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 #if NET_2_0
  44         [IODescription ("")]
  45 #endif
  46         public class FileSystemWatcher : Component, ISupportInitialize {
  47
  48                 #region Fields
  49
  50                 bool enableRaisingEvents;
  51                 string filter;
  52                 bool includeSubdirectories;
  53                 int internalBufferSize;
  54                 NotifyFilters notifyFilter;
  55                 string path;
  56                 string fullpath;
  57                 ISynchronizeInvoke synchronizingObject;
  58                 WaitForChangedResult lastData;
  59                 bool waiting;
  60                 SearchPattern2 pattern;
  61                 bool disposed;
  62                 string mangledFilter;
  63                 static IFileWatcher watcher;
  64                 static object lockobj = new object ();
  65
  66                 #endregion // Fields
  67
  68                 #region Constructors
  69
  70                 public FileSystemWatcher ()
  71                 {
  72                         this.notifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
  73                         this.enableRaisingEvents = false;
  74                         this.filter = "*.*";
  75                         this.includeSubdirectories = false;
  76                         this.internalBufferSize = 8192;
  77                         this.path = "";
  78                         InitWatcher ();
  79                 }
  80
  81                 public FileSystemWatcher (string path)
  82                         : this (path, "*.*")
  83                 {
  84                 }
  85
  86                 public FileSystemWatcher (string path, string filter)
  87                 {
  88                         if (path == null)
  89                                 throw new ArgumentNullException ("path");
  90
  91                         if (filter == null)
  92                                 throw new ArgumentNullException ("filter");
  93
  94                         if (path == String.Empty)
  95                                 throw new ArgumentException ("Empty path", "path");
  96
  97                         if (!Directory.Exists (path))
  98                                 throw new ArgumentException ("Directory does not exists", "path");
  99
 100                         this.enableRaisingEvents = false;
 101                         this.filter = filter;
 102                         this.includeSubdirectories = false;
 103                         this.internalBufferSize = 8192;
 104                         this.notifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
 105                         this.path = path;
 106                         this.synchronizingObject = null;
 107                         InitWatcher ();
 108                 }
 109
 110                 [EnvironmentPermission (SecurityAction.Assert, Read="MONO_MANAGED_WATCHER")]
 111                 void InitWatcher ()
 112                 {
 113                         lock (lockobj) {
 114                                 if (watcher != null)
 115                                         return;
 116
 117                                 string managed = Environment.GetEnvironmentVariable ("MONO_MANAGED_WATCHER");
 118                                 int mode = 0;
 119                                 if (managed == null)
 120                                         mode = InternalSupportsFSW ();
 121
 122                                 bool ok = false;
 123                                 switch (mode) {
 124                                 case 1: // windows
 125                                         ok = DefaultWatcher.GetInstance (out watcher);
 126                                         //ok = WindowsWatcher.GetInstance (out watcher);
 127                                         break;
 128                                 case 2: // libfam
 129                                         ok = FAMWatcher.GetInstance (out watcher, false);
 130                                         break;
 131                                 case 3: // kevent
 132                                         ok = KeventWatcher.GetInstance (out watcher);
 133                                         break;
 134                                 case 4: // libgamin
 135                                         ok = FAMWatcher.GetInstance (out watcher, true);
 136                                         break;
 137                                 case 5: // inotify
 138                                         ok = InotifyWatcher.GetInstance (out watcher, true);
 139                                         break;
 140                                 }
 141
 142                                 if (mode == 0 || !ok) {
 143                                         if (String.Compare (managed, "disabled", true) == 0)
 144                                                 NullFileWatcher.GetInstance (out watcher);
 145                                         else
 146                                                 DefaultWatcher.GetInstance (out watcher);
 147                                 }
 148
 149                                 ShowWatcherInfo ();
 150                         }
 151                 }
 152
 153                 [Conditional ("DEBUG"), Conditional ("TRACE")]
 154                 void ShowWatcherInfo ()
 155                 {
 156                         Console.WriteLine ("Watcher implementation: {0}", watcher != null ? watcher.GetType ().ToString () : "<none>");
 157                 }
 158
 159                 #endregion // Constructors
 160
 161                 #region Properties
 162
 163                 /* If this is enabled, we Pulse this instance */
 164                 internal bool Waiting {
 165                         get { return waiting; }
 166                         set { waiting = value; }
 167                 }
 168
 169                 internal string MangledFilter {
 170                         get {
 171                                 if (filter != "*.*")
 172                                         return filter;
 173
 174                                 if (mangledFilter != null)
 175                                         return mangledFilter;
 176
 177                                 string filterLocal = "*.*";
 178                                 if (!(watcher.GetType () == typeof (WindowsWatcher)))
 179                                         filterLocal = "*";
 180
 181                                 return filterLocal;
 182                         }
 183                 }
 184
 185                 internal SearchPattern2 Pattern {
 186                         get {
 187                                 if (pattern == null) {
 188                                         pattern = new SearchPattern2 (MangledFilter);
 189                                 }
 190                                 return pattern;
 191                         }
 192                 }
 193
 194                 internal string FullPath {
 195                         get {
 196                                 if (fullpath == null) {
 197                                         if (path == null || path == "")
 198                                                 fullpath = Environment.CurrentDirectory;
 199                                         else
 200                                                 fullpath = System.IO.Path.GetFullPath (path);
 201                                 }
 202
 203                                 return fullpath;
 204                         }
 205                 }
 206
 207                 [DefaultValue(false)]
 208                 [IODescription("Flag to indicate if this instance is active")]
 209                 public bool EnableRaisingEvents {
 210                         get { return enableRaisingEvents; }
 211                         set {
 212                                 if (value == enableRaisingEvents)
 213                                         return; // Do nothing
 214
 215                                 enableRaisingEvents = value;
 216                                 if (value) {
 217                                         Start ();
 218                                 } else {
 219                                         Stop ();
 220                                 }
 221                         }
 222                 }
 223
 224                 [DefaultValue("*.*")]
 225                 [IODescription("File name filter pattern")]
 226                 [RecommendedAsConfigurable(true)]
 227                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 228                 public string Filter {
 229                         get { return filter; }
 230                         set {
 231                                 if (value == null || value == "")
 232                                         value = "*.*";
 233
 234                                 if (filter != value) {
 235                                         filter = value;
 236                                         pattern = null;
 237                                         mangledFilter = null;
 238                                 }
 239                         }
 240                 }
 241
 242                 [DefaultValue(false)]
 243                 [IODescription("Flag to indicate we want to watch subdirectories")]
 244                 public bool IncludeSubdirectories {
 245                         get { return includeSubdirectories; }
 246                         set {
 247                                 if (includeSubdirectories == value)
 248                                         return;
 249
 250                                 includeSubdirectories = value;
 251                                 if (value && enableRaisingEvents) {
 252                                         Stop ();
 253                                         Start ();
 254                                 }
 255                         }
 256                 }
 257
 258                 [Browsable(false)]
 259                 [DefaultValue(8192)]
 260                 public int InternalBufferSize {
 261                         get { return internalBufferSize; }
 262                         set {
 263                                 if (internalBufferSize == value)
 264                                         return;
 265
 266                                 if (value < 4196)
 267                                         value = 4196;
 268
 269                                 internalBufferSize = value;
 270                                 if (enableRaisingEvents) {
 271                                         Stop ();
 272                                         Start ();
 273                                 }
 274                         }
 275                 }
 276
 277                 [DefaultValue(NotifyFilters.FileName | NotifyFilters.DirectoryName | NotifyFilters.LastWrite)]
 278                 [IODescription("Flag to indicate which change event we want to monitor")]
 279                 public NotifyFilters NotifyFilter {
 280                         get { return notifyFilter; }
 281                         set {
 282                                 if (notifyFilter == value)
 283                                         return;
 284
 285                                 notifyFilter = value;
 286                                 if (enableRaisingEvents) {
 287                                         Stop ();
 288                                         Start ();
 289                                 }
 290                         }
 291                 }
 292
 293                 [DefaultValue("")]
 294                 [IODescription("The directory to monitor")]
 295                 [RecommendedAsConfigurable(true)]
 296                 [TypeConverter ("System.Diagnostics.Design.StringValueConverter, " + Consts.AssemblySystem_Design)]
 297                 [Editor ("System.Diagnostics.Design.FSWPathEditor, " + Consts.AssemblySystem_Design, "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
 298                 public string Path {
 299                         get { return path; }
 300                         set {
 301                                 if (path == value)
 302                                         return;
 303
 304                                 bool exists = false;
 305                                 Exception exc = null;
 306
 307                                 try {
 308                                         exists = Directory.Exists (value);
 309                                 } catch (Exception e) {
 310                                         exc = e;
 311                                 }
 312
 313                                 if (exc != null)
 314                                         throw new ArgumentException ("Invalid directory name", "value", exc);
 315
 316                                 if (!exists)
 317                                         throw new ArgumentException ("Directory does not exists", "value");
 318
 319                                 path = value;
 320                                 fullpath = null;
 321                                 if (enableRaisingEvents) {
 322                                         Stop ();
 323                                         Start ();
 324                                 }
 325                         }
 326                 }
 327
 328                 [Browsable(false)]
 329                 public override ISite Site {
 330                         get { return base.Site; }
 331                         set { base.Site = value; }
 332                 }
 333
 334                 [DefaultValue(null)]
 335                 [IODescription("The object used to marshal the event handler calls resulting from a directory change")]
 336 #if NET_2_0
 337                 [Browsable (false)]
 338 #endif
 339                 public ISynchronizeInvoke SynchronizingObject {
 340                         get { return synchronizingObject; }
 341                         set { synchronizingObject = value; }
 342                 }
 343
 344                 #endregion // Properties
 345
 346                 #region Methods
 347
 348                 public void BeginInit ()
 349                 {
 350                         // Not necessary in Mono
 351                 }
 352
 353                 protected override void Dispose (bool disposing)
 354                 {
 355                         if (!disposed) {
 356                                 disposed = true;
 357                                 Stop ();
 358                         }
 359
 360                         base.Dispose (disposing);
 361                 }
 362
 363                 ~FileSystemWatcher ()
 364                 {
 365                         disposed = true;
 366                         Stop ();
 367                 }
 368
 369                 public void EndInit ()
 370                 {
 371                         // Not necessary in Mono
 372                 }
 373
 374                 enum EventType {
 375                         FileSystemEvent,
 376                         ErrorEvent,
 377                         RenameEvent
 378                 }
 379                 private void RaiseEvent (Delegate ev, EventArgs arg, EventType evtype)
 380                 {
 381                         if (ev == null)
 382                                 return;
 383
 384                         if (synchronizingObject == null) {
 385                                 switch (evtype) {
 386                                 case EventType.RenameEvent:
 387                                         ((RenamedEventHandler)ev).BeginInvoke (this, (RenamedEventArgs) arg, null, null);
 388                                         break;
 389                                 case EventType.ErrorEvent:
 390                                         ((ErrorEventHandler)ev).BeginInvoke (this, (ErrorEventArgs) arg, null, null);
 391                                         break;
 392                                 case EventType.FileSystemEvent:
 393                                         ((FileSystemEventHandler)ev).BeginInvoke (this, (FileSystemEventArgs) arg, null, null);
 394                                         break;
 395                                 }
 396                                 return;
 397                         }
 398
 399                         synchronizingObject.BeginInvoke (ev, new object [] {this, arg});
 400                 }
 401
 402                 protected void OnChanged (FileSystemEventArgs e)
 403                 {
 404                         RaiseEvent (Changed, e, EventType.FileSystemEvent);
 405                 }
 406
 407                 protected void OnCreated (FileSystemEventArgs e)
 408                 {
 409                         RaiseEvent (Created, e, EventType.FileSystemEvent);
 410                 }
 411
 412                 protected void OnDeleted (FileSystemEventArgs e)
 413                 {
 414                         RaiseEvent (Deleted, e, EventType.FileSystemEvent);
 415                 }
 416
 417                 protected void OnError (ErrorEventArgs e)
 418                 {
 419                         RaiseEvent (Error, e, EventType.ErrorEvent);
 420                 }
 421
 422                 protected void OnRenamed (RenamedEventArgs e)
 423                 {
 424                         RaiseEvent (Renamed, e, EventType.RenameEvent);
 425                 }
 426
 427                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType)
 428                 {
 429                         return WaitForChanged (changeType, Timeout.Infinite);
 430                 }
 431
 432                 public WaitForChangedResult WaitForChanged (WatcherChangeTypes changeType, int timeout)
 433                 {
 434                         WaitForChangedResult result = new WaitForChangedResult ();
 435                         bool prevEnabled = EnableRaisingEvents;
 436                         if (!prevEnabled)
 437                                 EnableRaisingEvents = true;
 438
 439                         bool gotData;
 440                         lock (this) {
 441                                 waiting = true;
 442                                 gotData = Monitor.Wait (this, timeout);
 443                                 if (gotData)
 444                                         result = this.lastData;
 445                         }
 446
 447                         EnableRaisingEvents = prevEnabled;
 448                         if (!gotData)
 449                                 result.TimedOut = true;
 450
 451                         return result;
 452                 }
 453
 454                 internal void DispatchEvents (FileAction act, string filename, ref RenamedEventArgs renamed)
 455                 {
 456                         if (waiting) {
 457                                 lastData = new WaitForChangedResult ();
 458                         }
 459
 460                         switch (act) {
 461                         case FileAction.Added:
 462                                 lastData.Name = filename;
 463                                 lastData.ChangeType = WatcherChangeTypes.Created;
 464                                 OnCreated (new FileSystemEventArgs (WatcherChangeTypes.Created, path, filename));
 465                                 break;
 466                         case FileAction.Removed:
 467                                 lastData.Name = filename;
 468                                 lastData.ChangeType = WatcherChangeTypes.Deleted;
 469                                 OnDeleted (new FileSystemEventArgs (WatcherChangeTypes.Deleted, path, filename));
 470                                 break;
 471                         case FileAction.Modified:
 472                                 lastData.Name = filename;
 473                                 lastData.ChangeType = WatcherChangeTypes.Changed;
 474                                 OnChanged (new FileSystemEventArgs (WatcherChangeTypes.Changed, path, filename));
 475                                 break;
 476                         case FileAction.RenamedOldName:
 477                                 if (renamed != null) {
 478                                         OnRenamed (renamed);
 479                                 }
 480                                 lastData.OldName = filename;
 481                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 482                                 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, filename, "");
 483                                 break;
 484                         case FileAction.RenamedNewName:
 485                                 lastData.Name = filename;
 486                                 lastData.ChangeType = WatcherChangeTypes.Renamed;
 487                                 if (renamed == null) {
 488                                         renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, path, "", filename);
 489                                 }
 490                                 OnRenamed (renamed);
 491                                 renamed = null;
 492                                 break;
 493                         default:
 494                                 break;
 495                         }
 496                 }
 497
 498                 void Start ()
 499                 {
 500                         watcher.StartDispatching (this);
 501                 }
 502
 503                 void Stop ()
 504                 {
 505                         watcher.StopDispatching (this);
 506                 }
 507                 #endregion // Methods
 508
 509                 #region Events and Delegates
 510
 511                 [IODescription("Occurs when a file/directory change matches the filter")]
 512                 public event FileSystemEventHandler Changed;
 513
 514                 [IODescription("Occurs when a file/directory creation matches the filter")]
 515                 public event FileSystemEventHandler Created;
 516
 517                 [IODescription("Occurs when a file/directory deletion matches the filter")]
 518                 public event FileSystemEventHandler Deleted;
 519
 520                 [Browsable(false)]
 521                 public event ErrorEventHandler Error;
 522
 523                 [IODescription("Occurs when a file/directory rename matches the filter")]
 524                 public event RenamedEventHandler Renamed;
 525
 526                 #endregion // Events and Delegates
 527
 528                 /* 0 -> not supported   */
 529                 /* 1 -> windows         */
 530                 /* 2 -> FAM             */
 531                 /* 3 -> Kevent          */
 532                 /* 4 -> gamin           */
 533                 /* 5 -> inotify         */
 534                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 535                 static extern int InternalSupportsFSW ();
 536         }
 537 }
 538