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                         QueryableState old_state = queryable.State;
  72                         queryable.State = QueryableState.Crawling;
  73
  74                         try {
  75                                 DoCrawl ();
  76                         } finally {
  77                                 queryable.State = old_state;
  78                         }
  79                 }
  80
  81                 private void DoCrawl ()
  82                 {
  83                         // If our last generator is still doing stuff, just reschedule
  84                         // and return.  This keeps us from generating more tasks until
  85                         // the last one we started runs to completion.
  86                         if ((current_generator != null && current_generator.HasNextIndexable ())
  87                                 || current_dir != null) {
  88                                 Reschedule = true;
  89                                 return;
  90                         }
  91
  92                         lock (big_lock) {
  93                                 is_active = true;
  94                                 current_dir = queryable.GetNextDirectoryToCrawl ();
  95                                 if (current_dir == null) {
  96                                         Logger.Log.Debug ("Done crawling!!!!");
  97                                         is_active = false;
  98                                         return;
  99                                 }
 100                         }
 101
 102                         if (!current_dir.IsAttached) {
 103                                 Reschedule = true;
 104                                 return;
 105                         }
 106
 107                         if (FileSystemQueryable.Debug)
 108                                 Logger.Log.Debug ("Starting crawl of '{0}'", current_dir.FullName);
 109
 110                         // Schedule a DirectoryIndexableGenerator
 111                         // for that directory, and then reschedule ourselves.
 112                         try {
 113                                 current_generator = new DirectoryIndexableGenerator (queryable, current_dir);
 114                         } catch (DirectoryNotFoundException ex) {
 115                                 Logger.Log.Debug ("Couldn't crawl '{0}'", current_dir.FullName);
 116
 117                                 // FIXME: If our attempt to crawl the directory fails, just
 118                                 // mark it as uncrawlable and move on.  This isn't optimal behavior,
 119                                 // but works around bugs involving weird permissions for now.
 120                                 current_dir.MarkAsUncrawlable ();
 121                                 current_dir = null;
 122                         }
 123
 124                         if (current_generator != null) {
 125                                 Scheduler.TaskGroup group;
 126                                 group = Scheduler.NewTaskGroup ("Crawl task group", null, our_post_hook);
 127
 128                                 Scheduler.Task task;
 129                                 task = queryable.NewAddTask (current_generator);
 130                                 task.AddTaskGroup (group);
 131                                 SpawnChild (task);
 132                         }
 133
 134                         Reschedule = true;
 135                 }
 136
 137
 138         }
 139 }