mcs/class/System/System.IO/FileSystemWatcher.cs

   1 //
   2 // System.IO.FileSystemWatcher.cs
   3 //
   4 // Authors:
   5 //      Tim Coleman (tim@timcoleman.com)
   6 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7 //
   8 // Copyright (C) Tim Coleman, 2002
   9 // (c) 2003 Ximian, Inc. (http://www.ximian.com)
  10 // Copyright (C) 2004, 2006 Novell, Inc (http://www.novell.com)
  11 //
  12
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System.ComponentModel;
  35 using System.Diagnostics;
  36 using System.Runtime.CompilerServices;
  37 using System.Runtime.InteropServices;
  38 using System.Security.Permissions;
  39 using System.Threading;
  40
  41 namespace System.IO {
  42         [DefaultEvent("Changed")]
  43         [IODescription ("")]
  44         public class FileSystemWatcher : Component, ISupportInitialize {
  45
  46                 #region Fields
  47
  48                 bool enableRaisingEvents;
  49                 string filter;
  50                 bool includeSubdirectories;
  51                 int internalBufferSize;
  52                 NotifyFilters notifyFilter;
  53                 string path;
  54                 string fullpath;
  55                 ISynchronizeInvoke synchronizingObject;
  56                 WaitForChangedResult lastData;
  57                 bool waiting;
  58                 SearchPattern2 pattern;
  59                 bool disposed;
  60                 string mangledFilter;
  61                 static IFileWatcher watcher;
  62                 static object lockobj = new object ();
  63
  64                 #endregion // Fields
  65
  66                 #region Constructors
  67
  68                 public FileSystemWatcher ()
  69                 {
  70                         this.notifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
  71                         this.enableRaisingEvents = false;
  72                         this.filter = "*.*";
  73                         this.includeSubdirectories = false;
  74                         this.internalBufferSize = 8192;
  75                         this.path = "";
  76                         InitWatcher ();
  77                 }
  78
  79                 public FileSystemWatcher (string path)
  80                         : this (path, "*.*")
  81                 {
  82                 }
  83
  84                 public FileSystemWatcher (string path, string filter)
  85                 {
  86                         if (path == null)
  87                                 throw new ArgumentNullException ("path");
  88
  89                         if (filter == null)
  90                                 throw new ArgumentNullException ("filter");
  91
  92                         if (path == String.Empty)
  93                                 throw new ArgumentException ("Empty path", "path");
  94
  95                         if (!Directory.Exists (path))
  96                                 throw new ArgumentException ("Directory does not exist", "path");
  97
  98                         this.enableRaisingEvents = false;
  99                         this.filter = filter;
 100                         this.includeSubdirectories = false;
 101                         this.internalBufferSize = 8192;
 102                         this.notifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
 103                         this.path = path;
 104                         this.synchronizingObject = null;
 105                         InitWatcher ();
 106                 }
 107
 108                 [EnvironmentPermission (SecurityAction.Assert, Read="MONO_MANAGED_WATCHER")]
 109                 void InitWatcher ()
 110                 {
 111                         lock (lockobj) {
 112                                 if (watcher != null)
 113                                         return;
 114
 115                                 string managed = Environment.GetEnvironmentVariable ("MONO_MANAGED_WATCHER");
 116                                 int mode = 0;
 117                                 if (managed == null)
 118                                         mode = InternalSupportsFSW ();
 119
 120                                 bool ok = false;
 121                                 switch (mode) {
 122                                 case 1: // windows
 123                                         ok = DefaultWatcher.GetInstance (out watcher);
 124                                         //ok = WindowsWatcher.GetInstance (out watcher);
 125                                         break;
 126                                 case 2: // libfam
 127                                         ok = FAMWatcher.GetInstance (out watcher, false);
 128                                         break;
 129                                 case 3: // kevent
 130                                         ok = KeventWatcher.GetInstance (out watcher);
 131                                         break;
 132                                 case 4: // libgamin
 133                                         ok = FAMWatcher.GetInstance (out watcher, true);
 134                                         break;
 135                                 case 5: // inotify
 136                                         ok = InotifyWatcher.GetInstance (out watcher, true);
 137                                         break;
 138                                 }
 139
 140                                 if (mode == 0 || !ok) {
 141                                         if (String.Compare (managed, "disabled", true) == 0)
 142                                                 NullFileWatcher.GetInstance (out watcher);
 143                                         else
 144                                                 DefaultWatcher.GetInstance (out watcher);
 145                                 }
 146
 147                                 ShowWatcherInfo ();
 148                         }
 149                 }
 150
 151                 [Conditional ("DEBUG"), Conditional ("TRACE")]
 152                 void ShowWatcherInfo ()
 153                 {
 154                         Console.WriteLine ("Watcher implementation: {0}", watcher != null ? watcher.GetType ().ToString () : "<none>");
 155                 }
 156
 157                 #endregion // Constructors
 158
 159                 #region Properties
 160
 161                 /* If this is enabled, we Pulse this instance */
 162                 internal bool Waiting {
 163                         get { return waiting; }
 164                         set { waiting = value; }
 165                 }
 166
 167                 internal string MangledFilter {
 168                         get {
 169                                 if (filter != "*.*")
 170                                         return filter;
 171
 172                                 if (mangledFilter != null)
 173                                         return mangledFilter;
 174
 175                                 string filterLocal = "*.*";
 176                                 if (!(watcher.GetType () == typeof (WindowsWatcher)))
 177                                         filterLocal = "*";
 178
 179                                 return filterLocal;
 180                         }
 181                 }
 182
 183                 internal SearchPattern2 Pattern {
 184                         get {
 185                                 if (pattern == null) {
 186                                         if (watcher.GetType () == typeof (KeventWatcher))
 187                                                 pattern = new SearchPattern2 (MangledFilter, true); //assume we want to ignore case (OS X)
 188                                         else
 189                                                 pattern = new SearchPattern2 (MangledFilter);
 190                                 }
 191                                 return pattern;
 192                         }
 193                 }
 194
 195                 internal string FullPath {
 196                         get {
 197                                 if (fullpath == null) {
 198                                         if (path == null || path == "")
 199                                                 fullpath = Environment.CurrentDirectory;
 200                                         else
 201                                                 fullpath = System.IO.Path.GetFullPath (path);
 202                                 }
 203
 204                                 return fullpath;
 205                         }
 206                 }
 207
 208                 [DefaultValue(false)]
 209                 [IODescription("Flag to indicate if this instance is active")]
 210                 public bool EnableRaisingEvents {
 211                         get { return enableRaisingEvents; }
 212                         set {
 213                                 if (value == enableRaisingEvents)
 214                                         return; // Do nothing
 215
 216                                 enableRaisingEvents = value;
 217                                 if (value) {
 218                                         Start ();
 219                                 } else {
 220                                         Stop ();
 221                                 }
 222                         }
 223                 }
 224
 225                 [DefaultValue("*.*")]
 226                 [IODescription("File name filter pattern")]
 227                 [RecommendedAsConfigurable(true)]
 228                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 229                 public string Filter {
 230                         get { return filter; }
 231                         set {
 232                                 if (value == null || value == "")
 233                                         value = "*.*";
 234
 235                                 if (filter != value) {
 236                                         filter = value;
 237                                         pattern = null;
 238                                         mangledFilter = null;
 239                                 }
 240                         }
 241                 }
 242
 243                 [DefaultValue(false)]
 244                 [IODescription("Flag to indicate we want to watch subdirectories")]
 245                 public bool IncludeSubdirectories {
 246                         get { return includeSubdirectories; }
 247                         set {
 248                                 if (includeSubdirectories == value)
 249                                         return;
 250
 251                                 includeSubdirectories = value;
 252                                 if (value && enableRaisingEvents) {
 253                                         Stop ();
 254                                         Start ();
 255                                 }
 256                         }
 257                 }
 258
 259                 [Browsable(false)]
 260                 [DefaultValue(8192)]
 261                 public int InternalBufferSize {
 262                         get { return internalBufferSize; }
 263                         set {
 264                                 if (internalBufferSize == value)
 265                                         return;
 266
 267                                 if (value < 4196)
 268                                         value = 4196;
 269
 270                                 internalBufferSize = value;
 271                                 if (enableRaisingEvents) {
 272                                         Stop ();
 273                                         Start ();
 274                                 }
 275                         }
 276                 }
 277
 278                 [DefaultValue(NotifyFilters.FileName | NotifyFilters.DirectoryName | NotifyFilters.LastWrite)]
 279                 [IODescription("Flag to indicate which change event we want to monitor")]
 280                 public NotifyFilters NotifyFilter {
 281                         get { return notifyFilter; }
 282                         set {
 283                                 if (notifyFilter == value)
 284                                         return;
 285
 286                                 notifyFilter = value;
 287                                 if (enableRaisingEvents) {
 288                                         Stop ();
 289                                         Start ();
 290                                 }
 291                         }
 292                 }
 293
 294                 [DefaultValue("")]
 295                 [IODescription("The directory to monitor")]
 296                 [RecommendedAsConfigurable(true)]
 297                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 298                 [Editor ("System.Diagnostics.Design.FSWPathEditor, " + Consts.AssemblySystem_Design, "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
 299                 public string Path {
 300                         get { return path; }
 301                         set {
 302                                 if (path == value)
 303                                         return;
 304
 305                                 bool exists = false;
 306                                 Exception exc = null;
 307
 308                                 try {
 309                                         exists = Directory.Exists (value);
 310                                 } catch (Exception e) {
 311                                         exc = e;
 312                                 }
 313
 314                                 if (exc != null)
 315                                         throw new ArgumentException ("Invalid directory name", "value", exc);
 316
 317                                 if (!exists)
 318                                         throw new ArgumentException ("Directory does not exist", "value");
 319
 320                                 path = value;
 321                                 fullpath = null;
 322                                 if (enableRaisingEvents) {
 323                                         Stop ();
 324                                         Start ();
 325                                 }
 326                         }
 327                 }
 328
 329                 [Browsable(false)]
 330                 public override ISite Site {
 331                         get { return base.Site; }
 332                         set { base.Site = value; }
 333                 }
 334
 335                 [DefaultValue(null)]
 336                 [IODescription("The object used to marshal the event handler calls resulting from a directory change")]
 337                 [Browsable (false)]
 338                 public ISynchronizeInvoke SynchronizingObject {
 339                         get { return synchronizingObject; }
 340                         set { synchronizingObject = value; }
 341                 }
 342
 343                 #endregion // Properties
 344
 345                 #region Methods
 346
 347                 public void BeginInit ()
 348                 {
 349                         // Not necessary in Mono
 350                 }
 351
 352                 protected override void Dispose (bool disposing)
 353                 {
 354                         if (!disposed) {
 355                                 disposed = true;
 356                                 Stop ();
 357                         }
 358
 359                         base.Dispose (disposing);
 360                 }
 361
 362                 ~FileSystemWatcher ()
 363                 {
 364                         disposed = true;
 365                         Stop ();
 366                 }
 367
 368                 public void EndInit ()
 369                 {
 370                         // Not necessary in Mono
 371                 }
 372
 373                 enum EventType {
 374                         FileSystemEvent,
 375                         ErrorEvent,
 376                         RenameEvent
 377                 }
 378
 379                 protected void OnChanged (FileSystemEventArgs e)
 380                 {
 381                         if (Changed == null)
 382                                 return;
 383
 384                         if (synchronizingObject == null)
 385                                 Changed (this, e);
 386                         else
 387                                 synchronizingObject.BeginInvoke (Changed, new object[] { this, e });
 388                 }
 389
 390                 protected void OnCreated (FileSystemEventArgs e)
 391                 {
 392                         if (Created == null)
 393                                 return;
 394
 395                         if (synchronizingObject == null)
 396                                 Created (this, e);
 397                         else
 398                                 synchronizingObject.BeginInvoke (Created, new object[] { this, e });
 399                 }
 400
 401                 protected void OnDeleted (FileSystemEventArgs e)
 402                 {
 403                         if (Deleted == null)
 404                                 return;
 405
 406                         if (synchronizingObject == null)
 407                                 Deleted (this, e);
 408                         else
 409                                 synchronizingObject.BeginInvoke (Deleted, new object[] { this, e });
 410                 }
 411
 412                 internal void OnError (ErrorEventArgs e)
 413                 {
 414                         if (Error == null)
 415                                 return;
 416
 417                         if (synchronizingObject == null)
 418                                 Error (this, e);
 419                         else
 420                                 synchronizingObject.BeginInvoke (Error, new object[] { this, e });
 421                 }
 422
 423                 protected void OnRenamed (RenamedEventArgs e)
 424                 {
 425                         if (Renamed == null)
 426                                 return;
 427
 428                         if (synchronizingObject == null)
 429                                 Renamed (this, e);
 430                         else
 431                                 synchronizingObject.BeginInvoke (Renamed, new object[] { this, e });
 432                 }
 433
 434                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType)
 435                 {
 436                         return WaitForChanged (changeType, Timeout.Infinite);
 437                 }
 438
 439                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType, int timeout)
 440                 {
 441                         WaitForChangedResult result = new WaitForChangedResult ();
 442                         bool prevEnabled = EnableRaisingEvents;
 443                         if (!prevEnabled)
 444                                 EnableRaisingEvents = true;
 445
 446                         bool gotData;
 447                         lock (this) {
 448                                 waiting = true;
 449                                 gotData = Monitor.Wait (this, timeout);
 450                                 if (gotData)
 451                                         result = this.lastData;
 452                         }
 453
 454                         EnableRaisingEvents = prevEnabled;
 455                         if (!gotData)
 456                                 result.TimedOut = true;
 457
 458                         return result;
 459                 }
 460
 461                 internal void DispatchEvents (FileAction act, string filename, ref RenamedEventArgs renamed)
 462                 {
 463                         if (waiting) {
 464                                 lastData = new WaitForChangedResult ();
 465                         }
 466
 467                         switch (act) {
 468                         case FileAction.Added:
 469                                 lastData.Name = filename;
 470                                 lastData.ChangeType = WatcherChangeTypes.Created;
 471                                 OnCreated (new FileSystemEventArgs (WatcherChangeTypes.Created, path, filename));
 472                                 break;
 473                         case FileAction.Removed:
 474                                 lastData.Name = filename;
 475                                 lastData.ChangeType = WatcherChangeTypes.Deleted;
 476                                 OnDeleted (new FileSystemEventArgs (WatcherChangeTypes.Deleted, path, filename));
 477                                 break;
 478                         case FileAction.Modified:
 479                                 lastData.Name = filename;
 480                                 lastData.ChangeType = WatcherChangeTypes.Changed;
 481                                 OnChanged (new FileSystemEventArgs (WatcherChangeTypes.Changed, path, filename));
 482                                 break;
 483                         case FileAction.RenamedOldName:
 484                                 if (renamed != null) {
 485                                         OnRenamed (renamed);
 486                                 }
 487                                 lastData.OldName = filename;
 488                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 489                                 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, filename, "");
 490                                 break;
 491                         case FileAction.RenamedNewName:
 492                                 lastData.Name = filename;
 493                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 494                                 if (renamed == null) {
 495                                         renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, "", filename);
 496                                 }
 497                                 OnRenamed (renamed);
 498                                 renamed = null;
 499                                 break;
 500                         default:
 501                                 break;
 502                         }
 503                 }
 504
 505                 void Start ()
 506                 {
 507                         watcher.StartDispatching (this);
 508                 }
 509
 510                 void Stop ()
 511                 {
 512                         watcher.StopDispatching (this);
 513                 }
 514                 #endregion // Methods
 515
 516                 #region Events and Delegates
 517
 518                 [IODescription("Occurs when a file/directory change matches the filter")]
 519                 public event FileSystemEventHandler Changed;
 520
 521                 [IODescription("Occurs when a file/directory creation matches the filter")]
 522                 public event FileSystemEventHandler Created;
 523
 524                 [IODescription("Occurs when a file/directory deletion matches the filter")]
 525                 public event FileSystemEventHandler Deleted;
 526
 527                 [Browsable(false)]
 528                 public event ErrorEventHandler Error;
 529
 530                 [IODescription("Occurs when a file/directory rename matches the filter")]
 531                 public event RenamedEventHandler Renamed;
 532
 533                 #endregion // Events and Delegates
 534
 535                 /* 0 -> not supported   */
 536                 /* 1 -> windows         */
 537                 /* 2 -> FAM             */
 538                 /* 3 -> Kevent          */
 539                 /* 4 -> gamin           */
 540                 /* 5 -> inotify         */
 541                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 542                 static extern int InternalSupportsFSW ();
 543         }
 544 }
 545