Examples of org.apache.lucene.index.sorter.EarlyTerminatingSortingCollector

org.apache.lucene.index.sorter.EarlyTerminatingSortingCollector

A {@link Collector} that early terminates collection of documents on aper-segment basis, if the segment was sorted according to the given {@link Sorter}.

NOTE: the {@link Collector} detects sorted segments according to{@link SortingMergePolicy}, so it's best used in conjunction with it. Also, it collects up to a specified num docs from each segment, and therefore is mostly suitable for use in conjunction with collectors such as {@link TopDocsCollector}, and not e.g. {@link TotalHitCountCollector}.

NOTE: If you wrap a {@link TopDocsCollector} that sorts in the sameorder as the index order, the returned {@link TopDocsCollector#topDocs()}will be correct. However the total of {@link TopDocsCollector#getTotalHits() hit count} will be underestimated since not all matching documents will havebeen collected.

NOTE: This {@link Collector} uses {@link Sorter#getID()} to detectwhether a segment was sorted with the same {@link Sorter} as the one given in{@link #EarlyTerminatingSortingCollector(Collector,Sorter,int)}. This has two implications:

if {@link Sorter#getID()} is not implemented correctly and returnsdifferent identifiers for equivalent {@link Sorter}s, this collector will not detect sorted segments,
if you suddenly change the {@link IndexWriter}'s {@link SortingMergePolicy} to sort according to another criterion and if boththe old and the new {@link Sorter}s have the same identifier, this {@link Collector} will incorrectly detect sorted segments.

@lucene.experimental

    // Sort by weight, descending:
    TopFieldCollector c = TopFieldCollector.create(SORT, num, true, false, false, false);


    // We sorted postings by weight during indexing, so we
    // only retrieve the first num hits now:
    Collector c2 = new EarlyTerminatingSortingCollector(c, SORT, num);
    IndexSearcher searcher = searcherMgr.acquire();
    List<LookupResult> results = null;
    try {
      //System.out.println("got searcher=" + searcher);
      searcher.search(finalQuery, c2);

    // Sort by weight, descending:
    TopFieldCollector c = TopFieldCollector.create(SORT, num, true, false, false, false);


    // We sorted postings by weight during indexing, so we
    // only retrieve the first num hits now:
    Collector c2 = new EarlyTerminatingSortingCollector(c, SORT, num);
    IndexSearcher searcher = searcherMgr.acquire();
    List<LookupResult> results = null;
    try {
      //System.out.println("got searcher=" + searcher);
      searcher.search(finalQuery, c2);

        {
            if (query instanceof ConstantScoreQuery)
            {
                FieldDoc start = after == null ? null : (FieldDoc) after;
                TopFieldCollector tfc = TopFieldCollector.create(this.sort, count, start, true, false, false, false);
                Collector collector = new EarlyTerminatingSortingCollector(tfc, this.sort, count);
                searcher.search(query, collector);
                return tfc.topDocs();
            }
            else
            {

Examples of org.apache.lucene.index.sorter.EarlyTerminatingSortingCollector

Related Classes of org.apache.lucene.index.sorter.EarlyTerminatingSortingCollector