/* * SPDX-License-Identifier: Apache-2.0 * * The OpenSearch Contributors require contributions made to * this file be licensed under the Apache-2.0 license or a * compatible open source license. */ /* * Licensed to Elasticsearch under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Elasticsearch 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. */ /* * Modifications Copyright OpenSearch Contributors. See * GitHub history for details. */ package org.opensearch.search.aggregations.bucket; /** * Helper functions for common Bucketing functions * * @opensearch.internal */ public final class BucketUtils { private BucketUtils() {} /** * Heuristic used to determine the size of shard-side PriorityQueues when * selecting the top N terms from a distributed index. * * @param finalSize * The number of terms required in the final reduce phase. * @return A suggested default for the size of any shard-side PriorityQueues */ public static int suggestShardSideQueueSize(int finalSize) { if (finalSize < 1) { throw new IllegalArgumentException("size must be positive, got " + finalSize); } // Request 50% more buckets on the shards in order to improve accuracy // as well as a small constant that should help with small values of 'size' final long shardSampleSize = (long) (finalSize * 1.5 + 10); return (int) Math.min(Integer.MAX_VALUE, shardSampleSize); } }