io.druid.indexing.common.task.MergeTask Maven / Gradle / Ivy

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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.indexing.common.task;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import io.druid.query.aggregation.AggregatorFactory;
import io.druid.segment.IndexIO;
import io.druid.segment.IndexMerger;
import io.druid.segment.IndexSpec;
import io.druid.segment.QueryableIndex;
import io.druid.timeline.DataSegment;

import javax.annotation.Nullable;
import java.io.File;
import java.util.List;
import java.util.Map;

/**
 */
public class MergeTask extends MergeTaskBase
{
  @JsonIgnore
  private final List aggregators;
  private final IndexSpec indexSpec;

  @JsonCreator
  public MergeTask(
      @JsonProperty("id") String id,
      @JsonProperty("dataSource") String dataSource,
      @JsonProperty("segments") List segments,
      @JsonProperty("aggregations") List aggregators,
      @JsonProperty("indexSpec") IndexSpec indexSpec,
      @JsonProperty("context") Map context

  )
  {
    super(id, dataSource, segments, context);
    this.aggregators = Preconditions.checkNotNull(aggregators, "null aggregations");
    this.indexSpec = indexSpec == null ? new IndexSpec() : indexSpec;
  }

  @Override
  public File merge(final Map segments, final File outDir)
      throws Exception
  {
    return IndexMerger.mergeQueryableIndex(
        Lists.transform(
            ImmutableList.copyOf(segments.values()),
            new Function()
            {
              @Override
              public QueryableIndex apply(@Nullable File input)
              {
                try {
                  return IndexIO.loadIndex(input);
                }
                catch (Exception e) {
                  throw Throwables.propagate(e);
                }
              }
            }
        ),
        aggregators.toArray(new AggregatorFactory[aggregators.size()]),
        outDir,
        indexSpec
    );
  }

  @Override
  public String getType()
  {
    return "merge";
  }

  @JsonProperty("aggregations")
  public List getAggregators()
  {
    return aggregators;
  }
}