Package icyllis.arc3d.engine

Class PriorityQueue<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractQueue<E>
icyllis.arc3d.engine.PriorityQueue<E>
Type Parameters:
E - the type of elements held in this queue
All Implemented Interfaces:
Iterable<E>, Collection<E>, Queue<E>
public class PriorityQueue<E> extends AbstractQueue<E>
Similar to PriorityQueue, but supports PriorityQueue.Access.

  • Field Details

    • mHeap

      protected transient E[] mHeap
      The heap array.

    • mSize

      protected int mSize
      The number of elements in this queue.

    • mComparator

      protected Comparator<? super E> mComparator
      The type-specific comparator used in this queue.

    • mAccess

      protected PriorityQueue.Access<? super E> mAccess
      The type-specific index accessor used in this queue.

  • Constructor Details

    • PriorityQueue

      public PriorityQueue()

    • PriorityQueue

      public PriorityQueue(int priority)

    • PriorityQueue

      public PriorityQueue(PriorityQueue.Access<? super E> access)

    • PriorityQueue

      public PriorityQueue(int capacity, PriorityQueue.Access<? super E> access)

    • PriorityQueue

      public PriorityQueue(Comparator<? super E> comparator, PriorityQueue.Access<? super E> access)

    • PriorityQueue

      public PriorityQueue(int capacity, Comparator<? super E> comparator, PriorityQueue.Access<? super E> access)
      Creates a PriorityQueue with a given capacity, comparator and index accessor.
      Parameters:
      capacity - the initial capacity of this queue.
      comparator - the comparator used in this queue, or null for the natural order.
      access - the index accessor used in this queue, or null.

  • Method Details

    • add

      public boolean add(E e)
      Inserts the specified element into this priority queue.
      Specified by:
      add in interface Collection<E>
      Specified by:
      add in interface Queue<E>
      Overrides:
      add in class AbstractQueue<E>
      Returns:
      true (as specified by Collection.add(E))
      Throws:
      ClassCastException - if the specified element cannot be compared with elements currently in this priority queue according to the priority queue's ordering
      NullPointerException - if the specified element is null

    • offer

      public boolean offer(E e)
      Inserts the specified element into this priority queue.
      Returns:
      true (as specified by Queue.offer(E))
      Throws:
      ClassCastException - if the specified element cannot be compared with elements currently in this priority queue according to the priority queue's ordering
      NullPointerException - if the specified element is null

    • peek

      public E peek()

    • remove

      public boolean remove(Object o)
      Removes a single instance of the specified element from this queue, if it is present. More formally, removes an element e such that o.equals(e), if this queue contains one or more such elements. Returns true if and only if this queue contained the specified element (or equivalently, if this queue changed as a result of the call).
      Specified by:
      remove in interface Collection<E>
      Overrides:
      remove in class AbstractCollection<E>
      Parameters:
      o - element to be removed from this queue, if present
      Returns:
      true if this queue changed as a result of the call

    • contains

      public boolean contains(Object o)
      Returns true if this queue contains the specified element. More formally, returns true if and only if this queue contains at least one element e such that o.equals(e).
      Specified by:
      contains in interface Collection<E>
      Overrides:
      contains in class AbstractCollection<E>
      Parameters:
      o - object to be checked for containment in this queue
      Returns:
      true if this queue contains the specified element

    • toArray

      public Object[] toArray()
      Returns an array containing all of the elements in this queue. The 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>
      Overrides:
      toArray in class AbstractCollection<E>
      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 the queue fits in the specified array with room to spare (i.e., the array has more elements than the queue), the element in the array immediately following the end of the collection 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.

      Suppose x is a queue known to contain only strings. The following code can be used to dump the queue into a newly allocated array of String: 

       String[] y = x.toArray(new String[0]);

      Note that toArray(new Object[0]) is identical in function to toArray().

      Specified by:
      toArray in interface Collection<E>
      Overrides:
      toArray in class AbstractCollection<E>
      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

    • iterator

      public Iterator<E> iterator()
      Returns an iterator over the elements in this queue. The iterator does not return the elements in any particular order.
      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Iterable<E>
      Specified by:
      iterator in class AbstractCollection<E>
      Returns:
      an iterator over the elements in this queue

    • size

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

    • clear

      public void clear()
      Removes all of the elements from this priority queue. The queue will be empty after this call returns.
      Specified by:
      clear in interface Collection<E>
      Overrides:
      clear in class AbstractQueue<E>

    • poll

      public E poll()

    • removeAt

      public void removeAt(int i)
      Removes the ith element from queue.

    • elementAt

      public E elementAt(int i)
      Gets the ith element in priority queue. elementAt(0) is equivalent to peek(). Otherwise, there is no guarantee about ordering of elements in the queue.

    • sort

      public void sort()
      Sorts the queue into priority order. The queue is only guaranteed to remain in sorted order until any other operation, other than elementAt(int), is performed.

    • heap

      public void heap()
      Makes the current array into a heap.

    • trim

      public void trim()
      Trims the underlying heap array so that it has exactly size() elements.

    • comparator

      public Comparator<? super E> comparator()
      Returns the comparator used to order the elements in this queue, or null if this queue is sorted according to the natural ordering of its elements.
      Returns:
      the comparator used to order this queue, or null if this queue is sorted according to the natural ordering of its elements

    • access

      public PriorityQueue.Access<? super E> access()