Package org.elasticsearch.common.collect

Class EvictingQueue<T>

java.lang.Object

org.elasticsearch.common.collect.EvictingQueue<T>

Type Parameters:

T - The type of elements in the queue.

All Implemented Interfaces:

Iterable<T>, Collection<T>, Queue<T>

public class EvictingQueue<T>
extends Object
implements Queue<T>

An EvictingQueue is a non-blocking queue which is limited to a maximum size; when new elements are added to a full queue, elements are evicted from the head of the queue to accommodate the new elements.

Constructor Summary

Constructors

Constructor	Description
EvictingQueue(int maximumSize)	Construct a new EvictingQueue that holds maximumSize elements.

Method Summary

Modifier and Type	Method	Description
boolean	add(T t)	Add the given element to the queue, possibly forcing an eviction from the head if remainingCapacity() is zero.
boolean	addAll(Collection<? extends T> c)	Add the given elements to the queue, possibly forcing evictions from the head if remainingCapacity() is zero or becomes zero during the execution of this method.
void	clear()
boolean	contains(Object o)
boolean	containsAll(Collection<?> c)
T	element()
boolean	isEmpty()
Iterator<T>	iterator()
boolean	offer(T t)
T	peek()
T	poll()
int	remainingCapacity()
T	remove()
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
boolean	retainAll(Collection<?> c)
int	size()
Object[]	toArray()
<T1> T1[]	toArray(T1[] a)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

EvictingQueue

public EvictingQueue(int maximumSize)

Construct a new EvictingQueue that holds maximumSize elements.

Parameters:

maximumSize - The maximum number of elements that the queue can hold

Throws:

IllegalArgumentException - if maximumSize is less than zero

Method Detail

remainingCapacity

public int remainingCapacity()

Returns:

the number of additional elements that the queue can accommodate before evictions occur

add

public boolean add(T t)

Add the given element to the queue, possibly forcing an eviction from the head if remainingCapacity() is zero.

Specified by:

add in interface Collection<T>

Specified by:

add in interface Queue<T>

Parameters:

t - the element to add

Returns:

true if the element was added (always the case for EvictingQueue

offer

public boolean offer(T t)

Specified by:

offer in interface Queue<T>

See Also:

add(Object)

remove

public T remove()

Specified by:

remove in interface Queue<T>

poll

public T poll()

Specified by:

poll in interface Queue<T>

element

public T element()

Specified by:

element in interface Queue<T>

peek

public T peek()

Specified by:

peek in interface Queue<T>

size

public int size()

Specified by:

size in interface Collection<T>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<T>

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<T>

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Collection<T>

Specified by:

iterator in interface Iterable<T>

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<T>

toArray

public <T1> T1[] toArray(T1[] a)

Specified by:

toArray in interface Collection<T>

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<T>

containsAll

public boolean containsAll(Collection<?> c)

Specified by:

containsAll in interface Collection<T>

addAll

public boolean addAll(Collection<? extends T> c)

Add the given elements to the queue, possibly forcing evictions from the head if remainingCapacity() is zero or becomes zero during the execution of this method.

Specified by:

addAll in interface Collection<T>

Parameters:

c - the collection of elements to add

Returns:

true if any elements were added to the queue

removeAll

public boolean removeAll(Collection<?> c)

Specified by:

removeAll in interface Collection<T>

retainAll

public boolean retainAll(Collection<?> c)

Specified by:

retainAll in interface Collection<T>

clear

public void clear()

Specified by:

clear in interface Collection<T>