/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001, 2002 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 "Xerces" 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) 2002 International
* Business Machines, Inc., http://www.apache.org. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xerces.impl.xs.dom;
import org.apache.xerces.dom.TextImpl;
import org.apache.xerces.dom.AttrNSImpl;
/**
* This class is pool that enables caching of DOM nodes, such as Element, Attr,
* Text, that are used to parse and later traverse XML Schemas.
* The pool is reset before a new set of schemas is traversed.
* Note: pool is not reset during traversals of imported/included
* schemas.
*
* @author Elena Litani, IBM
* @version $Id: DOMNodePool.java,v 1.1 2002/04/03 23:48:27 elena Exp $
*/
public final class DOMNodePool {
/** Chunk shift (8). */
private static final int CHUNK_SHIFT = 8; // 2^8 = 256
/** Chunk size (1 << CHUNK_SHIFT). */
private static final int CHUNK_SIZE = 1 << CHUNK_SHIFT;
/** Chunk mask (CHUNK_SIZE - 1). */
private static final int CHUNK_MASK = CHUNK_SIZE - 1;
/** Initial chunk count (). */
private static final int INITIAL_CHUNK_COUNT = (1 << (10 - CHUNK_SHIFT)); // 2^10 = 1k
/** Element nodes pool*/
private ElementNSImpl fElements[][] = new ElementNSImpl[INITIAL_CHUNK_COUNT][];
private int fElementIndex = 0;
/** Text nodes pool*/
private TextImpl fTextNode[][] = new TextImpl[INITIAL_CHUNK_COUNT][];
private int fTextNodeIndex = 0;
/** Attribute nodes pool*/
private AttrNSImpl fAttrNode[][] = new AttrNSImpl[INITIAL_CHUNK_COUNT][];
private int fAttrNodeIndex = 0;
/**
* This method creates a new element node or provides a
* free element node if such exists in the pool.
*
* @return
*/
public final ElementNSImpl getElementNode(){
int chunk = fElementIndex >> CHUNK_SHIFT;
int index = fElementIndex & CHUNK_MASK;
ensureElementsCapacity(chunk);
if (fElements[chunk][index] == null) {
fElements[chunk][index] = new ElementNSImpl();
}
fElementIndex++;
return fElements[chunk][index];
}
private boolean ensureElementsCapacity(int chunk) {
try {
return fElements[chunk][0] == null;
} catch (ArrayIndexOutOfBoundsException ex) {
fElements = resize(fElements, fElements.length * 2);
} catch (NullPointerException ex) {
// ignore
}
fElements[chunk] = new ElementNSImpl[CHUNK_SIZE];
return true;
}
private static ElementNSImpl[][] resize(ElementNSImpl array[][], int newsize) {
ElementNSImpl newarray[][] = new ElementNSImpl[newsize][];
System.arraycopy(array, 0, newarray, 0, array.length);
return newarray;
}
/**
* This methods creates text node or provides a free
* text node if such exists in the pool.
*
* @return
*/
public final TextImpl getTextNode(){
int chunk = fTextNodeIndex >> CHUNK_SHIFT;
int index = fTextNodeIndex & CHUNK_MASK;
ensureTextCapacity(chunk);
if (fTextNode[chunk][index] == null) {
fTextNode[chunk][index] = new TextImpl();
}
fTextNodeIndex++;
return fTextNode[chunk][index];
}
private boolean ensureTextCapacity(int chunk) {
try {
return fTextNode[chunk][0] == null;
} catch (ArrayIndexOutOfBoundsException ex) {
fTextNode = resize(fTextNode, fTextNode.length * 2);
} catch (NullPointerException ex) {
// ignore
}
fTextNode[chunk] = new TextImpl[CHUNK_SIZE];
return true;
}
private static TextImpl[][] resize(TextImpl array[][], int newsize) {
TextImpl newarray[][] = new TextImpl[newsize][];
System.arraycopy(array, 0, newarray, 0, array.length);
return newarray;
}
/**
* This methods creates attribute node or provides a free
* attribute node if such exists in the pool.
*
* @return
*/
public final AttrNSImpl getAttrNode(){
int chunk = fAttrNodeIndex >> CHUNK_SHIFT;
int index = fAttrNodeIndex & CHUNK_MASK;
ensureAttrsCapacity(chunk);
if (fAttrNode[chunk][index] == null) {
fAttrNode[chunk][index] = new AttrNSImpl();
}
fAttrNodeIndex++;
return fAttrNode[chunk][index];
}
private boolean ensureAttrsCapacity(int chunk) {
try {
return fAttrNode[chunk][0] == null;
} catch (ArrayIndexOutOfBoundsException ex) {
fAttrNode = resize(fAttrNode, fAttrNode.length * 2);
} catch (NullPointerException ex) {
// ignore
}
fAttrNode[chunk] = new AttrNSImpl[CHUNK_SIZE];
return true;
}
private static AttrNSImpl[][] resize(AttrNSImpl array[][], int newsize) {
AttrNSImpl newarray[][] = new AttrNSImpl[newsize][];
System.arraycopy(array, 0, newarray, 0, array.length);
return newarray;
}
/**
* Reset the pool. The nodes in the pool become 'free' nodes.
*/
public void reset(){
fElementIndex = 0;
fTextNodeIndex = 0;
fAttrNodeIndex = 0;
}
}