Class RegularImmutableMultiset<E>

  • All Implemented Interfaces:
    Multiset<E>, java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>

    class RegularImmutableMultiset<E>
    extends ImmutableMultiset<E>
    Implementation of ImmutableMultiset with zero or more elements.
    • Field Detail

      • MAX_LOAD_FACTOR

        static final double MAX_LOAD_FACTOR
        Closed addressing tends to perform well even with high load factors. Being conservative here ensures that the table is still likely to be relatively sparse (hence it misses fast) while saving space.
        See Also:
        Constant Field Values
      • HASH_FLOODING_FPP

        static final double HASH_FLOODING_FPP
        Maximum allowed false positive probability of detecting a hash flooding attack given random input.
        See Also:
        Constant Field Values
      • MAX_HASH_BUCKET_LENGTH

        static final int MAX_HASH_BUCKET_LENGTH
        Maximum allowed length of a hash table bucket before falling back to a j.u.HashMap based implementation. Experimentally determined.
        See Also:
        Constant Field Values
      • size

        private final transient int size
      • hashCode

        private final transient int hashCode
    • Method Detail

      • isPartialView

        boolean isPartialView()
        Description copied from class: ImmutableCollection
        Returns true if this immutable collection's implementation contains references to user-created objects that aren't accessible via this collection's methods. This is generally used to determine whether copyOf implementations should make an explicit copy to avoid memory leaks.
        Specified by:
        isPartialView in class ImmutableCollection<E>
      • count

        public int count​(java.lang.Object element)
        Description copied from interface: Multiset
        Returns the number of occurrences of an element in this multiset (the count of the element). Note that for an Object.equals(java.lang.Object)-based multiset, this gives the same result as Collections.frequency(java.util.Collection<?>, java.lang.Object) (which would presumably perform more poorly).

        Note: the utility method Iterables.frequency(java.lang.Iterable<?>, java.lang.Object) generalizes this operation; it correctly delegates to this method when dealing with a multiset, but it can also accept any other iterable type.

        Parameters:
        element - the element to count occurrences of
        Returns:
        the number of occurrences of the element in this multiset; possibly zero but never negative
      • size

        public int size()
        Description copied from interface: Multiset
        Returns the total number of all occurrences of all elements in this multiset.

        Note: this method does not return the number of distinct elements in the multiset, which is given by entrySet().size().

        Specified by:
        size in interface java.util.Collection<E>
        Specified by:
        size in interface Multiset<E>
        Specified by:
        size in class java.util.AbstractCollection<E>
      • elementSet

        public ImmutableSet<E> elementSet()
        Description copied from interface: Multiset
        Returns the set of distinct elements contained in this multiset. The element set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. The order of the elements in the element set is unspecified.

        If the element set supports any removal operations, these necessarily cause all occurrences of the removed element(s) to be removed from the multiset. Implementations are not expected to support the add operations, although this is possible.

        A common use for the element set is to find the number of distinct elements in the multiset: elementSet().size().

        Specified by:
        elementSet in interface Multiset<E>
        Specified by:
        elementSet in class ImmutableMultiset<E>
        Returns:
        a view of the set of distinct elements in this multiset
      • hashCode

        public int hashCode()
        Description copied from interface: Multiset
        Returns the hash code for this multiset. This is defined as the sum of
        
         ((element == null) ? 0 : element.hashCode()) ^ count(element)
         

        over all distinct elements in the multiset. It follows that a multiset and its entry set always have the same hash code.

        Specified by:
        hashCode in interface java.util.Collection<E>
        Specified by:
        hashCode in interface Multiset<E>
        Overrides:
        hashCode in class ImmutableMultiset<E>