io.druid.query.QueryRunnerHelper Maven / Gradle / Ivy

/*
 * 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;

import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicates;
import io.druid.java.util.common.granularity.Granularity;
import io.druid.java.util.common.guava.Sequence;
import io.druid.java.util.common.guava.Sequences;
import io.druid.java.util.common.logger.Logger;
import io.druid.query.filter.Filter;
import io.druid.segment.Cursor;
import io.druid.segment.StorageAdapter;
import io.druid.segment.VirtualColumns;
import org.joda.time.Interval;

import java.io.Closeable;
import java.util.List;
import java.util.Map;

/**
 */
public class QueryRunnerHelper
{
  private static final Logger log = new Logger(QueryRunnerHelper.class);

  public static  Sequence> makeCursorBasedQuery(
      final StorageAdapter adapter,
      List queryIntervals,
      Filter filter,
      VirtualColumns virtualColumns,
      boolean descending,
      Granularity granularity,
      final Function> mapFn
  )
  {
    Preconditions.checkArgument(
        queryIntervals.size() == 1, "Can only handle a single interval, got[%s]", queryIntervals
    );

    return Sequences.filter(
        Sequences.map(
            adapter.makeCursors(filter, queryIntervals.get(0), virtualColumns, granularity, descending, null),
            new Function>()
            {
              @Override
              public Result apply(Cursor input)
              {
                return mapFn.apply(input);
              }
            }
        ),
        Predicates.>notNull()
    );
  }

  public static  QueryRunner makeClosingQueryRunner(final QueryRunner runner, final Closeable closeable)
  {
    return new QueryRunner()
    {
      @Override
      public Sequence run(QueryPlus queryPlus, Map responseContext)
      {
        return Sequences.withBaggage(runner.run(queryPlus, responseContext), closeable);
      }
    };
  }
}