| /* |
| * 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.solr.handler.component; |
| |
| import org.apache.solr.search.SolrIndexSearcher; |
| |
| import java.util.Comparator; |
| import java.io.IOException; |
| |
| /** |
| * The MergeStrategy class defines custom merge logic for distributed searches. |
| * |
| * <b>Note: This API is experimental and may change in non backward-compatible ways in the future</b> |
| **/ |
| |
| |
| public interface MergeStrategy { |
| |
| /** |
| * merge defines the merging behaving of results that are collected from the |
| * shards during a distributed search. |
| * |
| **/ |
| |
| public void merge(ResponseBuilder rb, ShardRequest sreq); |
| |
| /** |
| * mergesIds must return true if the merge method merges document ids from the shards. |
| * If it merges other output from the shards it must return false. |
| * */ |
| |
| public boolean mergesIds(); |
| |
| |
| /** |
| * handlesMergeFields must return true if the MergeStrategy |
| * implements a custom handleMergeFields(ResponseBuilder rb, SolrIndexSearch searcher) |
| * */ |
| |
| public boolean handlesMergeFields(); |
| |
| |
| /** |
| * Implement handleMergeFields(ResponseBuilder rb, SolrIndexSearch searcher) if |
| * your merge strategy needs more complex data then the sort fields provide. |
| * */ |
| |
| public void handleMergeFields(ResponseBuilder rb, SolrIndexSearcher searcher) throws IOException; |
| |
| /** |
| * Defines the order that the mergeStrategies are applied. Lower costs are applied first. |
| * */ |
| public int getCost(); |
| |
| @SuppressWarnings({"rawtypes"}) |
| final Comparator MERGE_COMP = (o1, o2) -> { |
| MergeStrategy m1 = (MergeStrategy) o1; |
| MergeStrategy m2 = (MergeStrategy) o2; |
| return m1.getCost() - m2.getCost(); |
| }; |
| |
| } |