Package io.reactivex.rxjava3.internal.subscriptions

Enum Class EmptySubscription

java.lang.Object
java.lang.Enum<EmptySubscription>
io.reactivex.rxjava3.internal.subscriptions.EmptySubscription
All Implemented Interfaces:
QueueFuseable<Object>, QueueSubscription<Object>, SimpleQueue<Object>, Serializable, Comparable<EmptySubscription>, Constable, org.reactivestreams.Subscription
public enum EmptySubscription extends Enum<EmptySubscription> implements QueueSubscription<Object>
An empty subscription that does nothing other than validates the request amount.

  • Enum Constant Details

    • INSTANCE

      public static final EmptySubscription INSTANCE
      A singleton, stateless instance.

  • Constructor Details

    • EmptySubscription

      private EmptySubscription()

  • Method Details

    • values

      public static EmptySubscription[] values()
      Returns an array containing the constants of this enum class, in the order they are declared.
      Returns:
      an array containing the constants of this enum class, in the order they are declared

    • valueOf

      public static EmptySubscription valueOf(String name)
      Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (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:
      IllegalArgumentException - if this enum class has no constant with the specified name
      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 String toString()
      Overrides:
      toString in class Enum<EmptySubscription>

    • error

      public static void error(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 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<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<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<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<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(Object value)
      Description copied from interface: SimpleQueue
      Atomically enqueue a single value.
      Specified by:
      offer in interface SimpleQueue<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(Object v1, Object v2)
      Description copied from interface: SimpleQueue
      Atomically enqueue two values.
      Specified by:
      offer in interface SimpleQueue<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)