org.apache.lucene.search

Class DocIdSetIterator

    • Method Detail

      • docID

        public abstract int docID()
        Returns the following:

        Since:
        2.9
      • nextDoc

        public abstract int nextDoc()
                             throws IOException
        Advances to the next document in the set and returns the doc it is currently on, or 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.
        Throws:
        IOException
        Since:
        2.9
      • advance

        public abstract int advance(int target)
                             throws IOException
        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 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 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.

        Throws:
        IOException
        Since:
        2.9
      • cost

        public abstract long cost()
        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.