Interface IndexExtractor

All Known Subinterfaces:
BloomFilter, CellExtractor, CountingBloomFilter
All Known Implementing Classes:
ArrayCountingBloomFilter, LayeredBloomFilter, SimpleBloomFilter, SparseBloomFilter, WrappedBloomFilter
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

An object that produces indices of a Bloom filter.

The default implementation of asIndexArray is slow. Implementers should reimplement the method where possible.

Since:
4.5
  • Method Details

    • fromBitMapExtractor

      Creates an IndexExtractor from a BitMapExtractor.
      Parameters:
      bitMapExtractor - the BitMapExtractor
      Returns:
      a new IndexExtractor.
    • fromIndexArray

      static IndexExtractor fromIndexArray(int... values)
      Creates an IndexExtractor from an array of integers.
      Parameters:
      values - the index values
      Returns:
      an IndexExtractor that uses the values.
    • asIndexArray

      default int[] asIndexArray()
      Return a copy of the IndexExtractor data as an int array.

      Indices ordering and uniqueness is not guaranteed.

      The default implementation of this method creates an array and populates it. Implementations that have access to an index array should consider returning a copy of that array if possible.

      Returns:
      An int array of the data.
    • processIndices

      boolean processIndices(IntPredicate predicate)
      Each index is passed to the predicate. The predicate is applied to each index value, if the predicate returns false the execution is stopped, false is returned, and no further indices are processed.

      Any exceptions thrown by the action are relayed to the caller.

      Indices ordering and uniqueness is not guaranteed.

      Parameters:
      predicate - the action to be performed for each non-zero bit index.
      Returns:
      true if all indexes return true from consumer, false otherwise.
      Throws:
      NullPointerException - if the specified action is null
    • uniqueIndices

      Creates an IndexExtractor comprising the unique indices for this extractor.

      By default creates a new extractor with some overhead to remove duplicates. IndexExtractors that return unique indices by default should override this to return this.

      The default implementation will filter the indices from this instance and return them in ascending order.

      Returns:
      the IndexExtractor of unique values.
      Throws:
      IndexOutOfBoundsException - if any index is less than zero.