com.caucho.util.LongMap Maven / Gradle / Ivy
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/*
* Copyright (c) 1998-2012 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 SoftwareFoundation, 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.
*
* The convenience of IntMap is avoiding all the silly wrapping of
* integers.
*/
public class LongMap {
/**
* Encoding of a null entry. Since NULL is equal to Integer.MIN_VALUE,
* it's impossible to distinguish between the two.
*/
public final static long NULL = 0xffffffffffffffedL;
private static int DELETED = 0x1;
private K []_keys;
private long _nullValue;
private long []_values;
private byte []_flags;
private int _size;
private int _mask;
/**
* Create a new LongMap. Default size is 16.
*/
public LongMap()
{
_keys = (K []) new Object[16];
_values = new long[16];
_flags = new byte[16];
_mask = _keys.length - 1;
_size = 0;
_nullValue = NULL;
}
/**
* Create a new IntMap for cloning.
*/
private LongMap(boolean dummy)
{
}
/**
* Clear the hashmap.
*/
public void clear()
{
_nullValue = NULL;
for (int i = 0; i < _values.length; i++) {
_keys[i] = null;
_flags[i] = 0;
_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 long get(K key)
{
if (key == null)
return _nullValue;
int hash = key.hashCode() & _mask;
while (true) {
K mapKey = _keys[hash];
if (mapKey == key)
return _values[hash];
else if (mapKey == null) {
if ((_flags[hash] & DELETED) == 0)
return NULL;
}
else if (mapKey.equals(key))
return _values[hash];
hash = (hash + 1) & _mask;
}
}
/**
* Expands the property table
*/
private void resize(int newSize)
{
K []newKeys = (K []) new Object[newSize];
long []newValues = new long[newSize];
byte []newFlags = new byte[newSize];
_mask = newKeys.length - 1;
for (int i = 0; i < _keys.length; i++) {
if (_keys[i] == null || (_flags[i] & DELETED) != 0)
continue;
int hash = _keys[i].hashCode() & _mask;
while (true) {
if (newKeys[hash] == null) {
newKeys[hash] = _keys[i];
newValues[hash] = _values[i];
newFlags[hash] = _flags[i];
break;
}
hash = (hash + 1) & _mask;
}
}
_keys = newKeys;
_values = newValues;
_flags = newFlags;
}
/**
* Puts a new value in the property table with the appropriate flags
*/
public long put(K key, long value)
{
return put(key, value, false);
}
/**
* Puts a new value in the property table with the appropriate flags
*/
public long putIfNew(K key, long value)
{
return put(key, value, true);
}
/**
* Puts a new value in the property table with the appropriate flags
*/
private long put(K key, long value, boolean ifNew)
{
if (key == null) {
long old = _nullValue;
_nullValue = value;
return old;
}
int hash = key.hashCode() & _mask;
while (true) {
K testKey = _keys[hash];
if (testKey == null || (_flags[hash] & DELETED) != 0) {
_keys[hash] = key;
_values[hash] = value;
_flags[hash] = 0;
_size++;
if (_keys.length <= 2 * _size)
resize(2 * _keys.length);
return NULL;
}
else if (key != testKey && ! testKey.equals(key)) {
hash = (hash + 1) & _mask;
continue;
}
else if (ifNew) {
return _values[hash];
}
else {
long old = _values[hash];
_values[hash] = value;
return old;
}
}
}
/**
* Deletes the entry. Returns true if successful.
*/
public long remove(K key)
{
if (key == null) {
long old = _nullValue;
_nullValue = NULL;
return old;
}
int hash = key.hashCode() & _mask;
while (true) {
Object mapKey = _keys[hash];
if (mapKey == null)
return NULL;
else if (mapKey.equals(key)) {
_flags[hash] |= DELETED;
_size--;
_keys[hash] = null;
return _values[hash];
}
hash = (hash + 1) & _mask;
}
}
/**
* Returns an iterator of the keys.
*/
public Iterator iterator()
{
return new LongMapIterator();
}
public Object clone()
{
LongMap clone = new LongMap(true);
clone._keys = new Object[_keys.length];
System.arraycopy(_keys, 0, clone._keys, 0, _keys.length);
clone._values = new long[_values.length];
System.arraycopy(_values, 0, clone._values, 0, _values.length);
clone._flags = new byte[_flags.length];
System.arraycopy(_flags, 0, clone._flags, 0, _flags.length);
clone._mask = _mask;
clone._size = _size;
clone._nullValue = _nullValue;
return clone;
}
public String toString()
{
StringBuffer sbuf = new StringBuffer();
sbuf.append("LongMap[");
boolean isFirst = true;
for (int i = 0; i <= _mask; i++) {
if ((_flags[i] & DELETED) == 0 && _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 LongMapIterator implements Iterator {
int _index;
public boolean hasNext()
{
for (; _index < _keys.length; _index++)
if (_keys[_index] != null && (_flags[_index] & DELETED) == 0)
return true;
return false;
}
public Object next()
{
for (; _index < _keys.length; _index++)
if (_keys[_index] != null && (_flags[_index] & DELETED) == 0)
return _keys[_index++];
return null;
}
public void remove()
{
throw new RuntimeException();
}
}
}