io.druid.query.topn.NumericTopNMetricSpec.java Source code

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Here is the source code for io.druid.query.topn.NumericTopNMetricSpec.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * 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 io.druid.query.topn;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import io.druid.query.aggregation.AggregatorFactory;
import io.druid.query.aggregation.PostAggregator;
import io.druid.query.dimension.DimensionSpec;
import org.joda.time.DateTime;

import java.nio.ByteBuffer;
import java.util.Comparator;
import java.util.List;

/**
 */
public class NumericTopNMetricSpec implements TopNMetricSpec {
    private static final byte CACHE_TYPE_ID = 0x0;

    private final String metric;

    @JsonCreator
    public NumericTopNMetricSpec(@JsonProperty("metric") String metric) {
        this.metric = metric;
    }

    @Override
    public void verifyPreconditions(List<AggregatorFactory> aggregatorSpecs,
            List<PostAggregator> postAggregatorSpecs) {
        Preconditions.checkNotNull(metric, "metric can't be null");
        Preconditions.checkNotNull(aggregatorSpecs, "aggregations cannot be null");
        Preconditions.checkArgument(aggregatorSpecs.size() > 0, "Must have at least one AggregatorFactory");

        final AggregatorFactory aggregator = Iterables.tryFind(aggregatorSpecs, new Predicate<AggregatorFactory>() {
            @Override
            public boolean apply(AggregatorFactory input) {
                return input.getName().equals(metric);
            }
        }).orNull();

        final PostAggregator postAggregator = Iterables
                .tryFind(postAggregatorSpecs, new Predicate<PostAggregator>() {
                    @Override
                    public boolean apply(PostAggregator input) {
                        return input.getName().equals(metric);
                    }
                }).orNull();

        Preconditions.checkArgument(aggregator != null || postAggregator != null,
                "Must have an AggregatorFactory or PostAggregator for metric[%s], gave[%s] and [%s]", metric,
                aggregatorSpecs, postAggregatorSpecs);
    }

    @JsonProperty
    public String getMetric() {
        return metric;
    }

    @Override
    public Comparator getComparator(List<AggregatorFactory> aggregatorSpecs,
            List<PostAggregator> postAggregatorSpecs) {
        Comparator comp = null;
        for (AggregatorFactory factory : aggregatorSpecs) {
            if (metric.equals(factory.getName())) {
                comp = factory.getComparator();
                break;
            }
        }
        for (PostAggregator pf : postAggregatorSpecs) {
            if (metric.equals(pf.getName())) {
                comp = pf.getComparator();
                break;
            }
        }

        return comp;
    }

    @Override
    public TopNResultBuilder getResultBuilder(DateTime timestamp, DimensionSpec dimSpec, int threshold,
            Comparator comparator, List<AggregatorFactory> aggFactories, List<PostAggregator> postAggs) {
        return new TopNNumericResultBuilder(timestamp, dimSpec, metric, threshold, comparator, aggFactories,
                postAggs);
    }

    @Override
    public byte[] getCacheKey() {
        byte[] metricBytes = com.metamx.common.StringUtils.toUtf8(metric);

        return ByteBuffer.allocate(1 + metricBytes.length).put(CACHE_TYPE_ID).put(metricBytes).array();
    }

    @Override
    public <T> TopNMetricSpecBuilder<T> configureOptimizer(TopNMetricSpecBuilder<T> builder) {
        return builder;
    }

    @Override
    public void initTopNAlgorithmSelector(TopNAlgorithmSelector selector) {
        selector.setAggregateTopNMetricFirst(true);
    }

    @Override
    public String getMetricName(DimensionSpec dimSpec) {
        return metric;
    }

    @Override
    public boolean canBeOptimizedUnordered() {
        return true;
    }

    @Override
    public String toString() {
        return "NumericTopNMetricSpec{" + "metric='" + metric + '\'' + '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (o == null || getClass() != o.getClass())
            return false;

        NumericTopNMetricSpec that = (NumericTopNMetricSpec) o;

        if (metric != null ? !metric.equals(that.metric) : that.metric != null)
            return false;

        return true;
    }

    @Override
    public int hashCode() {
        return metric != null ? metric.hashCode() : 0;
    }
}