Package org.apache.lucene.util

Class BitSet

java.lang.Object
org.apache.lucene.util.BitSet
All Implemented Interfaces:
Accountable, Bits
Direct Known Subclasses:
FixedBitSet, SparseFixedBitSet
public abstract class BitSet extends Object implements Bits, Accountable
Base implementation for a bit set.
NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

  • Constructor Details

    • BitSet

      public BitSet()

  • Method Details

    • of

      public static BitSet of(DocIdSetIterator it, int maxDoc) throws IOException
      Build a BitSet from the content of the provided DocIdSetIterator. NOTE: this will fully consume the DocIdSetIterator.
      Throws:
      IOException

    • set

      public abstract void set(int i)
      Set the bit at i.

    • getAndSet

      public abstract boolean getAndSet(int i)
      Set the bit at i, returning true if it was previously set.

    • clear

      public abstract void clear(int i)
      Clear the bit at i.

    • clear

      public abstract void clear(int startIndex, int endIndex)
      Clears a range of bits.
      Parameters:
      startIndex - lower index
      endIndex - one-past the last bit to clear

    • cardinality

      public abstract int cardinality()
      Return the number of bits that are set. NOTE: this method is likely to run in linear time

    • approximateCardinality

      public abstract int approximateCardinality()
      Return an approximation of the cardinality of this set. Some implementations may trade accuracy for speed if they have the ability to estimate the cardinality of the set without iterating over all the data. The default implementation returns cardinality().

    • prevSetBit

      public abstract int prevSetBit(int index)
      Returns the index of the last set bit before or on the index specified. -1 is returned if there are no more set bits.

    • nextSetBit

      public abstract int nextSetBit(int index)
      Returns the index of the first set bit starting at the index specified. DocIdSetIterator.NO_MORE_DOCS is returned if there are no more set bits.

    • checkUnpositioned

      protected final void checkUnpositioned(DocIdSetIterator iter)
      Assert that the current doc is -1.

    • or

      public void or(DocIdSetIterator iter) throws IOException
      Does in-place OR of the bits provided by the iterator. The state of the iterator after this operation terminates is undefined.
      Throws:
      IOException