Class ShortOpenCustomHashSet

  • All Implemented Interfaces:
    Hash, ShortCollection, ShortIterable, ShortSet, Serializable, Cloneable, Iterable<Short>, Collection<Short>, Set<Short>

    public class ShortOpenCustomHashSet
    extends AbstractShortSet
    implements Serializable, Cloneable, Hash
    A type-specific hash set with a fast, small-footprint implementation whose hashing strategy is specified at creation time.

    Instances of this class use a hash table to represent a set. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is emptied below one fourth of the load factor, it is halved in size; however, the table is never reduced to a size smaller than that at creation time: this approach makes it possible to create sets with a large capacity in which insertions and deletions do not cause immediately rehashing. Moreover, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration process.

    Note that clear() does not modify the hash table size. Rather, a family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

    See Also:
    Hash, HashCommon, Serialized Form
    • Constructor Detail

      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(int expected,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set.

        The actual table size will be the least power of two greater than expected/f.

        Parameters:
        expected - the expected number of elements in the hash set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(int expected,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor.
        Parameters:
        expected - the expected number of elements in the hash set.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(Collection<? extends Short> c,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set copying a given collection.
        Parameters:
        c - a Collection to be copied into the new hash set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(ShortCollection c,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set copying a given type-specific collection.
        Parameters:
        c - a type-specific collection to be copied into the new hash set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(ShortCollection c,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific collection.
        Parameters:
        c - a type-specific collection to be copied into the new hash set.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(ShortIterator i,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set using elements provided by a type-specific iterator.
        Parameters:
        i - a type-specific iterator whose elements will fill the set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(ShortIterator i,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.
        Parameters:
        i - a type-specific iterator whose elements will fill the set.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(Iterator<?> i,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set using elements provided by an iterator.
        Parameters:
        i - an iterator whose elements will fill the set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(Iterator<?> i,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.
        Parameters:
        i - an iterator whose elements will fill the set.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(short[] a,
                                      int offset,
                                      int length,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set and fills it with the elements of a given array.
        Parameters:
        a - an array whose elements will be used to fill the set.
        offset - the first element to use.
        length - the number of elements to use.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(short[] a,
                                      int offset,
                                      int length,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor and fills it with the elements of a given array.
        Parameters:
        a - an array whose elements will be used to fill the set.
        offset - the first element to use.
        length - the number of elements to use.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(short[] a,
                                      float f,
                                      ShortHash.Strategy strategy)
        Creates a new hash set copying the elements of an array.
        Parameters:
        a - an array to be copied into the new hash set.
        f - the load factor.
        strategy - the strategy.
      • ShortOpenCustomHashSet

        public ShortOpenCustomHashSet​(short[] a,
                                      ShortHash.Strategy strategy)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying the elements of an array.
        Parameters:
        a - an array to be copied into the new hash set.
        strategy - the strategy.
    • Method Detail

      • strategy

        public ShortHash.Strategy strategy()
        Returns the hashing strategy.
        Returns:
        the hashing strategy of this custom hash set.
      • remove

        public boolean remove​(short k)
        Description copied from class: AbstractShortSet
        Removes an element from this set.

        Note that the corresponding method of a type-specific collection is rem(). This unfortunate situation is caused by the clash with the similarly named index-based method in the List interface. Delegates to the type-specific rem() method implemented by type-specific abstract Collection superclass.

        Specified by:
        remove in interface ShortSet
        Overrides:
        remove in class AbstractShortSet
        See Also:
        Collection.remove(Object)
      • trim

        public boolean trim()
        Rehashes this set, making the table as small as possible.

        This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.

        If the table size is already the minimum possible, this method does nothing.

        Returns:
        true if there was enough memory to trim the set.
        See Also:
        trim(int)
      • trim

        public boolean trim​(int n)
        Rehashes this set if the table is too large.

        Let N be the smallest table size that can hold max(n,size()) entries, still satisfying the load factor. If the current table size is smaller than or equal to N, this method does nothing. Otherwise, it rehashes this set in a table of size N.

        This method is useful when reusing sets. Clearing a set leaves the table size untouched. If you are reusing a set many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient sets.

        Parameters:
        n - the threshold for the trimming.
        Returns:
        true if there was enough memory to trim the set.
        See Also:
        trim()
      • clone

        public ShortOpenCustomHashSet clone()
        Returns a deep copy of this set.

        This method performs a deep copy of this hash set; the data stored in the set, however, is not cloned. Note that this makes a difference only for object keys.

        Returns:
        a deep copy of this set.
      • hashCode

        public int hashCode()
        Returns a hash code for this set. This method overrides the generic method provided by the superclass. Since equals() is not overriden, it is important that the value returned by this method is the same value as the one returned by the overriden method.
        Specified by:
        hashCode in interface Collection<Short>
        Specified by:
        hashCode in interface Set<Short>
        Overrides:
        hashCode in class AbstractShortSet
        Returns:
        a hash code for this set.