org.kairosdb.core.groupby.BinGroupBy Maven / Gradle / Ivy

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KairosDB is a fast distributed scalable time series abstraction on top of Cassandra.
There is a newer version: 1.2.28
/*
 * Copyright 2016 KairosDB Authors
 *
 *    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.kairosdb.core.groupby;

import org.json.JSONException;
import org.json.JSONWriter;
import org.kairosdb.core.DataPoint;
import org.kairosdb.core.annotation.FeatureComponent;
import org.kairosdb.core.annotation.FeatureProperty;
import org.kairosdb.core.annotation.ValidationProperty;
import org.kairosdb.core.formatter.FormatterException;
import org.kairosdb.plugin.GroupBy;

import java.io.StringWriter;
import java.util.Map;

import static com.google.common.base.Preconditions.checkArgument;

/**
 * Groups data points by bin values. Data points are a range of values specified by bins.
 * Bins array needs to be in ascending order.
 */
@FeatureComponent(
        name = "bin",
        description = "Groups data points by bins or buckets."
)
public class BinGroupBy implements GroupBy {
    @FeatureProperty(
            label = "Bin Values",
            description = "List of bin values. For example, if the list of bins is 10, 20, 30, then values less than 10 are placed in the first group, values between 10-19 into the second group, and so forth.",
            validations = {
                    @ValidationProperty(
                            expression = "value.length > 0",
                            message = "The list can't be empty."
                    ),
                    @ValidationProperty(
                            expression = "value.every((n) => !isNaN(parseFloat(n)) && isFinite(n))",
                            message = "The list must contain only numbers."
                    )
            }
    )
    private double[] bins;

    public BinGroupBy() {
    }

    public BinGroupBy(final double[] bins) {
        checkArgument(bins.length > 0);

        this.bins = bins;
    }

    @Override
    public int getGroupId(final DataPoint dataPoint, final Map tags) {
        double dataValue = 0;
        if (dataPoint.isLong())
            dataValue = dataPoint.getLongValue();
        else if (dataPoint.isDouble())
            dataValue = dataPoint.getDoubleValue();
        else
            return -1;
        if (dataValue < bins[0])
            return 0;
        for (int i = 0; i < bins.length - 1; i++) {
            if (dataValue >= bins[i] && dataValue < bins[i + 1])
                return i + 1;
        }
        return bins.length;
    }

    @Override
    public GroupByResult getGroupByResult(final int id) {
        return new GroupByResult() {
            @Override
            public String toJson() throws FormatterException {
                final StringWriter stringWriter = new StringWriter();
                try {
                    final JSONWriter writer = new JSONWriter(stringWriter);

                    writer.object();
                    writer.key("name").value("bin");
                    writer.key("bins").value(bins);

                    writer.key("group").object();
                    writer.key("bin_number").value(id);
                    writer.endObject();
                    writer.endObject();
                } catch (final JSONException e) {
                    throw new FormatterException(e);
                }

                return stringWriter.toString();
            }
        };
    }

    @Override
    public void setStartDate(final long startDate) {
    }

    public void setBins(final double[] bins) {
        this.bins = bins;
    }
}