org.argeo.security.core/src/org/argeo/security/log4j/SecureLogger.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.security.log4j;
  17
  18 import java.util.ArrayList;
  19 import java.util.Collections;
  20 import java.util.HashMap;
  21 import java.util.Iterator;
  22 import java.util.LinkedList;
  23 import java.util.List;
  24 import java.util.ListIterator;
  25 import java.util.Map;
  26 import java.util.Properties;
  27 import java.util.concurrent.BlockingQueue;
  28 import java.util.concurrent.LinkedBlockingQueue;
  29
  30 import org.apache.log4j.AppenderSkeleton;
  31 import org.apache.log4j.Level;
  32 import org.apache.log4j.LogManager;
  33 import org.apache.log4j.Logger;
  34 import org.apache.log4j.PropertyConfigurator;
  35 import org.apache.log4j.spi.LoggingEvent;
  36 import org.argeo.ArgeoException;
  37 import org.argeo.ArgeoLogListener;
  38 import org.argeo.ArgeoLogger;
  39 import org.argeo.security.SecurityUtils;
  40
  41 /** Not meant to be used directly in standard log4j config */
  42 public class SecureLogger implements ArgeoLogger {
  43
  44         private Boolean disabled = false;
  45
  46         private String level = null;
  47
  48         private Level log4jLevel = null;
  49         // private Layout layout;
  50
  51         private Properties configuration;
  52
  53         private AppenderImpl appender;
  54
  55         private final List<ArgeoLogListener> everythingListeners = Collections
  56                         .synchronizedList(new ArrayList<ArgeoLogListener>());
  57         private final List<ArgeoLogListener> allUsersListeners = Collections
  58                         .synchronizedList(new ArrayList<ArgeoLogListener>());
  59         private final Map<String, List<ArgeoLogListener>> userListeners = Collections
  60                         .synchronizedMap(new HashMap<String, List<ArgeoLogListener>>());
  61
  62         private BlockingQueue<LogEvent> events;
  63         private LogDispatcherThread logDispatcherThread = new LogDispatcherThread();
  64
  65         private Integer maxLastEventsCount = 10 * 1000;
  66
  67         /** Marker to prevent stack overflow */
  68         private ThreadLocal<Boolean> dispatching = new ThreadLocal<Boolean>() {
  69
  70                 @Override
  71                 protected Boolean initialValue() {
  72                         return false;
  73                 }
  74         };
  75
  76         public void init() {
  77                 try {
  78                         events = new LinkedBlockingQueue<LogEvent>();
  79
  80                         // if (layout != null)
  81                         // setLayout(layout);
  82                         // else
  83                         // setLayout(new PatternLayout(pattern));
  84                         appender = new AppenderImpl();
  85                         reloadConfiguration();
  86                         Logger.getRootLogger().addAppender(appender);
  87
  88                         logDispatcherThread = new LogDispatcherThread();
  89                         logDispatcherThread.start();
  90                 } catch (Exception e) {
  91                         throw new ArgeoException("Cannot initialize log4j");
  92                 }
  93         }
  94
  95         public void destroy() throws Exception {
  96                 Logger.getRootLogger().removeAppender(appender);
  97                 allUsersListeners.clear();
  98                 for (List<ArgeoLogListener> lst : userListeners.values())
  99                         lst.clear();
 100                 userListeners.clear();
 101
 102                 events.clear();
 103                 events = null;
 104                 logDispatcherThread.interrupt();
 105         }
 106
 107         // public void setLayout(Layout layout) {
 108         // this.layout = layout;
 109         // }
 110
 111         public synchronized void register(ArgeoLogListener listener,
 112                         Integer numberOfPreviousEvents) {
 113                 String username = SecurityUtils.getCurrentThreadUsername();
 114                 if (username == null)
 115                         throw new ArgeoException(
 116                                         "Only authenticated users can register a log listener");
 117
 118                 if (!userListeners.containsKey(username)) {
 119                         List<ArgeoLogListener> lst = Collections
 120                                         .synchronizedList(new ArrayList<ArgeoLogListener>());
 121                         userListeners.put(username, lst);
 122                 }
 123                 userListeners.get(username).add(listener);
 124                 List<LogEvent> lastEvents = logDispatcherThread.getLastEvents(username,
 125                                 numberOfPreviousEvents);
 126                 for (LogEvent evt : lastEvents)
 127                         dispatchEvent(listener, evt);
 128         }
 129
 130         public synchronized void registerForAll(ArgeoLogListener listener,
 131                         Integer numberOfPreviousEvents, boolean everything) {
 132                 if (everything)
 133                         everythingListeners.add(listener);
 134                 else
 135                         allUsersListeners.add(listener);
 136                 List<LogEvent> lastEvents = logDispatcherThread.getLastEvents(null,
 137                                 numberOfPreviousEvents);
 138                 for (LogEvent evt : lastEvents)
 139                         if (everything || evt.getUsername() != null)
 140                                 dispatchEvent(listener, evt);
 141         }
 142
 143         public synchronized void unregister(ArgeoLogListener listener) {
 144                 String username = SecurityUtils.getCurrentThreadUsername();
 145                 if (!userListeners.containsKey(username))
 146                         throw new ArgeoException("No user listeners " + listener
 147                                         + " registered for user " + username);
 148                 if (!userListeners.get(username).contains(listener))
 149                         throw new ArgeoException("No user listeners " + listener
 150                                         + " registered for user " + username);
 151                 userListeners.get(username).remove(listener);
 152                 if (userListeners.get(username).isEmpty())
 153                         userListeners.remove(username);
 154
 155         }
 156
 157         public synchronized void unregisterForAll(ArgeoLogListener listener) {
 158                 everythingListeners.remove(listener);
 159                 allUsersListeners.remove(listener);
 160         }
 161
 162         /** For development purpose, since using regular logging is not easy here */
 163         static void stdOut(Object obj) {
 164                 System.out.println(obj);
 165         }
 166
 167         // public void setPattern(String pattern) {
 168         // this.pattern = pattern;
 169         // }
 170
 171         public void setDisabled(Boolean disabled) {
 172                 this.disabled = disabled;
 173         }
 174
 175         public void setLevel(String level) {
 176                 this.level = level;
 177         }
 178
 179         public void setConfiguration(Properties configuration) {
 180                 this.configuration = configuration;
 181         }
 182
 183         public void updateConfiguration(Properties configuration) {
 184                 setConfiguration(configuration);
 185                 reloadConfiguration();
 186         }
 187
 188         public Properties getConfiguration() {
 189                 return configuration;
 190         }
 191
 192         /** Reloads configuration (if the configuration {@link Properties} is set) */
 193         protected void reloadConfiguration() {
 194                 if (configuration != null) {
 195                         LogManager.resetConfiguration();
 196                         PropertyConfigurator.configure(configuration);
 197                 }
 198         }
 199
 200         protected synchronized void processLoggingEvent(LogEvent event) {
 201                 if (disabled)
 202                         return;
 203
 204                 if (dispatching.get())
 205                         return;
 206
 207                 if (level != null && !level.trim().equals("")) {
 208                         if (log4jLevel == null || !log4jLevel.toString().equals(level))
 209                                 try {
 210                                         log4jLevel = Level.toLevel(level);
 211                                 } catch (Exception e) {
 212                                         System.err
 213                                                         .println("Log4j level could not be set for level '"
 214                                                                         + level + "', resetting it to null.");
 215                                         e.printStackTrace();
 216                                         level = null;
 217                                 }
 218
 219                         if (log4jLevel != null
 220                                         && !event.getLoggingEvent().getLevel()
 221                                                         .isGreaterOrEqual(log4jLevel)) {
 222                                 return;
 223                         }
 224                 }
 225
 226                 try {
 227                         // admin listeners
 228                         Iterator<ArgeoLogListener> everythingIt = everythingListeners
 229                                         .iterator();
 230                         while (everythingIt.hasNext())
 231                                 dispatchEvent(everythingIt.next(), event);
 232
 233                         if (event.getUsername() != null) {
 234                                 Iterator<ArgeoLogListener> allUsersIt = allUsersListeners
 235                                                 .iterator();
 236                                 while (allUsersIt.hasNext())
 237                                         dispatchEvent(allUsersIt.next(), event);
 238
 239                                 if (userListeners.containsKey(event.getUsername())) {
 240                                         Iterator<ArgeoLogListener> userIt = userListeners.get(
 241                                                         event.getUsername()).iterator();
 242                                         while (userIt.hasNext())
 243                                                 dispatchEvent(userIt.next(), event);
 244                                 }
 245                         }
 246                 } catch (Exception e) {
 247                         stdOut("Cannot process logging event");
 248                         e.printStackTrace();
 249                 }
 250         }
 251
 252         protected void dispatchEvent(ArgeoLogListener logListener, LogEvent evt) {
 253                 LoggingEvent event = evt.getLoggingEvent();
 254                 logListener.appendLog(evt.getUsername(), event.getTimeStamp(), event
 255                                 .getLevel().toString(), event.getLoggerName(), event
 256                                 .getThreadName(), event.getMessage(), event
 257                                 .getThrowableStrRep());
 258         }
 259
 260         private class AppenderImpl extends AppenderSkeleton {
 261                 public boolean requiresLayout() {
 262                         return false;
 263                 }
 264
 265                 public void close() {
 266                 }
 267
 268                 @Override
 269                 protected void append(LoggingEvent event) {
 270                         if (events != null) {
 271                                 try {
 272                                         String username = SecurityUtils.getCurrentThreadUsername();
 273                                         events.put(new LogEvent(username, event));
 274                                 } catch (InterruptedException e) {
 275                                         // silent
 276                                 }
 277                         }
 278                 }
 279
 280         }
 281
 282         private class LogDispatcherThread extends Thread {
 283                 /** encapsulated in order to simplify concurrency management */
 284                 private LinkedList<LogEvent> lastEvents = new LinkedList<LogEvent>();
 285
 286                 public LogDispatcherThread() {
 287                         super("Argeo Logging Dispatcher Thread");
 288                 }
 289
 290                 public void run() {
 291                         while (events != null) {
 292                                 try {
 293                                         LogEvent loggingEvent = events.take();
 294                                         processLoggingEvent(loggingEvent);
 295                                         addLastEvent(loggingEvent);
 296                                 } catch (InterruptedException e) {
 297                                         if (events == null)
 298                                                 return;
 299                                 }
 300                         }
 301                 }
 302
 303                 protected synchronized void addLastEvent(LogEvent loggingEvent) {
 304                         if (lastEvents.size() >= maxLastEventsCount)
 305                                 lastEvents.poll();
 306                         lastEvents.add(loggingEvent);
 307                 }
 308
 309                 public synchronized List<LogEvent> getLastEvents(String username,
 310                                 Integer maxCount) {
 311                         LinkedList<LogEvent> evts = new LinkedList<LogEvent>();
 312                         ListIterator<LogEvent> it = lastEvents.listIterator(lastEvents
 313                                         .size());
 314                         int count = 0;
 315                         while (it.hasPrevious() && (count < maxCount)) {
 316                                 LogEvent evt = it.previous();
 317                                 if (username == null || username.equals(evt.getUsername())) {
 318                                         evts.push(evt);
 319                                         count++;
 320                                 }
 321                         }
 322                         return evts;
 323                 }
 324         }
 325
 326         private class LogEvent {
 327                 private final String username;
 328                 private final LoggingEvent loggingEvent;
 329
 330                 public LogEvent(String username, LoggingEvent loggingEvent) {
 331                         super();
 332                         this.username = username;
 333                         this.loggingEvent = loggingEvent;
 334                 }
 335
 336                 @Override
 337                 public int hashCode() {
 338                         return loggingEvent.hashCode();
 339                 }
 340
 341                 @Override
 342                 public boolean equals(Object obj) {
 343                         return loggingEvent.equals(obj);
 344                 }
 345
 346                 @Override
 347                 public String toString() {
 348                         return username + "@ " + loggingEvent.toString();
 349                 }
 350
 351                 public String getUsername() {
 352                         return username;
 353                 }
 354
 355                 public LoggingEvent getLoggingEvent() {
 356                         return loggingEvent;
 357                 }
 358
 359         }
 360 }