beagled/FileSystemQueryable/FileCrawlTask.cs

   1 //
   2 // FileCrawlTask.cs
   3 //
   4 // Copyright (C) 2005 Novell, Inc.
   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.Collections;
  29 using System.IO;
  30
  31 using Beagle.Daemon;
  32 using Beagle.Util;
  33
  34 namespace Beagle.Daemon.FileSystemQueryable {
  35
  36         public class FileCrawlTask : Scheduler.Task {
  37
  38                 object big_lock = new object ();
  39                 FileSystemQueryable queryable;
  40                 DirectoryModel current_dir = null;
  41                 IIndexableGenerator current_generator = null;
  42                 bool is_active = false;
  43
  44                 Scheduler.Hook our_post_hook;
  45
  46                 public FileCrawlTask (FileSystemQueryable queryable)
  47                 {
  48                         this.queryable = queryable;
  49                         this.Tag = "File Crawler";
  50                         this.Priority = Scheduler.Priority.Delayed;
  51
  52                         this.our_post_hook = new Scheduler.Hook (PostCrawlHook);
  53                 }
  54
  55                 public bool IsActive {
  56                         get { lock (big_lock) return is_active; }
  57                 }
  58
  59                 private void PostCrawlHook ()
  60                 {
  61                         Logger.Log.Debug ("Done crawling '{0}'", current_dir.FullName);
  62
  63                         queryable.DoneCrawlingOneDirectory (current_dir);
  64
  65                         current_generator = null;
  66                         current_dir = null;
  67                 }
  68
  69                 override protected void DoTaskReal ()
  70                 {
  71                         // If our last generator is still doing stuff, just reschedule
  72                         // and return.  This keeps us from generating more tasks until
  73                         // the last one we started runs to completion.
  74                         if ((current_generator != null && current_generator.HasNextIndexable ())
  75                                 || current_dir != null) {
  76                                 Reschedule = true;
  77                                 return;
  78                         }
  79
  80                         lock (big_lock) {
  81                                 Log.Debug ("Running file crawl task");
  82                                 is_active = true;
  83                                 current_dir = queryable.GetNextDirectoryToCrawl ();
  84                                 if (current_dir == null) {
  85                                         Log.Debug ("Done crawling files!!!");
  86                                         is_active = false;
  87                                         return;
  88                                 }
  89                         }
  90
  91                         if (!current_dir.IsAttached) {
  92                                 Reschedule = true;
  93                                 return;
  94                         }
  95
  96                         if (FileSystemQueryable.Debug)
  97                                 Logger.Log.Debug ("Starting crawl of '{0}'", current_dir.FullName);
  98
  99                         // Schedule a DirectoryIndexableGenerator
 100                         // for that directory, and then reschedule ourselves.
 101                         try {
 102                                 current_generator = new DirectoryIndexableGenerator (queryable, current_dir);
 103                         } catch (DirectoryNotFoundException ex) {
 104                                 Logger.Log.Debug ("Couldn't crawl '{0}'", current_dir.FullName);
 105
 106                                 // FIXME: If our attempt to crawl the directory fails, just
 107                                 // mark it as uncrawlable and move on.  This isn't optimal behavior,
 108                                 // but works around bugs involving weird permissions for now.
 109                                 current_dir.MarkAsUncrawlable ();
 110                                 current_dir = null;
 111                         }
 112
 113                         if (current_generator != null) {
 114                                 Scheduler.TaskGroup group;
 115                                 group = Scheduler.NewTaskGroup ("Crawl task group", null, our_post_hook);
 116
 117                                 Scheduler.Task task;
 118                                 task = queryable.NewAddTask (current_generator);
 119                                 task.AddTaskGroup (group);
 120                                 SpawnChild (task);
 121                         }
 122
 123                         Reschedule = true;
 124                 }
 125         }
 126 }