1 files changed, 95 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/index/tree/Node.java b/src/de/lmu/ifi/dbs/elki/index/tree/Node.java
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+++ b/src/de/lmu/ifi/dbs/elki/index/tree/Node.java
@@ -0,0 +1,95 @@
+package de.lmu.ifi.dbs.elki.index.tree;
+/*
+This file is part of ELKI:
+Environment for Developing KDD-Applications Supported by Index-Structures
+
+Copyright (C) 2011
+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.Enumeration;
+
+import de.lmu.ifi.dbs.elki.persistent.Page;
+
+/**
+ * This interface defines the common requirements of nodes in an index
+ * structure. A node has to extend the page interface for persistent storage and
+ * has to provide an enumeration over its children.
+ * 
+ * @author Elke Achtert
+ * 
+ * @apiviz.composedOf Entry
+ * 
+ * @param <E> the type of Entry used in the index
+ */
+public interface Node<E extends Entry> extends Page {
+  /**
+   * Returns an enumeration of the children paths of this node.
+   * 
+   * @param parentPath the path to this node
+   * @return an enumeration of the children paths of this node
+   */
+  Enumeration<IndexTreePath<E>> children(IndexTreePath<E> parentPath);
+
+  /**
+   * Returns the number of entries of this node.
+   * 
+   * @return the number of entries of this node
+   */
+  int getNumEntries();
+
+  /**
+   * Returns true if this node is a leaf node, false otherwise.
+   * 
+   * @return true if this node is a leaf node, false otherwise
+   */
+  boolean isLeaf();
+
+  /**
+   * Returns the entry at the specified index.
+   * 
+   * @param index the index of the entry to be returned
+   * @return the entry at the specified index
+   */
+  E getEntry(int index);
+
+  /**
+   * Adds a new leaf entry to this node's children and returns the index of the
+   * entry in this node's children array. An UnsupportedOperationException will
+   * be thrown if the entry is not a leaf entry or this node is not a leaf node.
+   * 
+   * @param entry the leaf entry to be added
+   * @return the index of the entry in this node's children array
+   * @throws UnsupportedOperationException if entry is not a leaf entry or this
+   *         node is not a leaf node
+   */
+  int addLeafEntry(E entry);
+
+  /**
+   * Adds a new directory entry to this node's children and returns the index of
+   * the entry in this node's children array. An UnsupportedOperationException
+   * will be thrown if the entry is not a directory entry or this node is not a
+   * directory node.
+   * 
+   * @param entry the directory entry to be added
+   * @return the index of the entry in this node's children array
+   * @throws UnsupportedOperationException if entry is not a directory entry or
+   *         this node is not a directory node
+   */
+  int addDirectoryEntry(E entry);
+}
+\ No newline at end of file