Package it.unimi.dsi.fastutil.shorts

Class ShortLinkedOpenHashSet

java.lang.Object

java.util.AbstractCollection<java.lang.Short>

it.unimi.dsi.fastutil.shorts.AbstractShortCollection

it.unimi.dsi.fastutil.shorts.AbstractShortSet

it.unimi.dsi.fastutil.shorts.AbstractShortSortedSet

it.unimi.dsi.fastutil.shorts.ShortLinkedOpenHashSet

All Implemented Interfaces:

Hash, ShortBidirectionalIterable, ShortCollection, ShortIterable, ShortSet, ShortSortedSet, java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<java.lang.Short>, java.util.Collection<java.lang.Short>, java.util.Set<java.lang.Short>, java.util.SortedSet<java.lang.Short>

public class ShortLinkedOpenHashSet
extends AbstractShortSortedSet
implements java.io.Serializable, java.lang.Cloneable, Hash

A type-specific linked 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.

Iterators generated by this set will enumerate elements in the same order in which they have been added to the set (addition of elements already present in the set does not change the iteration order). Note that this order has nothing in common with the natural order of the keys. The order is kept by means of a doubly linked list, represented via an array of longs parallel to the table.

This class implements the interface of a sorted set, so to allow easy access of the iteration order: for instance, you can get the first element in iteration order with first() without having to create an iterator; however, this class partially violates the SortedSet contract because all subset methods throw an exception and comparator() returns always null.

Additional methods, such as addAndMoveToFirst(), make it easy to use instances of this class as a cache (e.g., with LRU policy).

The iterators provided by this class are type-specific list iterators, and can be started at any element which is in the set (if the provided element is not in the set, a NoSuchElementException exception will be thrown). If, however, the provided element is not the first or last element in the set, the first access to the list index will require linear time, as in the worst case the entire set must be scanned in iteration order to retrieve the positional index of the starting element. If you use just the methods of a type-specific BidirectionalIterator, however, all operations will be performed in constant time.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Hash.Strategy<K>

Field Summary

Fields inherited from interface it.unimi.dsi.fastutil.Hash

DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR

Constructor Summary

Constructors

Constructor	Description
ShortLinkedOpenHashSet()	Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements and Hash.DEFAULT_LOAD_FACTOR as load factor.
ShortLinkedOpenHashSet(int expected)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor.
ShortLinkedOpenHashSet(int expected, float f)	Creates a new hash set.
ShortLinkedOpenHashSet(short[] a)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying the elements of an array.
ShortLinkedOpenHashSet(short[] a, float f)	Creates a new hash set copying the elements of an array.
ShortLinkedOpenHashSet(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.
ShortLinkedOpenHashSet(short[] a, int offset, int length, float f)	Creates a new hash set and fills it with the elements of a given array.
ShortLinkedOpenHashSet(ShortCollection c)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific collection.
ShortLinkedOpenHashSet(ShortCollection c, float f)	Creates a new hash set copying a given type-specific collection.
ShortLinkedOpenHashSet(ShortIterator i)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.
ShortLinkedOpenHashSet(ShortIterator i, float f)	Creates a new hash set using elements provided by a type-specific iterator.
ShortLinkedOpenHashSet(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.
ShortLinkedOpenHashSet(java.util.Collection<? extends java.lang.Short> c, float f)	Creates a new hash set copying a given collection.
ShortLinkedOpenHashSet(java.util.Iterator<?> i)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.
ShortLinkedOpenHashSet(java.util.Iterator<?> i, float f)	Creates a new hash set using elements provided by an iterator.

Method Summary

Modifier and Type	Method	Description
boolean	add(short k)	Ensures that this collection contains the specified element (optional operation).
boolean	addAll(ShortCollection c)	Adds all elements of the given type-specific collection to this collection.
boolean	addAll(java.util.Collection<? extends java.lang.Short> c)
boolean	addAndMoveToFirst(short k)	Adds a key to the set; if the key is already present, it is moved to the first position of the iteration order.
boolean	addAndMoveToLast(short k)	Adds a key to the set; if the key is already present, it is moved to the last position of the iteration order.
void	clear()
ShortLinkedOpenHashSet	clone()	Returns a deep copy of this set.
ShortComparator	comparator()
boolean	contains(short k)	Returns true if this collection contains the specified element.
short	firstShort()	Returns the first element of this set in iteration order.
int	hashCode()	Returns a hash code for this set.
ShortSortedSet	headSet(short to)	Returns a view of the portion of this sorted set whose elements are strictly less than toElement.
boolean	isEmpty()
ShortListIterator	iterator()	Returns a type-specific list iterator on the elements in this set, starting from the first element.
ShortListIterator	iterator(short from)	Returns a type-specific list iterator on the elements in this set, starting from a given element of the set.
short	lastShort()	Returns the last element of this set in iteration order.
boolean	remove(short k)	Removes an element from this set.
short	removeFirstShort()	Removes the first key in iteration order.
short	removeLastShort()	Removes the the last key in iteration order.
int	size()
ShortSortedSet	subSet(short from, short to)	Returns a view of the portion of this sorted set whose elements range from fromElement, inclusive, to toElement, exclusive.
ShortSortedSet	tailSet(short from)	Returns a view of the portion of this sorted set whose elements are greater than or equal to fromElement.
boolean	trim()	Rehashes this set, making the table as small as possible.
boolean	trim(int n)	Rehashes this set if the table is too large.

Methods inherited from class java.util.AbstractCollection

containsAll, removeAll, retainAll, toArray, toArray

Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShortCollection

add, contains, containsAll, remove, removeAll, retainAll, toArray, toShortArray, toShortArray, toString

Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShortSet

equals, rem

Methods inherited from interface java.util.Collection

parallelStream, stream

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

containsAll, equals, removeAll, retainAll, toArray, toArray

Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortCollection

containsAll, removeAll, removeIf, removeIf, retainAll, toArray, toShortArray, toShortArray

Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortIterable

forEach, forEach

Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortSet

add, contains, rem, remove

Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortSortedSet

first, headSet, last, subSet, tailSet

Methods inherited from interface java.util.SortedSet

spliterator

Constructor Detail

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet()

Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements and Hash.DEFAULT_LOAD_FACTOR as load factor.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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.

ShortLinkedOpenHashSet

public ShortLinkedOpenHashSet(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)

removeFirstShort

public short removeFirstShort()

Removes the first key in iteration order.

Returns:

the first key.

Throws:

java.util.NoSuchElementException - is this set is empty.

removeLastShort

public short removeLastShort()

Removes the the last key in iteration order.

Returns:

the last key.

Throws:

java.util.NoSuchElementException - is this set is empty.

addAndMoveToFirst

public boolean addAndMoveToFirst(short k)

Adds a key to the set; if the key is already present, it is moved to the first position of the iteration order.

Parameters:

k - the key.

Returns:

true if the key was not present.

addAndMoveToLast

public boolean addAndMoveToLast(short k)

Adds a key to the set; if the key is already present, it is moved to the last position of the iteration order.

Parameters:

k - the key.

Returns:

true if the key was not present.

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>

firstShort

public short firstShort()

Returns the first element of this set in iteration order.

Specified by:

firstShort in interface ShortSortedSet

Returns:

the first element in iteration order.

See Also:

SortedSet.first()

lastShort

public short lastShort()

Returns the last element of this set in iteration order.

Specified by:

lastShort in interface ShortSortedSet

Returns:

the last element in iteration order.

See Also:

SortedSet.last()

tailSet

public ShortSortedSet tailSet(short from)

Returns a view of the portion of this sorted set whose elements are greater than or equal to fromElement.

Note that this specification strengthens the one given in SortedSet.headSet(Object).

This implementation just throws an UnsupportedOperationException.

Specified by:

tailSet in interface ShortSortedSet

See Also:

SortedSet.tailSet(Object)

headSet

public ShortSortedSet headSet(short to)

Returns a view of the portion of this sorted set whose elements are strictly less than toElement.

Note that this specification strengthens the one given in SortedSet.headSet(Object).

This implementation just throws an UnsupportedOperationException.

Specified by:

headSet in interface ShortSortedSet

See Also:

SortedSet.headSet(Object)

subSet

public ShortSortedSet subSet(short from,
                             short to)

Returns a view of the portion of this sorted set whose elements range from fromElement, inclusive, to toElement, exclusive.

Note that this specification strengthens the one given in SortedSet.subSet(Object,Object).

This implementation just throws an UnsupportedOperationException.

Specified by:

subSet in interface ShortSortedSet

See Also:

SortedSet.subSet(Object,Object)

comparator

public ShortComparator comparator()

Note that this specification strengthens the one given in SortedSet.comparator().

This implementation just returns null.

Specified by:

comparator in interface ShortSortedSet

Specified by:

comparator in interface java.util.SortedSet<java.lang.Short>

iterator

public ShortListIterator iterator(short from)

Returns a type-specific list iterator on the elements in this set, starting from a given element of the set. Please see the class documentation for implementation details.

Specified by:

iterator in interface ShortSortedSet

Parameters:

from - an element to start from.

Returns:

a type-specific list iterator starting at the given element.

Throws:

java.lang.IllegalArgumentException - if from does not belong to the set.

iterator

public ShortListIterator iterator()

Returns a type-specific list iterator on the elements in this set, starting from the first element. Please see the class documentation for implementation details.

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 ShortBidirectionalIterable

Specified by:

iterator in interface ShortCollection

Specified by:

iterator in interface ShortIterable

Specified by:

iterator in interface ShortSet

Specified by:

iterator in interface ShortSortedSet

Specified by:

iterator in class AbstractShortSortedSet

Returns:

a type-specific list iterator starting at the first element.

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 ShortLinkedOpenHashSet 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.