org.apache.activemq.artemis.utils.collections.LongHashSet

All Implemented Interfaces:: Serializable, Iterable<Long>, Collection<Long>, Set<Long>

public class LongHashSet extends AbstractSet<Long> implements Serializable

A hash set implementation of Set<Long> that uses open addressing values. To minimize the memory footprint, this class uses open addressing rather than chaining. Collisions are resolved using linear probing. Deletions implement compaction, so cost of remove can approach O(N) for full maps, which makes a small loadFactor recommended.

The implementation is based on Agrona IntHashSet but uses long primitive keys and a different MISSING_VALUE to account for Long.hashCode() being 0 for -1.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

final class

LongHashSet.LongIterator

Iterator which supports unboxed access to values.
Field Summary

Fields

Modifier and Type

Field

Description

static final int

DEFAULT_INITIAL_CAPACITY

The initial capacity used when none is specified in the constructor.

static final float

DEFAULT_LOAD_FACTOR
Constructor Summary

Constructors

Constructor

Description

LongHashSet()

Construct a hash set with DEFAULT_INITIAL_CAPACITY and DEFAULT_LOAD_FACTOR.

LongHashSet(int proposedCapacity)

Construct a hash set with a proposed capacity and DEFAULT_LOAD_FACTOR.

LongHashSet(int proposedCapacity, float loadFactor)

Construct a hash set with a proposed initial capacity and load factor.
Method Summary

Modifier and Type

Method

Description

boolean

add(long value)

Primitive specialised overload of {this#add(Long)}

boolean

add(Long value)

boolean

addAll(Collection<? extends Long> coll)

int

capacity()

Get the total capacity for the set to which the load factor with be a fraction of.

void

clear()

void

compact()

Compact the backing arrays by rehashing with a capacity just larger than current size and giving consideration to the load factor.

boolean

contains(long value)

Contains method that does not box values.

boolean

contains(Object value)

boolean

containsAll(LongHashSet other)

LongHashSet specialised variant of {this#containsAll(Collection)}.

boolean

equals(Object other)

int

hashCode()

boolean

isEmpty()

LongHashSet.LongIterator

iterator()

float

loadFactor()

Get the load factor beyond which the set will increase size.

boolean

remove(long value)

An int specialised version of {this#remove(Object)}.

boolean

remove(Object value)

boolean

removeAll(Collection<?> coll)

int

resizeThreshold()

Get the actual threshold which when reached the map will resize.

int

size()

Object[]

toArray()

<E> E[]

toArray(E[] a)

String

toString()

Methods inherited from class java.util.AbstractCollection
containsAll, retainAll

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable
forEach

Methods inherited from interface java.util.Set
containsAll, retainAll, spliterator

Field Details
- DEFAULT_INITIAL_CAPACITY
  
  public static final int DEFAULT_INITIAL_CAPACITY
  
  The initial capacity used when none is specified in the constructor.
  See Also:
  
  Constant Field Values
- DEFAULT_LOAD_FACTOR
  
  public static final float DEFAULT_LOAD_FACTOR
  See Also:
  
  Constant Field Values
Constructor Details
- LongHashSet
  
  public LongHashSet()
  
  Construct a hash set with DEFAULT_INITIAL_CAPACITY and DEFAULT_LOAD_FACTOR.
- LongHashSet
  
  public LongHashSet(int proposedCapacity)
  
  Construct a hash set with a proposed capacity and DEFAULT_LOAD_FACTOR.
  
  Parameters:
  
  proposedCapacity - for the initial capacity of the set.
- LongHashSet
  
  public LongHashSet(int proposedCapacity, float loadFactor)
  
  Construct a hash set with a proposed initial capacity and load factor.
  
  Parameters:
  
  proposedCapacity - for the initial capacity of the set.
  
  loadFactor - to be used for resizing.
Method Details
- loadFactor
  
  public float loadFactor()
  
  Get the load factor beyond which the set will increase size.
  
  Returns:
  
  load factor for when the set should increase size
- capacity
  
  public int capacity()
  
  Get the total capacity for the set to which the load factor with be a fraction of.
  
  Returns:
  
  the total capacity for the set
- resizeThreshold
  
  public int resizeThreshold()
  
  Get the actual threshold which when reached the map will resize. This is a function of the current capacity and load factor.
  
  Returns:
  
  the threshold when the map will resize
- add
  
  public boolean add(Long value)
  
  Specified by:
  
  add in interface Collection<Long>
  
  Specified by:
  
  add in interface Set<Long>
  
  Overrides:
  
  add in class AbstractCollection<Long>
- add
  
  public boolean add(long value)
  
  Primitive specialised overload of {this#add(Long)}
  
  Parameters:
  
  value - the value to add
  
  Returns:
  
  true if the collection has changed, false otherwise
  
  Throws:
  
  IllegalArgumentException - if value is missingValue
- remove
  
  public boolean remove(Object value)
  
  Specified by:
  
  remove in interface Collection<Long>
  
  Specified by:
  
  remove in interface Set<Long>
  
  Overrides:
  
  remove in class AbstractCollection<Long>
- remove
  
  public boolean remove(long value)
  
  An int specialised version of {this#remove(Object)}.
  
  Parameters:
  
  value - the value to remove
  
  Returns:
  
  true if the value was present, false otherwise
- compact
  
  public void compact()
  
  Compact the backing arrays by rehashing with a capacity just larger than current size and giving consideration to the load factor.
- contains
  
  public boolean contains(Object value)
  
  Specified by:
  
  contains in interface Collection<Long>
  
  Specified by:
  
  contains in interface Set<Long>
  
  Overrides:
  
  contains in class AbstractCollection<Long>
- contains
  
  public boolean contains(long value)
  
  Contains method that does not box values.
  Parameters:
  
  value - to be check for if the set contains it.
  
  Returns:
  
  true if the value is contained in the set otherwise false
  
  See Also:
  
  Collection.contains(Object)
- size
  
  public int size()
  
  Specified by:
  
  size in interface Collection<Long>
  
  Specified by:
  
  size in interface Set<Long>
  
  Specified by:
  
  size in class AbstractCollection<Long>
- isEmpty
  
  public boolean isEmpty()
  
  Specified by:
  
  isEmpty in interface Collection<Long>
  
  Specified by:
  
  isEmpty in interface Set<Long>
  
  Overrides:
  
  isEmpty in class AbstractCollection<Long>
- clear
  
  public void clear()
  
  Specified by:
  
  clear in interface Collection<Long>
  
  Specified by:
  
  clear in interface Set<Long>
  
  Overrides:
  
  clear in class AbstractCollection<Long>
- addAll
  
  public boolean addAll(Collection<? extends Long> coll)
  
  Specified by:
  
  addAll in interface Collection<Long>
  
  Specified by:
  
  addAll in interface Set<Long>
  
  Overrides:
  
  addAll in class AbstractCollection<Long>
- removeAll
  
  public boolean removeAll(Collection<?> coll)
  
  Specified by:
  
  removeAll in interface Collection<Long>
  
  Specified by:
  
  removeAll in interface Set<Long>
  
  Overrides:
  
  removeAll in class AbstractSet<Long>
- iterator
  
  public LongHashSet.LongIterator iterator()
  
  Specified by:
  
  iterator in interface Collection<Long>
  
  Specified by:
  
  iterator in interface Iterable<Long>
  
  Specified by:
  
  iterator in interface Set<Long>
  
  Specified by:
  
  iterator in class AbstractCollection<Long>
- toString
  
  public String toString()
  
  Overrides:
  
  toString in class AbstractCollection<Long>
- toArray
  
  public <E> E[] toArray(E[] a)
  
  Specified by:
  
  toArray in interface Collection<Long>
  
  Specified by:
  
  toArray in interface Set<Long>
  
  Overrides:
  
  toArray in class AbstractCollection<Long>
- toArray
  
  public Object[] toArray()
  
  Specified by:
  
  toArray in interface Collection<Long>
  
  Specified by:
  
  toArray in interface Set<Long>
  
  Overrides:
  
  toArray in class AbstractCollection<Long>
- containsAll
  
  public boolean containsAll(LongHashSet other)
  
  LongHashSet specialised variant of {this#containsAll(Collection)}.
  
  Parameters:
  
  other - int hash set to compare against.
  
  Returns:
  
  true if every element in other is in this
- equals
  
  public boolean equals(Object other)
  
  Specified by:
  
  equals in interface Collection<Long>
  
  Specified by:
  
  equals in interface Set<Long>
  
  Overrides:
  
  equals in class AbstractSet<Long>
- hashCode
  
  public int hashCode()
  
  Specified by:
  
  hashCode in interface Collection<Long>
  
  Specified by:
  
  hashCode in interface Set<Long>
  
  Overrides:
  
  hashCode in class AbstractSet<Long>

Class LongHashSet

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Methods inherited from interface java.util.Set

Field Details

DEFAULT_INITIAL_CAPACITY

DEFAULT_LOAD_FACTOR

Constructor Details

LongHashSet

LongHashSet

LongHashSet

Method Details

loadFactor

capacity

resizeThreshold

add

add

remove

remove

compact

contains

contains

size

isEmpty

clear

addAll

removeAll

iterator

toString

toArray

toArray

containsAll

equals

hashCode