| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 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 "Apache" 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 |
| * XMLBeans", 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) 2000-2003 BEA Systems |
| * Inc., <http://www.bea.com/>. For more information on the Apache Software |
| * Foundation, please see <http://www.apache.org/>. |
| */ |
| |
| package org.apache.xmlbeans; |
| |
| import javax.xml.namespace.QName; |
| |
| /** |
| * A cache that can be used to pool QName instances. Each thread has one. |
| */ |
| public final class QNameCache |
| { |
| private static final float DEFAULT_LOAD = 0.70f; |
| private final float loadFactor; |
| private int numEntries = 0; |
| private int threshold; |
| private int hashmask; |
| private QName[] table; |
| |
| /** |
| * Creates a QNameCache with the given initialCapacity and loadFactor. |
| * |
| * @param initialCapacity the number of entries to initially make space for |
| * @param loadFactor a number to control the density of the hashtable |
| */ |
| public QNameCache(int initialCapacity, float loadFactor) |
| { |
| assert initialCapacity > 0; |
| assert loadFactor > 0 && loadFactor < 1; |
| |
| // Find a power of 2 >= initialCapacity |
| int capacity = 16; |
| while (capacity < initialCapacity) |
| capacity <<= 1; |
| |
| this.loadFactor = loadFactor; |
| this.hashmask = capacity - 1; |
| threshold = (int)(capacity * loadFactor); |
| table = new QName[capacity]; |
| } |
| |
| /** |
| * Creates a QNameCache with the given initialCapacity. |
| * |
| * @param initialCapacity the number of entries to initially make space for |
| */ |
| public QNameCache(int initialCapacity) |
| { |
| this(initialCapacity, DEFAULT_LOAD); |
| } |
| |
| /** |
| * Fetches a QName with the given namespace and localname. |
| * Creates one if one is not found in the cache. |
| * |
| * @param uri the namespace |
| * @param localName the localname |
| * @return the cached QName |
| */ |
| public QName getName(String uri, String localName) |
| { |
| /* |
| return new QName(uri, localName); |
| */ |
| assert localName != null; |
| |
| if (uri == null) uri = ""; |
| |
| int index = hash(uri, localName) & hashmask; |
| while (true) { |
| QName q = table[index]; |
| if (q == null) |
| { |
| numEntries++; |
| if (numEntries >= threshold) |
| rehash(); |
| |
| return table[index] = new QName(uri, localName); |
| } |
| else if (equals(q, uri, localName)) |
| return q; |
| else |
| index = (index-1) & hashmask; |
| } |
| } |
| |
| private void rehash() |
| { |
| int newLength = table.length * 2; |
| QName[] newTable = new QName[newLength]; |
| int newHashmask = newLength - 1; |
| |
| for (int i = 0 ; i < table.length ; i++) |
| { |
| QName q = table[i]; |
| if (q != null) |
| { |
| int newIndex = hash(q.getNamespaceURI(), q.getLocalPart()) & newHashmask; |
| while (newTable[newIndex] != null) |
| newIndex = (newIndex - 1) & newHashmask; |
| newTable[newIndex] = q; |
| } |
| } |
| |
| table = newTable; |
| hashmask = newHashmask; |
| threshold = (int)(newLength * loadFactor); |
| } |
| private static int hash(String uri, String localName) |
| { |
| return (uri.hashCode() << 5) + localName.hashCode(); |
| } |
| |
| private static boolean equals(QName q, String uri, String localName) |
| { |
| return q.getLocalPart().equals(localName) && q.getNamespaceURI().equals(uri); |
| } |
| } |