Package org.apache.commons.collections4.bloomfilter

Class SparseBloomFilter

java.lang.Object
org.apache.commons.collections4.bloomfilter.SparseBloomFilter
All Implemented Interfaces:
BitMapExtractor, BloomFilter, IndexExtractor
public final class SparseBloomFilter extends Object implements BloomFilter
A bloom filter using a TreeSet of integers to track enabled bits. This is a standard implementation and should work well for most low cardinality Bloom filters.
Since:
4.5

  • Constructor Details

    • SparseBloomFilter

      public SparseBloomFilter(Shape shape)
      Constructs an empty BitSetBloomFilter.
      Parameters:
      shape - The shape of the filter.

  • Method Details

    • asBitMapArray

      public long[] asBitMapArray()
      Description copied from interface: BitMapExtractor
      Return a copy of the BitMapExtractor data as a bit map array.

      The default implementation of this method is slow. It is recommended that implementing classes reimplement this method.

      Specified by:
      asBitMapArray in interface BitMapExtractor
      Returns:
      An array of bit map data.

    • cardinality

      public int cardinality()
      Description copied from interface: BloomFilter
      Gets the cardinality (number of enabled bits) of this Bloom filter.

      This is also known as the Hamming value or Hamming number.

      Specified by:
      cardinality in interface BloomFilter
      Returns:
      the cardinality of this filter

    • characteristics

      public int characteristics()
      Description copied from interface: BloomFilter
      Returns the characteristics of the filter.

      Characteristics are defined as bits within the characteristics integer.

      Specified by:
      characteristics in interface BloomFilter
      Returns:
      the characteristics for this bloom filter.

    • clear

      public void clear()
      Description copied from interface: BloomFilter
      Resets the filter to its initial, unpopulated state.
      Specified by:
      clear in interface BloomFilter

    • contains

      public boolean contains(BitMapExtractor bitMapExtractor)
      Description copied from interface: BloomFilter
      Returns true if this filter contains the bits specified in the bit maps produced by the bitMapExtractor.
      Specified by:
      contains in interface BloomFilter
      Parameters:
      bitMapExtractor - the BitMapExtractor to provide the bit maps.
      Returns:
      true if this filter is enabled for all bits specified by the bit maps

    • contains

      public boolean contains(IndexExtractor indexExtractor)
      Description copied from interface: BloomFilter
      Returns true if this filter contains the indices specified IndexExtractor.

      Specifically this returns true if this filter is enabled for all bit indexes identified by the IndexExtractor.

      Specified by:
      contains in interface BloomFilter
      Parameters:
      indexExtractor - the IndexExtractor to provide the indexes
      Returns:
      true if this filter is enabled for all bits specified by the IndexExtractor

    • copy

      public SparseBloomFilter copy()
      Description copied from interface: BloomFilter
      Creates a new instance of the BloomFilter with the same properties as the current one.
      Specified by:
      copy in interface BloomFilter
      Returns:
      a copy of this BloomFilter

    • processBitMaps

      public boolean processBitMaps(LongPredicate consumer)
      Description copied from interface: BitMapExtractor
      Each bit map is passed to the predicate in order. The predicate is applied to each bit map value, if the predicate returns false the execution is stopped, false is returned, and no further bit maps are processed.

      If the extractor is empty this method will return true.

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

      Specified by:
      processBitMaps in interface BitMapExtractor
      Parameters:
      consumer - the function to execute
      Returns:
      true if all bit maps returned true, false otherwise.

    • processIndices

      public boolean processIndices(IntPredicate consumer)
      Description copied from interface: IndexExtractor
      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.

      Specified by:
      processIndices in interface IndexExtractor
      Parameters:
      consumer - the action to be performed for each non-zero bit index.
      Returns:
      true if all indexes return true from consumer, false otherwise.

    • getShape

      public Shape getShape()
      Description copied from interface: BloomFilter
      Gets the shape that was used when the filter was built.
      Specified by:
      getShape in interface BloomFilter
      Returns:
      The shape the filter was built with.

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: BloomFilter
      Determines if all the bits are off. This is equivalent to cardinality() == 0.

      Note: This method is optimised for non-sparse filters. Implementers are encouraged to implement faster checks if possible.

      Specified by:
      isEmpty in interface BloomFilter
      Returns:
      true if no bits are enabled, false otherwise.

    • merge

      public boolean merge(BitMapExtractor bitMapExtractor)
      Description copied from interface: BloomFilter
      Merges the specified hasher into this Bloom filter. Specifically all bit indexes that are identified by the bitMapExtractor will be enabled in this filter.

      Note: This method should return true even if no additional bit indexes were enabled. A false result indicates that this filter may or may not contain all the indexes enabled in the bitMapExtractor. This state may occur in complex Bloom filter implementations like counting Bloom filters.

      Specified by:
      merge in interface BloomFilter
      Parameters:
      bitMapExtractor - The BitMapExtractor to merge.
      Returns:
      true if the merge was successful

    • merge

      public boolean merge(BloomFilter other)
      Description copied from interface: BloomFilter
      Merges the specified Bloom filter into this Bloom filter.

      Specifically all bit indexes that are identified by the other will be enabled in this filter.

      Note: This method should return true even if no additional bit indexes were enabled. A false result indicates that this filter may or may not contain the other Bloom filter. This state may occur in complex Bloom filter implementations like counting Bloom filters.

      Specified by:
      merge in interface BloomFilter
      Parameters:
      other - The bloom filter to merge into this one.
      Returns:
      true if the merge was successful

    • merge

      public boolean merge(Hasher hasher)
      Description copied from interface: BloomFilter
      Merges the specified hasher into this Bloom filter. Specifically all bit indexes that are identified by the hasher will be enabled in this filter.

      Note: This method should return true even if no additional bit indexes were enabled. A false result indicates that this filter may or may not contain the hasher values. This state may occur in complex Bloom filter implementations like counting Bloom filters.

      Specified by:
      merge in interface BloomFilter
      Parameters:
      hasher - The hasher to merge.
      Returns:
      true if the merge was successful

    • merge

      public boolean merge(IndexExtractor indexExtractor)
      Description copied from interface: BloomFilter
      Merges the specified IndexExtractor into this Bloom filter. Specifically all bit indexes that are identified by the indexExtractor will be enabled in this filter.

      Note: This method should return true even if no additional bit indexes were enabled. A false result indicates that this filter may or may not contain all the indexes of the indexExtractor. This state may occur in complex Bloom filter implementations like counting Bloom filters.

      Specified by:
      merge in interface BloomFilter
      Parameters:
      indexExtractor - The IndexExtractor to merge.
      Returns:
      true if the merge was successful