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/*
 * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * 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 acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    [email protected].
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * 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 CAUCHO TECHNOLOGY 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.
 *
 * @author Scott Ferguson
 */

package com.alibaba.com.caucho.hessian.util;

/**
 * The IntMap provides a simple hashmap from keys to integers.  The API is
 * an abbreviation of the HashMap collection API.
 * 

*

The convenience of IntMap is avoiding all the silly wrapping of * integers. */ public class IntMap { /** * Encoding of a null entry. Since NULL is equal to Integer.MIN_VALUE, * it's impossible to distinguish between the two. */ public final static int NULL = 0xdeadbeef; // Integer.MIN_VALUE + 1; private static final Object DELETED = new Object(); private Object[] _keys; private int[] _values; private int _size; private int _mask; /** * Create a new IntMap. Default size is 16. */ public IntMap() { _keys = new Object[256]; _values = new int[256]; _mask = _keys.length - 1; _size = 0; } /** * Clear the hashmap. */ public void clear() { Object[] keys = _keys; int[] values = _values; for (int i = keys.length - 1; i >= 0; i--) { keys[i] = null; values[i] = 0; } _size = 0; } /** * Returns the current number of entries in the map. */ public int size() { return _size; } /** * Puts a new value in the property table with the appropriate flags */ public int get(Object key) { int mask = _mask; int hash = key.hashCode() % mask & mask; Object[] keys = _keys; while (true) { Object mapKey = keys[hash]; if (mapKey == null) return NULL; else if (mapKey == key || mapKey.equals(key)) return _values[hash]; hash = (hash + 1) % mask; } } /** * Expands the property table */ private void resize(int newSize) { Object[] newKeys = new Object[newSize]; int[] newValues = new int[newSize]; int mask = _mask = newKeys.length - 1; Object[] keys = _keys; int values[] = _values; for (int i = keys.length - 1; i >= 0; i--) { Object key = keys[i]; if (key == null || key == DELETED) continue; int hash = key.hashCode() % mask & mask; while (true) { if (newKeys[hash] == null) { newKeys[hash] = key; newValues[hash] = values[i]; break; } hash = (hash + 1) % mask; } } _keys = newKeys; _values = newValues; } /** * Puts a new value in the property table with the appropriate flags */ public int put(Object key, int value) { int mask = _mask; int hash = key.hashCode() % mask & mask; Object[] keys = _keys; while (true) { Object testKey = keys[hash]; if (testKey == null || testKey == DELETED) { keys[hash] = key; _values[hash] = value; _size++; if (keys.length <= 4 * _size) resize(4 * keys.length); return NULL; } else if (key != testKey && !key.equals(testKey)) { hash = (hash + 1) % mask; continue; } else { int old = _values[hash]; _values[hash] = value; return old; } } } /** * Deletes the entry. Returns true if successful. */ public int remove(Object key) { int mask = _mask; int hash = key.hashCode() % mask & mask; while (true) { Object mapKey = _keys[hash]; if (mapKey == null) return NULL; else if (mapKey == key) { _keys[hash] = DELETED; _size--; return _values[hash]; } hash = (hash + 1) % mask; } } @Override public String toString() { StringBuffer sbuf = new StringBuffer(); sbuf.append("IntMap["); boolean isFirst = true; for (int i = 0; i <= _mask; i++) { if (_keys[i] != null && _keys[i] != DELETED) { if (!isFirst) sbuf.append(", "); isFirst = false; sbuf.append(_keys[i]); sbuf.append(":"); sbuf.append(_values[i]); } } sbuf.append("]"); return sbuf.toString(); } }





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