Package org.apache.lucene.util

Class BitSetIterator

java.lang.Object
org.apache.lucene.search.DocIdSetIterator
org.apache.lucene.util.BitSetIterator
public class BitSetIterator extends DocIdSetIterator
A DocIdSetIterator which iterates over set bits in a bit set.
NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

  • Constructor Details

    • BitSetIterator

      public BitSetIterator(BitSet bits, long cost)
      Sole constructor.

  • Method Details

    • getFixedBitSetOrNull

      public static FixedBitSet getFixedBitSetOrNull(DocIdSetIterator iterator)
      If the provided iterator wraps a FixedBitSet, returns it, otherwise returns null.

    • getSparseFixedBitSetOrNull

      public static SparseFixedBitSet getSparseFixedBitSetOrNull(DocIdSetIterator iterator)
      If the provided iterator wraps a SparseFixedBitSet, returns it, otherwise returns null.

    • getBitSet

      public BitSet getBitSet()
      Return the wrapped BitSet.

    • docID

      public int docID()
      Description copied from class: DocIdSetIterator
      Returns the following:
      Specified by:
      docID in class DocIdSetIterator

    • setDocId

      public void setDocId(int docId)
      Set the current doc id that this iterator is on.

    • nextDoc

      public int nextDoc()
      Description copied from class: DocIdSetIterator
      Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
      NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.
      Specified by:
      nextDoc in class DocIdSetIterator

    • advance

      public int advance(int target)
      Description copied from class: DocIdSetIterator
      Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

      The behavior of this method is undefined when called with target ≤ current , or after the iterator has exhausted. Both cases may result in unpredicted behavior.

      When target > current it behaves as if written: 

       int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
      Some implementations are considerably more efficient than that.

      NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

      Specified by:
      advance in class DocIdSetIterator

    • cost

      public long cost()
      Description copied from class: DocIdSetIterator
      Returns the estimated cost of this DocIdSetIterator.

      This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

      Specified by:
      cost in class DocIdSetIterator