TimeMeasure.java

import android.support.annotation.NonNull;

/**
 * Measuring code runtime.
 * For example:
 *  long timeSpent = TimeMeasure.doTimeMeasureUs(() -> {
 *                 if (!nativeSendFrame(receiverName, videoBufferByte)) {
 *                     if (++mErrorCount >= ERROR_MAX_COUNT) {
 *                         throw new Exception("Send frame error.");
 *                     }
 *                 }
 *             });
 *  Log.d(TAG, "nativeSendFrame: " + TimeMeasure.toString(timeSpent));
 */
class TimeMeasure {
    private long startTimeNs;
    private long measureResultNs;

    private long getMeasureResultNs() {
        return measureResultNs;
    }

    private TimeMeasure start() {
        startTimeNs = System.nanoTime();
        return this;
    }

    private TimeMeasure stop() {
        measureResultNs = System.nanoTime() - startTimeNs;
        return this;
    }

    @NonNull
    @Override
    public String toString() {
        return toString(measureResultNs);
    }

    interface Callback {
        void measureCode() throws Exception;
    }

    static long doTimeMeasureUs(Callback callback) throws Exception {
        TimeMeasure timeMeasure = new TimeMeasure().start();
        callback.measureCode();
        return timeMeasure.stop().getMeasureResultNs();
    }

    static String toString(long timeSpentNs) {
        return "time spent " + (timeSpentNs / 1e6) + "ms, " + (timeSpentNs % 1e6) + "ns";
    }
}