Class ShortOpenHashSet

  • All Implemented Interfaces:
    Hash, ShortCollection, ShortIterable, ShortSet, java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<java.lang.Short>, java.util.Collection<java.lang.Short>, java.util.Set<java.lang.Short>

    public class ShortOpenHashSet
    extends AbstractShortSet
    implements java.io.Serializable, java.lang.Cloneable, Hash
    A type-specific hash set with with a fast, small-footprint implementation.

    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

      • ShortOpenHashSet

        public ShortOpenHashSet​(int expected,
                                float f)
        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.
      • ShortOpenHashSet

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

        public ShortOpenHashSet​(java.util.Collection<? extends java.lang.Short> c,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(java.util.Collection<? extends java.lang.Short> c)
        Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given collection.
        Parameters:
        c - a Collection to be copied into the new hash set.
      • ShortOpenHashSet

        public ShortOpenHashSet​(ShortCollection c,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(ShortCollection c)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(ShortIterator i,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(ShortIterator i)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(java.util.Iterator<?> i,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(java.util.Iterator<?> i)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(short[] a,
                                int offset,
                                int length,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(short[] a,
                                int offset,
                                int length)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(short[] a,
                                float f)
        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.
      • ShortOpenHashSet

        public ShortOpenHashSet​(short[] a)
        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.
    • Method Detail

      • addAll

        public boolean addAll​(ShortCollection c)
        Description copied from interface: ShortCollection
        Adds all elements of the given type-specific collection to this collection.
        Specified by:
        addAll in interface ShortCollection
        Overrides:
        addAll in class AbstractShortCollection
        Parameters:
        c - a type-specific collection.
        Returns:
        true if this collection changed as a result of the call.
        See Also:
        Collection.addAll(Collection)
      • addAll

        public boolean addAll​(java.util.Collection<? extends java.lang.Short> c)
        Specified by:
        addAll in interface java.util.Collection<java.lang.Short>
        Specified by:
        addAll in interface java.util.Set<java.lang.Short>
        Overrides:
        addAll in class java.util.AbstractCollection<java.lang.Short>
      • add

        public boolean add​(short k)
        Description copied from class: AbstractShortCollection
        Ensures that this collection contains the specified element (optional operation).

        This implementation always throws an UnsupportedOperationException.

        Specified by:
        add in interface ShortCollection
        Overrides:
        add in class AbstractShortCollection
        See Also:
        Collection.add(Object)
      • 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)
      • contains

        public boolean contains​(short k)
        Description copied from class: AbstractShortCollection
        Returns true if this collection contains the specified element.

        This implementation iterates over the elements in the collection, looking for the specified element.

        Specified by:
        contains in interface ShortCollection
        Overrides:
        contains in class AbstractShortCollection
        See Also:
        Collection.contains(Object)
      • clear

        public void clear()
        Specified by:
        clear in interface java.util.Collection<java.lang.Short>
        Specified by:
        clear in interface java.util.Set<java.lang.Short>
        Overrides:
        clear in class java.util.AbstractCollection<java.lang.Short>
      • size

        public int size()
        Specified by:
        size in interface java.util.Collection<java.lang.Short>
        Specified by:
        size in interface java.util.Set<java.lang.Short>
        Specified by:
        size in class java.util.AbstractCollection<java.lang.Short>
      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Collection<java.lang.Short>
        Specified by:
        isEmpty in interface java.util.Set<java.lang.Short>
        Overrides:
        isEmpty in class java.util.AbstractCollection<java.lang.Short>
      • iterator

        public ShortIterator iterator()
        Description copied from interface: ShortCollection
        Returns a type-specific iterator on the elements of this collection.

        Note that this specification strengthens the one given in Iterable.iterator(), which was already strengthened in the corresponding type-specific class, but was weakened by the fact that this interface extends Collection.

        Specified by:
        iterator in interface java.util.Collection<java.lang.Short>
        Specified by:
        iterator in interface java.lang.Iterable<java.lang.Short>
        Specified by:
        iterator in interface java.util.Set<java.lang.Short>
        Specified by:
        iterator in interface ShortCollection
        Specified by:
        iterator in interface ShortIterable
        Specified by:
        iterator in interface ShortSet
        Specified by:
        iterator in class AbstractShortSet
        Returns:
        a type-specific iterator on the elements of this collection.
        See Also:
        Iterable.iterator()
      • 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 ShortOpenHashSet 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 java.util.Collection<java.lang.Short>
        Specified by:
        hashCode in interface java.util.Set<java.lang.Short>
        Overrides:
        hashCode in class AbstractShortSet
        Returns:
        a hash code for this set.