeRecord) changeRecord);
267    }
268    else if (changeRecord instanceof LDIFModifyDNChangeRecord)
269    {
270      return new ModifyDNAuditLogMessage(fullMessageLines,
271           (LDIFModifyDNChangeRecord) changeRecord);
272    }
273    else
274    {
275      // This should never happen.
276      final String concatenatedLogLines = StaticUtils.concatenateStrings(
277           "[ ", "\"", ", ", "\"", " ]", fullMessageLines);
278      throw new AuditLogException(fullMessageLines,
279           ERR_AUDIT_LOG_READER_UNSUPPORTED_CHANGE_RECORD.get(
280                concatenatedLogLines, changeRecord.getChangeType().getName()));
281    }
282  }
283
284
285
286  /**
287   * Closes this error log reader.
288   *
289   * @throws  IOException  If a problem occurs while closing the reader.
290   */
291  @Override()
292  public void close()
293         throws IOException
294  {
295    reader.close();
296  }
297}