Java DocIdSetIterator.empty方法代碼示例

import org.apache.lucene.search.DocIdSetIterator; //導入方法依賴的package包/類
@Override
public Scorer scorer(AtomicReaderContext context, Bits acceptDocs) throws IOException {

	if (filter == null) {
		boolean debug = rb != null && rb.isDebug();
		long start = System.currentTimeMillis();
		resultSet = getDocSet();
		long delta = System.currentTimeMillis()-start;
		if (debug) {
			System.out.println("Graph Traverse took : " + delta + " ms.");
		}

		filter = resultSet.getTopFilter();
	}
	// TODO: understand this comment.
	// Although this set only includes live docs, other filters can be pushed down to queries.
	DocIdSet readerSet = filter.getDocIdSet(context, acceptDocs);
	// create a scrorer on the result set, if results from right query are empty, use empty iterator.
	return new GraphScorer(this, readerSet == null ? DocIdSetIterator.empty() : readerSet.iterator(), getBoost());
}
 

import org.apache.lucene.search.DocIdSetIterator; //導入方法依賴的package包/類
private DocIdSetIterator getDISI(Filter filter, AtomicReaderContext context)
    throws IOException {
  // we dont pass acceptDocs, we will filter at the end using an additional filter
  DocIdSet docIdSet = filter.getDocIdSet(context, null);
  if (docIdSet == null) {
    return DocIdSetIterator.empty();
  } else {
    DocIdSetIterator iter = docIdSet.iterator();
    if (iter == null) {
      return DocIdSetIterator.empty();
    } else {
      return iter;
    }
  }
}
 

import org.apache.lucene.search.DocIdSetIterator; //導入方法依賴的package包/類
@Override
public Scorer scorer(AtomicReaderContext context, Bits acceptDocs) throws IOException {
  if (filter == null) {
    boolean debug = rb != null && rb.isDebug();
    long start = debug ? System.currentTimeMillis() : 0;
    resultSet = getDocSet();
    long end = debug ? System.currentTimeMillis() : 0;

    if (debug) {
      SimpleOrderedMap<Object> dbg = new SimpleOrderedMap<>();
      dbg.add("time", (end-start));
      dbg.add("fromSetSize", fromSetSize);  // the input
      dbg.add("toSetSize", resultSet.size());    // the output

      dbg.add("fromTermCount", fromTermCount);
      dbg.add("fromTermTotalDf", fromTermTotalDf);
      dbg.add("fromTermDirectCount", fromTermDirectCount);
      dbg.add("fromTermHits", fromTermHits);
      dbg.add("fromTermHitsTotalDf", fromTermHitsTotalDf);
      dbg.add("toTermHits", toTermHits);
      dbg.add("toTermHitsTotalDf", toTermHitsTotalDf);
      dbg.add("toTermDirectCount", toTermDirectCount);
      dbg.add("smallSetsDeferred", smallSetsDeferred);
      dbg.add("toSetDocsAdded", resultListDocs);

      // TODO: perhaps synchronize  addDebug in the future...
      rb.addDebug(dbg, "join", JoinQuery.this.toString());
    }

    filter = resultSet.getTopFilter();
  }

  // Although this set only includes live docs, other filters can be pushed down to queries.
  DocIdSet readerSet = filter.getDocIdSet(context, acceptDocs);
  return new JoinScorer(this, readerSet == null ? DocIdSetIterator.empty() : readerSet.iterator(), getBoost());
}
 

import org.apache.lucene.search.DocIdSetIterator; //導入方法依賴的package包/類
private void doChain(FixedBitSet result, int logic, DocIdSet dis) throws IOException {
  if (dis instanceof FixedBitSet) {
    // optimized case for FixedBitSets
    switch (logic) {
      case OR:
        result.or((FixedBitSet) dis);
        break;
      case AND:
        result.and((FixedBitSet) dis);
        break;
      case ANDNOT:
        result.andNot((FixedBitSet) dis);
        break;
      case XOR:
        result.xor((FixedBitSet) dis);
        break;
      default:
        doChain(result, DEFAULT, dis);
        break;
    }
  } else {
    DocIdSetIterator disi;
    if (dis == null) {
      disi = DocIdSetIterator.empty();
    } else {
      disi = dis.iterator();
      if (disi == null) {
        disi = DocIdSetIterator.empty();
      }
    }

    switch (logic) {
      case OR:
        result.or(disi);
        break;
      case AND:
        result.and(disi);
        break;
      case ANDNOT:
        result.andNot(disi);
        break;
      case XOR:
        result.xor(disi);
        break;
      default:
        doChain(result, DEFAULT, dis);
        break;
    }
  }
}
 

import org.apache.lucene.search.DocIdSetIterator; //導入方法依賴的package包/類
public JoinScorer(Weight w, DocIdSetIterator iter, float score) throws IOException {
  super(w);
  this.score = score;
  this.iter = iter==null ? DocIdSetIterator.empty() : iter;
}