Example usage for org.apache.lucene.search DocIdSetIterator empty

Introduction

In this page you can find the example usage for org.apache.lucene.search DocIdSetIterator empty.

Prototype

public static final DocIdSetIterator empty() 

Source Link

Document

An empty DocIdSetIterator instance

Usage

From source file:org.hibernate.search.spatial.impl.SpatialHashQuery.java

License:LGPL

/**
 * Search the index for document having the correct spatial hash cell id at given grid level.
 *
 * @param context the {@link LeafReaderContext} for which to return the {@link DocIdSet}.
 * @return a {@link DocIdSetIterator} with the matching document ids
 *//*from  w  w w. j av  a 2s .  com*/
private DocIdSetIterator createDocIdSetIterator(LeafReaderContext context) throws IOException {
    if (spatialHashCellsIds.size() == 0) {
        return null;
    }

    final LeafReader atomicReader = context.reader();

    BitDocIdSet matchedDocumentsIds = new BitDocIdSet(new FixedBitSet(atomicReader.maxDoc()));
    boolean found = false;
    for (int i = 0; i < spatialHashCellsIds.size(); i++) {
        Term spatialHashCellTerm = new Term(fieldName, spatialHashCellsIds.get(i));
        PostingsEnum spatialHashCellsDocs = atomicReader.postings(spatialHashCellTerm);
        if (spatialHashCellsDocs != null) {
            while (true) {
                final int docId = spatialHashCellsDocs.nextDoc();
                if (docId == DocIdSetIterator.NO_MORE_DOCS) {
                    break;
                } else {
                    matchedDocumentsIds.bits().set(docId);
                    found = true;
                }
            }
        }
    }

    if (found) {
        return matchedDocumentsIds.iterator();
    } else {
        return DocIdSetIterator.empty();
    }
}

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From source file:org.tallison.lucene.search.concordance.charoffsets.SpansCrawler.java

License:Apache License

public static void crawl(SpanQuery query, Query filter, IndexSearcher searcher, DocTokenOffsetsVisitor visitor)
        throws IOException, TargetTokenNotFoundException {

    query = (SpanQuery) query.rewrite(searcher.getIndexReader());

    SpanWeight w = query.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1.0f);
    if (filter == null) {
        for (LeafReaderContext ctx : searcher.getIndexReader().leaves()) {

            Spans spans = w.getSpans(ctx, SpanWeight.Postings.POSITIONS);
            if (spans == null) {
                continue;
            }/*w  w w  . j  av  a 2s .c o  m*/
            boolean cont = visitLeafReader(ctx, spans, visitor);
            if (!cont) {
                break;
            }
        }
    } else {
        filter = searcher.rewrite(filter);
        Weight searcherWeight = searcher.createWeight(filter, ScoreMode.COMPLETE_NO_SCORES, 1.0f);
        for (LeafReaderContext ctx : searcher.getIndexReader().leaves()) {
            Scorer leafReaderContextScorer = searcherWeight.scorer(ctx);
            if (leafReaderContextScorer == null) {
                continue;
            }
            //Can we tell from the scorer that there were no hits?
            //in <= 5.x we could stop here if the filter query had no hits.

            Spans spans = w.getSpans(ctx, SpanWeight.Postings.POSITIONS);
            if (spans == null) {
                continue;
            }
            DocIdSetIterator filterItr = leafReaderContextScorer.iterator();

            if (filterItr == null || filterItr.equals(DocIdSetIterator.empty())) {
                continue;
            }
            boolean cont = visitLeafReader(ctx, spans, filterItr, visitor);
            if (!cont) {
                break;
            }
        }
    }
}

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