ObjectArrayFIFOQueue (fastutil-object-common 8.3.1 API)

java.lang.Object
- it.unimi.dsi.fastutil.objects.ObjectArrayFIFOQueue<K>

All Implemented Interfaces:

PriorityQueue<K>, Serializable
```
public class ObjectArrayFIFOQueue<K>
extends Object
implements PriorityQueue<K>, Serializable
```
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 and shrunk as needed. You can use the trim() method to reduce its memory usage, if necessary.
This class provides additional methods that implement a deque (double-ended queue).

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`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

Constructors
Constructor and Description
`ObjectArrayFIFOQueue()` Creates a new empty queue with standard initial capacity.
`ObjectArrayFIFOQueue(int capacity)` Creates a new empty queue with given capacity.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()` Removes all elements from this queue.
`Comparator<? super K>`	`comparator()` Returns the comparator associated with this queue, or `null` if it uses its elements' natural ordering.
`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, that is, the element the would be dequeued last (optional operation).
`int`	`size()` Returns the number of elements in this queue.
`void`	`trim()` Trims the queue to the smallest possible size.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.PriorityQueue
changed, isEmpty

- Field Detail
  - INITIAL_CAPACITY
```
public static final int INITIAL_CAPACITY
```
    The standard initial capacity of a queue.
    
    See Also:
    
    Constant Field Values
  - array
```
protected transient K[] array
```
    The backing array.
  - length
```
protected transient int length
```
    The current (cached) length of array.
  - start
```
protected transient int start
```
    The start position in array. It is always strictly smaller than length.
  - end
```
protected transient int end
```
    The end position in array. It is always strictly smaller than length. 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 the comparator associated with this queue, or null if it uses its elements' natural ordering.
    This implementation returns null (FIFO queues have no comparator).
    
    Specified by:
    
    comparator in interface PriorityQueue<K>
    
    Returns:
    
    the comparator associated with this sorted set, or null if it uses its elements' natural ordering.
  - dequeue
```
public K dequeue()
```
    Description copied from interface: PriorityQueue
    
    Dequeues the first element from the queue.
    
    Specified by:
    
    dequeue in interface PriorityQueue<K>
    
    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.
    
    Specified by:
    
    enqueue in interface PriorityQueue<K>
    
    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.
    
    Parameters:
    
    x - the element to enqueue.
  - first
```
public K first()
```
    Description copied from interface: PriorityQueue
    
    Returns the first element of the queue.
    
    Specified by:
    
    first in interface PriorityQueue<K>
    
    Returns:
    
    the first element.
  - last
```
public K last()
```
    Description copied from interface: PriorityQueue
    
    Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).
    This default implementation just throws an UnsupportedOperationException.
    
    Specified by:
    
    last in interface PriorityQueue<K>
    
    Returns:
    
    the last element.
  - clear
```
public void clear()
```
    Description copied from interface: PriorityQueue
    
    Removes all elements from this queue.
    
    Specified by:
    
    clear in interface PriorityQueue<K>
  - 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.
    
    Specified by:
    
    size in interface PriorityQueue<K>
    
    Returns:
    
    the number of elements in this queue.

Class ObjectArrayFIFOQueue<K>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface it.unimi.dsi.fastutil.PriorityQueue

Field Detail

INITIAL_CAPACITY

array

length

start

end

Constructor Detail

ObjectArrayFIFOQueue

ObjectArrayFIFOQueue

Method Detail

comparator

dequeue

dequeueLast

enqueue

enqueueFirst

first

last

clear

trim

size