// Copyright (C) 2015 The Android Open Source Project
//
// 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.google.gerrit.metrics;
abstract class TimerContext implements AutoCloseable {
private final long startNanos;
private boolean stopped;
TimerContext() {
this.startNanos = System.nanoTime();
}
/**
* Record the elapsed time to the timer.
*
* @param elapsed Elapsed time in nanoseconds.
*/
public abstract void record(long elapsed);
/** @return the start time in system time nanoseconds. */
public long getStartTime() {
return startNanos;
}
/**
* Stop the timer and record the elapsed time.
*
* @return the elapsed time in nanoseconds.
* @throws IllegalStateException if the timer is already stopped.
*/
public long stop() {
if (!stopped) {
stopped = true;
long elapsed = System.nanoTime() - startNanos;
record(elapsed);
return elapsed;
}
throw new IllegalStateException("Already stopped");
}
@Override
public void close() {
if (!stopped) {
stop();
}
}
}