dagger.producers.monitoring.TimingProducerMonitor.java Source code

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Here is the source code for dagger.producers.monitoring.TimingProducerMonitor.java

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/*
 * Copyright (C) 2015 The Dagger Authors.
 *
 * 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 dagger.producers.monitoring;

import static java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.base.Stopwatch;
import com.google.common.base.Ticker;

/**
 * A monitor that measures the timing of the execution of a producer method, and logs those timings
 * with the given recorder.
 */
final class TimingProducerMonitor extends ProducerMonitor {
    private final ProducerTimingRecorder recorder;
    private final Stopwatch stopwatch;
    private final Stopwatch componentStopwatch;
    private long startNanos = -1;

    TimingProducerMonitor(ProducerTimingRecorder recorder, Ticker ticker, Stopwatch componentStopwatch) {
        this.recorder = recorder;
        this.stopwatch = Stopwatch.createUnstarted(ticker);
        this.componentStopwatch = componentStopwatch;
    }

    @Override
    public void methodStarting() {
        startNanos = componentStopwatch.elapsed(NANOSECONDS);
        stopwatch.start();
    }

    @Override
    public void methodFinished() {
        // TODO(beder): Is a system ticker the appropriate way to track CPU time? Should we use
        // ThreadCpuTicker instead?
        long durationNanos = stopwatch.elapsed(NANOSECONDS);
        recorder.recordMethod(startNanos, durationNanos);
    }

    @Override
    public void succeeded(Object o) {
        long latencyNanos = stopwatch.elapsed(NANOSECONDS);
        recorder.recordSuccess(latencyNanos);
    }

    @Override
    public void failed(Throwable t) {
        if (stopwatch.isRunning()) {
            long latencyNanos = stopwatch.elapsed(NANOSECONDS);
            recorder.recordFailure(t, latencyNanos);
        } else {
            recorder.recordSkip(t);
        }
    }
}