Package io.reactivex.rxjava3.internal.subscriptions

Enum EmptySubscription

java.lang.Object

java.lang.Enum<EmptySubscription>

io.reactivex.rxjava3.internal.subscriptions.EmptySubscription

All Implemented Interfaces:

QueueFuseable<java.lang.Object>, QueueSubscription<java.lang.Object>, SimpleQueue<java.lang.Object>, java.io.Serializable, java.lang.Comparable<EmptySubscription>, org.reactivestreams.Subscription

public enum EmptySubscription
extends java.lang.Enum<EmptySubscription>
implements QueueSubscription<java.lang.Object>

An empty subscription that does nothing other than validates the request amount.

Enum Constant Summary

Enum Constants

Enum Constant	Description
INSTANCE	A singleton, stateless instance.

Field Summary

Fields inherited from interface io.reactivex.rxjava3.operators.QueueFuseable

ANY, ASYNC, BOUNDARY, NONE, SYNC

Constructor Summary

Constructors

Modifier	Constructor	Description
private	EmptySubscription()

Method Summary

Modifier and Type	Method	Description
void	cancel()
void	clear()	Removes all enqueued items from this queue.
static void	complete(org.reactivestreams.Subscriber<?> s)	Sets the empty subscription instance on the subscriber and then calls onComplete.
static void	error(java.lang.Throwable e, org.reactivestreams.Subscriber<?> s)	Sets the empty subscription instance on the subscriber and then calls onError with the supplied error.
boolean	isEmpty()	Returns true if the queue is empty.
boolean	offer(java.lang.Object value)	Atomically enqueue a single value.
boolean	offer(java.lang.Object v1, java.lang.Object v2)	Atomically enqueue two values.
@Nullable java.lang.Object	poll()	Tries to dequeue a value (non-null) or returns null if the queue is empty.
void	request(long n)
int	requestFusion(int mode)	Request a fusion mode from the upstream.
java.lang.String	toString()
static EmptySubscription	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static EmptySubscription[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

INSTANCE

public static final EmptySubscription INSTANCE

A singleton, stateless instance.

Constructor Detail

EmptySubscription

private EmptySubscription()

Method Detail

values

public static EmptySubscription[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (EmptySubscription c : EmptySubscription.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static EmptySubscription valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

request

public void request(long n)

Specified by:

request in interface org.reactivestreams.Subscription

cancel

public void cancel()

Specified by:

cancel in interface org.reactivestreams.Subscription

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Enum<EmptySubscription>

error

public static void error(java.lang.Throwable e,
                         org.reactivestreams.Subscriber<?> s)

Sets the empty subscription instance on the subscriber and then calls onError with the supplied error.

Make sure this is only called if the subscriber hasn't received a subscription already (there is no way of telling this).

Parameters:

e - the error to deliver to the subscriber

s - the target subscriber

complete

public static void complete(org.reactivestreams.Subscriber<?> s)

Sets the empty subscription instance on the subscriber and then calls onComplete.

Make sure this is only called if the subscriber hasn't received a subscription already (there is no way of telling this).

Parameters:

s - the target subscriber

poll

@Nullable
public @Nullable java.lang.Object poll()

Description copied from interface: SimpleQueue

Tries to dequeue a value (non-null) or returns null if the queue is empty.

If the producer uses SimpleQueue.offer(Object, Object) and when polling in pairs, if the first poll() returns a non-null item, the second poll() is guaranteed to return a non-null item as well.

Specified by:

poll in interface SimpleQueue<java.lang.Object>

Returns:

the item or null to indicate an empty queue

isEmpty

public boolean isEmpty()

Description copied from interface: SimpleQueue

Returns true if the queue is empty.

Note however that due to potential fused functions in SimpleQueue.poll() it is possible this method returns false but then poll() returns null because the fused function swallowed the available item(s).

Specified by:

isEmpty in interface SimpleQueue<java.lang.Object>

Returns:

true if the queue is empty

clear

public void clear()

Description copied from interface: SimpleQueue

Removes all enqueued items from this queue.

Specified by:

clear in interface SimpleQueue<java.lang.Object>

requestFusion

public int requestFusion(int mode)

Description copied from interface: QueueFuseable

Request a fusion mode from the upstream.

This should be called before onSubscribe returns.

Calling this method multiple times or after onSubscribe finished is not allowed and may result in undefined behavior.

Specified by:

requestFusion in interface QueueFuseable<java.lang.Object>

Parameters:

mode - the requested fusion mode, allowed values are QueueFuseable.SYNC, QueueFuseable.ASYNC, QueueFuseable.ANY combined with QueueFuseable.BOUNDARY (e.g., requestFusion(SYNC | BOUNDARY)).

Returns:

the established fusion mode: QueueFuseable.NONE, QueueFuseable.SYNC, QueueFuseable.ASYNC.

offer

public boolean offer(java.lang.Object value)

Description copied from interface: SimpleQueue

Atomically enqueue a single value.

Specified by:

offer in interface SimpleQueue<java.lang.Object>

Parameters:

value - the value to enqueue, not null

Returns:

true if successful, false if the value was not enqueued likely due to reaching the queue capacity)

offer

public boolean offer(java.lang.Object v1,
                     java.lang.Object v2)

Description copied from interface: SimpleQueue

Atomically enqueue two values.

Specified by:

offer in interface SimpleQueue<java.lang.Object>

Parameters:

v1 - the first value to enqueue, not null

v2 - the second value to enqueue, not null

Returns:

true if successful, false if the value was not enqueued likely due to reaching the queue capacity)