/*
* @(#)$Id$
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.util.concurrent.counter;
import java.util.concurrent.atomic.AtomicInteger;
import xbird.util.lang.HashUtils;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public final class FixedStripeAtomicIntCounter implements ICounter {
private static final long serialVersionUID = -1886936728047307997L;
private final AtomicInteger _cnts1, _cnts2, _cnts3, _cnts4;
private volatile int _fuzzy_sum_cache;
private volatile long _fuzzy_time;
public FixedStripeAtomicIntCounter() {
this._cnts1 = new AtomicInteger();
this._cnts2 = new AtomicInteger();
this._cnts3 = new AtomicInteger();
this._cnts4 = new AtomicInteger();
}
public int get() {
return _cnts1.get() + _cnts2.get() + _cnts3.get() + _cnts4.get();
}
public int estimateGet() {
final long millis = System.currentTimeMillis();
if(_fuzzy_time != millis) {
_fuzzy_sum_cache = get();
_fuzzy_time = millis; // Indicate freshness of cached value
}
return _fuzzy_sum_cache;
}
public void add(final int x) {
final int idx = HashUtils.hash(Thread.currentThread(), 3);
switch(idx) {
case 0:
_cnts1.addAndGet(x);
break;
case 1:
_cnts2.addAndGet(x);
break;
case 2:
_cnts3.addAndGet(x);
break;
case 3:
_cnts4.addAndGet(x);
break;
}
}
public void add2(final int x) {
int hash = HashUtils.hash(Thread.currentThread());
final int idx = hash & 3;
switch(idx) {
case 0:
_cnts1.addAndGet(x);
break;
case 1:
_cnts2.addAndGet(x);
break;
case 2:
_cnts3.addAndGet(x);
break;
case 3:
_cnts4.addAndGet(x);
break;
}
}
public int getAndAdd(final int x) {
int l = get();
add(x);
return l;
}
public int addAndGet(final int x) {
add(x);
return get();
}
public int incrementAndGet() {
return addAndGet(1);
}
public int decrementAndGet() {
return addAndGet(-1);
}
public int getAndIncrement() {
return getAndAdd(1);
}
public int getAndDecrement() {
return getAndAdd(-1);
}
}