Package net.solarnetwork.central.support

Class DelayQueueSet<E extends Delayed>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractQueue<E>
net.solarnetwork.central.support.DelayQueueSet<E>
All Implemented Interfaces:
Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>
public class DelayQueueSet<E extends Delayed> extends AbstractQueue<E> implements BlockingQueue<E>
A combination of BlockingQueue and Set.

Adapted from

  • Constructor Details

    • DelayQueueSet

      public DelayQueueSet()
      Creates a new DelayQueue that is initially empty.

    • DelayQueueSet

      public DelayQueueSet(int capacity)
      Creates a new DelayQueue that is initially empty.
      Parameters:
      capacity - an initial estimated capacity

    • DelayQueueSet

      public DelayQueueSet(Set<E> delegateSet)
      Creates a new DelayQueue that is initially empty.
      Parameters:
      delegateSet - a specific set instance to use

    • DelayQueueSet

      public DelayQueueSet(Collection<? extends E> c)
      Creates a DelayQueue initially containing the elements of the given collection of Delayed instances.
      Parameters:
      c - the collection of elements to initially contain
      Throws:
      NullPointerException - if the specified collection or any of its elements are null

  • Method Details

    • add

      public boolean add(E e)
      Inserts the specified element into this delay queue.
      Specified by:
      add in interface BlockingQueue<E extends Delayed>
      Specified by:
      add in interface Collection<E extends Delayed>
      Specified by:
      add in interface Queue<E extends Delayed>
      Overrides:
      add in class AbstractQueue<E extends Delayed>
      Parameters:
      e - the element to add
      Returns:
      true (as specified by Collection.add(E))
      Throws:
      NullPointerException - if the specified element is null

    • offer

      public boolean offer(E e)
      Inserts the specified element into this delay queue.
      Specified by:
      offer in interface BlockingQueue<E extends Delayed>
      Specified by:
      offer in interface Queue<E extends Delayed>
      Parameters:
      e - the element to add
      Returns:
      true
      Throws:
      NullPointerException - if the specified element is null

    • put

      public void put(E e)
      Inserts the specified element into this delay queue. As the queue is unbounded this method will never block.
      Specified by:
      put in interface BlockingQueue<E extends Delayed>
      Parameters:
      e - the element to add

    • offer

      public boolean offer(E e, long timeout, TimeUnit unit)
      Inserts the specified element into this delay queue. As the queue is unbounded this method will never block.
      Specified by:
      offer in interface BlockingQueue<E extends Delayed>
      Parameters:
      e - the element to add
      timeout - This parameter is ignored as the method never blocks
      unit - This parameter is ignored as the method never blocks
      Returns:
      true

    • poll

      public E poll()
      Retrieves and removes the expired head of this queue, or returns null if this queue has no expired elements.
      Specified by:
      poll in interface Queue<E extends Delayed>
      Returns:
      the expired head of this queue, or null if this queue has no elements with an expired delay

    • take

      public E take() throws InterruptedException
      Retrieves and removes the expired head of this queue, waiting if necessary until an expired element is available on this queue.
      Specified by:
      take in interface BlockingQueue<E extends Delayed>
      Returns:
      the expired head of this queue

    • poll

      public E poll(long timeout, TimeUnit unit) throws InterruptedException
      Retrieves and removes the expired head of this queue, waiting if necessary until an expired element is available on this queue, or the specified wait time expires.
      Specified by:
      poll in interface BlockingQueue<E extends Delayed>
      Returns:
      the expired head of this queue, or null if the specified waiting time elapses before an element with an expired delay becomes available

    • remove

      public E remove()
      Retrieves and removes the expired head of this queue, or throws an exception if this queue has no expired elements.
      Specified by:
      remove in interface Queue<E extends Delayed>
      Overrides:
      remove in class AbstractQueue<E extends Delayed>
      Returns:
      the expired head of this queue
      Throws:
      NoSuchElementException - if this queue has no elements with an expired delay

    • peek

      public E peek()
      Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. Unlike poll, if no expired elements are available in the queue, this method returns the element that will expire next, if one exists.
      Specified by:
      peek in interface Queue<E extends Delayed>
      Returns:
      the head of this queue, or null if this queue is empty

    • size

      public int size()
      Specified by:
      size in interface Collection<E extends Delayed>
      Specified by:
      size in class AbstractCollection<E extends Delayed>

    • drainTo

      public int drainTo(Collection<? super E> c)
      Specified by:
      drainTo in interface BlockingQueue<E extends Delayed>

    • drainTo

      public int drainTo(Collection<? super E> c, int maxElements)
      Specified by:
      drainTo in interface BlockingQueue<E extends Delayed>

    • clear

      public void clear()
      Atomically removes all of the elements from this delay queue. The queue will be empty after this call returns. Elements with an unexpired delay are not waited for; they are simply discarded from the queue.
      Specified by:
      clear in interface Collection<E extends Delayed>
      Overrides:
      clear in class AbstractQueue<E extends Delayed>

    • remainingCapacity

      public int remainingCapacity()
      Always returns Integer.MAX_VALUE because a DelayQueue is not capacity constrained.
      Specified by:
      remainingCapacity in interface BlockingQueue<E extends Delayed>
      Returns:
      Integer.MAX_VALUE

    • toArray

      public Object[] toArray()
      Returns an array containing all of the elements in this queue. The returned array elements are in no particular order.

      The returned array will be "safe" in that no references to it are maintained by this queue. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.

      This method acts as bridge between array-based and collection-based APIs.

      Specified by:
      toArray in interface Collection<E extends Delayed>
      Overrides:
      toArray in class AbstractCollection<E extends Delayed>
      Returns:
      an array containing all of the elements in this queue

    • toArray

      public <T> T[] toArray(T[] a)
      Returns an array containing all of the elements in this queue; the runtime type of the returned array is that of the specified array. The returned array elements are in no particular order. If the queue fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this queue.

      If this queue fits in the specified array with room to spare (i.e., the array has more elements than this queue), the element in the array immediately following the end of the queue is set to null.

      Like the toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.

      The following code can be used to dump a delay queue into a newly allocated array of Delayed: 

       
 
 Delayed[] a = q.toArray(new Delayed[0]);
      Note that toArray(new Object[0]) is identical in function to toArray().
      Specified by:
      toArray in interface Collection<E extends Delayed>
      Overrides:
      toArray in class AbstractCollection<E extends Delayed>
      Parameters:
      a - the array into which the elements of the queue are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose
      Returns:
      an array containing all of the elements in this queue
      Throws:
      ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this queue
      NullPointerException - if the specified array is null

    • remove

      public boolean remove(Object o)
      Removes a single instance of the specified element from this queue, if it is present, whether or not it has expired.
      Specified by:
      remove in interface BlockingQueue<E extends Delayed>
      Specified by:
      remove in interface Collection<E extends Delayed>
      Overrides:
      remove in class AbstractCollection<E extends Delayed>

    • iterator

      public Iterator<E> iterator()
      Returns an iterator over all the elements (both expired and unexpired) in this queue. The iterator does not return the elements in any particular order.

      The returned iterator is weakly consistent.

      Specified by:
      iterator in interface Collection<E extends Delayed>
      Specified by:
      iterator in interface Iterable<E extends Delayed>
      Specified by:
      iterator in class AbstractCollection<E extends Delayed>
      Returns:
      an iterator over the elements in this queue