LongArrayQueue (Agrona)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractQueue<Long>
  - - org.agrona.collections.LongArrayQueue

All Implemented Interfaces:

Iterable<Long>, Collection<Long>, Queue<Long>
```
public class LongArrayQueue
extends AbstractQueue<Long>
```
Queue of longs which stores the elements without boxing. Null is represented by a special nullValue().
The LongArrayQueue.LongIterator is cached by default to avoid allocation unless directed to do so in the constructor.
Note: This class is not threadsafe.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`class`	`LongArrayQueue.LongIterator` Specialised `Iterator` from which the value can be retrieved without boxing via `LongArrayQueue.LongIterator.nextValue()`.

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`DEFAULT_NULL_VALUE` Default representation of null for an element.
`static int`	`MIN_CAPACITY` Minimum capacity for the queue which must also be a power of 2.

Constructor Summary

Constructors
Constructor and Description
`LongArrayQueue()` Construct a new queue defaulting to `MIN_CAPACITY` capacity, `DEFAULT_NULL_VALUE` and cached iterators.
`LongArrayQueue(int initialCapacity, long nullValue)` Construct a new queue default to cached iterators.
`LongArrayQueue(int initialCapacity, long nullValue, boolean shouldAvoidAllocation)` Construct a new queue providing all the config options.
`LongArrayQueue(long nullValue)` Construct a new queue defaulting to `MIN_CAPACITY` capacity and cached iterators.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(Long element)`
`boolean`	`addLong(long element)` Offer an element to the tail of the queue without boxing.
`int`	`capacity()` The current capacity for the collection.
`void`	`clear()`
`Long`	`element()`
`long`	`elementLong()` Peek at the element on the head of the queue without boxing.
`void`	`forEach(Consumer<? super Long> action)`
`void`	`forEachLong(LongConsumer action)` Iterate over the collection without boxing.
`boolean`	`isEmpty()`
`LongArrayQueue.LongIterator`	`iterator()`
`long`	`nullValue()` The value representing a null element.
`boolean`	`offer(Long element)`
`boolean`	`offerLong(long element)` Offer an element to the tail of the queue without boxing.
`Long`	`peek()`
`long`	`peekLong()` Peek at the element on the head of the queue without boxing.
`Long`	`poll()`
`long`	`pollLong()` Poll the element from the head of the queue without boxing.
`Long`	`remove()`
`long`	`removeLong()` Remove the element at the head of the queue without boxing.
`int`	`size()`
`String`	`toString()`

Methods inherited from class java.util.AbstractQueue
addAll

Methods inherited from class java.util.AbstractCollection
contains, containsAll, remove, removeAll, retainAll, toArray, toArray

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

Methods inherited from interface java.util.Collection
contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray

- Field Detail
  - DEFAULT_NULL_VALUE
```
public static final long DEFAULT_NULL_VALUE
```
    Default representation of null for an element.
    
    See Also:
    
    Constant Field Values
  - MIN_CAPACITY
```
public static final int MIN_CAPACITY
```
    Minimum capacity for the queue which must also be a power of 2.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - LongArrayQueue
```
public LongArrayQueue()
```
    Construct a new queue defaulting to MIN_CAPACITY capacity, DEFAULT_NULL_VALUE and cached iterators.
  - LongArrayQueue
```
public LongArrayQueue(long nullValue)
```
    Construct a new queue defaulting to MIN_CAPACITY capacity and cached iterators.
    
    Parameters:
    
    nullValue - cannot be stored in the queue and used as a sentinel.
  - LongArrayQueue
```
public LongArrayQueue(int initialCapacity,
                      long nullValue)
```
    Construct a new queue default to cached iterators.
    
    Parameters:
    
    initialCapacity - for the queue which will be rounded up to the nearest power of 2.
    
    nullValue - which cannot be stored in the queue and used as a sentinel.
  - LongArrayQueue
```
public LongArrayQueue(int initialCapacity,
                      long nullValue,
                      boolean shouldAvoidAllocation)
```
    Construct a new queue providing all the config options.
    
    Parameters:
    
    initialCapacity - for the queue which will be rounded up to the nearest power of 2.
    
    nullValue - which cannot be stored in the queue and used as a sentinel.
    
    shouldAvoidAllocation - true to cache the iterator otherwise false to allocate a new iterator each time.
- Method Detail
  - nullValue
```
public long nullValue()
```
    The value representing a null element.
    
    Returns:
    
    value representing a null element.
  - capacity
```
public int capacity()
```
    The current capacity for the collection.
    
    Returns:
    
    the current capacity for the collection.
  - size
```
public int size()
```
    Specified by:
    
    size in interface Collection<Long>
    
    Specified by:
    
    size in class AbstractCollection<Long>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Collection<Long>
    
    Overrides:
    
    isEmpty in class AbstractCollection<Long>
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Collection<Long>
    
    Overrides:
    
    clear in class AbstractQueue<Long>
  - offer
```
public boolean offer(Long element)
```
  - offerLong
```
public boolean offerLong(long element)
```
    Offer an element to the tail of the queue without boxing.
    
    Parameters:
    
    element - to be offered to the queue.
    
    Returns:
    
    will always be true as long as the underlying array can be expanded.
  - add
```
public boolean add(Long element)
```
    Specified by:
    
    add in interface Collection<Long>
    
    Specified by:
    
    add in interface Queue<Long>
    
    Overrides:
    
    add in class AbstractQueue<Long>
  - addLong
```
public boolean addLong(long element)
```
    Offer an element to the tail of the queue without boxing.
    
    Parameters:
    
    element - to be offered to the queue.
    
    Returns:
    
    will always be true as long as the underlying array can be expanded.
  - peek
```
public Long peek()
```
  - peekLong
```
public long peekLong()
```
    Peek at the element on the head of the queue without boxing.
    
    Returns:
    
    the element at the head of the queue without removing it.
  - poll
```
public Long poll()
```
  - pollLong
```
public long pollLong()
```
    Poll the element from the head of the queue without boxing.
    
    Returns:
    
    the element at the head of the queue removing it. If empty then nullValue.
  - remove
```
public Long remove()
```
    Specified by:
    
    remove in interface Queue<Long>
    
    Overrides:
    
    remove in class AbstractQueue<Long>
  - element
```
public Long element()
```
    Specified by:
    
    element in interface Queue<Long>
    
    Overrides:
    
    element in class AbstractQueue<Long>
  - elementLong
```
public long elementLong()
```
    Peek at the element on the head of the queue without boxing.
    
    Returns:
    
    the element at the head of the queue without removing it.
    
    Throws:
    
    NoSuchElementException - if the queue is empty.
  - removeLong
```
public long removeLong()
```
    Remove the element at the head of the queue without boxing.
    
    Returns:
    
    the element at the head of the queue.
    
    Throws:
    
    NoSuchElementException - if the queue is empty.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class AbstractCollection<Long>
  - forEach
```
public void forEach(Consumer<? super Long> action)
```
  - forEachLong
```
public void forEachLong(LongConsumer action)
```
    Iterate over the collection without boxing.
    
    Parameters:
    
    action - to be taken for each element.
  - iterator
```
public LongArrayQueue.LongIterator iterator()
```
    Specified by:
    
    iterator in interface Iterable<Long>
    
    Specified by:
    
    iterator in interface Collection<Long>
    
    Specified by:
    
    iterator in class AbstractCollection<Long>

Class LongArrayQueue

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractQueue

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Collection

Field Detail

DEFAULT_NULL_VALUE

MIN_CAPACITY

Constructor Detail

LongArrayQueue

LongArrayQueue

LongArrayQueue

LongArrayQueue

Method Detail

nullValue

capacity

size

isEmpty

clear

offer

offerLong

add

addLong

peek

peekLong

poll

pollLong

remove

element

elementLong

removeLong

toString

forEach

forEachLong

iterator