com.metamx.emitter.core.ConcurrentTimeCounter Maven / Gradle / Ivy
/*
* Copyright 2016 Metamarkets Group Inc.
*
* 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.
*
*/
package com.metamx.emitter.core;
import com.google.common.primitives.UnsignedInts;
import java.util.concurrent.atomic.AtomicLong;
/**
* A class to accumulate simple stats of some time points. All methods are safe to use from multiple threads.
*/
public class ConcurrentTimeCounter
{
/** Lower 32 bits for sum of {@link #add}ed times, higher 32 bits for the count */
private final AtomicLong timeSumAndCount = new AtomicLong(0L);
/** Lower 32 bits for the max {@link #add}ed time, 63th bit for indication if any value is added. */
private final AtomicLong max = new AtomicLong(-1);
/** Similar to {@link #max} */
private final AtomicLong min = new AtomicLong(-1);
public void add(int time)
{
long x = (1L << 32) | time;
timeSumAndCount.addAndGet(x);
updateMax(time);
updateMin(time);
}
private void updateMax(int time)
{
long max;
do {
max = this.max.get();
if (max >= 0 && ((int) max) >= time) {
return;
}
} while (!this.max.compareAndSet(max, UnsignedInts.toLong(time)));
}
private void updateMin(int time)
{
long min;
do {
min = this.min.get();
if (min >= 0 && ((int) min) <= time) {
return;
}
} while (!this.min.compareAndSet(min, UnsignedInts.toLong(time)));
}
public long getTimeSumAndCountAndReset()
{
return timeSumAndCount.getAndSet(0L);
}
public int getAndResetMaxTime()
{
long max = this.max.getAndSet(-1);
// If max < 0, means no times added yet, then return 0
return max >= 0 ? (int) max : 0;
}
public int getAndResetMinTime()
{
long min = this.min.getAndSet(-1);
// If min < 0, means no times added yet, then return 0
return min >= 0 ? (int) min : 0;
}
public static int timeSum(long timeSumAndCount)
{
return (int) timeSumAndCount;
}
public static int count(long timeSumAndCount)
{
return (int) (timeSumAndCount >> 32);
}
}