1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.layoutlib.bridge.intensive.util.perf;
18
19import android.annotation.NonNull;
20import android.util.LongArray;
21
22import java.util.Arrays;
23import java.util.function.LongConsumer;
24
25/**
26 * Class that collect a series of longs and produces the median, min and max values.
27 */
28public class LongStatsCollector implements LongConsumer {
29    private final LongArray mAllValues;
30    private long mMin = Long.MAX_VALUE;
31    private long mMax = Long.MIN_VALUE;
32    public LongStatsCollector(int estimatedRuns) {
33        mAllValues = new LongArray(estimatedRuns);
34    }
35
36    public int size() {
37        return mAllValues.size();
38    }
39
40    @NonNull
41    public Stats getStats() {
42        if (mAllValues.size() == 0) {
43            throw new IndexOutOfBoundsException("No data");
44        }
45
46        double median;
47        int size = mAllValues.size();
48        long[] buffer = new long[size];
49        for (int i = 0; i < size; i++) {
50            buffer[i] = mAllValues.get(i);
51        }
52
53        Arrays.sort(buffer);
54
55        int midPoint = size / 2;
56        median = (size % 2 == 0) ? (buffer[midPoint - 1] + buffer[midPoint]) / 2 : buffer[midPoint];
57
58        return new Stats(mAllValues.size(), mMin, mMax, median);
59    }
60
61    @Override
62    public void accept(long value) {
63        mMin = Math.min(mMin, value);
64        mMax = Math.max(mMax, value);
65        mAllValues.add(value);
66    }
67
68    public static class Stats {
69        private final int mSamples;
70        private final long mMin;
71        private final long mMax;
72        private final double mMedian;
73
74        private Stats(int samples, long min, long max, double median) {
75            mSamples = samples;
76            mMin = min;
77            mMax = max;
78            mMedian = median;
79        }
80
81        public int getSampleCount() {
82            return mSamples;
83        }
84
85        public long getMin() {
86            return mMin;
87        }
88
89        public long getMax() {
90            return mMax;
91        }
92
93        public double getMedian() {
94            return mMedian;
95        }
96    }
97}
98