Example usage for org.apache.lucene.search.grouping SearchGroup merge

Introduction

In this page you can find the example usage for org.apache.lucene.search.grouping SearchGroup merge.

Prototype

public static <T> Collection<SearchGroup<T>> merge(List<Collection<SearchGroup<T>>> topGroups, int offset,
        int topN, Sort groupSort) 

Source Link

Document

Merges multiple collections of top groups, for example obtained from separate index shards.

Usage

From source file:org.apache.solr.search.grouping.distributed.responseprocessor.SearchGroupShardResponseProcessor.java

License:Apache License

/**
 * {@inheritDoc}/*w  w  w  .ja  va  2  s . c  o m*/
 */
@Override
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<BytesRef>>>> commandSearchGroups = new HashMap<String, List<Collection<SearchGroup<BytesRef>>>>();
    Map<String, Map<SearchGroup<BytesRef>, Set<String>>> tempSearchGroupToShards = new HashMap<String, Map<SearchGroup<BytesRef>, Set<String>>>();
    for (String field : fields) {
        commandSearchGroups.put(field,
                new ArrayList<Collection<SearchGroup<BytesRef>>>(shardRequest.responses.size()));
        tempSearchGroupToShards.put(field, new HashMap<SearchGroup<BytesRef>, Set<String>>());
        if (!rb.searchGroupToShards.containsKey(field)) {
            rb.searchGroupToShards.put(field, new HashMap<SearchGroup<BytesRef>, Set<String>>());
        }
    }

    SearchGroupsResultTransformer serializer = new SearchGroupsResultTransformer(rb.req.getSearcher());
    try {
        int maxElapsedTime = 0;
        int hitCountDuringFirstPhase = 0;

        NamedList<Object> shardInfo = null;
        if (rb.req.getParams().getBool(ShardParams.SHARDS_INFO, false)) {
            shardInfo = new SimpleOrderedMap<Object>();
            rb.rsp.getValues().add(ShardParams.SHARDS_INFO + ".firstPhase", shardInfo);
        }

        for (ShardResponse srsp : shardRequest.responses) {
            if (shardInfo != null) {
                SimpleOrderedMap<Object> nl = new SimpleOrderedMap<Object>();

                if (srsp.getException() != null) {
                    Throwable t = srsp.getException();
                    if (t instanceof SolrServerException) {
                        t = ((SolrServerException) t).getCause();
                    }
                    nl.add("error", t.toString());
                    StringWriter trace = new StringWriter();
                    t.printStackTrace(new PrintWriter(trace));
                    nl.add("trace", trace.toString());
                } else {
                    nl.add("numFound", (Integer) srsp.getSolrResponse().getResponse().get("totalHitCount"));
                }
                if (srsp.getSolrResponse() != null) {
                    nl.add("time", srsp.getSolrResponse().getElapsedTime());
                }

                shardInfo.add(srsp.getShard(), nl);
            }
            if (rb.req.getParams().getBool(ShardParams.SHARDS_TOLERANT, false) && srsp.getException() != null) {
                continue; // continue if there was an error and we're tolerant.  
            }
            maxElapsedTime = (int) Math.max(maxElapsedTime, srsp.getSolrResponse().getElapsedTime());
            @SuppressWarnings("unchecked")
            NamedList<NamedList> firstPhaseResult = (NamedList<NamedList>) srsp.getSolrResponse().getResponse()
                    .get("firstPhase");
            Map<String, Pair<Integer, Collection<SearchGroup<BytesRef>>>> result = serializer
                    .transformToNative(firstPhaseResult, groupSort, null, srsp.getShard());
            for (String field : commandSearchGroups.keySet()) {
                Pair<Integer, Collection<SearchGroup<BytesRef>>> firstPhaseCommandResult = result.get(field);
                Integer groupCount = firstPhaseCommandResult.getA();
                if (groupCount != null) {
                    Integer existingGroupCount = rb.mergedGroupCounts.get(field);
                    // Assuming groups don't cross shard boundary...
                    rb.mergedGroupCounts.put(field,
                            existingGroupCount != null ? existingGroupCount + groupCount : groupCount);
                }

                Collection<SearchGroup<BytesRef>> searchGroups = firstPhaseCommandResult.getB();
                if (searchGroups == null) {
                    continue;
                }

                commandSearchGroups.get(field).add(searchGroups);
                for (SearchGroup<BytesRef> searchGroup : searchGroups) {
                    Map<SearchGroup<BytesRef>, java.util.Set<String>> map = tempSearchGroupToShards.get(field);
                    Set<String> shards = map.get(searchGroup);
                    if (shards == null) {
                        shards = new HashSet<String>();
                        map.put(searchGroup, shards);
                    }
                    shards.add(srsp.getShard());
                }
            }
            hitCountDuringFirstPhase += (Integer) srsp.getSolrResponse().getResponse().get("totalHitCount");
        }
        rb.totalHitCount = hitCountDuringFirstPhase;
        rb.firstPhaseElapsedTime = maxElapsedTime;
        for (String groupField : commandSearchGroups.keySet()) {
            List<Collection<SearchGroup<BytesRef>>> topGroups = commandSearchGroups.get(groupField);
            Collection<SearchGroup<BytesRef>> mergedTopGroups = SearchGroup.merge(topGroups, ss.getOffset(),
                    ss.getCount(), groupSort);
            if (mergedTopGroups == null) {
                continue;
            }

            rb.mergedSearchGroups.put(groupField, mergedTopGroups);
            for (SearchGroup<BytesRef> mergedTopGroup : mergedTopGroups) {
                rb.searchGroupToShards.get(groupField).put(mergedTopGroup,
                        tempSearchGroupToShards.get(groupField).get(mergedTopGroup));
            }
        }
    } catch (IOException e) {
        throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e);
    }
}

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