Java example source code file (DuplicateAttributeVerifier.java)

This example Java source code file (DuplicateAttributeVerifier.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

duplicateattributeverifier, entry, fastinfosetexception, map_size

The DuplicateAttributeVerifier.java Java example source code

/*
 * Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 * THIS FILE WAS MODIFIED BY SUN MICROSYSTEMS, INC.
 */

package com.sun.xml.internal.fastinfoset.util;

import com.sun.xml.internal.org.jvnet.fastinfoset.FastInfosetException;
import com.sun.xml.internal.fastinfoset.CommonResourceBundle;


public class DuplicateAttributeVerifier {
    public static final int MAP_SIZE = 256;

    public int _currentIteration;

    public static class Entry {
        private int iteration;
        private int value;

        private Entry hashNext;

        private Entry poolNext;
    }

    private Entry[] _map;

    public final Entry _poolHead;
    public Entry _poolCurrent;
    private Entry _poolTail;


    public DuplicateAttributeVerifier() {
        _poolTail = _poolHead = new Entry();
    }

    public final void clear() {
        _currentIteration = 0;

        Entry e = _poolHead;
        while (e != null) {
            e.iteration = 0;
            e = e.poolNext;
        }

        reset();
    }

    public final void reset() {
        _poolCurrent = _poolHead;
        if (_map == null) {
            _map = new Entry[MAP_SIZE];
        }
    }

    private final void increasePool(int capacity) {
        if (_map == null) {
            _map = new Entry[MAP_SIZE];
            _poolCurrent = _poolHead;
        } else {
            final Entry tail = _poolTail;
            for (int i = 0; i < capacity; i++) {
                final Entry e = new Entry();
                _poolTail.poolNext = e;
                _poolTail = e;
            }

            _poolCurrent = tail.poolNext;
        }
    }

    public final void checkForDuplicateAttribute(int hash, int value) throws FastInfosetException {
        if (_poolCurrent == null) {
            increasePool(16);
        }

        // Get next free entry
        final Entry newEntry = _poolCurrent;
        _poolCurrent = _poolCurrent.poolNext;

        final Entry head = _map[hash];
        if (head == null || head.iteration < _currentIteration) {
            newEntry.hashNext = null;
            _map[hash] = newEntry;
            newEntry.iteration = _currentIteration;
            newEntry.value = value;
        } else {
            Entry e = head;
            do {
                if (e.value == value) {
                    reset();
                    throw new FastInfosetException(CommonResourceBundle.getInstance().getString("message.duplicateAttribute"));
                }
            } while ((e = e.hashNext) != null);

            newEntry.hashNext = head;
            _map[hash] = newEntry;
            newEntry.iteration = _currentIteration;
            newEntry.value = value;
        }
    }
}