Class LongOpenCustomHashSet
- java.lang.Object
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- java.util.AbstractCollection<java.lang.Long>
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- it.unimi.dsi.fastutil.longs.AbstractLongCollection
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- it.unimi.dsi.fastutil.longs.AbstractLongSet
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- it.unimi.dsi.fastutil.longs.LongOpenCustomHashSet
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- All Implemented Interfaces:
Hash
,LongCollection
,LongIterable
,LongSet
,java.io.Serializable
,java.lang.Cloneable
,java.lang.Iterable<java.lang.Long>
,java.util.Collection<java.lang.Long>
,java.util.Set<java.lang.Long>
public class LongOpenCustomHashSet extends AbstractLongSet implements java.io.Serializable, java.lang.Cloneable, Hash
A type-specific hash set with a fast, small-footprint implementation whose hashing strategy is specified at creation time.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
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Nested Class Summary
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Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash
Hash.Strategy<K>
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Field Summary
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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
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Constructor Summary
Constructors Constructor Description LongOpenCustomHashSet(int expected, float f, LongHash.Strategy strategy)
Creates a new hash set.LongOpenCustomHashSet(int expected, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor.LongOpenCustomHashSet(long[] a, float f, LongHash.Strategy strategy)
Creates a new hash set copying the elements of an array.LongOpenCustomHashSet(long[] a, int offset, int length, float f, LongHash.Strategy strategy)
Creates a new hash set and fills it with the elements of a given array.LongOpenCustomHashSet(long[] a, int offset, int length, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor and fills it with the elements of a given array.LongOpenCustomHashSet(long[] a, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor copying the elements of an array.LongOpenCustomHashSet(LongCollection c, float f, LongHash.Strategy strategy)
Creates a new hash set copying a given type-specific collection.LongOpenCustomHashSet(LongCollection c, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given type-specific collection.LongOpenCustomHashSet(LongHash.Strategy strategy)
Creates a new hash set with initial expectedHash.DEFAULT_INITIAL_SIZE
elements andHash.DEFAULT_LOAD_FACTOR
as load factor.LongOpenCustomHashSet(LongIterator i, float f, LongHash.Strategy strategy)
Creates a new hash set using elements provided by a type-specific iterator.LongOpenCustomHashSet(LongIterator i, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor using elements provided by a type-specific iterator.LongOpenCustomHashSet(java.util.Collection<? extends java.lang.Long> c, float f, LongHash.Strategy strategy)
Creates a new hash set copying a given collection.LongOpenCustomHashSet(java.util.Collection<? extends java.lang.Long> c, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given collection.LongOpenCustomHashSet(java.util.Iterator<?> i, float f, LongHash.Strategy strategy)
Creates a new hash set using elements provided by an iterator.LongOpenCustomHashSet(java.util.Iterator<?> i, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor using elements provided by an iterator.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(long k)
Ensures that this collection contains the specified element (optional operation).boolean
addAll(LongCollection c)
Adds all elements of the given type-specific collection to this collection.boolean
addAll(java.util.Collection<? extends java.lang.Long> c)
void
clear()
LongOpenCustomHashSet
clone()
Returns a deep copy of this set.boolean
contains(long k)
Returnstrue
if this collection contains the specified element.int
hashCode()
Returns a hash code for this set.boolean
isEmpty()
LongIterator
iterator()
Returns a type-specific iterator on the elements of this collection.boolean
remove(long k)
Removes an element from this set.int
size()
LongHash.Strategy
strategy()
Returns the hashing strategy.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.longs.AbstractLongSet
equals, rem
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Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongCollection
add, contains, containsAll, remove, removeAll, retainAll, toArray, toLongArray, toLongArray, toString
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Methods inherited from class java.util.AbstractCollection
containsAll, removeAll, retainAll, toArray, toArray
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Methods inherited from interface it.unimi.dsi.fastutil.longs.LongCollection
containsAll, removeAll, removeIf, removeIf, retainAll, toArray, toLongArray, toLongArray
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Methods inherited from interface it.unimi.dsi.fastutil.longs.LongIterable
forEach, forEach
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Constructor Detail
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LongOpenCustomHashSet
public LongOpenCustomHashSet(int expected, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(int expected, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor.- Parameters:
expected
- the expected number of elements in the hash set.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(LongHash.Strategy strategy)
Creates a new hash set with initial expectedHash.DEFAULT_INITIAL_SIZE
elements andHash.DEFAULT_LOAD_FACTOR
as load factor.- Parameters:
strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(java.util.Collection<? extends java.lang.Long> c, float f, LongHash.Strategy strategy)
Creates a new hash set copying a given collection.- Parameters:
c
- aCollection
to be copied into the new hash set.f
- the load factor.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(java.util.Collection<? extends java.lang.Long> c, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given collection.- Parameters:
c
- aCollection
to be copied into the new hash set.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(LongCollection c, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(LongCollection c, LongHash.Strategy strategy)
Creates a new hash set withHash.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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(LongIterator i, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(LongIterator i, LongHash.Strategy strategy)
Creates a new hash set withHash.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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(java.util.Iterator<?> i, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(java.util.Iterator<?> i, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor using elements provided by an iterator.- Parameters:
i
- an iterator whose elements will fill the set.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(long[] a, int offset, int length, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(long[] a, int offset, int length, LongHash.Strategy strategy)
Creates a new hash set withHash.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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(long[] a, float f, LongHash.Strategy strategy)
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.strategy
- the strategy.
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LongOpenCustomHashSet
public LongOpenCustomHashSet(long[] a, LongHash.Strategy strategy)
Creates a new hash set withHash.DEFAULT_LOAD_FACTOR
as load factor copying the elements of an array.- Parameters:
a
- an array to be copied into the new hash set.strategy
- the strategy.
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Method Detail
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strategy
public LongHash.Strategy strategy()
Returns the hashing strategy.- Returns:
- the hashing strategy of this custom hash set.
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addAll
public boolean addAll(LongCollection c)
Description copied from interface:LongCollection
Adds all elements of the given type-specific collection to this collection.- Specified by:
addAll
in interfaceLongCollection
- Overrides:
addAll
in classAbstractLongCollection
- Parameters:
c
- a type-specific collection.- Returns:
true
if this collection changed as a result of the call.- See Also:
Collection.addAll(Collection)
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addAll
public boolean addAll(java.util.Collection<? extends java.lang.Long> c)
- Specified by:
addAll
in interfacejava.util.Collection<java.lang.Long>
- Specified by:
addAll
in interfacejava.util.Set<java.lang.Long>
- Overrides:
addAll
in classjava.util.AbstractCollection<java.lang.Long>
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add
public boolean add(long k)
Description copied from class:AbstractLongCollection
Ensures that this collection contains the specified element (optional operation).This implementation always throws an
UnsupportedOperationException
.- Specified by:
add
in interfaceLongCollection
- Overrides:
add
in classAbstractLongCollection
- See Also:
Collection.add(Object)
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remove
public boolean remove(long k)
Description copied from class:AbstractLongSet
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 theList
interface. Delegates to the type-specificrem()
method implemented by type-specific abstractCollection
superclass.- Specified by:
remove
in interfaceLongSet
- Overrides:
remove
in classAbstractLongSet
- See Also:
Collection.remove(Object)
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contains
public boolean contains(long k)
Description copied from class:AbstractLongCollection
Returnstrue
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 interfaceLongCollection
- Overrides:
contains
in classAbstractLongCollection
- See Also:
Collection.contains(Object)
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clear
public void clear()
- Specified by:
clear
in interfacejava.util.Collection<java.lang.Long>
- Specified by:
clear
in interfacejava.util.Set<java.lang.Long>
- Overrides:
clear
in classjava.util.AbstractCollection<java.lang.Long>
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size
public int size()
- Specified by:
size
in interfacejava.util.Collection<java.lang.Long>
- Specified by:
size
in interfacejava.util.Set<java.lang.Long>
- Specified by:
size
in classjava.util.AbstractCollection<java.lang.Long>
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isEmpty
public boolean isEmpty()
- Specified by:
isEmpty
in interfacejava.util.Collection<java.lang.Long>
- Specified by:
isEmpty
in interfacejava.util.Set<java.lang.Long>
- Overrides:
isEmpty
in classjava.util.AbstractCollection<java.lang.Long>
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iterator
public LongIterator iterator()
Description copied from interface:LongCollection
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 extendsCollection
.- Specified by:
iterator
in interfacejava.util.Collection<java.lang.Long>
- Specified by:
iterator
in interfacejava.lang.Iterable<java.lang.Long>
- Specified by:
iterator
in interfaceLongCollection
- Specified by:
iterator
in interfaceLongIterable
- Specified by:
iterator
in interfaceLongSet
- Specified by:
iterator
in interfacejava.util.Set<java.lang.Long>
- Specified by:
iterator
in classAbstractLongSet
- Returns:
- a type-specific iterator on the elements of this collection.
- See Also:
Iterable.iterator()
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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)
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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,
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.
- Parameters:
n
- the threshold for the trimming.- Returns:
- true if there was enough memory to trim the set.
- See Also:
trim()
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clone
public LongOpenCustomHashSet 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.
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hashCode
public int hashCode()
Returns a hash code for this set. This method overrides the generic method provided by the superclass. Sinceequals()
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 interfacejava.util.Collection<java.lang.Long>
- Specified by:
hashCode
in interfacejava.util.Set<java.lang.Long>
- Overrides:
hashCode
in classAbstractLongSet
- Returns:
- a hash code for this set.
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