io.druid.indexing.common.task.MergeTask.java Source code

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Here is the source code for io.druid.indexing.common.task.MergeTask.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.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<AggregatorFactory> aggregators;
    private final IndexSpec indexSpec;

    @JsonCreator
    public MergeTask(@JsonProperty("id") String id, @JsonProperty("dataSource") String dataSource,
            @JsonProperty("segments") List<DataSegment> segments,
            @JsonProperty("aggregations") List<AggregatorFactory> aggregators,
            @JsonProperty("indexSpec") IndexSpec indexSpec, @JsonProperty("context") Map<String, Object> 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<DataSegment, File> segments, final File outDir) throws Exception {
        return IndexMerger.mergeQueryableIndex(
                Lists.transform(ImmutableList.copyOf(segments.values()), new Function<File, QueryableIndex>() {
                    @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<AggregatorFactory> getAggregators() {
        return aggregators;
    }
}