Package ch.qos.logback.core.util

Class COWArrayList<E>

  • All Implemented Interfaces:
    java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>
    public class COWArrayList<E>
extends java.lang.Object
implements java.util.List<E>
    A GC-free lock-free thread-safe implementation of the List interface for use cases where iterations over the list vastly out-number modifications on the list.

    Underneath, it wraps an instance of CopyOnWriteArrayList and exposes a copy of the array used by that instance.

    Typical use:

       COWArrayList list = new COWArrayList(new Integer[0]);
   
   // modify the list
   list.add(1);
   list.add(2);
   
   Integer[] intArray = list.asTypedArray();
   int sum = 0;
   // iteration over the array is thread-safe
   for(int i = 0; i < intArray.length; i++) {
     sum != intArray[i];
   }

    If the list is not modified, then repetitive calls to asTypedArray(), toArray() and toArray(Object[]) are guaranteed to be GC-free. Note that iterating over the list using iterator() and listIterator() are not GC-free.

    Since:
    1.1.10

    • Constructor Summary

      Constructors 
      Constructor Description
      COWArrayList​(E[] modelArray)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(int index, E element)  
      boolean add​(E e)  
      boolean addAll​(int index, java.util.Collection<? extends E> col)  
      boolean addAll​(java.util.Collection<? extends E> c)  
      void addIfAbsent​(E e)  
      E[] asTypedArray()
      Return an array of type E[].
      void clear()  
      boolean contains​(java.lang.Object o)  
      boolean containsAll​(java.util.Collection<?> c)  
      E get​(int index)  
      int indexOf​(java.lang.Object o)  
      boolean isEmpty()  
      java.util.Iterator<E> iterator()  
      int lastIndexOf​(java.lang.Object o)  
      java.util.ListIterator<E> listIterator()  
      java.util.ListIterator<E> listIterator​(int index)  
      E remove​(int index)  
      boolean remove​(java.lang.Object o)  
      boolean removeAll​(java.util.Collection<?> col)  
      boolean retainAll​(java.util.Collection<?> col)  
      E set​(int index, E element)  
      int size()  
      java.util.List<E> subList​(int fromIndex, int toIndex)  
      java.lang.Object[] toArray()  
      <T> T[] toArray​(T[] a)  

      • Methods inherited from class java.lang.Object

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

      • Methods inherited from interface java.util.Collection

        parallelStream, removeIf, stream, toArray

      • Methods inherited from interface java.lang.Iterable

        forEach

      • Methods inherited from interface java.util.List

        equals, hashCode, replaceAll, sort, spliterator

    • Constructor Detail

      • COWArrayList

        public COWArrayList​(E[] modelArray)

    • Method Detail

      • size

        public int size()
        Specified by:
        size in interface java.util.Collection<E>
        Specified by:
        size in interface java.util.List<E>

      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Collection<E>
        Specified by:
        isEmpty in interface java.util.List<E>

      • contains

        public boolean contains​(java.lang.Object o)
        Specified by:
        contains in interface java.util.Collection<E>
        Specified by:
        contains in interface java.util.List<E>

      • iterator

        public java.util.Iterator<E> iterator()
        Specified by:
        iterator in interface java.util.Collection<E>
        Specified by:
        iterator in interface java.lang.Iterable<E>
        Specified by:
        iterator in interface java.util.List<E>

      • toArray

        public java.lang.Object[] toArray()
        Specified by:
        toArray in interface java.util.Collection<E>
        Specified by:
        toArray in interface java.util.List<E>

      • toArray

        public <T> T[] toArray​(T[] a)
        Specified by:
        toArray in interface java.util.Collection<E>
        Specified by:
        toArray in interface java.util.List<E>

      • asTypedArray

        public E[] asTypedArray()
        Return an array of type E[]. The returned array is intended to be iterated over. If the list is modified, subsequent calls to this method will return different/modified array instances.
        Returns:

      • addIfAbsent

        public void addIfAbsent​(E e)

      • add

        public boolean add​(E e)
        Specified by:
        add in interface java.util.Collection<E>
        Specified by:
        add in interface java.util.List<E>

      • remove

        public boolean remove​(java.lang.Object o)
        Specified by:
        remove in interface java.util.Collection<E>
        Specified by:
        remove in interface java.util.List<E>

      • containsAll

        public boolean containsAll​(java.util.Collection<?> c)
        Specified by:
        containsAll in interface java.util.Collection<E>
        Specified by:
        containsAll in interface java.util.List<E>

      • addAll

        public boolean addAll​(java.util.Collection<? extends E> c)
        Specified by:
        addAll in interface java.util.Collection<E>
        Specified by:
        addAll in interface java.util.List<E>

      • addAll

        public boolean addAll​(int index,
                      java.util.Collection<? extends E> col)
        Specified by:
        addAll in interface java.util.List<E>

      • removeAll

        public boolean removeAll​(java.util.Collection<?> col)
        Specified by:
        removeAll in interface java.util.Collection<E>
        Specified by:
        removeAll in interface java.util.List<E>

      • retainAll

        public boolean retainAll​(java.util.Collection<?> col)
        Specified by:
        retainAll in interface java.util.Collection<E>
        Specified by:
        retainAll in interface java.util.List<E>

      • clear

        public void clear()
        Specified by:
        clear in interface java.util.Collection<E>
        Specified by:
        clear in interface java.util.List<E>

      • get

        public E get​(int index)
        Specified by:
        get in interface java.util.List<E>

      • set

        public E set​(int index,
             E element)
        Specified by:
        set in interface java.util.List<E>

      • add

        public void add​(int index,
                E element)
        Specified by:
        add in interface java.util.List<E>

      • remove

        public E remove​(int index)
        Specified by:
        remove in interface java.util.List<E>

      • indexOf

        public int indexOf​(java.lang.Object o)
        Specified by:
        indexOf in interface java.util.List<E>

      • lastIndexOf

        public int lastIndexOf​(java.lang.Object o)
        Specified by:
        lastIndexOf in interface java.util.List<E>

      • listIterator

        public java.util.ListIterator<E> listIterator()
        Specified by:
        listIterator in interface java.util.List<E>

      • listIterator

        public java.util.ListIterator<E> listIterator​(int index)
        Specified by:
        listIterator in interface java.util.List<E>

      • subList

        public java.util.List<E> subList​(int fromIndex,
                                 int toIndex)
        Specified by:
        subList in interface java.util.List<E>