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 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 Details

    • 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 Details

    • 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>