public class ShortLinkedOpenHashSet extends AbstractShortSortedSet implements java.io.Serializable, java.lang.Cloneable, Hash
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.
Hash
,
HashCommon
,
Serialized FormHash.Strategy<K>
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
Constructor and Description |
---|
ShortLinkedOpenHashSet()
Creates a new hash set with initial expected
Hash.DEFAULT_INITIAL_SIZE elements and
Hash.DEFAULT_LOAD_FACTOR as load factor. |
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(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(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.
|
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.
|
Modifier and Type | Method and Description |
---|---|
boolean |
add(short k)
Ensures that this collection contains the specified element (optional
operation).
|
boolean |
addAll(java.util.Collection<? extends java.lang.Short> c) |
boolean |
addAll(ShortCollection c)
Adds all elements of the given type-specific collection to this collection.
|
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()
Note that this specification strengthens the one given in
SortedSet.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.
|
equals, rem
add, contains, containsAll, remove, removeAll, retainAll, toArray, toShortArray, toShortArray, toString
containsAll, removeAll, retainAll, toArray, toArray
first, headSet, last, subSet, tailSet
containsAll, removeAll, removeIf, removeIf, retainAll, toArray, toShortArray, toShortArray
forEach, forEach
public ShortLinkedOpenHashSet(int expected, float f)
The actual table size will be the least power of two greater than
expected
/f
.
expected
- the expected number of elements in the hash set.f
- the load factor.public ShortLinkedOpenHashSet(int expected)
Hash.DEFAULT_LOAD_FACTOR
as load factor.expected
- the expected number of elements in the hash set.public ShortLinkedOpenHashSet()
Hash.DEFAULT_INITIAL_SIZE
elements and
Hash.DEFAULT_LOAD_FACTOR
as load factor.public ShortLinkedOpenHashSet(java.util.Collection<? extends java.lang.Short> c, float f)
c
- a Collection
to be copied into the new hash set.f
- the load factor.public ShortLinkedOpenHashSet(java.util.Collection<? extends java.lang.Short> c)
Hash.DEFAULT_LOAD_FACTOR
as load factor
copying a given collection.c
- a Collection
to be copied into the new hash set.public ShortLinkedOpenHashSet(ShortCollection c, float f)
c
- a type-specific collection to be copied into the new hash set.f
- the load factor.public ShortLinkedOpenHashSet(ShortCollection c)
Hash.DEFAULT_LOAD_FACTOR
as load factor
copying a given type-specific collection.c
- a type-specific collection to be copied into the new hash set.public ShortLinkedOpenHashSet(ShortIterator i, float f)
i
- a type-specific iterator whose elements will fill the set.f
- the load factor.public ShortLinkedOpenHashSet(ShortIterator i)
Hash.DEFAULT_LOAD_FACTOR
as load factor
using elements provided by a type-specific iterator.i
- a type-specific iterator whose elements will fill the set.public ShortLinkedOpenHashSet(java.util.Iterator<?> i, float f)
i
- an iterator whose elements will fill the set.f
- the load factor.public ShortLinkedOpenHashSet(java.util.Iterator<?> i)
Hash.DEFAULT_LOAD_FACTOR
as load factor
using elements provided by an iterator.i
- an iterator whose elements will fill the set.public ShortLinkedOpenHashSet(short[] a, int offset, int length, float f)
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.public ShortLinkedOpenHashSet(short[] a, int offset, int length)
Hash.DEFAULT_LOAD_FACTOR
as load factor
and fills it with the elements of a given array.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.public ShortLinkedOpenHashSet(short[] a, float f)
a
- an array to be copied into the new hash set.f
- the load factor.public ShortLinkedOpenHashSet(short[] a)
Hash.DEFAULT_LOAD_FACTOR
as load factor
copying the elements of an array.a
- an array to be copied into the new hash set.public boolean addAll(ShortCollection c)
ShortCollection
addAll
in interface ShortCollection
addAll
in class AbstractShortCollection
c
- a type-specific collection.true
if this collection changed as a result of the call.Collection.addAll(Collection)
public boolean addAll(java.util.Collection<? extends java.lang.Short> c)
addAll
in interface java.util.Collection<java.lang.Short>
addAll
in interface java.util.Set<java.lang.Short>
addAll
in class java.util.AbstractCollection<java.lang.Short>
public boolean add(short k)
AbstractShortCollection
This implementation always throws an UnsupportedOperationException
.
add
in interface ShortCollection
add
in class AbstractShortCollection
Collection.add(Object)
public boolean remove(short k)
AbstractShortSet
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.
remove
in interface ShortSet
remove
in class AbstractShortSet
Collection.remove(Object)
public boolean contains(short k)
AbstractShortCollection
true
if this collection contains the specified element.
This implementation iterates over the elements in the collection, looking for the specified element.
contains
in interface ShortCollection
contains
in class AbstractShortCollection
Collection.contains(Object)
public short removeFirstShort()
java.util.NoSuchElementException
- is this set is empty.public short removeLastShort()
java.util.NoSuchElementException
- is this set is empty.public boolean addAndMoveToFirst(short k)
k
- the key.public boolean addAndMoveToLast(short k)
k
- the key.public void clear()
clear
in interface java.util.Collection<java.lang.Short>
clear
in interface java.util.Set<java.lang.Short>
clear
in class java.util.AbstractCollection<java.lang.Short>
public int size()
size
in interface java.util.Collection<java.lang.Short>
size
in interface java.util.Set<java.lang.Short>
size
in class java.util.AbstractCollection<java.lang.Short>
public boolean isEmpty()
isEmpty
in interface java.util.Collection<java.lang.Short>
isEmpty
in interface java.util.Set<java.lang.Short>
isEmpty
in class java.util.AbstractCollection<java.lang.Short>
public short firstShort()
firstShort
in interface ShortSortedSet
SortedSet.first()
public short lastShort()
lastShort
in interface ShortSortedSet
SortedSet.last()
public ShortSortedSet tailSet(short from)
fromElement
.
Note that this specification strengthens the one given in
SortedSet.headSet(Object)
.
This implementation just throws an UnsupportedOperationException
.
tailSet
in interface ShortSortedSet
SortedSet.tailSet(Object)
public ShortSortedSet headSet(short to)
toElement
.
Note that this specification strengthens the one given in
SortedSet.headSet(Object)
.
This implementation just throws an UnsupportedOperationException
.
headSet
in interface ShortSortedSet
SortedSet.headSet(Object)
public ShortSortedSet subSet(short from, short to)
fromElement
, inclusive, to toElement
, exclusive.
Note that this specification strengthens the one given in
SortedSet.subSet(Object,Object)
.
This implementation just throws an UnsupportedOperationException
.
subSet
in interface ShortSortedSet
SortedSet.subSet(Object,Object)
public ShortComparator comparator()
Note that this specification strengthens the one given in
SortedSet.comparator()
.
This implementation just returns null
.
comparator
in interface ShortSortedSet
comparator
in interface java.util.SortedSet<java.lang.Short>
public ShortListIterator iterator(short from)
iterator
in interface ShortSortedSet
from
- an element to start from.java.lang.IllegalArgumentException
- if from
does not belong to the set.public ShortListIterator iterator()
iterator
in interface ShortBidirectionalIterable
iterator
in interface ShortCollection
iterator
in interface ShortIterable
iterator
in interface ShortSet
iterator
in interface ShortSortedSet
iterator
in interface java.lang.Iterable<java.lang.Short>
iterator
in interface java.util.Collection<java.lang.Short>
iterator
in interface java.util.Set<java.lang.Short>
iterator
in class AbstractShortSortedSet
Iterable.iterator()
public boolean trim()
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.
trim(int)
public boolean trim(int n)
Let N be the smallest table size that can hold
max(n,
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.
size()
)
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.
n
- the threshold for the trimming.trim()
public ShortLinkedOpenHashSet clone()
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.
clone
in class java.lang.Object
public int hashCode()
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.hashCode
in interface java.util.Collection<java.lang.Short>
hashCode
in interface java.util.Set<java.lang.Short>
hashCode
in class AbstractShortSet