Package org.agrona.collections

Class LongArrayQueue

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractQueue<Long>
org.agrona.collections.LongArrayQueue
All Implemented Interfaces:
Iterable<Long>, Collection<Long>, Queue<Long>
public class LongArrayQueue extends AbstractQueue<Long>
Queue of longs which stores the elements without boxing. Null is represented by a special nullValue().

The LongArrayQueue.LongIterator is cached by default to avoid allocation unless directed to do so in the constructor.

Note: This class is not threadsafe.

  • Field Details

    • DEFAULT_NULL_VALUE

      public static final long DEFAULT_NULL_VALUE
      Default representation of null for an element.
      See Also:

    • MIN_CAPACITY

      public static final int MIN_CAPACITY
      Minimum capacity for the queue which must also be a power of 2.
      See Also:

  • Constructor Details

    • LongArrayQueue

      public LongArrayQueue()
      Construct a new queue defaulting to MIN_CAPACITY capacity, DEFAULT_NULL_VALUE and cached iterators.

    • LongArrayQueue

      public LongArrayQueue(long nullValue)
      Construct a new queue defaulting to MIN_CAPACITY capacity and cached iterators.
      Parameters:
      nullValue - cannot be stored in the queue and used as a sentinel.

    • LongArrayQueue

      public LongArrayQueue(int initialCapacity, long nullValue)
      Construct a new queue default to cached iterators.
      Parameters:
      initialCapacity - for the queue which will be rounded up to the nearest power of 2.
      nullValue - which cannot be stored in the queue and used as a sentinel.

    • LongArrayQueue

      public LongArrayQueue(int initialCapacity, long nullValue, boolean shouldAvoidAllocation)
      Construct a new queue providing all the config options.
      Parameters:
      initialCapacity - for the queue which will be rounded up to the nearest power of 2.
      nullValue - which cannot be stored in the queue and used as a sentinel.
      shouldAvoidAllocation - true to cache the iterator otherwise false to allocate a new iterator each time.

  • Method Details

    • nullValue

      public long nullValue()
      The value representing a null element.
      Returns:
      value representing a null element.

    • capacity

      public int capacity()
      The current capacity for the collection.
      Returns:
      the current capacity for the collection.

    • size

      public int size()
      Specified by:
      size in interface Collection<Long>
      Specified by:
      size in class AbstractCollection<Long>

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface Collection<Long>
      Overrides:
      isEmpty in class AbstractCollection<Long>

    • clear

      public void clear()
      Specified by:
      clear in interface Collection<Long>
      Overrides:
      clear in class AbstractQueue<Long>

    • offer

      public boolean offer(Long element)

    • offerLong

      public boolean offerLong(long element)
      Offer an element to the tail of the queue without boxing.
      Parameters:
      element - to be offered to the queue.
      Returns:
      will always be true as long as the underlying array can be expanded.

    • add

      public boolean add(Long element)
      Specified by:
      add in interface Collection<Long>
      Specified by:
      add in interface Queue<Long>
      Overrides:
      add in class AbstractQueue<Long>

    • addLong

      public boolean addLong(long element)
      Offer an element to the tail of the queue without boxing.
      Parameters:
      element - to be offered to the queue.
      Returns:
      will always be true as long as the underlying array can be expanded.

    • peek

      public Long peek()

    • peekLong

      public long peekLong()
      Peek at the element on the head of the queue without boxing.
      Returns:
      the element at the head of the queue without removing it.

    • poll

      public Long poll()

    • pollLong

      public long pollLong()
      Poll the element from the head of the queue without boxing.
      Returns:
      the element at the head of the queue removing it. If empty then nullValue.

    • remove

      public Long remove()
      Specified by:
      remove in interface Queue<Long>
      Overrides:
      remove in class AbstractQueue<Long>

    • element

      public Long element()
      Specified by:
      element in interface Queue<Long>
      Overrides:
      element in class AbstractQueue<Long>

    • elementLong

      public long elementLong()
      Peek at the element on the head of the queue without boxing.
      Returns:
      the element at the head of the queue without removing it.
      Throws:
      NoSuchElementException - if the queue is empty.

    • removeLong

      public long removeLong()
      Remove the element at the head of the queue without boxing.
      Returns:
      the element at the head of the queue.
      Throws:
      NoSuchElementException - if the queue is empty.

    • toString

      public String toString()
      Overrides:
      toString in class AbstractCollection<Long>

    • forEach

      public void forEach(Consumer<? super Long> action)

    • forEachLong

      public void forEachLong(LongConsumer action)
      Iterate over the collection without boxing.
      Parameters:
      action - to be taken for each element.

    • iterator

      public LongArrayQueue.LongIterator iterator()
      Specified by:
      iterator in interface Collection<Long>
      Specified by:
      iterator in interface Iterable<Long>
      Specified by:
      iterator in class AbstractCollection<Long>