src/main/java/com/android/vts/util/Histogram.java

/*
 * Copyright (c) 2016 Google Inc. All Rights Reserved.
 *
 * 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 com.android.vts.util;

import com.android.vts.entity.ProfilingPointRunEntity;
import com.google.common.primitives.Doubles;
import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.math3.stat.descriptive.rank.Percentile;

/** Helper object for describing graph data. */
public class Histogram extends Graph {
    public static final String PERCENTILES_KEY = "percentiles";
    public static final String PERCENTILE_VALUES_KEY = "percentile_values";
    public static final String MIN_KEY = "min";
    public static final String MAX_KEY = "max";

    private List<Double> values;
    private List<String> ids;
    private String xLabel;
    private String yLabel;
    private String name;
    private GraphType type = GraphType.HISTOGRAM;
    private Double min = null;
    private Double max = null;

    public Histogram(String name) {
        this.name = name;
        this.values = new ArrayList<>();
        this.ids = new ArrayList<>();
    }

    /**
     * Get the x axis label.
     *
     * @return The x axis label.
     */
    @Override
    public String getXLabel() {
        return xLabel;
    }

    /**
     * Get the graph type.
     *
     * @return The graph type.
     */
    @Override
    public GraphType getType() {
        return type;
    }

    /**
     * Get the name of the graph.
     *
     * @return The name of the graph.
     */
    @Override
    public String getName() {
        return name;
    }

    /**
     * Get the y axis label.
     *
     * @return The y axis label.
     */
    @Override
    public String getYLabel() {
        return yLabel;
    }

    /**
     * Get the number of data points stored in the graph.
     *
     * @return The number of data points stored in the graph.
     */
    @Override
    public int size() {
        return values.size();
    }

    /**
     * Get the minimum value.
     *
     * @return The minimum value.
     */
    public Double getMin() {
        return min;
    }

    /**
     * Get the maximum value.
     *
     * @return The maximum value.
     */
    public Double getMax() {
        return max;
    }

    /**
     * Add data to the graph.
     *
     * @param id The name of the graph.
     * @param profilingPoint The ProfilingPointRunEntity containing data to add.
     */
    @Override
    public void addData(String id, ProfilingPointRunEntity profilingPoint) {
        if (profilingPoint.getValues().size() == 0)
            return;
        xLabel = profilingPoint.getXLabel();
        yLabel = profilingPoint.getYLabel();
        for (long v : profilingPoint.getValues()) {
            double value = v;
            values.add(value);
            ids.add(id);
            if (max == null || value > max)
                max = value;
            if (min == null || value < min)
                min = value;
        }
    }

    /**
     * Serializes the graph to json format.
     *
     * @return A JsonElement object representing the graph object.
     */
    @Override
    public JsonObject toJson() {
        int[] percentiles = {1, 2, 5, 10, 25, 50, 75, 90, 95, 98, 99};
        double[] percentileValues = new double[percentiles.length];
        double[] valueList = Doubles.toArray(values);
        for (int i = 0; i < percentiles.length; i++) {
            percentileValues[i] =
                    Math.round(new Percentile().evaluate(valueList, percentiles[i]) * 1000d)
                    / 1000d;
        }
        JsonObject json = super.toJson();
        json.add(VALUE_KEY, new Gson().toJsonTree(values).getAsJsonArray());
        json.add(PERCENTILES_KEY, new Gson().toJsonTree(percentiles).getAsJsonArray());
        json.add(PERCENTILE_VALUES_KEY, new Gson().toJsonTree(percentileValues).getAsJsonArray());
        json.add(IDS_KEY, new Gson().toJsonTree(ids).getAsJsonArray());
        json.add(MIN_KEY, new JsonPrimitive(min));
        json.add(MAX_KEY, new JsonPrimitive(max));
        return json;
    }
}