# Class WrappedBloomFilter<T extends WrappedBloomFilter<T,W>,W extends BloomFilter<W>>

java.lang.Object
org.apache.commons.collections4.bloomfilter.WrappedBloomFilter<T,W>

Type Parameters:
  `T` - The WrappedBloomFilter type.
  `W` - The wrapped BloomFilter type.

All Implemented Interfaces:
  `BitMapExtractor`, `BloomFilter<T>`, `IndexExtractor`

public abstract class WrappedBloomFilter<T extends WrappedBloomFilter<T,W>,W extends BloomFilter<W>> extends Object implements BloomFilter<T>
An abstract class to assist in implementing Bloom filter decorators.

Since:
  4.5.0-M1

- ## Field Summary

  ### Fields inherited from interface org.apache.commons.collections4.bloomfilter.BloomFilter

  `SPARSE`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `WrappedBloomFilter(W wrapped)`
  Wraps a Bloom filter.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `long[]`
  `asBitMapArray()`
  Return a copy of the BitMapExtractor data as a bit map array.
  `int[]`
  `asIndexArray()`
  Return a copy of the IndexExtractor data as an int array.
  `int`
  `cardinality()`
  Gets the cardinality (number of enabled bits) of this Bloom filter.
  `int`
  `characteristics()`
  Gets the characteristics of the filter.
  `void`
  `clear()`
  Clears the filter to by resetting it to its initial, unpopulated state.
  `boolean`
  `contains(BitMapExtractor bitMapExtractor)`
  Returns `true` if this filter contains the bits specified in the bit maps produced by the bitMapExtractor.
  `boolean`
  `contains(BloomFilter<?> other)`
  Returns `true` if this filter contains the specified filter.
  `boolean`
  `contains(Hasher hasher)`
  Returns `true` if this filter contains the bits specified in the hasher.
  `boolean`
  `contains(IndexExtractor indexExtractor)`
  Returns `true` if this filter contains the indices specified IndexExtractor.
  `int`
  `estimateIntersection(BloomFilter<?> other)`
  Estimates the number of items in the intersection of this Bloom filter with the other bloom filter.
  `int`
  `estimateN()`
  Estimates the number of items in the Bloom filter.
  `int`
  `estimateUnion(BloomFilter<?> other)`
  Estimates the number of items in the union of this Bloom filter with the other bloom filter.
  `Shape`
  `getShape()`
  Gets the shape that was used when the filter was built.
  `protected W`
  `getWrapped()`
  Gets the wrapped BloomFilter.
  `boolean`
  `isFull()`
  Determines if the bloom filter is "full".
  `boolean`
  `merge(BitMapExtractor bitMapExtractor)`
  Merges the specified hasher into this Bloom filter.
  `boolean`
  `merge(BloomFilter<?> other)`
  Merges the specified Bloom filter into this Bloom filter.
  `boolean`
  `merge(Hasher hasher)`
  Merges the specified hasher into this Bloom filter.
  `boolean`
  `merge(IndexExtractor indexExtractor)`
  Merges the specified IndexExtractor into this Bloom filter.
  `boolean`
  `processBitMapPairs(BitMapExtractor other, LongBiPredicate func)`
  Applies the `func` to each bit map pair in order.
  `boolean`
  `processBitMaps(LongPredicate predicate)`
  Each bit map is passed to the predicate in order.
  `boolean`
  `processIndices(IntPredicate predicate)`
  Each index is passed to the predicate.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

  ### Methods inherited from interface org.apache.commons.collections4.bloomfilter.BloomFilter

  `copy, isEmpty, uniqueIndices`

- ## Constructor Details

  - ### WrappedBloomFilter

    public WrappedBloomFilter(W wrapped)
    Wraps a Bloom filter. The wrapped filter is maintained as a reference not a copy. Changes in one will be reflected in the other.
    Parameters:
      `wrapped` - The Bloom 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.

  - ### asIndexArray

    public int[] asIndexArray()
    Description copied from interface: `IndexExtractor`
    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.

    Specified by:
      `asIndexArray` in interface `IndexExtractor`
    Returns:
      An int array of the 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<T extends WrappedBloomFilter<T,W>>`
    Returns:
      the cardinality of this filter

  - ### characteristics

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

    Characteristics are defined as bits within the characteristics integer.

    Specified by:
      `characteristics` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Returns:
      the characteristics for this bloom filter.

  - ### clear

    public void clear()
    Description copied from interface: `BloomFilter`
    Clears the filter to by resetting it to its initial, unpopulated state.
    Specified by:
      `clear` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`

  - ### 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<T extends WrappedBloomFilter<T,W>>`
    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(BloomFilter<?> other)
    Description copied from interface: `BloomFilter`
    Returns `true` if this filter contains the specified filter.

    Specifically this returns `true` if this filter is enabled for all bits that are enabled in the `other` filter. Using the bit representations this is effectively `(this AND other) == other`.

    Specified by:
      `contains` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `other` - the other Bloom filter
    Returns:
      true if all enabled bits in the other filter are enabled in this filter.

  - ### contains

    public boolean contains(Hasher hasher)
    Description copied from interface: `BloomFilter`
    Returns `true` if this filter contains the bits specified in the hasher.

    Specifically this returns `true` if this filter is enabled for all bit indexes identified by the `hasher`. Using the bit map representations this is effectively `(this AND hasher) == hasher`.

    Specified by:
      `contains` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `hasher` - the hasher to provide the indexes
    Returns:
      true if this filter is enabled for all bits specified by the hasher

  - ### 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<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `indexExtractor` - the IndexExtractor to provide the indexes
    Returns:
      `true` if this filter is enabled for all bits specified by the IndexExtractor

  - ### estimateIntersection

    public int estimateIntersection(BloomFilter<?> other)
    Description copied from interface: `BloomFilter`
    Estimates the number of items in the intersection of this Bloom filter with the other bloom filter.

    This method produces estimate is roughly equivalent to the number of unique Hashers that have been merged into both of the filters by rounding the value from the calculation described in the `Shape` class Javadoc.

    `estimateIntersection` should only be called with Bloom filters of the same Shape. If called on Bloom filters of differing shape this method is not symmetric. If `other` has more bits an `IllegalArgumentException` may be thrown.

    Specified by:
      `estimateIntersection` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `other` - The other Bloom filter
    Returns:
      an estimate of the number of items in the intersection. If the calculated estimate is larger than Integer.MAX_VALUE then MAX_VALUE is returned.
    See Also:
      - `BloomFilter.estimateN()`
      - `Shape`

  - ### estimateN

    public int estimateN()
    Description copied from interface: `BloomFilter`
    Estimates the number of items in the Bloom filter.

    By default this is the rounding of the `Shape.estimateN(cardinality)` calculation for the shape and cardinality of this filter.

    This produces an estimate roughly equivalent to the number of Hashers that have been merged into the filter by rounding the value from the calculation described in the `Shape` class Javadoc.

    Note:

    - if cardinality == numberOfBits, then result is Integer.MAX_VALUE.
    - if cardinality > numberOfBits, then an IllegalArgumentException is thrown.
    Specified by:
      `estimateN` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Returns:
      an estimate of the number of items in the bloom filter. Will return Integer.MAX_VALUE if the estimate is larger than Integer.MAX_VALUE.
    See Also:
      - `Shape.estimateN(int)`
      - `Shape`

  - ### estimateUnion

    public int estimateUnion(BloomFilter<?> other)
    Description copied from interface: `BloomFilter`
    Estimates the number of items in the union of this Bloom filter with the other bloom filter.

    This produces an estimate roughly equivalent to the number of unique Hashers that have been merged into either of the filters by rounding the value from the calculation described in the `Shape` class Javadoc.

    `estimateUnion` should only be called with Bloom filters of the same Shape. If called on Bloom filters of differing shape this method is not symmetric. If `other` has more bits an `IllegalArgumentException` may be thrown.

    Specified by:
      `estimateUnion` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `other` - The other Bloom filter
    Returns:
      an estimate of the number of items in the union. Will return Integer.MAX_VALUE if the estimate is larger than Integer.MAX_VALUE.
    See Also:
      - `BloomFilter.estimateN()`
      - `Shape`

  - ### 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<T extends WrappedBloomFilter<T,W>>`
    Returns:
      The shape the filter was built with.

  - ### getWrapped

    protected W getWrapped()
    Gets the wrapped BloomFilter.
    Returns:
      the wrapped BloomFilter.

  - ### isFull

    public boolean isFull()
    Description copied from interface: `BloomFilter`
    Determines if the bloom filter is "full".

    Full is defined as having no unset bits.

    Specified by:
      `isFull` in interface `BloomFilter<T extends WrappedBloomFilter<T,W>>`
    Returns:
      `true` if the filter is full, `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<T extends WrappedBloomFilter<T,W>>`
    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<T extends WrappedBloomFilter<T,W>>`
    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<T extends WrappedBloomFilter<T,W>>`
    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<T extends WrappedBloomFilter<T,W>>`
    Parameters:
      `indexExtractor` - The IndexExtractor to merge.
    Returns:
      true if the merge was successful

  - ### processBitMapPairs

    public boolean processBitMapPairs(BitMapExtractor other, LongBiPredicate func)
    Description copied from interface: `BitMapExtractor`
    Applies the `func` to each bit map pair in order. Will apply all of the bit maps from the other BitMapExtractor to this extractor. If this extractor does not have as many bit maps it will provide 0 (zero) for all excess calls to the LongBiPredicate.

    The default implementation of this method uses `asBitMapArray()`. It is recommended that implementations of BitMapExtractor that have local arrays reimplement this method.

    Specified by:
      `processBitMapPairs` in interface `BitMapExtractor`
    Parameters:
      `other` - The other BitMapExtractor that provides the y values in the (x,y) pair.
      `func` - The function to apply.
    Returns:
      A LongPredicate that tests this BitMapExtractor's bitmap values in order.

  - ### processBitMaps

    public boolean processBitMaps(LongPredicate predicate)
    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:
      `predicate` - the function to execute
    Returns:
      `true` if all bit maps returned `true`, `false` otherwise.

  - ### processIndices

    public boolean processIndices(IntPredicate predicate)
    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:
      `predicate` - the action to be performed for each non-zero bit index.
    Returns:
      `true` if all indexes return true from consumer, `false` otherwise.