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

Introduction

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

Prototype

public static <T> TopGroups<T> merge(TopGroups<T>[] shardGroups, Sort groupSort, Sort docSort, int docOffset,
        int docTopN, ScoreMergeMode scoreMergeMode) 

Source Link

Document

Merges an array of TopGroups, for example obtained from the second-pass collector across multiple shards.

Usage

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

License:Apache License

/**
 * {@inheritDoc}/* w w w . ja v  a 2  s .co m*/
 */
@Override
@SuppressWarnings("unchecked")
public void process(ResponseBuilder rb, ShardRequest shardRequest) {
    Sort groupSort = rb.getGroupingSpec().getGroupSort();
    String[] fields = rb.getGroupingSpec().getFields();
    String[] queries = rb.getGroupingSpec().getQueries();
    Sort sortWithinGroup = rb.getGroupingSpec().getSortWithinGroup();

    // If group.format=simple group.offset doesn't make sense
    int groupOffsetDefault;
    if (rb.getGroupingSpec().getResponseFormat() == Grouping.Format.simple || rb.getGroupingSpec().isMain()) {
        groupOffsetDefault = 0;
    } else {
        groupOffsetDefault = rb.getGroupingSpec().getGroupOffset();
    }
    int docsPerGroupDefault = rb.getGroupingSpec().getGroupLimit();

    Map<String, List<TopGroups<BytesRef>>> commandTopGroups = new HashMap<String, List<TopGroups<BytesRef>>>();
    for (String field : fields) {
        commandTopGroups.put(field, new ArrayList<TopGroups<BytesRef>>());
    }

    Map<String, List<QueryCommandResult>> commandTopDocs = new HashMap<String, List<QueryCommandResult>>();
    for (String query : queries) {
        commandTopDocs.put(query, new ArrayList<QueryCommandResult>());
    }

    TopGroupsResultTransformer serializer = new TopGroupsResultTransformer(rb);

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

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

            if (srsp.getException() != null) {
                Throwable t = srsp.getException();
                if (t instanceof SolrServerException) {
                    t = ((SolrServerException) t).getCause();
                }
                individualShardInfo.add("error", t.toString());
                StringWriter trace = new StringWriter();
                t.printStackTrace(new PrintWriter(trace));
                individualShardInfo.add("trace", trace.toString());
            } else {
                // summary for successful shard response is added down below
            }
            if (srsp.getSolrResponse() != null) {
                individualShardInfo.add("time", srsp.getSolrResponse().getElapsedTime());
            }

            shardInfo.add(srsp.getShard(), individualShardInfo);
        }
        if (rb.req.getParams().getBool(ShardParams.SHARDS_TOLERANT, false) && srsp.getException() != null) {
            continue; // continue if there was an error and we're tolerant.  
        }
        NamedList<NamedList> secondPhaseResult = (NamedList<NamedList>) srsp.getSolrResponse().getResponse()
                .get("secondPhase");
        Map<String, ?> result = serializer.transformToNative(secondPhaseResult, groupSort, sortWithinGroup,
                srsp.getShard());
        int numFound = 0;
        float maxScore = Float.NaN;
        for (String field : commandTopGroups.keySet()) {
            TopGroups<BytesRef> topGroups = (TopGroups<BytesRef>) result.get(field);
            if (topGroups == null) {
                continue;
            }
            if (individualShardInfo != null) { // keep track of this when shards.info=true
                numFound += topGroups.totalHitCount;
                if (Float.isNaN(maxScore) || topGroups.maxScore > maxScore)
                    maxScore = topGroups.maxScore;
            }
            commandTopGroups.get(field).add(topGroups);
        }
        for (String query : queries) {
            QueryCommandResult queryCommandResult = (QueryCommandResult) result.get(query);
            if (individualShardInfo != null) { // keep track of this when shards.info=true
                numFound += queryCommandResult.getMatches();
                float thisMax = queryCommandResult.getTopDocs().getMaxScore();
                if (Float.isNaN(maxScore) || thisMax > maxScore)
                    maxScore = thisMax;
            }
            commandTopDocs.get(query).add(queryCommandResult);
        }
        if (individualShardInfo != null) { // when shards.info=true
            individualShardInfo.add("numFound", numFound);
            individualShardInfo.add("maxScore", maxScore);
        }
    }
    try {
        for (String groupField : commandTopGroups.keySet()) {
            List<TopGroups<BytesRef>> topGroups = commandTopGroups.get(groupField);
            if (topGroups.isEmpty()) {
                continue;
            }

            TopGroups<BytesRef>[] topGroupsArr = new TopGroups[topGroups.size()];
            rb.mergedTopGroups.put(groupField, TopGroups.merge(topGroups.toArray(topGroupsArr), groupSort,
                    sortWithinGroup, groupOffsetDefault, docsPerGroupDefault, TopGroups.ScoreMergeMode.None));
        }

        for (String query : commandTopDocs.keySet()) {
            List<QueryCommandResult> queryCommandResults = commandTopDocs.get(query);
            List<TopDocs> topDocs = new ArrayList<TopDocs>(queryCommandResults.size());
            int mergedMatches = 0;
            for (QueryCommandResult queryCommandResult : queryCommandResults) {
                topDocs.add(queryCommandResult.getTopDocs());
                mergedMatches += queryCommandResult.getMatches();
            }

            int topN = rb.getGroupingSpec().getOffset() + rb.getGroupingSpec().getLimit();
            TopDocs mergedTopDocs = TopDocs.merge(sortWithinGroup, topN,
                    topDocs.toArray(new TopDocs[topDocs.size()]));
            rb.mergedQueryCommandResults.put(query, new QueryCommandResult(mergedTopDocs, mergedMatches));
        }

        Map<Object, ShardDoc> resultIds = new HashMap<Object, ShardDoc>();
        int i = 0;
        for (TopGroups<BytesRef> topGroups : rb.mergedTopGroups.values()) {
            for (GroupDocs<BytesRef> group : topGroups.groups) {
                for (ScoreDoc scoreDoc : group.scoreDocs) {
                    ShardDoc solrDoc = (ShardDoc) scoreDoc;
                    solrDoc.positionInResponse = i++;
                    resultIds.put(solrDoc.id, solrDoc);
                }
            }
        }
        for (QueryCommandResult queryCommandResult : rb.mergedQueryCommandResults.values()) {
            for (ScoreDoc scoreDoc : queryCommandResult.getTopDocs().scoreDocs) {
                ShardDoc solrDoc = (ShardDoc) scoreDoc;
                solrDoc.positionInResponse = i++;
                resultIds.put(solrDoc.id, solrDoc);
            }
        }

        rb.resultIds = resultIds;
    } catch (IOException e) {
        throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e);
    }
}

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