mcs/class/System/System.IO/FAMWatcher.cs

   1 //
   2 // System.IO.FAM.cs: interface with libfam
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (c) 2004 Novell, Inc. (http://www.novell.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.Collections;
  33 using System.ComponentModel;
  34 using System.Runtime.CompilerServices;
  35 using System.Runtime.InteropServices;
  36 using System.Text;
  37 using System.Threading;
  38
  39 namespace System.IO {
  40         struct FAMConnection {
  41                 public int FD;
  42                 public IntPtr opaque;
  43         }
  44
  45         struct FAMRequest {
  46                 public int ReqNum;
  47         }
  48
  49         enum FAMCodes {
  50                 Changed = 1,
  51                 Deleted = 2,
  52                 StartExecuting = 3,
  53                 StopExecuting = 4,
  54                 Created = 5,
  55                 Moved = 6,
  56                 Acknowledge = 7,
  57                 Exists = 8,
  58                 EndExist = 9
  59         };
  60
  61         class FAMData {
  62                 public FileSystemWatcher FSW;
  63                 public string Directory;
  64                 public string FileMask;
  65                 public bool IncludeSubdirs;
  66                 public bool Enabled;
  67                 public FAMRequest Request;
  68                 public Hashtable SubDirs;
  69         }
  70
  71         class FAMWatcher : IFileWatcher
  72         {
  73                 static bool failed;
  74                 static FAMWatcher instance;
  75                 static Hashtable watches;
  76                 static Hashtable requests;
  77                 static FAMConnection conn;
  78                 static Thread thread;
  79                 static bool stop;
  80
  81                 private FAMWatcher ()
  82                 {
  83                 }
  84
  85                 // Locked by caller
  86                 public static bool GetInstance (out IFileWatcher watcher)
  87                 {
  88                         if (failed == true) {
  89                                 watcher = null;
  90                                 return false;
  91                         }
  92
  93                         if (instance != null) {
  94                                 watcher = instance;
  95                                 return true;
  96                         }
  97
  98                         watches = Hashtable.Synchronized (new Hashtable ());
  99                         requests = Hashtable.Synchronized (new Hashtable ());
 100                         if (FAMOpen (out conn) == -1) {
 101                                 failed = true;
 102                                 watcher = null;
 103                                 return false;
 104                         }
 105
 106                         instance = new FAMWatcher ();
 107                         watcher = instance;
 108                         return true;
 109                 }
 110
 111                 public void StartDispatching (FileSystemWatcher fsw)
 112                 {
 113                         FAMData data;
 114                         lock (this) {
 115                                 if (thread == null) {
 116                                         thread = new Thread (new ThreadStart (Monitor));
 117                                         thread.IsBackground = true;
 118                                         thread.Start ();
 119                                 }
 120
 121                                 data = (FAMData) watches [fsw];
 122                         }
 123
 124                         if (data == null) {
 125                                 data = new FAMData ();
 126                                 data.FSW = fsw;
 127                                 data.Directory = fsw.FullPath;
 128                                 data.FileMask = fsw.MangledFilter;
 129                                 data.IncludeSubdirs = fsw.IncludeSubdirectories;
 130                                 if (data.IncludeSubdirs)
 131                                         data.SubDirs = new Hashtable ();
 132
 133                                 data.Enabled = true;
 134                                 StartMonitoringDirectory (data);
 135                                 lock (this) {
 136                                         watches [fsw] = data;
 137                                         requests [data.Request.ReqNum] = data;
 138                                         stop = false;
 139                                 }
 140                         }
 141                 }
 142
 143                 static void StartMonitoringDirectory (FAMData data)
 144                 {
 145                         FAMRequest fr;
 146                         if (FAMMonitorDirectory (ref conn, data.Directory, out fr, IntPtr.Zero) == -1)
 147                                 throw new Win32Exception ();
 148
 149                         data.Request = fr;
 150                         if (!data.IncludeSubdirs)
 151                                 return;
 152
 153                         foreach (string directory in Directory.GetDirectories (data.Directory)) {
 154                                 FAMData fd = new FAMData ();
 155                                 fd.FSW = data.FSW;
 156                                 fd.Directory = directory;
 157                                 fd.FileMask = data.FSW.MangledFilter;
 158                                 fd.IncludeSubdirs = true;
 159                                 fd.SubDirs = new Hashtable ();
 160                                 fd.Enabled = true;
 161
 162                                 StartMonitoringDirectory (fd);
 163                                 data.SubDirs [directory] = fd;
 164                                 requests [fd.Request.ReqNum] = fd;
 165                         }
 166                 }
 167
 168                 public void StopDispatching (FileSystemWatcher fsw)
 169                 {
 170                         FAMData data;
 171                         lock (this) {
 172                                 data = (FAMData) watches [fsw];
 173                                 if (data == null)
 174                                         return;
 175
 176                                 StopMonitoringDirectory (data);
 177                                 watches.Remove (fsw);
 178                                 requests.Remove (data.Request.ReqNum);
 179                                 if (watches.Count == 0)
 180                                         stop = true;
 181
 182                                 if (!data.IncludeSubdirs)
 183                                         return;
 184
 185                                 foreach (FAMData fd in data.SubDirs.Values) {
 186                                         StopMonitoringDirectory (fd);
 187                                         requests.Remove (fd.Request.ReqNum);
 188                                 }
 189                         }
 190                 }
 191
 192                 static void StopMonitoringDirectory (FAMData data)
 193                 {
 194                         if (FAMCancelMonitor (ref conn, ref data.Request) == -1)
 195                                 throw new Win32Exception ();
 196                 }
 197
 198                 void Monitor ()
 199                 {
 200                         while (!stop) {
 201                                 int haveEvents;
 202                                 lock (this) {
 203                                         haveEvents = FAMPending (ref conn);
 204                                 }
 205
 206                                 if (haveEvents > 0) {
 207                                         ProcessEvents ();
 208                                 } else {
 209                                         Thread.Sleep (500);
 210                                 }
 211                         }
 212
 213                         lock (this) {
 214                                 thread = null;
 215                                 stop = false;
 216                         }
 217                 }
 218
 219                 const NotifyFilters changed =   NotifyFilters.Attributes |
 220                                                 NotifyFilters.LastAccess |
 221                                                 NotifyFilters.Size      |
 222                                                 NotifyFilters.LastWrite;
 223
 224                 void ProcessEvents ()
 225                 {
 226                         ArrayList newdirs = null;
 227                         lock (this) {
 228                                 do {
 229                                         int code;
 230                                         string filename;
 231                                         int requestNumber;
 232                                         FileSystemWatcher fsw;
 233
 234                                         if (InternalFAMNextEvent (ref conn, out filename,
 235                                                                   out code, out requestNumber) != 1)
 236                                                 return;
 237
 238                                         bool found = false;
 239                                         switch ((FAMCodes) code) {
 240                                         case FAMCodes.Changed:
 241                                         case FAMCodes.Deleted:
 242                                         case FAMCodes.Created:
 243                                                 found = requests.ContainsKey (requestNumber);
 244                                                 break;
 245                                         case FAMCodes.Moved:
 246                                         case FAMCodes.StartExecuting:
 247                                         case FAMCodes.StopExecuting:
 248                                         case FAMCodes.Acknowledge:
 249                                         case FAMCodes.Exists:
 250                                         case FAMCodes.EndExist:
 251                                         default:
 252                                                 found = false;
 253                                                 break;
 254                                         }
 255
 256                                         if (!found)
 257                                                 continue;
 258
 259                                         FAMData data = (FAMData) requests [requestNumber];
 260                                         if (!data.Enabled)
 261                                                 continue;
 262
 263                                         fsw = data.FSW;
 264                                         NotifyFilters flt = fsw.NotifyFilter;
 265                                         RenamedEventArgs renamed = null;
 266                                         FileAction fa = 0;
 267                                         if (code == (int) FAMCodes.Changed && (flt & changed) != 0)
 268                                                 fa = FileAction.Modified;
 269                                         else if (code == (int) FAMCodes.Deleted)
 270                                                 fa = FileAction.Removed;
 271                                         else if (code == (int) FAMCodes.Created)
 272                                                 fa = FileAction.Added;
 273
 274                                         if (fa == 0)
 275                                                 continue;
 276
 277                                         if (fsw.IncludeSubdirectories) {
 278                                                 string full = fsw.FullPath;
 279                                                 string datadir = data.Directory;
 280                                                 if (datadir != full) {
 281                                                         string reldir = datadir.Substring (full.Length + 1);
 282                                                         datadir = Path.Combine (datadir, filename);
 283                                                         filename = Path.Combine (reldir, filename);
 284                                                 } else {
 285                                                         datadir = Path.Combine (fsw.FullPath, filename);
 286                                                 }
 287
 288                                                 if (fa == FileAction.Added && Directory.Exists (datadir)) {
 289                                                         if (newdirs == null)
 290                                                                 newdirs = new ArrayList (4);
 291
 292                                                         FAMData fd = new FAMData ();
 293                                                         fd.FSW = fsw;
 294                                                         fd.Directory = datadir;
 295                                                         fd.FileMask = fsw.MangledFilter;
 296                                                         fd.IncludeSubdirs = true;
 297                                                         fd.SubDirs = new Hashtable ();
 298                                                         fd.Enabled = true;
 299                                                         newdirs.Add (fd);
 300                                                         newdirs.Add (data);
 301                                                         requests [fd.Request.ReqNum] = fd;
 302                                                 }
 303                                         }
 304
 305                                         if (filename != data.Directory && !fsw.Pattern.IsMatch (filename))
 306                                                 continue;
 307
 308                                         lock (fsw) {
 309                                                 fsw.DispatchEvents (fa, filename, ref renamed);
 310                                                 if (fsw.Waiting) {
 311                                                         fsw.Waiting = false;
 312                                                         System.Threading.Monitor.PulseAll (fsw);
 313                                                 }
 314                                         }
 315                                 } while (FAMPending (ref conn) > 0);
 316                         }
 317
 318
 319                         if (newdirs != null) {
 320                                 int count = newdirs.Count;
 321                                 for (int n = 0; n < count; n++) {
 322                                         FAMData newdir = (FAMData) newdirs [n];
 323                                         FAMData parent = (FAMData) newdirs [n + 1];
 324                                         StartMonitoringDirectory (newdir);
 325                                         lock (parent) {
 326                                                 parent.SubDirs [newdir.Directory] = newdir;
 327                                         }
 328                                 }
 329                                 newdirs.Clear ();
 330                         }
 331                 }
 332
 333                 ~FAMWatcher ()
 334                 {
 335                         FAMClose (ref conn);
 336                 }
 337
 338                 [DllImport ("libfam.so.0")]
 339                 extern static int FAMOpen (out FAMConnection fc);
 340
 341                 [DllImport ("libfam.so.0")]
 342                 extern static int FAMClose (ref FAMConnection fc);
 343
 344                 [DllImport ("libfam.so.0")]
 345                 extern static int FAMMonitorDirectory (ref FAMConnection fc, string filename,
 346                                                         out FAMRequest fr, IntPtr user_data);
 347
 348                 [DllImport ("libfam.so.0")]
 349                 extern static int FAMCancelMonitor (ref FAMConnection fc, ref FAMRequest fr);
 350
 351                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 352                 extern static int InternalFAMNextEvent (ref FAMConnection fc, out string filename,
 353                                                         out int code, out int reqnum);
 354
 355                 [DllImport ("libfam.so.0")]
 356                 extern static int FAMPending (ref FAMConnection fc);
 357         }
 358 }
 359