io.druid.query.datasourcemetadata.DataSourceQueryQueryToolChest Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of druid-processing Show documentation
A module that is everything required to understands Druid Segments
There is a newer version: 0.12.3
/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets licenses this file
 * to you 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.datasourcemetadata;

import com.fasterxml.jackson.core.type.TypeReference;
import com.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.metamx.common.guava.Sequence;
import com.metamx.common.guava.Sequences;
import com.metamx.emitter.service.ServiceMetricEvent;
import io.druid.query.BySegmentSkippingQueryRunner;
import io.druid.query.CacheStrategy;
import io.druid.query.DataSourceUtil;
import io.druid.query.Query;
import io.druid.query.QueryRunner;
import io.druid.query.QueryToolChest;
import io.druid.query.Result;
import io.druid.query.aggregation.MetricManipulationFn;
import io.druid.timeline.LogicalSegment;

import java.util.List;
import java.util.Map;

/**
 */
public class DataSourceQueryQueryToolChest
    extends QueryToolChest, DataSourceMetadataQuery>
{
  private static final TypeReference> TYPE_REFERENCE = new TypeReference>()
  {
  };

  @Override
  public  List filterSegments(DataSourceMetadataQuery query, List segments)
  {
    if (segments.size() <= 1) {
      return segments;
    }

    final T max = segments.get(segments.size() - 1);

    return Lists.newArrayList(
        Iterables.filter(
            segments,
            new Predicate()
            {
              @Override
              public boolean apply(T input)
              {
                return max != null && input.getInterval().overlaps(max.getInterval());
              }
            }
        )
    );
  }

  @Override
  public QueryRunner> mergeResults(
      final QueryRunner> runner
  )
  {
    return new BySegmentSkippingQueryRunner>(runner)
    {
      @Override
      protected Sequence> doRun(
          QueryRunner> baseRunner,
          Query> input,
          Map context
      )
      {
        DataSourceMetadataQuery query = (DataSourceMetadataQuery) input;
        return Sequences.simple(
            query.mergeResults(
                Sequences.toList(
                    baseRunner.run(query, context),
                    Lists.>newArrayList()
                )
            )
        );
      }
    };
  }

  @Override
  public ServiceMetricEvent.Builder makeMetricBuilder(DataSourceMetadataQuery query)
  {
    return new ServiceMetricEvent.Builder()
        .setDimension("dataSource", DataSourceUtil.getMetricName(query.getDataSource()))
        .setDimension("type", query.getType());
  }

  @Override
  public Function, Result> makePreComputeManipulatorFn(
      DataSourceMetadataQuery query, MetricManipulationFn fn
  )
  {
    return Functions.identity();
  }

  @Override
  public TypeReference> getResultTypeReference()
  {
    return TYPE_REFERENCE;
  }

  @Override
  public CacheStrategy getCacheStrategy(DataSourceMetadataQuery query)
  {
    return null;
  }
}