it.unimi.dsi.fastutil.objects
Class ObjectArrayFIFOQueue<K>

java.lang.Object
  extended by it.unimi.dsi.fastutil.AbstractPriorityQueue<K>
      extended by it.unimi.dsi.fastutil.objects.ObjectArrayFIFOQueue<K>
All Implemented Interfaces:
PriorityQueue<K>

public class ObjectArrayFIFOQueue<K>
extends AbstractPriorityQueue<K>

A type-specific array-based FIFO queue, supporting also deque operations.

Instances of this class represent a FIFO queue using a backing array in a circular way. The array is enlarged as needed, but it is never shrunk. Use the trim() method to reduce its size, if necessary.

This class provides additional methods that implement a deque (double-ended queue).


Field Summary
static int INITIAL_CAPACITY
          The standard initial capacity of a queue.
 
Constructor Summary
ObjectArrayFIFOQueue()
          Creates a new empty queue with standard initial capacity.
ObjectArrayFIFOQueue(int capacity)
          Creates a new empty queue with given capacity.
 
Method Summary
 void clear()
          Removes all elements from this queue.
 Comparator<? super K> comparator()
          Returns null (FIFO queues have no comparator).
 K dequeue()
          Dequeues the first element from the queue.
 K dequeueLast()
          Dequeues the last element from the queue.
 void enqueue(K x)
          Enqueues a new element.
 void enqueueFirst(K x)
          Enqueues a new element as the first element (in dequeuing order) of the queue.
 K first()
          Returns the first element of the queue.
 K last()
          Returns the last element of the queue.
 int size()
          Returns the number of elements in this queue.
 void trim()
          Trims the queue to the smallest possible size.
 
Methods inherited from class it.unimi.dsi.fastutil.AbstractPriorityQueue
changed, isEmpty
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

INITIAL_CAPACITY

public static final int INITIAL_CAPACITY
The standard initial capacity of a queue.

See Also:
Constant Field Values
Constructor Detail

ObjectArrayFIFOQueue

public ObjectArrayFIFOQueue(int capacity)
Creates a new empty queue with given capacity.

Parameters:
capacity - the initial capacity of this queue.

ObjectArrayFIFOQueue

public ObjectArrayFIFOQueue()
Creates a new empty queue with standard initial capacity.

Method Detail

comparator

public Comparator<? super K> comparator()
Returns null (FIFO queues have no comparator).

Returns:
null.

dequeue

public K dequeue()
Description copied from interface: PriorityQueue
Dequeues the first element from the queue.

Returns:
the dequeued element.

dequeueLast

public K dequeueLast()
Dequeues the last element from the queue.

Returns:
the dequeued element.
Throws:
NoSuchElementException - if the queue is empty.

enqueue

public void enqueue(K x)
Description copied from interface: PriorityQueue
Enqueues a new element.

Parameters:
x - the element to enqueue..

enqueueFirst

public void enqueueFirst(K x)
Enqueues a new element as the first element (in dequeuing order) of the queue.


first

public K first()
Returns the first element of the queue.

Returns:
the first element of the queue.

last

public K last()
Returns the last element of the queue.

Specified by:
last in interface PriorityQueue<K>
Overrides:
last in class AbstractPriorityQueue<K>
Returns:
the last element of the queue.

clear

public void clear()
Description copied from interface: PriorityQueue
Removes all elements from this queue.


trim

public void trim()
Trims the queue to the smallest possible size.


size

public int size()
Description copied from interface: PriorityQueue
Returns the number of elements in this queue.

Returns:
the number of elements in this queue.