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.

Instances of this class represent a FIFO 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.


Field Summary
protected  K[] array
          The backing array.
protected  int end
          The end position in array.
static int INITIAL_CAPACITY
          The standard initial capacity of a queue.
protected  int length
          The current (cached) length of array.
protected  int start
          The start position in array.
 
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 PriorityQueue.first() element from the queue.
 void enqueue(K x)
          Enqueues a new element.
 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
clone, equals, finalize, 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

array

protected K[] array
The backing array.


length

protected int length
The current (cached) length of array.


start

protected int start
The start position in array.


end

protected int end
The end position in array. Might be actually smaller than start because array is used cyclically.

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 PriorityQueue.first() element from the queue.

Returns:
the dequeued element.

enqueue

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

Parameters:
x - the element to enqueue..

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.


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