com.uber.m3.tally.CounterImpl Maven / Gradle / Ivy
// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package com.uber.m3.tally;
import com.uber.m3.util.ImmutableMap;
import java.util.concurrent.atomic.AtomicLong;
/**
* Default implementation of a {@link Counter}.
*/
class CounterImpl implements Counter {
private AtomicLong prev = new AtomicLong(0);
private AtomicLong curr = new AtomicLong(0);
@Override
public void inc(long delta) {
curr.getAndAdd(delta);
}
long value() {
long current = curr.get();
long previous = prev.get();
if (current == previous) {
return 0;
}
prev.set(current);
return current - previous;
}
void report(String name, ImmutableMap tags, StatsReporter reporter) {
long delta = value();
if (delta == 0) {
return;
}
reporter.reportCounter(name, tags, delta);
}
long snapshot() {
return curr.get() - prev.get();
}
}