Package org.apache.activemq.artemis.utils.collections

Class SparseArrayLinkedList<E>

java.lang.Object
org.apache.activemq.artemis.utils.collections.SparseArrayLinkedList<E>
public final class SparseArrayLinkedList<E> extends Object
This list share the same motivation and structure of https://en.wikipedia.org/wiki/Unrolled_linked_list: it's a linked list of arrays/chunks of T.

Differently from an UnrolledLinkedList this list doesn't optimize addition and removal to achieve a balanced utilization among chunks ie a chunk is removed only if empty and chunks can't be merged. This list has been optimized for small-sized chunks (ideally <= 32 elements): this allow search/removal to be performed with a greedy approach despite a sparse chunk utilization (ie chunks contains few sparse elements).

From the memory footprint's point of view, this list won't remove the last remaining array although empty to optimize the case where its capacity would be enough to hold incoming elements, hence saving a new array allocation.

  • Constructor Details

    • SparseArrayLinkedList

      public SparseArrayLinkedList()

    • SparseArrayLinkedList

      public SparseArrayLinkedList(int sparseArrayCapacity)

  • Method Details

    • removeFromSparseArrayList

      public static <E> long removeFromSparseArrayList(List<org.apache.activemq.artemis.utils.collections.SparseArrayLinkedList.SparseArray<E>> sparseArrayList, Predicate<? super E> filter)

    • addToSparseArrayList

      public static <E> void addToSparseArrayList(List<org.apache.activemq.artemis.utils.collections.SparseArrayLinkedList.SparseArray<E>> sparseArrayList, E e, int sparseArrayCapacity)

    • clearSparseArrayList

      public static <E> long clearSparseArrayList(List<org.apache.activemq.artemis.utils.collections.SparseArrayLinkedList.SparseArray<E>> sparseArrayList, Consumer<? super E> consumer)

    • add

      public void add(E e)
      Appends e to the end of this list.

    • remove

      public long remove(Predicate<? super E> filter)
      Removes any element of the list matching the given predicate.

    • clear

      public long clear(Consumer<? super E> consumer)
      Clear while consuming (using the given consumer all the elements of this list.

    • size

      public long size()
      Returns the number of elements of this list.
      Returns:
      the number of elements of this list

    • sparseArrayCapacity

      public int sparseArrayCapacity()
      Returns the configured capacity of each sparse array/chunk.
      Returns:
      the configured capacity of each sparse array/chunk

    • sparseArraysCount

      public int sparseArraysCount()
      Returns the number of sparse arrays/chunks of this list.
      Returns:
      the number of sparse arrays/chunks of this list