io.druid.query.scan.ScanQueryQueryToolChest.java Source code

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Here is the source code for io.druid.query.scan.ScanQueryQueryToolChest.java

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/*
 * 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.scan;

import com.fasterxml.jackson.core.type.TypeReference;
import com.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.inject.Inject;
import io.druid.java.util.common.guava.BaseSequence;
import io.druid.java.util.common.guava.CloseQuietly;
import io.druid.java.util.common.guava.Sequence;
import io.druid.query.GenericQueryMetricsFactory;
import io.druid.query.Query;
import io.druid.query.QueryMetrics;
import io.druid.query.QueryPlus;
import io.druid.query.QueryRunner;
import io.druid.query.QueryToolChest;
import io.druid.query.aggregation.MetricManipulationFn;

import java.util.Map;

public class ScanQueryQueryToolChest extends QueryToolChest<ScanResultValue, ScanQuery> {
    private static final TypeReference<ScanResultValue> TYPE_REFERENCE = new TypeReference<ScanResultValue>() {
    };

    private final ScanQueryConfig scanQueryConfig;
    private final GenericQueryMetricsFactory queryMetricsFactory;

    @Inject
    public ScanQueryQueryToolChest(final ScanQueryConfig scanQueryConfig,
            final GenericQueryMetricsFactory queryMetricsFactory) {
        this.scanQueryConfig = scanQueryConfig;
        this.queryMetricsFactory = queryMetricsFactory;
    }

    @Override
    public QueryRunner<ScanResultValue> mergeResults(final QueryRunner<ScanResultValue> runner) {
        return new QueryRunner<ScanResultValue>() {
            @Override
            public Sequence<ScanResultValue> run(final QueryPlus<ScanResultValue> queryPlus,
                    final Map<String, Object> responseContext) {
                // Ensure "legacy" is a non-null value, such that all other nodes this query is forwarded to will treat it
                // the same way, even if they have different default legacy values.
                final ScanQuery scanQuery = ((ScanQuery) queryPlus.getQuery()).withNonNullLegacy(scanQueryConfig);
                final QueryPlus<ScanResultValue> queryPlusWithNonNullLegacy = queryPlus.withQuery(scanQuery);

                if (scanQuery.getLimit() == Long.MAX_VALUE) {
                    return runner.run(queryPlusWithNonNullLegacy, responseContext);
                }
                return new BaseSequence<>(
                        new BaseSequence.IteratorMaker<ScanResultValue, ScanQueryLimitRowIterator>() {
                            @Override
                            public ScanQueryLimitRowIterator make() {
                                return new ScanQueryLimitRowIterator(runner, queryPlusWithNonNullLegacy,
                                        responseContext);
                            }

                            @Override
                            public void cleanup(ScanQueryLimitRowIterator iterFromMake) {
                                CloseQuietly.close(iterFromMake);
                            }
                        });
            }
        };
    }

    @Override
    public QueryMetrics<Query<?>> makeMetrics(ScanQuery query) {
        return queryMetricsFactory.makeMetrics(query);
    }

    @Override
    public Function<ScanResultValue, ScanResultValue> makePreComputeManipulatorFn(ScanQuery query,
            MetricManipulationFn fn) {
        return Functions.identity();
    }

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

    @Override
    public QueryRunner<ScanResultValue> preMergeQueryDecoration(final QueryRunner<ScanResultValue> runner) {
        return new QueryRunner<ScanResultValue>() {
            @Override
            public Sequence<ScanResultValue> run(QueryPlus<ScanResultValue> queryPlus,
                    Map<String, Object> responseContext) {
                ScanQuery scanQuery = (ScanQuery) queryPlus.getQuery();
                if (scanQuery.getFilter() != null) {
                    scanQuery = scanQuery.withDimFilter(scanQuery.getFilter().optimize());
                    queryPlus = queryPlus.withQuery(scanQuery);
                }
                return runner.run(queryPlus, responseContext);
            }
        };
    }
}