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                                         pattern = new SearchPattern2 (MangledFilter);
 187                                 }
 188                                 return pattern;
 189                         }
 190                 }
 191
 192                 internal string FullPath {
 193                         get {
 194                                 if (fullpath == null) {
 195                                         if (path == null || path == "")
 196                                                 fullpath = Environment.CurrentDirectory;
 197                                         else
 198                                                 fullpath = System.IO.Path.GetFullPath (path);
 199                                 }
 200
 201                                 return fullpath;
 202                         }
 203                 }
 204
 205                 [DefaultValue(false)]
 206                 [IODescription("Flag to indicate if this instance is active")]
 207                 public bool EnableRaisingEvents {
 208                         get { return enableRaisingEvents; }
 209                         set {
 210                                 if (value == enableRaisingEvents)
 211                                         return; // Do nothing
 212
 213                                 enableRaisingEvents = value;
 214                                 if (value) {
 215                                         Start ();
 216                                 } else {
 217                                         Stop ();
 218                                 }
 219                         }
 220                 }
 221
 222                 [DefaultValue("*.*")]
 223                 [IODescription("File name filter pattern")]
 224                 [RecommendedAsConfigurable(true)]
 225                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 226                 public string Filter {
 227                         get { return filter; }
 228                         set {
 229                                 if (value == null || value == "")
 230                                         value = "*.*";
 231
 232                                 if (filter != value) {
 233                                         filter = value;
 234                                         pattern = null;
 235                                         mangledFilter = null;
 236                                 }
 237                         }
 238                 }
 239
 240                 [DefaultValue(false)]
 241                 [IODescription("Flag to indicate we want to watch subdirectories")]
 242                 public bool IncludeSubdirectories {
 243                         get { return includeSubdirectories; }
 244                         set {
 245                                 if (includeSubdirectories == value)
 246                                         return;
 247
 248                                 includeSubdirectories = value;
 249                                 if (value && enableRaisingEvents) {
 250                                         Stop ();
 251                                         Start ();
 252                                 }
 253                         }
 254                 }
 255
 256                 [Browsable(false)]
 257                 [DefaultValue(8192)]
 258                 public int InternalBufferSize {
 259                         get { return internalBufferSize; }
 260                         set {
 261                                 if (internalBufferSize == value)
 262                                         return;
 263
 264                                 if (value < 4196)
 265                                         value = 4196;
 266
 267                                 internalBufferSize = value;
 268                                 if (enableRaisingEvents) {
 269                                         Stop ();
 270                                         Start ();
 271                                 }
 272                         }
 273                 }
 274
 275                 [DefaultValue(NotifyFilters.FileName | NotifyFilters.DirectoryName | NotifyFilters.LastWrite)]
 276                 [IODescription("Flag to indicate which change event we want to monitor")]
 277                 public NotifyFilters NotifyFilter {
 278                         get { return notifyFilter; }
 279                         set {
 280                                 if (notifyFilter == value)
 281                                         return;
 282
 283                                 notifyFilter = value;
 284                                 if (enableRaisingEvents) {
 285                                         Stop ();
 286                                         Start ();
 287                                 }
 288                         }
 289                 }
 290
 291                 [DefaultValue("")]
 292                 [IODescription("The directory to monitor")]
 293                 [RecommendedAsConfigurable(true)]
 294                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 295                 [Editor ("System.Diagnostics.Design.FSWPathEditor, " + Consts.AssemblySystem_Design, "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
 296                 public string Path {
 297                         get { return path; }
 298                         set {
 299                                 if (path == value)
 300                                         return;
 301
 302                                 bool exists = false;
 303                                 Exception exc = null;
 304
 305                                 try {
 306                                         exists = Directory.Exists (value);
 307                                 } catch (Exception e) {
 308                                         exc = e;
 309                                 }
 310
 311                                 if (exc != null)
 312                                         throw new ArgumentException ("Invalid directory name", "value", exc);
 313
 314                                 if (!exists)
 315                                         throw new ArgumentException ("Directory does not exist", "value");
 316
 317                                 path = value;
 318                                 fullpath = null;
 319                                 if (enableRaisingEvents) {
 320                                         Stop ();
 321                                         Start ();
 322                                 }
 323                         }
 324                 }
 325
 326                 [Browsable(false)]
 327                 public override ISite Site {
 328                         get { return base.Site; }
 329                         set { base.Site = value; }
 330                 }
 331
 332                 [DefaultValue(null)]
 333                 [IODescription("The object used to marshal the event handler calls resulting from a directory change")]
 334                 [Browsable (false)]
 335                 public ISynchronizeInvoke SynchronizingObject {
 336                         get { return synchronizingObject; }
 337                         set { synchronizingObject = value; }
 338                 }
 339
 340                 #endregion // Properties
 341
 342                 #region Methods
 343
 344                 public void BeginInit ()
 345                 {
 346                         // Not necessary in Mono
 347                 }
 348
 349                 protected override void Dispose (bool disposing)
 350                 {
 351                         if (!disposed) {
 352                                 disposed = true;
 353                                 Stop ();
 354                         }
 355
 356                         base.Dispose (disposing);
 357                 }
 358
 359                 ~FileSystemWatcher ()
 360                 {
 361                         disposed = true;
 362                         Stop ();
 363                 }
 364
 365                 public void EndInit ()
 366                 {
 367                         // Not necessary in Mono
 368                 }
 369
 370                 enum EventType {
 371                         FileSystemEvent,
 372                         ErrorEvent,
 373                         RenameEvent
 374                 }
 375                 private void RaiseEvent (Delegate ev, EventArgs arg, EventType evtype)
 376                 {
 377                         if (ev == null)
 378                                 return;
 379
 380                         if (synchronizingObject == null) {
 381                                 switch (evtype) {
 382                                 case EventType.RenameEvent:
 383                                         ((RenamedEventHandler)ev).BeginInvoke (this, (RenamedEventArgs) arg, null, null);
 384                                         break;
 385                                 case EventType.ErrorEvent:
 386                                         ((ErrorEventHandler)ev).BeginInvoke (this, (ErrorEventArgs) arg, null, null);
 387                                         break;
 388                                 case EventType.FileSystemEvent:
 389                                         ((FileSystemEventHandler)ev).BeginInvoke (this, (FileSystemEventArgs) arg, null, null);
 390                                         break;
 391                                 }
 392                                 return;
 393                         }
 394
 395                         synchronizingObject.BeginInvoke (ev, new object [] {this, arg});
 396                 }
 397
 398                 protected void OnChanged (FileSystemEventArgs e)
 399                 {
 400                         RaiseEvent (Changed, e, EventType.FileSystemEvent);
 401                 }
 402
 403                 protected void OnCreated (FileSystemEventArgs e)
 404                 {
 405                         RaiseEvent (Created, e, EventType.FileSystemEvent);
 406                 }
 407
 408                 protected void OnDeleted (FileSystemEventArgs e)
 409                 {
 410                         RaiseEvent (Deleted, e, EventType.FileSystemEvent);
 411                 }
 412
 413                 protected void OnError (ErrorEventArgs e)
 414                 {
 415                         RaiseEvent (Error, e, EventType.ErrorEvent);
 416                 }
 417
 418                 protected void OnRenamed (RenamedEventArgs e)
 419                 {
 420                         RaiseEvent (Renamed, e, EventType.RenameEvent);
 421                 }
 422
 423                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType)
 424                 {
 425                         return WaitForChanged (changeType, Timeout.Infinite);
 426                 }
 427
 428                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType, int timeout)
 429                 {
 430                         WaitForChangedResult result = new WaitForChangedResult ();
 431                         bool prevEnabled = EnableRaisingEvents;
 432                         if (!prevEnabled)
 433                                 EnableRaisingEvents = true;
 434
 435                         bool gotData;
 436                         lock (this) {
 437                                 waiting = true;
 438                                 gotData = Monitor.Wait (this, timeout);
 439                                 if (gotData)
 440                                         result = this.lastData;
 441                         }
 442
 443                         EnableRaisingEvents = prevEnabled;
 444                         if (!gotData)
 445                                 result.TimedOut = true;
 446
 447                         return result;
 448                 }
 449
 450                 internal void DispatchEvents (FileAction act, string filename, ref RenamedEventArgs renamed)
 451                 {
 452                         if (waiting) {
 453                                 lastData = new WaitForChangedResult ();
 454                         }
 455
 456                         switch (act) {
 457                         case FileAction.Added:
 458                                 lastData.Name = filename;
 459                                 lastData.ChangeType = WatcherChangeTypes.Created;
 460                                 OnCreated (new FileSystemEventArgs (WatcherChangeTypes.Created, path, filename));
 461                                 break;
 462                         case FileAction.Removed:
 463                                 lastData.Name = filename;
 464                                 lastData.ChangeType = WatcherChangeTypes.Deleted;
 465                                 OnDeleted (new FileSystemEventArgs (WatcherChangeTypes.Deleted, path, filename));
 466                                 break;
 467                         case FileAction.Modified:
 468                                 lastData.Name = filename;
 469                                 lastData.ChangeType = WatcherChangeTypes.Changed;
 470                                 OnChanged (new FileSystemEventArgs (WatcherChangeTypes.Changed, path, filename));
 471                                 break;
 472                         case FileAction.RenamedOldName:
 473                                 if (renamed != null) {
 474                                         OnRenamed (renamed);
 475                                 }
 476                                 lastData.OldName = filename;
 477                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 478                                 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, filename, "");
 479                                 break;
 480                         case FileAction.RenamedNewName:
 481                                 lastData.Name = filename;
 482                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 483                                 if (renamed == null) {
 484                                         renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, "", filename);
 485                                 }
 486                                 OnRenamed (renamed);
 487                                 renamed = null;
 488                                 break;
 489                         default:
 490                                 break;
 491                         }
 492                 }
 493
 494                 void Start ()
 495                 {
 496                         watcher.StartDispatching (this);
 497                 }
 498
 499                 void Stop ()
 500                 {
 501                         watcher.StopDispatching (this);
 502                 }
 503                 #endregion // Methods
 504
 505                 #region Events and Delegates
 506
 507                 [IODescription("Occurs when a file/directory change matches the filter")]
 508                 public event FileSystemEventHandler Changed;
 509
 510                 [IODescription("Occurs when a file/directory creation matches the filter")]
 511                 public event FileSystemEventHandler Created;
 512
 513                 [IODescription("Occurs when a file/directory deletion matches the filter")]
 514                 public event FileSystemEventHandler Deleted;
 515
 516                 [Browsable(false)]
 517                 public event ErrorEventHandler Error;
 518
 519                 [IODescription("Occurs when a file/directory rename matches the filter")]
 520                 public event RenamedEventHandler Renamed;
 521
 522                 #endregion // Events and Delegates
 523
 524                 /* 0 -> not supported   */
 525                 /* 1 -> windows         */
 526                 /* 2 -> FAM             */
 527                 /* 3 -> Kevent          */
 528                 /* 4 -> gamin           */
 529                 /* 5 -> inotify         */
 530                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 531                 static extern int InternalSupportsFSW ();
 532         }
 533 }
 534