1 files changed, 128 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/datasource/PresortedBlindJoinDatabaseConnection.java b/src/de/lmu/ifi/dbs/elki/datasource/PresortedBlindJoinDatabaseConnection.java
new file mode 100644
index 00000000..b5b59e40
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+++ b/src/de/lmu/ifi/dbs/elki/datasource/PresortedBlindJoinDatabaseConnection.java
@@ -0,0 +1,128 @@
+package de.lmu.ifi.dbs.elki.datasource;
+
+/*
+ This file is part of ELKI:
+ Environment for Developing KDD-Applications Supported by Index-Structures
+
+ Copyright (C) 2012
+ Ludwig-Maximilians-Universität München
+ Lehr- und Forschungseinheit für Datenbanksysteme
+ ELKI Development Team
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+
+import de.lmu.ifi.dbs.elki.datasource.bundle.MultipleObjectsBundle;
+import de.lmu.ifi.dbs.elki.datasource.filter.ObjectFilter;
+import de.lmu.ifi.dbs.elki.logging.Logging;
+import de.lmu.ifi.dbs.elki.utilities.documentation.Description;
+import de.lmu.ifi.dbs.elki.utilities.exceptions.AbortException;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.Parameterizable;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
+import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectListParameter;
+
+/**
+ * Joins multiple data sources by their existing order. Make sure the data
+ * sources are ordered appropriately!
+ * 
+ * @author Erich Schubert
+ */
+@Description("Blindly joins multiple data sources, assuming they are ordered the same way.")
+public class PresortedBlindJoinDatabaseConnection extends AbstractDatabaseConnection implements Parameterizable {
+  /**
+   * Logger
+   */
+  private static final Logging logger = Logging.getLogger(PresortedBlindJoinDatabaseConnection.class);
+
+  /**
+   * The filters to invoke
+   */
+  final protected List<DatabaseConnection> sources;
+
+  /**
+   * Constructor.
+   * 
+   * @param filters Filters to use.
+   * @param sources Data sources to join.
+   */
+  public PresortedBlindJoinDatabaseConnection(List<ObjectFilter> filters, List<DatabaseConnection> sources) {
+    super(filters);
+    this.sources = sources;
+  }
+
+  @Override
+  public MultipleObjectsBundle loadData() {
+    List<MultipleObjectsBundle> bundles = new ArrayList<MultipleObjectsBundle>(sources.size());
+    for(DatabaseConnection dbc : sources) {
+      bundles.add(dbc.loadData());
+    }
+
+    MultipleObjectsBundle first = bundles.get(0);
+    // Process additional columns
+    for(int c = 1; c < sources.size(); c++) {
+      MultipleObjectsBundle cur = bundles.get(c);
+      if(cur.dataLength() != first.dataLength()) {
+        throw new AbortException("Data set sizes do not agree - cannot join!");
+      }
+      for(int i = 0; i < cur.metaLength(); i++) {
+        first.appendColumn(cur.meta(i), cur.getColumn(i));
+      }
+    }
+
+    return first;
+  }
+
+  @Override
+  protected Logging getLogger() {
+    return logger;
+  }
+
+  /**
+   * Parameterization class.
+   * 
+   * @author Erich Schubert
+   * 
+   * @apiviz.exclude
+   */
+  public static class Parameterizer extends AbstractDatabaseConnection.Parameterizer {
+    /**
+     * The static option ID
+     */
+    public static final OptionID SOURCES_ID = OptionID.getOrCreateOptionID("join.sources", "The data sources to join.");
+
+    /**
+     * The data souces to use.
+     */
+    protected List<DatabaseConnection> sources;
+
+    @Override
+    protected void makeOptions(Parameterization config) {
+      super.makeOptions(config);
+      super.configFilters(config);
+      final ObjectListParameter<DatabaseConnection> sourcesParam = new ObjectListParameter<DatabaseConnection>(SOURCES_ID, DatabaseConnection.class);
+      if(config.grab(sourcesParam)) {
+        sources = sourcesParam.instantiateClasses(config);
+      }
+    }
+
+    @Override
+    protected PresortedBlindJoinDatabaseConnection makeInstance() {
+      return new PresortedBlindJoinDatabaseConnection(filters, sources);
+    }
+  }
+}
+\ No newline at end of file