beagled/FileAttributesStore_Mixed.cs

   1 //
   2 // FileAttributesStore_Mixed.cs
   3 //
   4 // Copyright (C) 2004 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 Beagle.Util;
  29
  30 namespace Beagle.Daemon {
  31
  32         public class FileAttributesStore_Mixed : IFileAttributesStore {
  33
  34                 FileAttributesStore_ExtendedAttribute store_ea;
  35                 FileAttributesStore_Sqlite store_sqlite;
  36
  37                 public FileAttributesStore_Mixed (string directory, string index_fingerprint)
  38                 {
  39                         store_ea = new FileAttributesStore_ExtendedAttribute (index_fingerprint);
  40                         store_sqlite = new FileAttributesStore_Sqlite (directory, index_fingerprint);
  41                 }
  42
  43                 // We always have to query the Sqlite store first, because of our
  44                 // EA nightmare scenario: a file whose permissions or ownership get
  45                 // changed after the EAs have been attached.  Thus attributes in
  46                 // the database always trump those found in EAs.
  47
  48                 public FileAttributes Read (string path)
  49                 {
  50                         FileAttributes attr;
  51                         attr = store_sqlite.Read (path);
  52
  53                         if (attr!= null) {
  54                                 // If we have write access to the path but it has attributes
  55                                 // stored in the sqlite file attributes db, we should attach them
  56                                 // to the file with EAs and delete the record from the db.
  57                                 // Check if we have write access ?
  58                                 if (! FileSystem.IsWritable (path))
  59                                         return attr;
  60
  61                                 // What are the other cases when writing an xattr would fail ?
  62                                 // FIXME: Should also check if extended attributes is supported ?
  63                                 // Can that be done without incurring much cost, in which case
  64                                 // we may try to write it anyway ?
  65
  66                                 bool success = store_ea.Write (attr);
  67                                 if (success)
  68                                         store_sqlite.Drop (path);
  69                         } else
  70                                 attr = store_ea.Read (path);
  71                         return attr;
  72                 }
  73
  74                 public bool Write (FileAttributes attr)
  75                 {
  76                         return store_ea.Write (attr) || store_sqlite.Write (attr);
  77                 }
  78
  79                 public void Drop (string path)
  80                 {
  81                         store_ea.Drop (path);
  82                         store_sqlite.Drop (path);
  83                 }
  84
  85                 // Transactions do nothing for the EA store, so there is no
  86                 // point in calling it BeginTransaction or CommitTransaction
  87                 // on store_ea.
  88
  89                 public void BeginTransaction ()
  90                 {
  91                         store_sqlite.BeginTransaction ();
  92                 }
  93
  94                 public void CommitTransaction ()
  95                 {
  96                         store_sqlite.CommitTransaction ();
  97                 }
  98
  99         }
 100
 101 }