beagled/ThunderbirdQueryable/ThunderbirdInotify.cs

   1 //
   2 // ThunderbirdInotify.cs. This class will sumnarize inotify events and raise an event every 30 seconds (to prevent inotify hammering)
   3 //
   4 // Copyright (C) 2006 Pierre Östlund
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a copy
   9 // of this software and associated documentation files (the "Software"), to deal
  10 // in the Software without restriction, including without limitation the rights
  11 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 // copies of the Software, and to permit persons to whom the Software is
  13 // furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in all
  16 // copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 // SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.IO;
  29 using System.Collections;
  30
  31 using Beagle;
  32 using Beagle.Util;
  33
  34 namespace Beagle.Daemon.ThunderbirdQueryable {
  35
  36         public class ThunderbirdInotify {
  37                 protected struct Event {
  38                         public Inotify.Watch Watch;
  39                         public string Path;
  40                         public string Subitem;
  41                         public string Srcpath;
  42                         public Inotify.EventType Type;
  43                         public long OldFileSize;
  44                         public long CurrentFileSize;
  45
  46                         public Event (Inotify.Watch watch, string path, string subitem,
  47                                 string srcpath, Inotify.EventType type, long old_size, long current_size)
  48                         {
  49                                 this.Watch = watch;
  50                                 this.Path = path;
  51                                 this.Subitem = subitem;
  52                                 this.Srcpath = srcpath;
  53                                 this.Type = type;
  54                                 this.OldFileSize = old_size;
  55                                 this.CurrentFileSize = current_size;
  56                         }
  57                 }
  58
  59                 private Queue queue;
  60
  61                 public ThunderbirdInotify ()
  62                 {
  63                         queue = new Queue ();
  64
  65                         GLib.Timeout.Add (30000, new GLib.TimeoutHandler (Process));
  66                 }
  67
  68                 public void Watch (string path, Inotify.EventType type)
  69                 {
  70                         Inotify.Subscribe (path, OnInotify, type);
  71                 }
  72
  73                 private void OnInotify (Inotify.Watch watch,
  74                                         string path,
  75                                         string subitem,
  76                                         string srcpath,
  77                                         Inotify.EventType type)
  78                 {
  79                         if (subitem == null)
  80                                 return;
  81
  82                         // Unsubscribe to directories that have been removed
  83                         if ((type & Inotify.EventType.Delete) != 0 && (type & Inotify.EventType.IsDirectory) != 0)
  84                                 watch.Unsubscribe ();
  85
  86                         lock (queue.SyncRoot) {
  87                                 bool found = false;
  88                                 for (int i = 0; i < queue.Count; i++) {
  89                                         Event ev = (Event) queue.Dequeue ();
  90
  91                                         if (ev.Path == path && ev.Subitem == subitem && ev.Srcpath == srcpath) {
  92                                                 found = true;
  93                                                 ev.Type = (ev.Type | type);
  94                                                 queue.Enqueue (ev);
  95                                                 break;
  96                                         }
  97
  98                                         queue.Enqueue (ev);
  99                                 }
 100
 101                                 if (!found) {
 102                                         queue.Enqueue (new Event (watch, path, subitem, srcpath,
 103                                                 type, -1, Thunderbird.GetFileSize (Path.Combine (path, subitem))));
 104                                 }
 105                         }
 106                 }
 107
 108                 private bool Process ()
 109                 {
 110                         Queue tmp = new Queue ();
 111
 112                         lock (queue.SyncRoot) {
 113                                 while (queue.Count > 0) {
 114                                         Event ev = (Event) queue.Dequeue();
 115                                         long size = Thunderbird.GetFileSize (Path.Combine (ev.Path, ev.Subitem));
 116
 117                                         if (Thunderbird.Debug) {
 118                                                 Logger.Log.Debug ("EVENT: {0} ({1}) [{2}, {3}]",
 119                                                         Path.Combine (ev.Path, ev.Subitem).ToString (), ev.Type, ev.CurrentFileSize, size);
 120                                         }
 121
 122                                         if (size != ev.CurrentFileSize) {
 123                                                 ev.OldFileSize = ev.CurrentFileSize;
 124                                                 ev.CurrentFileSize = size;
 125                                                 tmp.Enqueue (ev);
 126                                                 continue;
 127                                         }
 128
 129                                         OnInotifyEvent (ev);
 130                                 }
 131
 132                                 while (tmp.Count > 0)
 133                                         queue.Enqueue (tmp.Dequeue ());
 134                         }
 135
 136                         return true;
 137                 }
 138
 139                 protected virtual void OnInotifyEvent (Event ev)
 140                 {
 141                         if (InotifyEvent != null)
 142                                 InotifyEvent (ev.Watch, ev.Path, ev.Subitem, ev.Srcpath, ev.Type);
 143                 }
 144
 145                 public event Inotify.InotifyCallback InotifyEvent;
 146         }
 147
 148 }