src/org/apache/xalan/xsltc/dom/CachedNodeListIterator.java

/*
 * @(#)$Id$
 *
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2001, Sun
 * Microsystems., http://www.sun.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.xalan.xsltc.dom;

import org.apache.xml.dtm.DTMAxisIterator;
import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
import org.apache.xalan.xsltc.util.IntegerArray;

/**
 * CachedNodeListIterator is used for select expressions in a 
 * variable or parameter. This iterator caches all nodes in an 
 * IntegerArray. Its cloneIterator() method is overridden to 
 * return an object of ClonedNodeListIterator.
 */
public final class CachedNodeListIterator extends DTMAxisIteratorBase {

    /**
     * Source for this iterator.
     */
    private DTMAxisIterator _source;
    private IntegerArray _nodes = new IntegerArray();
    private int _numCachedNodes = 0;
    private int _index = 0;
    private boolean _isEnded = false;

    public CachedNodeListIterator(DTMAxisIterator source) {
	_source = source;
    }

    public void setRestartable(boolean isRestartable) {
	//_isRestartable = isRestartable;
	//_source.setRestartable(isRestartable);
    }

    public DTMAxisIterator setStartNode(int node) {
	if (_isRestartable) {
	    _startNode = node;
	    _source.setStartNode(node);
	    resetPosition();
	    
	    _isRestartable = false;
	}
	return this;
    }

    public int next() {
        return getNode(_index++);
    }
    
    public int getPosition() {
    	return _index == 0 ? 1 : _index;
    }
    
    public int getNodeByPosition(int pos) {
    	return getNode(pos);
    }
        
    public int getNode(int index) {
        if (index < _numCachedNodes) {
            return _nodes.at(index);
        }
        else if (!_isEnded){
            int node = _source.next();
            if (node != END) {
            	_nodes.add(node);
            	_numCachedNodes++;
            }
            else {
            	_isEnded = true;
            }
            return node;
        }
        else
            return END;
    }

    public DTMAxisIterator cloneIterator() {
	ClonedNodeListIterator clone = new ClonedNodeListIterator(this);
	return clone;
    }

    public DTMAxisIterator reset() {
    	_index = 0;
    	return this;
    }
    
    public void setMark() {
	_source.setMark();
    }

    public void gotoMark() {
	_source.gotoMark();
    }
}