Util/DigikamTags.cs

   1 //
   2 // DigikamTags.cs
   3 //
   4 // Copyright (C) 2006 Debajyoti Bera <dbera.web@gmail.com>
   5 // Copyright (C) 2006 Novell, Inc.
   6 //
   7
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining a
  10 // copy of this software and associated documentation files (the "Software"),
  11 // to deal in the Software without restriction, including without limitation
  12 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13 // and/or sell copies of the Software, and to permit persons to whom the
  14 // Software is furnished to do so, subject to the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be included in
  17 // all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25 // DEALINGS IN THE SOFTWARE.
  26 //
  27
  28 // Big FIXME: There is a basic problem in retrieving information from Digikam DB.
  29 // If some metadata is added to the DB, the DB will be changed and beagle
  30 // will pick up the changed information _only_ when it indexes the file in
  31 // question. Which means, under normal circumstances, if a user adds some
  32 // information/tags to an image and the image file is not modified on disk,
  33 // beagle will _not_ get the updated information for that file.
  34 // Is there any way to force beagle to re-index the file ? Maybe send an
  35 // IndexableChange message or something like that ... simply doing that
  36 // might cause double indexing of the file.
  37
  38 using System;
  39 using System.Collections;
  40 using System.IO;
  41 using Mono.Data.SqliteClient;
  42
  43 namespace Beagle.Util {
  44
  45         public static class DigikamTags {
  46
  47                 public class DigikamData {
  48                         public string caption;
  49                         private ArrayList tags = null;
  50                         // FIXME: Icon ? KdeIcon ?
  51
  52                         public IEnumerable Tags {
  53                                 get { return tags; }
  54                         }
  55
  56                         internal void AddTag (string tag) {
  57                                 if (tags == null)
  58                                         tags = new ArrayList ();
  59                                 tags.Add (tag);
  60                         }
  61                 }
  62
  63                 private static string album_path = null;
  64                 private static string db_path = null;
  65                 private static string digikamrc = null;
  66                 private const string tags_sql_string = @"SELECT images.caption, tags.name, tags.pid
  67 FROM albums, images, imagetags, tags
  68 WHERE images.id=imagetags.imageid AND imagetags.tagid=tags.id AND
  69 albums.url LIKE '{0}' and images.name LIKE '{1}'";
  70                 private const string tags_parenttags_sql_string = @"SELECT t1.name, t2.name
  71 FROM tags t1, tags t2
  72 WHERE t1.pid=t2.id";
  73
  74                 // need to cache a lot of things
  75                 private static DateTime db_last_modified_date;
  76                 private static SqliteConnection connection = null;
  77                 private static Hashtable tag_parent_cache = null;
  78
  79                 // Every value has to be a property since they need to be checked everytime.
  80                 // User may install/start using digikam in the middle of running beagle.
  81                 private static string DBPath {
  82                         get {
  83                                 if (db_path != null)
  84                                         return db_path;
  85
  86                                 // FIXME: Also check the last write time of digikamrc.
  87                                 string digikamrc = Path.Combine (PathFinder.HomeDir, ".kde");
  88                                 digikamrc = Path.Combine (digikamrc, "share");
  89                                 digikamrc = Path.Combine (digikamrc, "config");
  90                                 digikamrc = Path.Combine (digikamrc, "digikamrc");
  91
  92                                 //Console.WriteLine ("Checking digikamrc at :" + digikamrc);
  93                                 if ( ! File.Exists (digikamrc))
  94                                         return null;
  95
  96                                 StreamReader reader = new StreamReader (digikamrc);
  97                                 string section = "";
  98                                 string line;
  99                                 while ((line = reader.ReadLine ()) != null) {
 100                                         if (line.StartsWith ("[") && line.EndsWith ("]")) {
 101                                                 section = line;
 102                                         }
 103                                         if (section == "[Album Settings]") {
 104                                                 if (line.StartsWith ("Album Path=") && line.Length > 11) {
 105                                                         album_path = StringFu.ExpandEnvVariables (line.Substring(11));
 106                                                 }
 107                                         }
 108                                 }
 109
 110                                 // FIXME: Also support the old-age sqlite-2 based digikam.db ?
 111                                 db_path = Path.Combine (album_path, "digikam3.db");
 112
 113                                 // remove trailing '/'
 114                                 if (album_path.EndsWith ("/"))
 115                                         album_path = album_path.Substring (0, album_path.LastIndexOf ("/"));
 116
 117                                 //Console.WriteLine ("db should be at:" + db_path);
 118                                 return db_path;
 119                         }
 120                 }
 121
 122                 private static SqliteConnection Connection {
 123                         get {
 124                                 if (connection != null) {
 125                                         /*
 126                                         // FIXME: Following lines will enable refreshing cache information
 127                                         // if digikam3.db is modified. Not sure how beagled will be able
 128                                         // to handle the situation when a user is on a marathon tagging
 129                                         // mission. Beware fragile! Take care.
 130                                         if (File.GetLastWriteTimeUtc (album_path) <= db_last_modified_date)
 131                                                 return connection;
 132                                         else {
 133                                                 connection.Close ();
 134                                                 connection = null;
 135                                                 tag_parent_cache.Clear ();
 136                                                 tag_parent_cache = null;
 137                                         }
 138                                         */
 139                                         return connection;
 140                                 }
 141
 142                                 if (File.Exists (DBPath)) {
 143                                         db_last_modified_date = File.GetLastWriteTimeUtc(db_path);
 144                                         connection = new SqliteConnection ();
 145                                         connection.ConnectionString = "URI=file:" + db_path + ",version=3";
 146                                         connection.Open ();
 147                                 }
 148
 149                                 return connection;
 150                         }
 151                 }
 152
 153                 private static bool IsPresent {
 154                         get { return (Connection != null); }
 155                 }
 156
 157                 public static DigikamData GetDigikamData (string path)
 158                 {
 159                         //Console.WriteLine ("Fetching digikam information about:" + path);
 160                         if (! IsPresent)
 161                                 return null;
 162
 163                         if (! path.StartsWith (album_path))
 164                                 return null;
 165
 166                         string filename = Path.GetFileName (path);
 167                         string dirname = Path.GetDirectoryName (path);
 168                         string relative_path = dirname.Remove (0, album_path.Length);
 169                         //Console.WriteLine ("location=[" + relative_path + "]/[" + filename + "]");
 170
 171                         SqliteCommand command = new SqliteCommand ();
 172                         command.Connection = Connection;
 173                         command.CommandText = String.Format (tags_sql_string, relative_path, filename);
 174                         //Console.WriteLine ("SQL string: " + command.CommandText);
 175
 176                         SqliteDataReader reader = command.ExecuteReader ();
 177                         DigikamData imagedata = null;
 178                         string tag = null;
 179                         if (reader.Read ()) {
 180                                 imagedata = new DigikamData ();
 181                                 imagedata.caption = (string) reader [0];
 182                                 tag = ((string) reader [1]);
 183                                 //Console.WriteLine ("Found caption:" + imagedata.caption);
 184                         }
 185
 186                         reader.Close ();
 187                         reader = null;
 188                         command.Dispose ();
 189                         command = null;
 190
 191                         if (imagedata == null)
 192                                 return null;
 193                         while (tag != null && tag != String.Empty) {
 194                                 //Console.WriteLine ("Found tag: " + tag);
 195                                 imagedata.AddTag (tag);
 196                                 tag = GetParentTag (tag);
 197                         }
 198
 199                         return imagedata;
 200                 }
 201
 202                 private static string GetParentTag (string tag)
 203                 {
 204                         if (! IsPresent)
 205                                 return null;
 206
 207                         if (tag_parent_cache != null)
 208                                 return (string) tag_parent_cache [tag];
 209
 210                         tag_parent_cache = new Hashtable ();
 211                         SqliteCommand command = new SqliteCommand ();
 212                         command.Connection = Connection;
 213                         command.CommandText = tags_parenttags_sql_string;
 214
 215                         SqliteDataReader reader = command.ExecuteReader ();
 216                         while (reader.Read ()) {
 217                             string name = (string) reader [0];
 218                             string parent_name = (string) reader [1];
 219                             tag_parent_cache [name] = parent_name;
 220                         }
 221
 222                         command.Dispose ();
 223
 224                         return (string) tag_parent_cache [tag];
 225                 }
 226
 227         }
 228 }