/*
* 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
* info@caucho.com.
*
* 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.caucho.hessian.util;
/**
* The IntMap provides a simple hashmap from keys to integers. The API is
* an abbreviation of the HashMap collection API.
*
* <p>The convenience of IntMap is avoiding all the silly wrapping of
* integers.
*/
public class IdentityIntMap {
/**
* 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 Object []_keys;
private int []_values;
private int _size;
private int _prime;
/**
* Create a new IntMap. Default size is 16.
*/
public IdentityIntMap(int capacity)
{
_keys = new Object[capacity];
_values = new int[capacity];
_prime = getBiggestPrime(_keys.length);
_size = 0;
}
/**
* Clear the hashmap.
*/
public void clear()
{
final Object []keys = _keys;
final 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 final int size()
{
return _size;
}
/**
* Puts a new value in the property table with the appropriate flags
*/
public final int get(Object key)
{
int prime = _prime;
int hash = System.identityHashCode(key) % prime;
// int hash = key.hashCode() & mask;
final Object []keys = _keys;
while (true) {
Object mapKey = keys[hash];
if (mapKey == null)
return NULL;
else if (mapKey == key)
return _values[hash];
hash = (hash + 1) % prime;
}
}
/**
* Puts a new value in the property table with the appropriate flags
*/
public final int put(Object key, int value, boolean isReplace)
{
int prime = _prime;
int hash = System.identityHashCode(key) % prime;
// int hash = key.hashCode() % prime;
Object []keys = _keys;
while (true) {
Object testKey = keys[hash];
if (testKey == null) {
keys[hash] = key;
_values[hash] = value;
_size++;
if (keys.length <= 4 * _size)
resize(4 * keys.length);
return value;
}
else if (key != testKey) {
hash = (hash + 1) % prime;
continue;
}
else if (isReplace){
int old = _values[hash];
_values[hash] = value;
return old;
}
else {
return _values[hash];
}
}
}
/**
* Removes a value in the property table.
*/
public final void remove(Object key)
{
if (put(key, NULL, true) != NULL) {
_size--;
}
}
/**
* Expands the property table
*/
private void resize(int newSize)
{
Object []keys = _keys;
int values[] = _values;
_keys = new Object[newSize];
_values = new int[newSize];
_size = 0;
_prime = getBiggestPrime(_keys.length);
for (int i = keys.length - 1; i >= 0; i--) {
Object key = keys[i];
int value = values[i];
if (key != null && value != NULL) {
put(key, value, true);
}
}
}
protected int hashCode(Object value)
{
return System.identityHashCode(value);
}
public String toString()
{
StringBuffer sbuf = new StringBuffer();
sbuf.append("IntMap[");
boolean isFirst = true;
for (int i = 0; i <= _keys.length; i++) {
if (_keys[i] != null) {
if (! isFirst)
sbuf.append(", ");
isFirst = false;
sbuf.append(_keys[i]);
sbuf.append(":");
sbuf.append(_values[i]);
}
}
sbuf.append("]");
return sbuf.toString();
}
public static final int []PRIMES =
{
1, /* 1<< 0 = 1 */
2, /* 1<< 1 = 2 */
3, /* 1<< 2 = 4 */
7, /* 1<< 3 = 8 */
13, /* 1<< 4 = 16 */
31, /* 1<< 5 = 32 */
61, /* 1<< 6 = 64 */
127, /* 1<< 7 = 128 */
251, /* 1<< 8 = 256 */
509, /* 1<< 9 = 512 */
1021, /* 1<<10 = 1024 */
2039, /* 1<<11 = 2048 */
4093, /* 1<<12 = 4096 */
8191, /* 1<<13 = 8192 */
16381, /* 1<<14 = 16384 */
32749, /* 1<<15 = 32768 */
65521, /* 1<<16 = 65536 */
131071, /* 1<<17 = 131072 */
262139, /* 1<<18 = 262144 */
524287, /* 1<<19 = 524288 */
1048573, /* 1<<20 = 1048576 */
2097143, /* 1<<21 = 2097152 */
4194301, /* 1<<22 = 4194304 */
8388593, /* 1<<23 = 8388608 */
16777213, /* 1<<24 = 16777216 */
33554393, /* 1<<25 = 33554432 */
67108859, /* 1<<26 = 67108864 */
134217689, /* 1<<27 = 134217728 */
268435399, /* 1<<28 = 268435456 */
};
public static int getBiggestPrime(int value)
{
for (int i = PRIMES.length - 1; i >= 0; i--) {
if (PRIMES[i] <= value)
return PRIMES[i];
}
return 2;
}
}