/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.util;
import java.util.Iterator;
/**
* 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 IntMap {
/**
* Encoding of a null entry. Since NULL is equal to Integer.MIN_VALUE,
* it's impossible to distinguish between the two.
*/
private final static Object NULL_KEY = new Object();
public final static int NULL = -65536; // Integer.MIN_VALUE + 1;
private static int DELETED = 0x1;
private final Item []_entries;
private final int _mask;
private int _size;
/**
* Create a new IntMap. Default size is 256
*/
public IntMap()
{
this(256);
}
/**
* Create a new IntMap.
*/
public IntMap(int initialCapacity)
{
int capacity;
for (capacity = 16; capacity < 2 * initialCapacity; capacity *= 2) {
}
_entries = new Item[capacity];
_mask = capacity - 1;
}
/**
* Create copy of an IntMap
*/
private IntMap(Item []entries)
{
_entries = new Item[entries.length];
_mask = _entries.length - 1;
for (Item item : entries) {
for (; item != null; item = item._next) {
put(item._key, item._value);
}
}
}
/**
* Clear the hashmap.
*/
public void clear()
{
for (int i = 0; i < _entries.length; i++) {
_entries[i] = null;
}
_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)
{
if (key == null)
key = NULL_KEY;
int hash = key.hashCode() & _mask;
for (Item item = _entries[hash]; item != null; item = item._next) {
Object itemKey = item._key;
if (itemKey == key || itemKey.equals(key))
return item._value;
}
return NULL;
}
/**
* Puts a new value in the property table with the appropriate flags
*/
public int put(Object key, int value)
{
if (key == null)
key = NULL_KEY;
synchronized (this) {
int hash = key.hashCode() & _mask;
for (Item item = _entries[hash]; item != null; item = item._next) {
Object testKey = item._key;
if (testKey == key || testKey.equals(key)) {
int oldValue = item._value;
item._value = value;
return oldValue;
}
}
Item item = new Item(key, value);
item._next = _entries[hash];
_entries[hash] = item;
_size++;
}
return NULL;
}
/**
* Deletes the entry. Returns true if successful.
*/
public int remove(Object key)
{
if (key == null)
key = NULL_KEY;
int hash = key.hashCode() & _mask;
synchronized (this) {
Item prev = null;
for (Item item = _entries[hash]; item != null; item = item._next) {
Object itemKey = item._key;
if (itemKey == key || itemKey.equals(key)) {
int oldValue = item._value;
if (prev != null)
prev._next = item._next;
else
_entries[hash] = item._next;
_size--;
return oldValue;
}
prev = item;
}
}
return NULL;
}
/**
* Returns an iterator of the keys.
*/
public Iterator iterator()
{
return new IntMapIterator();
}
public Object clone()
{
return new IntMap(_entries);
}
public String toString()
{
return "IntMap[]";
/*
StringBuffer sbuf = new StringBuffer();
sbuf.append("IntMap[");
boolean isFirst = true;
for (int i = 0; i <= _mask; 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();
*/
}
class IntMapIterator implements Iterator {
int _index = -1;
Item _item;
public boolean hasNext()
{
if (_item != null)
return true;
for (_index++; _index < _entries.length; _index++) {
_item = _entries[_index];
if (_item != null)
return true;
}
return false;
}
public Object next()
{
if (_item != null) {
Object key = _item._key;
_item = _item._next;
return key;
}
for (_index++; _index < _entries.length; _index++) {
_item = _entries[_index];
if (_item != null) {
Object key = _item._key;
_item = _item._next;
return key;
}
}
return null;
}
public void remove()
{
throw new RuntimeException();
}
}
static class Item {
final Object _key;
int _value;
Item _next;
Item(Object key, int value)
{
_key = key;
_value = value;
}
}
}