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java.lang.Objectit.unimi.dsi.fastutil.objects.AbstractReferenceCollection<K>
it.unimi.dsi.fastutil.objects.AbstractReferenceSet<K>
it.unimi.dsi.fastutil.objects.AbstractReferenceSortedSet<K>
it.unimi.dsi.fastutil.objects.ReferenceLinkedOpenHashSet<K>
public class ReferenceLinkedOpenHashSet<K>
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
enlarged as needed when new entries are created, but it is never made
smaller (even on a clear()
). A family of trimming
methods lets you control the size of the table; this is particularly useful
if you reuse instances of this class.
The enlargement speed is controlled by the growth factor, a
positive number. If the growth factor is p, then the table is
enlarged each time roughly by a factor 2p/16. By default, p is
Hash.DEFAULT_GROWTH_FACTOR
, which means that the table is doubled at
each enlargement, but one can easily set more or less aggressive policies by
calling growthFactor(int)
(note that the growth factor is not serialized:
deserialized tables gets the default growth factor).
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
.
The iterators provided by this class are type-specific list iterators. However, creation of an iterator
using a starting point is going to be very expensive, as the chosen starting
point must be linearly searched for, unless it is last()
, in which
case the iterator is created in constant time.
Note that deletions in a linked table require scanning the list until the element to be removed is found. The only exceptions are the first element, the last element, and deletions performed using an iterator.
Hash
,
HashCommon
,
Serialized FormNested Class Summary |
---|
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash |
---|
Hash.Strategy<K> |
Field Summary | |
---|---|
static long |
serialVersionUID
|
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 | |
---|---|
ReferenceLinkedOpenHashSet()
Creates a new hash set with Hash.DEFAULT_INITIAL_SIZE elements
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
|
ReferenceLinkedOpenHashSet(java.util.Collection<? extends K> c)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given collection. |
|
ReferenceLinkedOpenHashSet(java.util.Collection<? extends K> c,
float f)
Creates a new hash set copying a given collection. |
|
ReferenceLinkedOpenHashSet(int n)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor. |
|
ReferenceLinkedOpenHashSet(int n,
float f)
Creates a new hash set. |
|
ReferenceLinkedOpenHashSet(K[] a)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor
copying the elements of an array. |
|
ReferenceLinkedOpenHashSet(K[] a,
float f)
Creates a new hash set copying the elements of an array. |
|
ReferenceLinkedOpenHashSet(K[] 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. |
|
ReferenceLinkedOpenHashSet(K[] a,
int offset,
int length,
float f)
Creates a new hash set and fills it with the elements of a given array. |
|
ReferenceLinkedOpenHashSet(ObjectIterator<K> i)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator. |
|
ReferenceLinkedOpenHashSet(ObjectIterator<K> i,
float f)
Creates a new hash set using elements provided by a type-specific iterator. |
|
ReferenceLinkedOpenHashSet(ReferenceCollection<? extends K> c)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given type-specific collection. |
|
ReferenceLinkedOpenHashSet(ReferenceCollection<? extends K> c,
float f)
Creates a new hash set copying a given type-specific collection. |
Method Summary | |
---|---|
boolean |
add(K k)
|
void |
clear()
|
java.lang.Object |
clone()
Returns a deep copy of this set. |
java.util.Comparator<? super K> |
comparator()
|
boolean |
contains(java.lang.Object k)
|
K |
first()
Returns the first element of this set in iteration order. |
int |
growthFactor()
Gets the growth factor. |
void |
growthFactor(int growthFactor)
Sets the growth factor. |
int |
hashCode()
Returns a hash code for this set. |
ReferenceSortedSet<K> |
headSet(K to)
Returns a view of the portion of this sorted set whose elements are strictly less than toElement . |
boolean |
isEmpty()
|
ObjectBidirectionalIterator<K> |
iterator()
Returns a type-specific iterator. |
ObjectBidirectionalIterator<K> |
iterator(K from)
Returns a type-specific list iterator on the elements in this set, starting from a given element of the set. |
K |
last()
Returns the last element of this set in iteration order. |
boolean |
rehash()
Rehashes this set without changing the table size. |
boolean |
remove(java.lang.Object k)
Removes an element from this set. |
int |
size()
|
ReferenceSortedSet<K> |
subSet(K from,
K to)
Returns a view of the portion of this sorted set whose elements range from fromElement , inclusive, to toElement , exclusive. |
ReferenceSortedSet<K> |
tailSet(K 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 it.unimi.dsi.fastutil.objects.AbstractReferenceSortedSet |
---|
objectIterator |
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReferenceSet |
---|
equals |
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReferenceCollection |
---|
addAll, containsAll, removeAll, retainAll, toArray, toArray, toString |
Methods inherited from class java.lang.Object |
---|
getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface it.unimi.dsi.fastutil.objects.ReferenceCollection |
---|
toArray |
Methods inherited from interface java.util.Set |
---|
addAll, containsAll, equals, removeAll, retainAll, toArray, toArray |
Methods inherited from interface java.util.Set |
---|
addAll, containsAll, equals, removeAll, retainAll, toArray, toArray |
Field Detail |
---|
public static final long serialVersionUID
Constructor Detail |
---|
public ReferenceLinkedOpenHashSet(int n, float f)
n
/f
.
n
- the expected number of elements in the hash set.f
- the load factor.Hash.PRIMES
public ReferenceLinkedOpenHashSet(int n)
Hash.DEFAULT_LOAD_FACTOR
as load factor.
n
- the expected number of elements in the hash set.public ReferenceLinkedOpenHashSet()
Hash.DEFAULT_INITIAL_SIZE
elements
and Hash.DEFAULT_LOAD_FACTOR
as load factor.
public ReferenceLinkedOpenHashSet(java.util.Collection<? extends K> c, float f)
c
- a Collection
to be copied into the new hash set.f
- the load factor.public ReferenceLinkedOpenHashSet(java.util.Collection<? extends K> c)
Hash.DEFAULT_LOAD_FACTOR
as load factor
copying a given collection.
c
- a Collection
to be copied into the new hash set.public ReferenceLinkedOpenHashSet(ReferenceCollection<? extends K> c, float f)
c
- a type-specific collection to be copied into the new hash set.f
- the load factor.public ReferenceLinkedOpenHashSet(ReferenceCollection<? extends K> 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 ReferenceLinkedOpenHashSet(ObjectIterator<K> i, float f)
i
- a type-specific iterator whose elements will fill the set.f
- the load factor.public ReferenceLinkedOpenHashSet(ObjectIterator<K> 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 ReferenceLinkedOpenHashSet(K[] 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 ReferenceLinkedOpenHashSet(K[] 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 ReferenceLinkedOpenHashSet(K[] a, float f)
a
- an array to be copied into the new hash set.f
- the load factor.public ReferenceLinkedOpenHashSet(K[] 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.Method Detail |
---|
public void growthFactor(int growthFactor)
growthFactor
- the new growth factor; it must be positive.public int growthFactor()
growthFactor(int)
public boolean add(K k)
add
in interface java.util.Collection<K>
add
in interface java.util.Set<K>
add
in class AbstractReferenceCollection<K>
public boolean remove(java.lang.Object k)
ReferenceSet
Note that the corresponding method of the type-specific collection is rem()
.
This unfortunate situation is caused by the clash
with the similarly named index-based method in the List
interface.
remove
in interface ReferenceSet<K>
remove
in interface java.util.Collection<K>
remove
in interface java.util.Set<K>
remove
in class AbstractReferenceSet<K>
Collection.remove(Object)
public boolean contains(java.lang.Object k)
contains
in interface java.util.Collection<K>
contains
in interface java.util.Set<K>
public void clear()
clear
in interface java.util.Collection<K>
clear
in interface java.util.Set<K>
clear
in class AbstractReferenceCollection<K>
public K first()
first
in interface java.util.SortedSet<K>
public K last()
last
in interface java.util.SortedSet<K>
public ReferenceSortedSet<K> tailSet(K from)
ReferenceSortedSet
fromElement
.
Note that this specification strengthens the one given in SortedSet.tailSet(Object)
.
tailSet
in interface ReferenceSortedSet<K>
tailSet
in interface java.util.SortedSet<K>
SortedSet.tailSet(Object)
public ReferenceSortedSet<K> headSet(K to)
ReferenceSortedSet
toElement
.
Note that this specification strengthens the one given in SortedSet.headSet(Object)
.
headSet
in interface ReferenceSortedSet<K>
headSet
in interface java.util.SortedSet<K>
SortedSet.headSet(Object)
public ReferenceSortedSet<K> subSet(K from, K to)
ReferenceSortedSet
fromElement
, inclusive, to toElement
, exclusive.
Note that this specification strengthens the one given in SortedSet.subSet(Object,Object)
.
subSet
in interface ReferenceSortedSet<K>
subSet
in interface java.util.SortedSet<K>
SortedSet.subSet(Object,Object)
public java.util.Comparator<? super K> comparator()
comparator
in interface java.util.SortedSet<K>
public ObjectBidirectionalIterator<K> iterator(K from)
This method provides an iterator positioned immediately after the
given element. That is, the next call to previous()
will
return from
, whereas the next call to next()
will return the element immediately after from
. This
allows to call iterator(last())
and obtain an iterator starting
from the end of the iteration order.
Because of the way linking is implemented, generating an iterator using this method
requires constant time only if the argument is last()
. In all other cases,
a linear search for the given element will be necessary.
Note that this method returns a bidirectional iterator, which, however, can be safely cast to a type-specific list iterator.
iterator
in interface ReferenceSortedSet<K>
from
- an element to start from.
java.lang.IllegalArgumentException
- if from
does not belong to the set.public ObjectBidirectionalIterator<K> iterator()
ObjectIterable
Iterable.iterator()
.
iterator
in interface ObjectIterable<K>
iterator
in interface ReferenceCollection<K>
iterator
in interface ReferenceSet<K>
iterator
in interface ReferenceSortedSet<K>
iterator
in interface java.lang.Iterable<K>
iterator
in interface java.util.Collection<K>
iterator
in interface java.util.Set<K>
iterator
in class AbstractReferenceSortedSet<K>
public boolean rehash()
This method should be called when the set underwent numerous deletions and insertions. In this case, free entries become rare, and unsuccessful searches require probing all entries. For reasonable load factors this method is linear in the number of entries. You will need as much additional free memory as that occupied by the table.
If you need to reduce the table siza to fit exactly
this set, you must use trim()
.
trim()
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 (by collecting deleted entries) and size.
If the table size is already the minimum possible, this method
does nothing. If you want to guarantee rehashing, use rehash()
.
trim(int)
,
rehash()
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()
,
rehash()
public int size()
size
in interface java.util.Collection<K>
size
in interface java.util.Set<K>
public boolean isEmpty()
isEmpty
in interface java.util.Collection<K>
isEmpty
in interface java.util.Set<K>
isEmpty
in class AbstractReferenceCollection<K>
public java.lang.Object 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<K>
hashCode
in interface java.util.Set<K>
hashCode
in class AbstractReferenceSet<K>
|
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