Package org.jenkinsci.plugins.cloudstats

Class CyclicThreadSafeCollection<E>

java.lang.Object
org.jenkinsci.plugins.cloudstats.CyclicThreadSafeCollection<E>
All Implemented Interfaces:
Iterable<E>, Collection<E>
@ThreadSafe public class CyclicThreadSafeCollection<E> extends Object implements Collection<E>
Circular thread-safe Collection.

At most capacity elements are preserved and when more added, oldest elements are deleted. Collection preserves insertion order of the elements so the oldest is the first one.

The class does not implement selective deletion operations (remove(), removeAll(), retainAll()) but it implements clear().

All operations, including iteration, are thread safe. Operations add(), size() and isEmpty() performs in constant time. The rest of the operations have linear time complexity, while never holding the lock to perform any custom logic (such as calling contains() on elements) or entering synchronized section on any other monitor except for the internal lock. In such cases, lock is used only to make the copy of the content.

Author:
ogondza.

  • Constructor Details

    • CyclicThreadSafeCollection

      public CyclicThreadSafeCollection(int capacity)

  • Method Details

    • add

      public boolean add(E e)
      Specified by:
      add in interface Collection<E>

    • addAll

      public boolean addAll(@NonNull Collection<? extends E> c)
      Add several elements at once.

      It is not guaranteed the elements will be consecutive in the collection (other thread can add elements in between) but it is guaranteed to preserve order.

      Specified by:
      addAll in interface Collection<E>

    • clear

      public void clear()
      Specified by:
      clear in interface Collection<E>

    • iterator

      @NonNull public Iterator<E> iterator()
      Create thread-safe iterator for collection snapshot.

      Iterated elements represent a snapshot of the collection.

      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Iterable<E>

    • size

      @Nonnegative public int size()
      Number of contained elements, never more than capacity.
      Specified by:
      size in interface Collection<E>

    • capacity

      @Nonnegative public int capacity()
      Maximal collection capacity.

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface Collection<E>

    • contains

      public boolean contains(Object o)
      Specified by:
      contains in interface Collection<E>

    • containsAll

      public boolean containsAll(@NonNull Collection<?> c)
      Specified by:
      containsAll in interface Collection<E>

    • toList

      @NonNull public List<E> toList()
      Get elements in separate collection.

    • toArray

      @NonNull public E[] toArray()
      Specified by:
      toArray in interface Collection<E>

    • toArray

      @NonNull public <T> T[] toArray(@NonNull T[] ret)
      Specified by:
      toArray in interface Collection<E>

    • remove

      public boolean remove(Object o)
      Specified by:
      remove in interface Collection<E>

    • removeAll

      public boolean removeAll(@NonNull Collection<?> c)
      Specified by:
      removeAll in interface Collection<E>

    • retainAll

      public boolean retainAll(@NonNull Collection<?> c)
      Specified by:
      retainAll in interface Collection<E>