/*******************************************************************************
* This file is part of logisim-evolution.
*
* logisim-evolution 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 3 of the License, or
* (at your option) any later version.
*
* logisim-evolution 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with logisim-evolution. If not, see <http://www.gnu.org/licenses/>.
*
* Original code by Carl Burch (http://www.cburch.com), 2011.
* Subsequent modifications by :
* + Haute École Spécialisée Bernoise
* http://www.bfh.ch
* + Haute École du paysage, d'ingénierie et d'architecture de Genève
* http://hepia.hesge.ch/
* + Haute École d'Ingénierie et de Gestion du Canton de Vaud
* http://www.heig-vd.ch/
* The project is currently maintained by :
* + REDS Institute - HEIG-VD
* Yverdon-les-Bains, Switzerland
* http://reds.heig-vd.ch
*******************************************************************************/
package com.cburch.logisim.util;
/**
* Allows immutable objects to be cached in memory in order to reduce the
* creation of duplicate objects.
*/
public class Cache {
private int mask;
private Object[] data;
public Cache() {
this(8);
}
public Cache(int logSize) {
if (logSize > 12)
logSize = 12;
data = new Object[1 << logSize];
mask = data.length - 1;
}
public Object get(int hashCode) {
return data[hashCode & mask];
}
public Object get(Object value) {
if (value == null)
return null;
int code = value.hashCode() & mask;
Object ret = data[code];
if (ret != null && ret.equals(value)) {
return ret;
} else {
data[code] = value;
return value;
}
}
public void put(int hashCode, Object value) {
if (value != null) {
data[hashCode & mask] = value;
}
}
}