content: package org.apache.solr.search.grouping.distributed.responseprocessor;
  
  /*
   * 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.
   */
  
  import org.apache.lucene.search.Sort;
  import org.apache.lucene.search.grouping.SearchGroup;
  import org.apache.solr.common.SolrException;
  import org.apache.solr.common.util.NamedList;
  import org.apache.solr.handler.component.ResponseBuilder;
  import org.apache.solr.handler.component.ShardRequest;
  import org.apache.solr.handler.component.ShardResponse;
  import org.apache.solr.search.SortSpec;
  import org.apache.solr.search.grouping.distributed.ShardResponseProcessor;
  import org.apache.solr.search.grouping.distributed.shardresultserializer.SearchGroupsResultTransformer;
  
  import java.io.IOException;
  import java.util.*;
  
  /**
   * Concrete implementation for merging {@link SearchGroup} instances from shard responses.
   */
  public class SearchGroupShardResponseProcessor implements ShardResponseProcessor {
  
    /**
     * {@inheritDoc}
     */
    public void process(ResponseBuilder rb, ShardRequest shardRequest) {
      SortSpec ss = rb.getSortSpec();
      Sort groupSort = rb.getGroupingSpec().getGroupSort();
      String[] fields = rb.getGroupingSpec().getFields();
  
      Map<String, List<Collection<SearchGroup<String>>>> commandSearchGroups = new HashMap<String, List<Collection<SearchGroup<String>>>>();
      Map<String, Map<SearchGroup<String>, String>> tempSearchGroupToShard = new HashMap<String, Map<SearchGroup<String>, String>>();
      for (String field : fields) {
        commandSearchGroups.put(field, new ArrayList<Collection<SearchGroup<String>>>(shardRequest.responses.size()));
        tempSearchGroupToShard.put(field, new HashMap<SearchGroup<String>, String>());
        if (!rb.searchGroupToShard.containsKey(field)) {
          rb.searchGroupToShard.put(field, new HashMap<SearchGroup<String>, String>());
        }
      }
  
      SearchGroupsResultTransformer serializer = new SearchGroupsResultTransformer(rb.req.getSearcher());
      try {
        for (ShardResponse srsp : shardRequest.responses) {
          @SuppressWarnings("unchecked")
          NamedList<NamedList> firstPhaseResult = (NamedList<NamedList>) srsp.getSolrResponse().getResponse().get("firstPhase");
          Map<String, Collection<SearchGroup<String>>> result = serializer.transformToNative(firstPhaseResult, groupSort, null, srsp.getShard());
          for (String field : commandSearchGroups.keySet()) {
            Collection<SearchGroup<String>> searchGroups = result.get(field);
            if (searchGroups == null) {
              continue;
            }
  
            commandSearchGroups.get(field).add(searchGroups);
            for (SearchGroup<String> searchGroup : searchGroups) {
              tempSearchGroupToShard.get(field).put(searchGroup, srsp.getShard());
            }
          }
        }
        for (String groupField : commandSearchGroups.keySet()) {
          List<Collection<SearchGroup<String>>> topGroups = commandSearchGroups.get(groupField);
          Collection<SearchGroup<String>> mergedTopGroups = SearchGroup.merge(topGroups, ss.getOffset(), ss.getCount(), groupSort);
          if (mergedTopGroups == null) {
            continue;
          }
  
          rb.mergedSearchGroups.put(groupField, mergedTopGroups);
          for (SearchGroup<String> mergedTopGroup : mergedTopGroups) {
            rb.searchGroupToShard.get(groupField).put(mergedTopGroup, tempSearchGroupToShard.get(groupField).get(mergedTopGroup));
          }
        }
      } catch (IOException e) {
        throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e);
      }
    }
  
  }
  