io.micrometer.core.instrument.step.StepLong Maven / Gradle / Ivy
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/**
* Copyright 2017 Pivotal Software, 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 io.micrometer.core.instrument.step;
import io.micrometer.core.instrument.Clock;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAdder;
public class StepLong {
private final Clock clock;
private final long stepMillis;
private final LongAdder current = new LongAdder();
private final AtomicLong lastInitPos;
private volatile double previous = 0.0;
public StepLong(Clock clock, long stepMillis) {
this.clock = clock;
this.stepMillis = stepMillis;
lastInitPos = new AtomicLong(clock.wallTime() / stepMillis);
}
private void rollCount(long now) {
final long stepTime = now / stepMillis;
final long lastInit = lastInitPos.get();
if (lastInit < stepTime && lastInitPos.compareAndSet(lastInit, stepTime)) {
final double v = current.sumThenReset();
// Need to check if there was any activity during the previous step interval. If there was
// then the init position will move forward by 1, otherwise it will be older. No activity
// means the previous interval should be set to the `init` value.
previous = (lastInit == stepTime - 1) ? v : 0.0;
}
}
public LongAdder getCurrent() {
return current;
}
/**
* @return The value for the last completed interval.
*/
public double poll() {
rollCount(clock.wallTime());
return previous;
}
}