AbstractTimer.java

/**
 * 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 org.springframework.metrics.instrument.internal;

import org.springframework.metrics.instrument.Clock;
import org.springframework.metrics.instrument.ThrowableCallable;
import org.springframework.metrics.instrument.Timer;

import java.util.concurrent.TimeUnit;

public abstract class AbstractTimer implements Timer {
    protected Clock clock;
    protected String name;

    protected AbstractTimer(String name, Clock clock) {
        this.clock = clock;
        this.name = name;
    }

    @Override
    public <T> T recordThrowable(ThrowableCallable<T> f) throws Throwable {
        final long s = clock.monotonicTime();
        try {
            return f.call();
        } finally {
            final long e = clock.monotonicTime();
            record(e - s, TimeUnit.NANOSECONDS);
        }
    }

    @Override
    public void record(Runnable f) {
        final long s = clock.monotonicTime();
        try {
            f.run();
        } finally {
            final long e = clock.monotonicTime();
            record(e - s, TimeUnit.NANOSECONDS);
        }
    }

    /**
     * @return Convert a nanos to seconds without truncation.
     * @see TimeUnit#convert(long, TimeUnit)
     */
    protected static double nanosToUnit(double nanos, TimeUnit destinationUnit) {
        switch (destinationUnit) {
            case MICROSECONDS:
                return nanos / (C1 / C0);
            case MILLISECONDS:
                return nanos / (C2 / C0);
            case SECONDS:
                return nanos / (C3 / C0);
            case MINUTES:
                return nanos / (C4 / C0);
            case HOURS:
                return nanos / (C5 / C0);
            case DAYS:
                return nanos / (C6 / C0);

            case NANOSECONDS:
            default:
                return nanos;
        }
    }

    protected static double secondsToUnit(double seconds, TimeUnit destinationUnit) {
        switch (destinationUnit) {
            case NANOSECONDS:
                return seconds * (C3 / C0);
            case MICROSECONDS:
                return seconds * (C3 / C1);
            case MILLISECONDS:
                return seconds * (C3 / C2);
            case MINUTES:
                return seconds / (C4 / C3);
            case HOURS:
                return seconds / (C5 / C3);
            case DAYS:
                return seconds / (C6 / C3);

            case SECONDS:
            default:
                return seconds;
        }
    }

    private static final long C0 = 1L;
    private static final long C1 = C0 * 1000L;
    private static final long C2 = C1 * 1000L;
    private static final long C3 = C2 * 1000L;
    private static final long C4 = C3 * 60L;
    private static final long C5 = C4 * 60L;
    private static final long C6 = C5 * 24L;

    @Override
    public String getName() {
        return name;
    }
}