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                 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                 public static bool GetInstance (out IFileWatcher watcher)
  86                 {
  87                         lock (typeof (FAMWatcher)) {
  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
 112                 public void StartDispatching (FileSystemWatcher fsw)
 113                 {
 114                         FAMData data;
 115                         lock (this) {
 116                                 if (thread == null) {
 117                                         thread = new Thread (new ThreadStart (Monitor));
 118                                         thread.IsBackground = true;
 119                                         thread.Start ();
 120                                 }
 121
 122                                 data = (FAMData) watches [fsw];
 123                         }
 124
 125                         if (data == null) {
 126                                 data = new FAMData ();
 127                                 data.FSW = fsw;
 128                                 data.Directory = fsw.FullPath;
 129                                 data.FileMask = fsw.MangledFilter;
 130                                 data.IncludeSubdirs = fsw.IncludeSubdirectories;
 131                                 if (data.IncludeSubdirs)
 132                                         data.SubDirs = new Hashtable ();
 133
 134                                 data.Enabled = true;
 135                                 lock (this) {
 136                                         StartMonitoringDirectory (data);
 137                                         watches [fsw] = data;
 138                                         requests [data.Request.ReqNum] = data;
 139                                         stop = false;
 140                                 }
 141                         }
 142                 }
 143
 144                 static void StartMonitoringDirectory (FAMData data)
 145                 {
 146                         FAMRequest fr;
 147                         if (FAMMonitorDirectory (ref conn, data.Directory, out fr, IntPtr.Zero) == -1)
 148                                 throw new Win32Exception ();
 149
 150                         data.Request = fr;
 151                         if (!data.IncludeSubdirs)
 152                                 return;
 153
 154                         foreach (string directory in Directory.GetDirectories (data.Directory)) {
 155                                 FAMData fd = new FAMData ();
 156                                 fd.FSW = data.FSW;
 157                                 fd.Directory = directory;
 158                                 fd.FileMask = data.FSW.MangledFilter;
 159                                 fd.IncludeSubdirs = true;
 160                                 fd.SubDirs = new Hashtable ();
 161                                 fd.Enabled = true;
 162
 163                                 StartMonitoringDirectory (fd);
 164                                 data.SubDirs [directory] = fd;
 165                                 requests [fd.Request.ReqNum] = fd;
 166                         }
 167                 }
 168
 169                 public void StopDispatching (FileSystemWatcher fsw)
 170                 {
 171                         FAMData data;
 172                         lock (this) {
 173                                 data = (FAMData) watches [fsw];
 174                                 if (data == null)
 175                                         return;
 176
 177                                 StopMonitoringDirectory (data);
 178                                 watches.Remove (fsw);
 179                                 requests.Remove (data.Request.ReqNum);
 180                                 if (watches.Count == 0)
 181                                         stop = true;
 182
 183                                 if (!data.IncludeSubdirs)
 184                                         return;
 185
 186                                 foreach (FAMData fd in data.SubDirs) {
 187                                         StopMonitoringDirectory (fd);
 188                                         requests.Remove (fd.Request.ReqNum);
 189                                 }
 190                         }
 191                 }
 192
 193                 static void StopMonitoringDirectory (FAMData data)
 194                 {
 195                         if (FAMCancelMonitor (ref conn, ref data.Request) == -1)
 196                                 throw new Win32Exception ();
 197                 }
 198
 199                 void Monitor ()
 200                 {
 201                         while (!stop) {
 202                                 int haveEvents;
 203                                 lock (this) {
 204                                         haveEvents = FAMPending (ref conn);
 205                                 }
 206
 207                                 if (haveEvents > 0) {
 208                                         ProcessEvents ();
 209                                 } else {
 210                                         Thread.Sleep (500);
 211                                 }
 212                         }
 213
 214                         lock (this) {
 215                                 thread = null;
 216                                 stop = false;
 217                         }
 218                 }
 219
 220                 const NotifyFilters changed =   NotifyFilters.Attributes |
 221                                                 NotifyFilters.LastAccess |
 222                                                 NotifyFilters.Size      |
 223                                                 NotifyFilters.LastWrite;
 224
 225                 void ProcessEvents ()
 226                 {
 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                                                         FAMData fd = new FAMData ();
 290                                                         fd.FSW = fsw;
 291                                                         fd.Directory = datadir;
 292                                                         fd.FileMask = fsw.MangledFilter;
 293                                                         fd.IncludeSubdirs = true;
 294                                                         fd.SubDirs = new Hashtable ();
 295                                                         fd.Enabled = true;
 296
 297                                                         lock (instance) {
 298                                                                 StartMonitoringDirectory (fd);
 299                                                         }
 300
 301                                                         lock (data) {
 302                                                                 data.SubDirs [datadir] = fd;
 303                                                         }
 304
 305                                                         requests [fd.Request.ReqNum] = fd;
 306                                                 }
 307                                         }
 308
 309                                         if (filename != data.Directory && !fsw.Pattern.IsMatch (filename))
 310                                                 continue;
 311
 312                                         lock (fsw) {
 313                                                 fsw.DispatchEvents (fa, filename, ref renamed);
 314                                                 if (fsw.Waiting) {
 315                                                         fsw.Waiting = false;
 316                                                         System.Threading.Monitor.PulseAll (fsw);
 317                                                 }
 318                                         }
 319                                 } while (FAMPending (ref conn) > 0);
 320                         }
 321                 }
 322
 323                 [DllImport ("libfam.so.0")]
 324                 extern static int FAMOpen (out FAMConnection fc);
 325
 326                 [DllImport ("libfam.so.0")]
 327                 extern static int FAMClose (ref FAMConnection fc);
 328
 329                 [DllImport ("libfam.so.0")]
 330                 extern static int FAMMonitorDirectory (ref FAMConnection fc, string filename,
 331                                                         out FAMRequest fr, IntPtr user_data);
 332
 333                 [DllImport ("libfam.so.0")]
 334                 extern static int FAMCancelMonitor (ref FAMConnection fc, ref FAMRequest fr);
 335
 336                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 337                 extern static int InternalFAMNextEvent (ref FAMConnection fc, out string filename,
 338                                                         out int code, out int reqnum);
 339
 340                 [DllImport ("libfam.so.0")]
 341                 extern static int FAMPending (ref FAMConnection fc);
 342         }
 343 }
 344