Add lazy track implementation and creator.
[demoscenemusic.git] / src / main / java / net / pterodactylus / demoscenemusic / data / DataManager.java
index e6d58bf..5523bbe 100644 (file)
@@ -23,12 +23,15 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
+import java.util.concurrent.Callable;
 
+import net.pterodactylus.util.collection.Memoizer;
 import net.pterodactylus.util.database.Database;
 import net.pterodactylus.util.database.DatabaseException;
 import net.pterodactylus.util.database.Field;
 import net.pterodactylus.util.database.Join;
 import net.pterodactylus.util.database.Join.JoinType;
+import net.pterodactylus.util.database.ObjectCreator;
 import net.pterodactylus.util.database.OrderField;
 import net.pterodactylus.util.database.OrderField.Order;
 import net.pterodactylus.util.database.Parameter.StringParameter;
@@ -45,6 +48,10 @@ import net.pterodactylus.util.database.ValueFieldWhereClause;
  */
 public class DataManager {
 
+       private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
+       private final ObjectCreator<Group> groupCreator = new GroupCreator();
+       private final ObjectCreator<Track> trackCreator = new TrackCreator();
+
        private final Database database;
 
        public DataManager(Database database) {
@@ -54,28 +61,22 @@ public class DataManager {
        public Collection<Artist> getAllArtists() throws DatabaseException {
                Query query = new Query(Type.SELECT, "ARTISTS");
                query.addField(new Field("ARTISTS.*"));
-               query.addField(new Field("GROUP_ARTISTS.*"));
-               query.addField(new Field("GROUPS.*"));
-               query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
-               query.addJoin(new Join(JoinType.INNER, "GROUPS", new Field("GROUP_ARTISTS.GROUP_"), new Field("GROUPS.ID")));
-               query.addOrderField(new OrderField(new Field("ARTISTS.ID")));
-               ArtistLoader artistLoader = new ArtistLoader();
-               database.process(query, artistLoader);
-               return artistLoader.all();
+               return database.getMultiple(query, artistCreator);
        }
 
        public Artist getArtistById(String id) throws DatabaseException {
                Query query = new Query(Type.SELECT, "ARTISTS");
                query.addField(new Field("ARTISTS.*"));
-               query.addField(new Field("GROUP_ARTISTS.*"));
-               query.addField(new Field("GROUPS.*"));
-               query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
-               query.addJoin(new Join(JoinType.INNER, "GROUPS", new Field("GROUP_ARTISTS.GROUP_"), new Field("GROUPS.ID")));
                query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
-               query.addOrderField(new OrderField(new Field("ARTISTS.ID")));
-               ArtistLoader artistLoader = new ArtistLoader();
-               database.process(query, artistLoader);
-               return artistLoader.get();
+               return database.getSingle(query, artistCreator);
+       }
+
+       public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
+               Query query = new Query(Type.SELECT, "ARTISTS");
+               query.addField(new Field("ARTISTS.*"));
+               query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
+               query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
+               return database.getMultiple(query, artistCreator);
        }
 
        public Track trackById(String id) throws DatabaseException {
@@ -116,6 +117,14 @@ public class DataManager {
                return trackLoader.all();
        }
 
+       public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
+               Query query = new Query(Type.SELECT, "GROUPS");
+               query.addField(new Field("GROUPS.*"));
+               query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
+               query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
+               return database.getMultiple(query, groupCreator);
+       }
+
        private class TrackLoader implements ResultProcessor {
 
                private final List<Track> loadedTracks = new ArrayList<Track>();
@@ -138,7 +147,7 @@ public class DataManager {
                                track = new DefaultTrack(trackId).name(resultSet.getString("TRACKS.NAME")).artists(new ArrayList<Artist>()).styles(new HashSet<Style>());
                                loadedTracks.add(track);
                        }
-                       Artist artist = new DefaultArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
+                       Artist artist = new LazyArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
                        if (!track.artists().contains(artist)) {
                                track.artists().add(artist);
                        }
@@ -171,7 +180,7 @@ public class DataManager {
                public void processResult(ResultSet resultSet) throws SQLException {
                        String artistId = resultSet.getString("ARTISTS.ID");
                        if ((artist == null) || (!artist.id().equals(artistId))) {
-                               artist = new DefaultArtist(artistId).name(resultSet.getString("ARTISTS.NAME")).groups(new HashSet<Group>());
+                               artist = new LazyArtist(artistId).name(resultSet.getString("ARTISTS.NAME")).groups(new HashSet<Group>());
                                artists.add(artist);
                        }
 
@@ -181,4 +190,153 @@ public class DataManager {
 
        }
 
+       private class LazyArtist extends DefaultArtist {
+
+               private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
+                       public Void call() throws DatabaseException {
+                               if (!hasValue("tracks")) {
+                                       value("tracks", Collection.class).set(getTracksByArtist(id()));
+                               }
+                               return null;
+                       }
+               });
+
+               private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+                       @Override
+                       public Void call() throws Exception {
+                               if (!hasValue("groups")) {
+                                       value("groups", Collection.class).set(getGroupsByArtist(id()));
+                               }
+                               return null;
+                       }
+
+               });
+
+               public LazyArtist(String id) {
+                       super(id);
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Collection<Group> groups() {
+                       groupsMemoizer.get();
+                       return super.groups();
+               }
+
+               public Collection<Track> tracks() {
+                       tracksMemoizer.get();
+                       return super.tracks();
+               }
+
+       }
+
+       private class ArtistCreator implements ObjectCreator<Artist> {
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Artist createObject(ResultSet resultSet) throws SQLException {
+                       return new LazyArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
+               }
+
+       }
+
+       private class LazyGroup extends DefaultGroup {
+
+               private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+                       @Override
+                       public Void call() throws Exception {
+                               if (!hasValue("artists")) {
+                                       value("artists", Collection.class).set(getArtistsByGroup(id()));
+                               }
+                               return null;
+                       }
+
+               });
+
+               public LazyGroup(String id) {
+                       super(id);
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Collection<Artist> artists() {
+                       artistsMemoizer.get();
+                       return super.artists();
+               }
+
+       }
+
+       private class GroupCreator implements ObjectCreator<Group> {
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Group createObject(ResultSet resultSet) throws SQLException {
+                       return new LazyGroup(resultSet.getString("GROUPS.ID")).name(resultSet.getString("GROUPS.NAME")).url(resultSet.getString("GROUPS.URL"));
+               }
+
+       }
+
+       private class LazyTrack extends DefaultTrack {
+
+               private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+                       @Override
+                       public Void call() throws Exception {
+                               if (!hasValue("artists")) {
+                                       value("artists", List.class).set(getArtistsByTrack(id()));
+                               }
+                               return null;
+                       }
+
+               });
+
+               /**
+                * @param id
+                */
+               public LazyTrack(String id) {
+                       super(id);
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public List<Artist> artists() {
+                       artistsMemoizer.get();
+                       return super.artists();
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Collection<Style> styles() {
+                       // TODO Auto-generated method stub
+                       return super.styles();
+               }
+
+       }
+
+       private class TrackCreator implements ObjectCreator<Track> {
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               public Track createObject(ResultSet resultSet) throws SQLException {
+                       return new LazyTrack(resultSet.getString("TRACKS.ID")).name(resultSet.getString("TRACKS.NAME"));
+               }
+
+       }
+
 }