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:

java.lang.Iterable<T>, java.util.Collection<T>, java.util.Queue<T>

public class EvictingQueue<T>
extends java.lang.Object
implements java.util.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(java.util.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(java.lang.Object o)
boolean	containsAll(java.util.Collection<?> c)
T	element()
boolean	isEmpty()
java.util.Iterator<T>	iterator()
boolean	offer(T t)
T	peek()
T	poll()
int	remainingCapacity()
T	remove()
boolean	remove(java.lang.Object o)
boolean	removeAll(java.util.Collection<?> c)
boolean	retainAll(java.util.Collection<?> c)
int	size()
java.lang.Object[]	toArray()
<T1> T1[]	toArray(T1[] a)

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from class java.lang.Object

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

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:

java.lang.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 java.util.Collection<T>

Specified by:

add in interface java.util.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 java.util.Queue<T>

See Also:

add(Object)

remove

public T remove()

Specified by:

remove in interface java.util.Queue<T>

poll

public T poll()

Specified by:

poll in interface java.util.Queue<T>

element

public T element()

Specified by:

element in interface java.util.Queue<T>

peek

public T peek()

Specified by:

peek in interface java.util.Queue<T>

size

public int size()

Specified by:

size in interface java.util.Collection<T>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<T>

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection<T>

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.util.Collection<T>

Specified by:

iterator in interface java.lang.Iterable<T>

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<T>

toArray

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

Specified by:

toArray in interface java.util.Collection<T>

remove

public boolean remove(java.lang.Object o)

Specified by:

remove in interface java.util.Collection<T>

containsAll

public boolean containsAll(java.util.Collection<?> c)

Specified by:

containsAll in interface java.util.Collection<T>

addAll

public boolean addAll(java.util.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 java.util.Collection<T>

Parameters:

c - the collection of elements to add

Returns:

true if any elements were added to the queue

removeAll

public boolean removeAll(java.util.Collection<?> c)

Specified by:

removeAll in interface java.util.Collection<T>

retainAll

public boolean retainAll(java.util.Collection<?> c)

Specified by:

retainAll in interface java.util.Collection<T>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<T>