IntHashSet (Agrona)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractSet<Integer>
  - - org.agrona.collections.IntHashSet

All Implemented Interfaces:

Iterable<Integer>, Collection<Integer>, Set<Integer>
```
public class IntHashSet
extends AbstractSet<Integer>
```
Open-addressing with linear-probing expandable hash set. Allocation free in steady state use when expanded.
By storing elements as int primitives this significantly reduces memory consumption compared with Java's builtin HashSet<Integer>. It implements Set<Integer> for convenience, but calling functionality via those methods can add boxing overhead to your usage.
This class is not Threadsafe.
This HashSet caches its iterator object by default, so nested iteration is not supported. You can override this behaviour at construction by indicating that the iterator should not be cached.

See Also:

IntHashSet.IntIterator, Set

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

class IntHashSet.IntIterator
Iterator which supports unboxed access to the values via IntHashSet.IntIterator.nextValue().

Nested Classes
Modifier and Type	Class and Description
`class`	`IntHashSet.IntIterator` Iterator which supports unboxed access to the values via `IntHashSet.IntIterator.nextValue()`.

Field Summary

Fields
Modifier and Type Field and Description

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

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_INITIAL_CAPACITY` The initial capacity used when none is specified in the constructor.

Constructor Summary

Constructors
Constructor and Description
`IntHashSet()` Construct a hash set with `DEFAULT_INITIAL_CAPACITY`, `Hashing.DEFAULT_LOAD_FACTOR`, and iterator caching support.
`IntHashSet(int proposedCapacity)` Construct a hash set with a proposed capacity, `Hashing.DEFAULT_LOAD_FACTOR`, and iterator caching support.
`IntHashSet(int proposedCapacity, float loadFactor)` Construct a hash set with a proposed initial capacity, load factor, and iterator caching support.
`IntHashSet(int proposedCapacity, float loadFactor, boolean shouldAvoidAllocation)` Construct a hash set with a proposed initial capacity, load factor, and indicated iterator caching support.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(int value)` Primitive specialised overload of {this#add(Integer)}.
`boolean`	`add(Integer value)`
`boolean`	`addAll(Collection<? extends Integer> coll)`
`boolean`	`addAll(IntHashSet coll)` Alias for `addAll(Collection)` for the specialized case when adding another IntHashSet, avoids boxing and allocations.
`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(int value)` Contains method that does not box values.
`boolean`	`contains(Object value)`
`boolean`	`containsAll(IntHashSet other)` IntHashSet specialised variant of {this#containsAll(Collection)}.
`void`	`copy(IntHashSet that)` Copye values from another `IntHashSet` into this one.
`IntHashSet`	`difference(IntHashSet other)` Fast Path set difference for comparison with another IntHashSet.
`boolean`	`equals(Object other)`
`int`	`hashCode()`
`boolean`	`isEmpty()`
`IntHashSet.IntIterator`	`iterator()`
`float`	`loadFactor()` Get the load factor beyond which the set will increase size.
`boolean`	`remove(int value)` Specialised version of {this#remove(Object)} for int.
`boolean`	`remove(Object value)`
`boolean`	`removeAll(Collection<?> coll)`
`boolean`	`removeAll(IntHashSet coll)` Alias for `removeAll(Collection)` for the specialized case when removing another IntHashSet, avoids boxing and allocations
`int`	`resizeThreshold()` Get the actual threshold which when reached the map will resize.
`int`	`size()`
`Object[]`	`toArray()`
`<T> T[]`	`toArray(T[] 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.Set
containsAll, retainAll, spliterator

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

Methods inherited from interface java.lang.Iterable
forEach

- Field Detail
  - 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
- Constructor Detail
  - IntHashSet
```
public IntHashSet()
```
    Construct a hash set with DEFAULT_INITIAL_CAPACITY, Hashing.DEFAULT_LOAD_FACTOR, and iterator caching support.
  - IntHashSet
```
public IntHashSet(int proposedCapacity)
```
    Construct a hash set with a proposed capacity, Hashing.DEFAULT_LOAD_FACTOR, and iterator caching support.
    
    Parameters:
    
    proposedCapacity - for the initial capacity of the set.
  - IntHashSet
```
public IntHashSet(int proposedCapacity,
                  float loadFactor)
```
    Construct a hash set with a proposed initial capacity, load factor, and iterator caching support.
    
    Parameters:
    
    proposedCapacity - for the initial capacity of the set.
    
    loadFactor - to be used for resizing.
  - IntHashSet
```
public IntHashSet(int proposedCapacity,
                  float loadFactor,
                  boolean shouldAvoidAllocation)
```
    Construct a hash set with a proposed initial capacity, load factor, and indicated iterator caching support.
    
    Parameters:
    
    proposedCapacity - for the initial capacity of the set.
    
    loadFactor - to be used for resizing.
    
    shouldAvoidAllocation - should the iterator be cached to avoid further allocation.
- Method Detail
  - 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(Integer value)
```
    Specified by:
    
    add in interface Collection<Integer>
    
    Specified by:
    
    add in interface Set<Integer>
    
    Overrides:
    
    add in class AbstractCollection<Integer>
  - add
```
public boolean add(int value)
```
    Primitive specialised overload of {this#add(Integer)}.
    
    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<Integer>
    
    Specified by:
    
    remove in interface Set<Integer>
    
    Overrides:
    
    remove in class AbstractCollection<Integer>
  - remove
```
public boolean remove(int value)
```
    Specialised version of {this#remove(Object)} for int.
    
    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<Integer>
    
    Specified by:
    
    contains in interface Set<Integer>
    
    Overrides:
    
    contains in class AbstractCollection<Integer>
  - contains
```
public boolean contains(int value)
```
    Contains method that does not box values.
    
    Parameters:
    
    value - to be checked 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<Integer>
    
    Specified by:
    
    size in interface Set<Integer>
    
    Specified by:
    
    size in class AbstractCollection<Integer>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Collection<Integer>
    
    Specified by:
    
    isEmpty in interface Set<Integer>
    
    Overrides:
    
    isEmpty in class AbstractCollection<Integer>
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Collection<Integer>
    
    Specified by:
    
    clear in interface Set<Integer>
    
    Overrides:
    
    clear in class AbstractCollection<Integer>
  - addAll
```
public boolean addAll(Collection<? extends Integer> coll)
```
    Specified by:
    
    addAll in interface Collection<Integer>
    
    Specified by:
    
    addAll in interface Set<Integer>
    
    Overrides:
    
    addAll in class AbstractCollection<Integer>
  - addAll
```
public boolean addAll(IntHashSet coll)
```
    Alias for addAll(Collection) for the specialized case when adding another IntHashSet, avoids boxing and allocations.
    
    Parameters:
    
    coll - containing the values to be added.
    
    Returns:
    
    true if this set changed as a result of the call.
  - containsAll
```
public boolean containsAll(IntHashSet other)
```
    IntHashSet specialised variant of {this#containsAll(Collection)}.
    
    Parameters:
    
    other - int hash set to compare against.
    
    Returns:
    
    true if every element in other is in this.
  - difference
```
public IntHashSet difference(IntHashSet other)
```
    Fast Path set difference for comparison with another IntHashSet.
    Note: garbage free in the identical case, allocates otherwise.
    
    Parameters:
    
    other - the other set to subtract.
    
    Returns:
    
    null if identical, otherwise the set of differences.
  - removeAll
```
public boolean removeAll(Collection<?> coll)
```
    Specified by:
    
    removeAll in interface Collection<Integer>
    
    Specified by:
    
    removeAll in interface Set<Integer>
    
    Overrides:
    
    removeAll in class AbstractSet<Integer>
  - removeAll
```
public boolean removeAll(IntHashSet coll)
```
    Alias for removeAll(Collection) for the specialized case when removing another IntHashSet, avoids boxing and allocations
    
    Parameters:
    
    coll - containing the values to be removed.
    
    Returns:
    
    true if this set changed as a result of the call.
  - iterator
```
public IntHashSet.IntIterator iterator()
```
    Specified by:
    
    iterator in interface Iterable<Integer>
    
    Specified by:
    
    iterator in interface Collection<Integer>
    
    Specified by:
    
    iterator in interface Set<Integer>
    
    Specified by:
    
    iterator in class AbstractCollection<Integer>
  - copy
```
public void copy(IntHashSet that)
```
    Copye values from another IntHashSet into this one.
    
    Parameters:
    
    that - set to copy values from.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class AbstractCollection<Integer>
  - toArray
```
public <T> T[] toArray(T[] a)
```
    Specified by:
    
    toArray in interface Collection<Integer>
    
    Specified by:
    
    toArray in interface Set<Integer>
    
    Overrides:
    
    toArray in class AbstractCollection<Integer>
  - toArray
```
public Object[] toArray()
```
    Specified by:
    
    toArray in interface Collection<Integer>
    
    Specified by:
    
    toArray in interface Set<Integer>
    
    Overrides:
    
    toArray in class AbstractCollection<Integer>
  - equals
```
public boolean equals(Object other)
```
    Specified by:
    
    equals in interface Collection<Integer>
    
    Specified by:
    
    equals in interface Set<Integer>
    
    Overrides:
    
    equals in class AbstractSet<Integer>
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Collection<Integer>
    
    Specified by:
    
    hashCode in interface Set<Integer>
    
    Overrides:
    
    hashCode in class AbstractSet<Integer>

Class IntHashSet

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.Set

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Field Detail

DEFAULT_INITIAL_CAPACITY

Constructor Detail

IntHashSet

IntHashSet

IntHashSet

IntHashSet

Method Detail

loadFactor

capacity

resizeThreshold

add

add

remove

remove

compact

contains

contains

size

isEmpty

clear

addAll

addAll

containsAll

difference

removeAll

removeAll

iterator

copy

toString

toArray

toArray

equals

hashCode