| /* |
| * 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.Preconditions; |
| import org.apache.druid.common.guava.CombiningSequence; |
| import org.apache.druid.guice.annotations.PublicApi; |
| import org.apache.druid.java.util.common.guava.Sequence; |
| import org.apache.druid.query.context.ResponseContext; |
| |
| import java.util.Comparator; |
| import java.util.function.BinaryOperator; |
| import java.util.function.Function; |
| |
| /** |
| */ |
| @PublicApi |
| public class ResultMergeQueryRunner<T> extends BySegmentSkippingQueryRunner<T> |
| { |
| private final Function<Query<T>, Comparator<T>> comparatorGenerator; |
| private final Function<Query<T>, BinaryOperator<T>> mergeFnGenerator; |
| |
| public ResultMergeQueryRunner( |
| QueryRunner<T> baseRunner, |
| Function<Query<T>, Comparator<T>> comparatorGenerator, |
| Function<Query<T>, BinaryOperator<T>> mergeFnGenerator |
| ) |
| { |
| super(baseRunner); |
| Preconditions.checkNotNull(comparatorGenerator); |
| Preconditions.checkNotNull(mergeFnGenerator); |
| this.comparatorGenerator = comparatorGenerator; |
| this.mergeFnGenerator = mergeFnGenerator; |
| } |
| |
| @Override |
| public Sequence<T> doRun(QueryRunner<T> baseRunner, QueryPlus<T> queryPlus, ResponseContext context) |
| { |
| Query<T> query = queryPlus.getQuery(); |
| return CombiningSequence.create( |
| baseRunner.run(queryPlus, context), |
| comparatorGenerator.apply(query), |
| mergeFnGenerator.apply(query)); |
| } |
| } |