| /* |
| * Copyright (C) 2017 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 android.multiuser; |
| |
| import android.os.Bundle; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.concurrent.TimeUnit; |
| |
| public class BenchmarkResults { |
| private final ArrayList<Long> mResults = new ArrayList<>(); |
| |
| public void addDuration(long duration) { |
| mResults.add(TimeUnit.NANOSECONDS.toMillis(duration)); |
| } |
| |
| public Bundle getStatsToReport() { |
| final Bundle stats = new Bundle(); |
| stats.putDouble("Mean (ms)", mean()); |
| return stats; |
| } |
| |
| public Bundle getStatsToLog() { |
| final Bundle stats = new Bundle(); |
| stats.putDouble("Mean (ms)", mean()); |
| stats.putDouble("Median (ms)", median()); |
| stats.putDouble("Sigma (ms)", standardDeviation()); |
| return stats; |
| } |
| |
| public ArrayList<Long> getAllDurations() { |
| return mResults; |
| } |
| |
| private double mean() { |
| final int size = mResults.size(); |
| long sum = 0; |
| for (int i = 0; i < size; ++i) { |
| sum += mResults.get(i); |
| } |
| return (double) sum / size; |
| } |
| |
| private double median() { |
| final int size = mResults.size(); |
| if (size == 0) { |
| return 0f; |
| } |
| Collections.sort(mResults); |
| final int idx = size / 2; |
| return size % 2 == 0 |
| ? (double) (mResults.get(idx) + mResults.get(idx - 1)) / 2 |
| : mResults.get(idx); |
| } |
| |
| private double standardDeviation() { |
| final int size = mResults.size(); |
| if (size == 0) { |
| return 0f; |
| } |
| final double mean = mean(); |
| double sd = 0; |
| for (int i = 0; i < size; ++i) { |
| double diff = mResults.get(i) - mean; |
| sd += diff * diff; |
| } |
| return Math.sqrt(sd / size); |
| } |
| } |