svn commit: r792841 - /directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java

[el...@apache.org]

Author: elecharny
Date: Fri Jul 10 09:01:52 2009
New Revision: 792841

URL: http://svn.apache.org/viewvc?rev=792841&view=rev
Log:
First version of the arrayTree cursor. Tests need to be added

Added:
    directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java

Added: directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java
URL: http://svn.apache.org/viewvc/directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java?rev=792841&view=auto
==============================================================================
--- directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java (added)
+++ directory/apacheds/trunk/core-avl/src/main/java/org/apache/directory/server/core/avltree/ArrayTreeCursor.java Fri Jul 10 09:01:52 2009
@@ -0,0 +1,275 @@
+/*
+ *   Licensed to the Apache Software Foundation (ASF) under one
+ *   or more contributor license agreements.  See the NOTICE file
+ *   distributed with this work for additional information
+ *   regarding copyright ownership.  The ASF licenses this file
+ *   to you under the Apache License, Version 2.0 (the
+ *   "License"); you may not use this file except in compliance
+ *   with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing,
+ *   software distributed under the License is distributed on an
+ *   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *   KIND, either express or implied.  See the License for the
+ *   specific language governing permissions and limitations
+ *   under the License.
+ *
+ */
+package org.apache.directory.server.core.avltree;
+
+import org.apache.directory.shared.ldap.cursor.AbstractCursor;
+import org.apache.directory.shared.ldap.cursor.InvalidCursorPositionException;
+
+
+
+
+/**
+ * A Cursor for an ArrayTree.
+ *
+ * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
+ * @version $Rev$, $Date$
+ */
+public class ArrayTreeCursor<K> extends AbstractCursor<K>
+{
+    /** The underlying ArrayTree */
+    private ArrayTree<K> array;
+    
+    /** The current node */
+    private K node;
+    
+    /** A flag set to true if we are pointing to a node */
+    private boolean onNode = false;
+    
+    /** A flag to tell if we are after the last node */
+    private boolean isAfterLast = false;
+
+    /** A flag to tell if we are before the first node */
+    private boolean isBeforeFirst = true;
+ 
+    
+    /**
+     * Create a cursor on an ArrayTree
+     * @param array The array we want a cursor for
+     */
+    public ArrayTreeCursor( ArrayTree<K> array )
+    {
+        this.array = array;
+    }
+
+    
+    /**
+     * {@inheritDoc}
+     */
+    public void after( K element ) throws Exception 
+    {
+        checkNotClosed( "after" );
+
+        if ( element == null )
+        {
+            afterLast();
+            return;
+        }
+
+        K found = array.findGreater( element );
+        
+        if ( found == null )
+        {
+            node = array.getLast();
+            onNode = false;
+            isAfterLast = true;
+            isBeforeFirst = false;
+            return;
+        }
+
+        node = found;
+        isAfterLast = false;
+        isBeforeFirst = false;
+        onNode = false;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public void afterLast() throws Exception 
+    {
+        checkNotClosed( "afterLast" );
+        node = array.getLast();
+        isBeforeFirst = false;
+        isAfterLast = true;
+        onNode = false;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean available()
+    {
+        return onNode;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public void before( K element ) throws Exception 
+    {
+        checkNotClosed( "before" );
+
+        if ( element == null )
+        {
+            beforeFirst();
+            return;
+        }
+
+        K found = array.findLess( element );
+        
+        if ( found == null )
+        {
+            node = array.getFirst();
+            isAfterLast = false;
+            isBeforeFirst = true;
+        }
+        else
+        {
+            node = found;
+            isAfterLast = false;
+            isBeforeFirst = false;
+        }
+        
+        onNode = false;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public void beforeFirst() throws Exception 
+    {
+        checkNotClosed( "beforeFirst" );
+        node = array.getFirst();
+        isBeforeFirst = true;
+        isAfterLast = false;
+        onNode = false;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean first() throws Exception 
+    {
+        checkNotClosed( "first" );
+        
+        node = array.getFirst();
+        isBeforeFirst = false;
+        isAfterLast = false;
+        return onNode = node != null;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public K get() throws Exception 
+    {
+        checkNotClosed( "get" );
+        
+        if ( onNode )
+        {
+            return node;
+        }
+        
+        throw new InvalidCursorPositionException();
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean isElementReused()
+    {
+        return true;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean last() throws Exception 
+    {
+        checkNotClosed( "last" );
+        node = array.getLast();
+        isBeforeFirst = false;
+        isAfterLast = false;
+        return onNode = node != null;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean next() throws Exception 
+    {
+        checkNotClosed( "next" );
+        
+        if ( isAfterLast )
+        {
+            return false;
+        }
+
+        if ( isBeforeFirst )
+        {
+            node = array.getFirst();
+            isBeforeFirst = false;
+            isAfterLast = false;
+            onNode = node != null;
+            return onNode;
+        }
+
+        node = array.getNext();
+        onNode = node != null;
+        
+        if ( !onNode )
+        {
+            isAfterLast = true;
+        }
+        
+        return onNode;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public boolean previous() throws Exception
+    {
+        checkNotClosed( "previous" );
+
+        if ( isBeforeFirst )
+        {
+            return false;
+        }
+
+        if ( isAfterLast )
+        {
+            node = array.getLast();
+            isBeforeFirst = false;
+            isAfterLast = false;
+            return onNode = node != null;
+        }
+
+        node = array.getPrevious();
+        onNode = node != null;
+        
+        if ( !onNode )
+        {
+            isBeforeFirst = true;
+        }
+        
+        return onNode;
+    }
+}