org.apache.flink.runtime.io.network.partition

Class PrioritizedDeque<T>

java.lang.Object

org.apache.flink.runtime.io.network.partition.PrioritizedDeque<T>

Type Parameters:

T - the element type.

All Implemented Interfaces:

Iterable<T>

@Internal
public final class PrioritizedDeque<T>
extends Object
implements Iterable<T>

A deque-like data structure that supports prioritization of elements, such they will be polled before any non-priority elements.

Note that all element tests are performed by identity.

Constructor Summary

Constructors

Constructor and Description
PrioritizedDeque()

Method Summary

Modifier and Type	Method and Description
void	add(T element) Adds a non-priority element to this deque, which will be polled last.
void	add(T element, boolean priority, boolean prioritize) Convenience method for adding an element with optional priority and prior removal.
void	addPriorityElement(T element) Adds a priority element to this deque, such that it will be polled after all existing priority elements but before any non-priority element.
Collection<T>	asUnmodifiableCollection() Returns an unmodifiable collection view.
void	clear() Removes all priority and non-priority elements.
boolean	contains(T element) Returns whether the given element is contained in this list.
boolean	containsPriorityElement(T element) Returns whether the given element is a known priority element.
boolean	equals(Object o)
T	getAndRemove(java.util.function.Predicate<T> preCondition) Find first element matching the Predicate, remove it from the PrioritizedDeque and return it.
int	getNumPriorityElements() Returns the current number of priority elements ([0; size()]).
int	getNumUnprioritizedElements() Returns the number of non-priority elements.
int	hashCode()
boolean	isEmpty() Returns true if there are no elements.
Iterator<T>	iterator()
T	peek() Returns the first priority element or non-priority element if the former does not exist.
T	peekLast() Returns the last non-priority element or priority element if the former does not exist.
T	poll() Polls the first priority element or non-priority element if the former does not exist.
void	prioritize(T element) Prioritizes an already existing element.
int	size() Returns the number of priority and non-priority elements.
java.util.stream.Stream<T>	stream()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

PrioritizedDeque

public PrioritizedDeque()

Method Detail

addPriorityElement

public void addPriorityElement(T element)

Adds a priority element to this deque, such that it will be polled after all existing priority elements but before any non-priority element.

Parameters:

element - the element to add

add

public void add(T element)

Adds a non-priority element to this deque, which will be polled last.

Parameters:

element - the element to add

add

public void add(T element,
                boolean priority,
                boolean prioritize)

Convenience method for adding an element with optional priority and prior removal.

Parameters:

element - the element to add

priority - flag indicating if it's a priority or non-priority element

prioritize - flag that hints that the element is already in this deque, potentially as non-priority element.

prioritize

public void prioritize(T element)

Prioritizes an already existing element. Note that this method assumes identity.

Parameters:

element - the element to prioritize.

asUnmodifiableCollection

public Collection<T> asUnmodifiableCollection()

Returns an unmodifiable collection view.

getAndRemove

public T getAndRemove(java.util.function.Predicate<T> preCondition)

Find first element matching the Predicate, remove it from the PrioritizedDeque and return it.

Returns:

removed element

poll

@Nullable
public T poll()

Polls the first priority element or non-priority element if the former does not exist.

Returns:

the first element or null.

peek

@Nullable
public T peek()

Returns the first priority element or non-priority element if the former does not exist.

Returns:

the first element or null.

getNumPriorityElements

public int getNumPriorityElements()

Returns the current number of priority elements ([0; size()]).

containsPriorityElement

public boolean containsPriorityElement(T element)

Returns whether the given element is a known priority element. Test is performed by identity.

size

public int size()

Returns the number of priority and non-priority elements.

getNumUnprioritizedElements

public int getNumUnprioritizedElements()

Returns the number of non-priority elements.

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>

Returns:

read-only iterator

clear

public void clear()

Removes all priority and non-priority elements.

isEmpty

public boolean isEmpty()

Returns true if there are no elements.

contains

public boolean contains(T element)

Returns whether the given element is contained in this list. Test is performed by identity.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

peekLast

@Nullable
public T peekLast()

Returns the last non-priority element or priority element if the former does not exist.

Returns:

the last element or null.

stream

public java.util.stream.Stream<T> stream()