Class ObservableMap.MapObserver<T,U>

java.lang.Object

io.reactivex.rxjava3.internal.observers.BasicFuseableObserver<T,U>

io.reactivex.rxjava3.internal.operators.observable.ObservableMap.MapObserver<T,U>

All Implemented Interfaces:

Observer<T>, Disposable, QueueDisposable<U>, QueueFuseable<U>, SimpleQueue<U>

Enclosing class:

ObservableMap<T,U>

static final class ObservableMap.MapObserver<T,U>
extends BasicFuseableObserver<T,U>

Field Summary

Fields

Modifier and Type	Field	Description
(package private) final Function<? super T, ? extends U>	mapper

Fields inherited from class BasicFuseableObserver

done, downstream, qd, sourceMode, upstream

Fields inherited from interface QueueFuseable

ANY, ASYNC, BOUNDARY, NONE, SYNC

Constructor Summary

Constructors

Constructor	Description
MapObserver(Observer<? super U> actual, Function<? super T, ? extends U> mapper)

Method Summary

Modifier and Type	Method	Description
void	onNext(T t)	Provides the Observer with a new item to observe.
U	poll()	Tries to dequeue a value (non-null) or returns null if the queue is empty.
int	requestFusion(int mode)	Request a fusion mode from the upstream.

Methods inherited from class BasicFuseableObserver

afterDownstream, beforeDownstream, clear, dispose, fail, isDisposed, isEmpty, offer, offer, onComplete, onError, onSubscribe, transitiveBoundaryFusion

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

mapper

final Function<? super T, ? extends U> mapper

Constructor Details

MapObserver

MapObserver(Observer<? super U> actual,
 Function<? super T, ? extends U> mapper)

Method Details

onNext

public void onNext(T t)

Description copied from interface: Observer

Provides the Observer with a new item to observe.

The Observable may call this method 0 or more times.

The Observable will not call this method again after it calls either Observer.onComplete() or Observer.onError(Throwable).

Parameters:

t - the item emitted by the Observable

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.

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.

poll

@Nullable
public U poll()
       throws Throwable

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.

Returns:

the item or null to indicate an empty queue

Throws:

Throwable - if some pre-processing of the dequeued item (usually through fused functions) throws.