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java.lang.Objectjava.util.AbstractCollection<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
public class ShortLinkedOpenHashSet
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 by doubling its size 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.
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 AbstractShortSortedSet.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 FormNested Class Summary |
---|
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash |
---|
Hash.Strategy<K> |
Field Summary | |
---|---|
protected float |
f
The acceptable load factor. |
protected int |
first
The index of the first entry in iteration order. |
protected short[] |
key
The array of keys. |
protected int |
last
The index of the last entry in iteration order. |
protected long[] |
link
For each entry, the next and the previous entry in iteration order, stored as ((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL) . |
protected int |
mask
The mask for wrapping a position counter. |
protected int |
maxFill
Threshold after which we rehash. |
protected int |
n
The current table size. |
static long |
serialVersionUID
|
protected int |
size
Number of entries in the set. |
protected boolean[] |
used
The array telling whether a position is used. |
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 | |
---|---|
ShortLinkedOpenHashSet()
Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
|
ShortLinkedOpenHashSet(Collection<? extends Short> c)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given collection. |
|
ShortLinkedOpenHashSet(Collection<? extends 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(Iterator<?> i)
Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator. |
|
ShortLinkedOpenHashSet(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. |
Method Summary | |
---|---|
boolean |
add(short k)
|
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()
Returns the comparator associated with this sorted set, or null if it uses its elements' natural ordering. |
boolean |
contains(short k)
|
short |
firstShort()
Returns the first element of this set in iteration order. |
protected void |
fixPointers(int i)
Modifies the link vector so that the given entry is removed. |
protected void |
fixPointers(int s,
int d)
Modifies the link vector for a shift from s to d. |
int |
growthFactor()
Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full. |
void |
growthFactor(int growthFactor)
Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full. |
int |
hashCode()
Returns a hash code for this set. |
ShortSortedSet |
headSet(short to)
|
boolean |
isEmpty()
|
ShortListIterator |
iterator()
Returns a type-specific iterator on the elements of this collection. |
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 |
rehash()
Deprecated. A no-op. |
protected void |
rehash(int newN)
Resizes the set. |
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. |
protected int |
shiftKeys(int pos)
Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry. |
int |
size()
|
ShortSortedSet |
subSet(short from,
short to)
|
ShortSortedSet |
tailSet(short from)
|
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.shorts.AbstractShortSortedSet |
---|
first, headSet, last, shortIterator, subSet, tailSet |
Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShortSet |
---|
equals, rem, remove |
Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShortCollection |
---|
add, addAll, addAll, contains, containsAll, containsAll, rem, removeAll, removeAll, retainAll, retainAll, toArray, toArray, toArray, toShortArray, toShortArray, toString |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortCollection |
---|
addAll, containsAll, rem, removeAll, retainAll, toArray, toArray, toShortArray, toShortArray |
Methods inherited from interface java.util.Set |
---|
add, addAll, contains, containsAll, equals, remove, removeAll, retainAll, toArray, toArray |
Field Detail |
---|
public static final long serialVersionUID
protected transient short[] key
protected transient boolean[] used
protected final float f
protected transient int n
protected transient int maxFill
f
.
protected transient int mask
protected int size
protected transient int first
size
is nonzero; otherwise, it contains -1.
protected transient int last
size
is nonzero; otherwise, it contains -1.
protected transient long[] link
((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL)
.
The first entry contains predecessor -1, and the last entry
contains successor -1.
Constructor Detail |
---|
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(Collection<? extends Short> c, float f)
c
- a Collection
to be copied into the new hash set.f
- the load factor.public ShortLinkedOpenHashSet(Collection<? extends 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(Iterator<?> i, float f)
i
- an iterator whose elements will fill the set.f
- the load factor.public ShortLinkedOpenHashSet(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.Method Detail |
---|
public boolean add(short k)
add
in interface ShortCollection
add
in class AbstractShortCollection
Collection.add(Object)
protected final int shiftKeys(int pos)
pos
- a starting position.
public boolean remove(short k)
ShortSet
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 ShortSet
remove
in class AbstractShortSet
Collection.remove(Object)
public boolean contains(short k)
contains
in interface ShortCollection
contains
in class AbstractShortCollection
Collection.contains(Object)
public short removeFirstShort()
NoSuchElementException
- is this set is empty.public short removeLastShort()
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 Collection<Short>
clear
in interface Set<Short>
clear
in class AbstractCollection<Short>
public int size()
size
in interface Collection<Short>
size
in interface Set<Short>
size
in class AbstractCollection<Short>
public boolean isEmpty()
isEmpty
in interface Collection<Short>
isEmpty
in interface Set<Short>
isEmpty
in class AbstractShortCollection
@Deprecated public void growthFactor(int growthFactor)
fastutil
6.1.0, hash tables are doubled when they are too full.
growthFactor
- unused.@Deprecated public int growthFactor()
fastutil
6.1.0, hash tables are doubled when they are too full.
growthFactor(int)
protected void fixPointers(int i)
link
vector so that the given entry is removed.
If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.
i
- the index of an entry.protected void fixPointers(int s, int d)
link
vector for a shift from s to d.
If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.
s
- the source position.d
- the destination position.public short firstShort()
firstShort
in interface ShortSortedSet
SortedSet.first()
public short lastShort()
lastShort
in interface ShortSortedSet
SortedSet.last()
public ShortSortedSet tailSet(short from)
tailSet
in interface ShortSortedSet
SortedSet.tailSet(Object)
public ShortSortedSet headSet(short to)
headSet
in interface ShortSortedSet
SortedSet.headSet(Object)
public ShortSortedSet subSet(short from, short to)
subSet
in interface ShortSortedSet
SortedSet.subSet(Object,Object)
public ShortComparator comparator()
ShortSortedSet
Note that this specification strengthens the one given in SortedSet.comparator()
.
comparator
in interface ShortSortedSet
comparator
in interface SortedSet<Short>
SortedSet.comparator()
public ShortListIterator iterator(short from)
iterator
in interface ShortSortedSet
from
- an element to start from.
IllegalArgumentException
- if from
does not belong to the set.public ShortListIterator iterator()
ShortCollection
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
.
iterator
in interface ShortCollection
iterator
in interface ShortIterable
iterator
in interface ShortSet
iterator
in interface ShortSortedSet
iterator
in interface Iterable<Short>
iterator
in interface Collection<Short>
iterator
in interface Set<Short>
iterator
in class AbstractShortSortedSet
@Deprecated public boolean rehash()
If you need to reduce the table size to fit exactly
this set, 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 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()
protected void rehash(int newN)
This method implements the basic rehashing strategy, and may be overriden by subclasses implementing different rehashing strategies (e.g., disk-based rehashing). However, you should not override this method unless you understand the internal workings of this class.
newN
- the new sizepublic 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 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 Collection<Short>
hashCode
in interface Set<Short>
hashCode
in class AbstractShortSet
|
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