org.apache.druid.query.QueryRunnerHelper.java Source code

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Here is the source code for org.apache.druid.query.QueryRunnerHelper.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.druid.query;

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

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

/**
 */
public class QueryRunnerHelper {

    public static <T> Sequence<Result<T>> makeCursorBasedQuery(final StorageAdapter adapter,
            List<Interval> queryIntervals, Filter filter, VirtualColumns virtualColumns, boolean descending,
            Granularity granularity, final Function<Cursor, Result<T>> 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<Cursor, Result<T>>() {
                    @Override
                    public Result<T> apply(Cursor input) {
                        return mapFn.apply(input);
                    }
                }), Predicates.notNull());
    }

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