beagled/LuceneFileQueryable.cs

   1 //
   2 // LuceneFileQueryable.cs
   3 //
   4 // Copyright (C) 2005 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a
   9 // copy of this software and associated documentation files (the "Software"),
  10 // to deal in the Software without restriction, including without limitation
  11 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12 // and/or sell copies of the Software, and to permit persons to whom the
  13 // Software is furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in
  16 // all 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
  23 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 // DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 //
  28 // This queryable just takes the LuceneQueryable and adds some sane
  29 // default behavior for indexing files.
  30 //
  31
  32 using System;
  33 using System.Collections;
  34 using System.IO;
  35
  36 using Beagle.Util;
  37
  38 namespace Beagle.Daemon {
  39
  40         public abstract class LuceneFileQueryable : LuceneQueryable {
  41
  42                 public LuceneFileQueryable (string index_name, int minor_version, bool disable_locking) :
  43                         base (index_name, minor_version, disable_locking)
  44                 { }
  45
  46                 public LuceneFileQueryable (string index_name) : this (index_name, -1, false) { }
  47
  48                 public LuceneFileQueryable (string index_name, bool disable_locking) : this (index_name, -1, disable_locking) { }
  49
  50                 public LuceneFileQueryable (string index_name, int minor_version) : this (index_name, minor_version, false) { }
  51
  52                 ///////////////////////////////////////////////////////////////////////////
  53
  54                 private Hashtable file_references_count = new Hashtable ();
  55
  56                 private void IncrementReferenceCount (string path)
  57                 {
  58                         if (! file_references_count.Contains (path)) {
  59                                 file_references_count [path] = 1;
  60                                 return;
  61                         }
  62
  63                         file_references_count [path] = (int) file_references_count [path] + 1;
  64                 }
  65
  66                 // returns
  67                 // true : reference left
  68                 // false: no more reference left
  69                 private bool DecrementReferenceCount (string path)
  70                 {
  71                         if (! file_references_count.Contains (path))
  72                                 throw new Exception ("Shared file is not referenced: " + path);
  73
  74                         int reference_count = (int) file_references_count [path] - 1;
  75
  76                         if (reference_count == 0) {
  77                                 file_references_count.Remove (path);
  78                                 return false;
  79                         }
  80
  81                         file_references_count [path] = reference_count;
  82                         return true;
  83                 }
  84
  85                 ///////////////////////////////////////////////////////////////////////////
  86
  87                 private class CachedFileInfo {
  88                         public Uri Uri;
  89                         public string Path;
  90                         public DateTime Mtime;
  91                         public bool Shared = false;
  92                 }
  93
  94                 private Hashtable file_info_cache = UriFu.NewHashtable ();
  95
  96                 override protected bool PreAddIndexableHook (Indexable indexable)
  97                 {
  98                         // None of this applies for Removes
  99                         if (indexable.Type == IndexableType.Remove)
 100                                 return true;
 101
 102                         CachedFileInfo info = (CachedFileInfo) file_info_cache [indexable.Uri];
 103
 104                         if (info == null)
 105                                 info = new CachedFileInfo ();
 106
 107                         info.Uri = indexable.Uri;
 108
 109                         if (indexable.Uri.IsFile && indexable.IsNonTransient)
 110                                 info.Path = indexable.Uri.LocalPath;
 111                         else if (indexable.ContentUri.IsFile && indexable.IsNonTransient)
 112                                 info.Path = indexable.ContentUri.LocalPath;
 113                         else if (indexable.ParentUri != null && indexable.ParentUri.IsFile) {
 114                                 info.Path = indexable.ParentUri.LocalPath;
 115                                 info.Shared = true;
 116                                 IncrementReferenceCount (info.Path);
 117                         }
 118
 119                         // The path could be null in certain cases:
 120                         //    * The indexable is a non-file URI and no
 121                         //      parent URI is set.
 122                         //    * The indexable is a child indexable and the
 123                         //      parent URI is not a file URI.
 124                         if (info.Path == null)
 125                                 return true;
 126
 127                         try {
 128                                 info.Mtime = FileSystem.GetLastWriteTimeUtc (info.Path);
 129                         } catch (FileNotFoundException ex) {
 130                                 // If we can't get an mtime for the file, it must
 131                                 // have disappeared out from under us.  In that case,
 132                                 // don't bother adding anything.
 133                                 return false;
 134                         }
 135
 136                         file_info_cache [info.Uri] = info;
 137
 138                         return true;
 139                 }
 140
 141                 override protected void PostAddHook (Indexable indexable, IndexerAddedReceipt receipt)
 142                 {
 143                         // Retrieve our cached info about the file.
 144                         CachedFileInfo info;
 145                         info = file_info_cache [receipt.Uri] as CachedFileInfo;
 146                         if (info == null)
 147                                 return;
 148
 149                         // Yeah, this is ghetto. If it's a file that's shared across multiple
 150                         // indexables, only tag it with when the last indexable has been indexed.
 151                         if (info.Shared && DecrementReferenceCount (info.Path))
 152                                 return;
 153
 154                         // Since we know that the file has been successfully
 155                         // indexed, update the file attributes accordingly.
 156                         // Don't set filter information on a file if multiple
 157                         // indexables has been created from it.
 158                         FileAttributes attr;
 159                         attr = FileAttributesStore.ReadOrCreate (info.Path);
 160
 161                         attr.LastWriteTime = info.Mtime;
 162
 163                         // Don't set filter information on a file if multiple indexables has been
 164                         // created from it.
 165                         if (! info.Shared) {
 166                                 attr.FilterName = receipt.FilterName;
 167                                 attr.FilterVersion = receipt.FilterVersion;
 168                         }
 169
 170                         if (! FileAttributesStore.Write (attr))
 171                                 Logger.Log.Warn ("Couldn't write attributes for {0}", info.Path);
 172
 173                         file_info_cache.Remove (info.Uri);
 174                 }
 175
 176                 override protected void PostRemoveHook (Indexable indexable, IndexerRemovedReceipt receipt)
 177                 {
 178                         file_info_cache.Remove (indexable.Uri);
 179                 }
 180
 181                 override protected bool HitIsValid (Uri uri)
 182                 {
 183                         // Do the right thing if the Uri is a file.
 184                         // If the file Uri we need is the ContentUri, this won't work.
 185                         if (! uri.IsFile)
 186                                 return true;
 187
 188                         try {
 189                                 return FileSystem.Exists (uri.LocalPath);
 190                         } catch (Exception e) {
 191                                 Logger.Log.Warn ("Exception executing HitIsValid on {0}", uri.LocalPath);
 192                                 return false;
 193                         }
 194                 }
 195
 196                 ///////////////////////////////////////////////////////////////////////////
 197
 198                 // Convenience functions
 199
 200                 public bool IsUpToDate (string path, Filter filter)
 201                 {
 202                         return FileAttributesStore.IsUpToDate (path, filter);
 203                 }
 204
 205                 public bool IsUpToDate (string path)
 206                 {
 207                         return FileAttributesStore.IsUpToDate (path);
 208                 }
 209
 210         }
 211
 212 }