Package io.servicetalk.concurrent.internal

Class SubscriberUtils

java.lang.Object

io.servicetalk.concurrent.internal.SubscriberUtils

public final class SubscriberUtils
extends java.lang.Object

A set of utilities for common PublisherSource.Subscriber tasks.

Method Summary

Modifier and Type	Method	Description
static <T> int	calculateSourceRequested(java.util.concurrent.atomic.AtomicLongFieldUpdater<T> requestNUpdater, java.util.concurrent.atomic.AtomicLongFieldUpdater<T> sourceRequestedUpdater, java.util.concurrent.atomic.AtomicLongFieldUpdater<T> emittedUpdater, int limit, T owner)	Attempts to increment sourceRequestedUpdater in order to make it the same as requestNUpdater while not exceeding the limit.
static boolean	checkDuplicateSubscription(PublisherSource.Subscription existing, PublisherSource.Subscription next)	Checks for an already existing PublisherSource.Subscription and if one is given calls Cancellable.cancel() on next and returns false.
static void	deliverCompleteFromSource(CompletableSource.Subscriber subscriber)	Deliver a terminal complete to a CompletableSource.Subscriber that has not yet had CompletableSource.Subscriber.onSubscribe(Cancellable) called.
static <T> void	deliverCompleteFromSource(PublisherSource.Subscriber<T> subscriber)	Deliver a terminal complete to a PublisherSource.Subscriber that has not yet had PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) called.
static void	deliverErrorFromSource(CompletableSource.Subscriber subscriber, java.lang.Throwable cause)	Deliver a terminal error to a CompletableSource.Subscriber that has not yet had CompletableSource.Subscriber.onSubscribe(Cancellable) called.
static <T> void	deliverErrorFromSource(PublisherSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Deliver a terminal error to a PublisherSource.Subscriber that has not yet had PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) called.
static <T> void	deliverErrorFromSource(SingleSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Deliver a terminal error to a SingleSource.Subscriber that has not yet had SingleSource.Subscriber.onSubscribe(Cancellable) called.
static <T> void	deliverSuccessFromSource(SingleSource.Subscriber<T> subscriber, T value)	Invokes SingleSource.Subscriber.onSuccess(Object) ignoring an occurred exception if any.
static void	handleExceptionFromOnSubscribe(CompletableSource.Subscriber subscriber, java.lang.Throwable cause)	Handle the case when a call to CompletableSource.Subscriber.onSubscribe(Cancellable) throws from a source.
static <T> void	handleExceptionFromOnSubscribe(PublisherSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Handle the case when a call to PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) throws from a source.
static <T> void	handleExceptionFromOnSubscribe(SingleSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Handle the case when a call to SingleSource.Subscriber.onSubscribe(Cancellable) throws from a source.
static boolean	isRequestNValid(long n)	Returns false if the requested amount of elements n is not-positive, true otherwise.
static java.lang.IllegalArgumentException	newExceptionForInvalidRequestN(long n)	Create a new exception for an invalid amount of PublisherSource.Subscription.request(long) according to Reactive Streams, Rule 3.9.
static void	safeCancel(Cancellable cancellable)	Invokes Cancellable.cancel() ignoring any exceptions that are thrown.
static void	safeOnComplete(CompletableSource.Subscriber subscriber)	Invokes CompletableSource.Subscriber.onComplete() ignoring an occurred exception if any.
static <T> void	safeOnComplete(PublisherSource.Subscriber<T> subscriber)	Invokes PublisherSource.Subscriber.onComplete() ignoring an occurred exception if any.
static void	safeOnError(CompletableSource.Subscriber subscriber, java.lang.Throwable cause)	Invokes CompletableSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.
static <T> void	safeOnError(PublisherSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Invokes PublisherSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.
static <T> void	safeOnError(SingleSource.Subscriber<T> subscriber, java.lang.Throwable cause)	Invokes SingleSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.
static <T> void	safeOnSuccess(SingleSource.Subscriber<T> subscriber, T value)	Invokes SingleSource.Subscriber.onSuccess(Object) ignoring an occurred exception if any.

Methods inherited from class java.lang.Object

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

Method Detail

checkDuplicateSubscription

public static boolean checkDuplicateSubscription(@Nullable
                                                 PublisherSource.Subscription existing,
                                                 PublisherSource.Subscription next)

Checks for an already existing PublisherSource.Subscription and if one is given calls Cancellable.cancel() on next and returns false.

Parameters:

existing - the existing PublisherSource.Subscription or null if none exists.

next - the next PublisherSource.Subscription to use.

Returns:

true if no PublisherSource.Subscription exists, false otherwise.

isRequestNValid

public static boolean isRequestNValid(long n)

Returns false if the requested amount of elements n is not-positive, true otherwise.

Parameters:

n - the number of elements to request.

Returns:

false if the requested amount of elements n is not-positive, true otherwise.

newExceptionForInvalidRequestN

public static java.lang.IllegalArgumentException newExceptionForInvalidRequestN(long n)

Create a new exception for an invalid amount of PublisherSource.Subscription.request(long) according to Reactive Streams, Rule 3.9.

Parameters:

n - the invalid request count.

Returns:

The exception which clarifies the invalid behavior.

calculateSourceRequested

public static <T> int calculateSourceRequested(java.util.concurrent.atomic.AtomicLongFieldUpdater<T> requestNUpdater,
                                               java.util.concurrent.atomic.AtomicLongFieldUpdater<T> sourceRequestedUpdater,
                                               java.util.concurrent.atomic.AtomicLongFieldUpdater<T> emittedUpdater,
                                               int limit,
                                               T owner)

Attempts to increment sourceRequestedUpdater in order to make it the same as requestNUpdater while not exceeding the limit.

Type Parameters:

T - The type of object which owns the atomic updater parameters.

Parameters:

requestNUpdater - The total number which has been requested (typically from PublisherSource.Subscription.request(long)).

sourceRequestedUpdater - The total number which has actually been passed to PublisherSource.Subscription.request(long). This outstanding count sourceRequestedUpdater() - emittedUpdater.get() should never exceed limit.

emittedUpdater - The amount of data that has been emitted/delivered by the source.

limit - The maximum outstanding demand from the source at any given time.

owner - The object which all atomic updater parameters are associated with.

Returns:

The amount that sourceRequestedUpdater was increased by. This value is typically used to call PublisherSource.Subscription.request(long).

deliverCompleteFromSource

public static <T> void deliverCompleteFromSource(PublisherSource.Subscriber<T> subscriber)

Deliver a terminal complete to a PublisherSource.Subscriber that has not yet had PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) called.

Type Parameters:

T - The type of PublisherSource.Subscriber.

Parameters:

subscriber - The PublisherSource.Subscriber to terminate.

deliverSuccessFromSource

public static <T> void deliverSuccessFromSource(SingleSource.Subscriber<T> subscriber,
                                                @Nullable
                                                T value)

Invokes SingleSource.Subscriber.onSuccess(Object) ignoring an occurred exception if any.

Type Parameters:

T - The type of SingleSource.Subscriber.

Parameters:

subscriber - The SingleSource.Subscriber that may throw an exception from SingleSource.Subscriber.onSuccess(Object).

value - The value to pass to SingleSource.Subscriber.onSuccess(Object).

deliverCompleteFromSource

public static void deliverCompleteFromSource(CompletableSource.Subscriber subscriber)

Deliver a terminal complete to a CompletableSource.Subscriber that has not yet had CompletableSource.Subscriber.onSubscribe(Cancellable) called.

Parameters:

subscriber - The CompletableSource.Subscriber to terminate.

deliverErrorFromSource

public static <T> void deliverErrorFromSource(PublisherSource.Subscriber<T> subscriber,
                                              java.lang.Throwable cause)

Deliver a terminal error to a PublisherSource.Subscriber that has not yet had PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) called.

Type Parameters:

T - The type of PublisherSource.Subscriber.

Parameters:

subscriber - The PublisherSource.Subscriber to terminate.

cause - The terminal event.

deliverErrorFromSource

public static <T> void deliverErrorFromSource(SingleSource.Subscriber<T> subscriber,
                                              java.lang.Throwable cause)

Deliver a terminal error to a SingleSource.Subscriber that has not yet had SingleSource.Subscriber.onSubscribe(Cancellable) called.

Type Parameters:

T - The type of SingleSource.Subscriber.

Parameters:

subscriber - The SingleSource.Subscriber to terminate.

cause - The terminal event.

deliverErrorFromSource

public static void deliverErrorFromSource(CompletableSource.Subscriber subscriber,
                                          java.lang.Throwable cause)

Deliver a terminal error to a CompletableSource.Subscriber that has not yet had CompletableSource.Subscriber.onSubscribe(Cancellable) called.

Parameters:

subscriber - The CompletableSource.Subscriber to terminate.

cause - The terminal event.

handleExceptionFromOnSubscribe

public static <T> void handleExceptionFromOnSubscribe(PublisherSource.Subscriber<T> subscriber,
                                                      java.lang.Throwable cause)

Handle the case when a call to PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription) throws from a source.

Type Parameters:

T - The type of PublisherSource.Subscriber.

Parameters:

subscriber - The PublisherSource.Subscriber that threw an exception from PublisherSource.Subscriber.onSubscribe(PublisherSource.Subscription).

cause - The exception thrown by subscriber.

handleExceptionFromOnSubscribe

public static <T> void handleExceptionFromOnSubscribe(SingleSource.Subscriber<T> subscriber,
                                                      java.lang.Throwable cause)

Handle the case when a call to SingleSource.Subscriber.onSubscribe(Cancellable) throws from a source.

Type Parameters:

T - The type of SingleSource.Subscriber.

Parameters:

subscriber - The SingleSource.Subscriber that threw an exception from SingleSource.Subscriber.onSubscribe(Cancellable).

cause - The exception thrown by subscriber.

handleExceptionFromOnSubscribe

public static void handleExceptionFromOnSubscribe(CompletableSource.Subscriber subscriber,
                                                  java.lang.Throwable cause)

Handle the case when a call to CompletableSource.Subscriber.onSubscribe(Cancellable) throws from a source.

Parameters:

subscriber - The CompletableSource.Subscriber that threw an exception from CompletableSource.Subscriber.onSubscribe(Cancellable).

cause - The exception thrown by subscriber.

safeOnError

public static void safeOnError(CompletableSource.Subscriber subscriber,
                               java.lang.Throwable cause)

Invokes CompletableSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.

Parameters:

subscriber - The CompletableSource.Subscriber that may throw an exception from CompletableSource.Subscriber.onError(Throwable).

cause - The occurred Throwable for CompletableSource.Subscriber.onError(Throwable).

safeOnError

public static <T> void safeOnError(SingleSource.Subscriber<T> subscriber,
                                   java.lang.Throwable cause)

Invokes SingleSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.

Type Parameters:

T - The type of SingleSource.Subscriber.

Parameters:

subscriber - The SingleSource.Subscriber that may throw an exception from SingleSource.Subscriber.onError(Throwable).

cause - The occurred Throwable for SingleSource.Subscriber.onError(Throwable).

safeOnError

public static <T> void safeOnError(PublisherSource.Subscriber<T> subscriber,
                                   java.lang.Throwable cause)

Invokes PublisherSource.Subscriber.onError(Throwable) ignoring an occurred exception if any.

Type Parameters:

T - The type of PublisherSource.Subscriber.

Parameters:

subscriber - The PublisherSource.Subscriber that may throw an exception from PublisherSource.Subscriber.onError(Throwable).

cause - The occurred Throwable for PublisherSource.Subscriber.onError(Throwable).

safeOnComplete

public static <T> void safeOnComplete(PublisherSource.Subscriber<T> subscriber)

Invokes PublisherSource.Subscriber.onComplete() ignoring an occurred exception if any.

Type Parameters:

T - The type of PublisherSource.Subscriber.

Parameters:

subscriber - The PublisherSource.Subscriber that may throw an exception from PublisherSource.Subscriber.onComplete().

safeOnSuccess

public static <T> void safeOnSuccess(SingleSource.Subscriber<T> subscriber,
                                     @Nullable
                                     T value)

Invokes SingleSource.Subscriber.onSuccess(Object) ignoring an occurred exception if any.

Type Parameters:

T - The type of SingleSource.Subscriber.

Parameters:

subscriber - The SingleSource.Subscriber that may throw an exception from SingleSource.Subscriber.onSuccess(Object).

value - The value to pass to SingleSource.Subscriber.onSuccess(Object).

safeOnComplete

public static void safeOnComplete(CompletableSource.Subscriber subscriber)

Invokes CompletableSource.Subscriber.onComplete() ignoring an occurred exception if any.

Parameters:

subscriber - The CompletableSource.Subscriber that may throw an exception from CompletableSource.Subscriber.onComplete().

safeCancel

public static void safeCancel(Cancellable cancellable)

Invokes Cancellable.cancel() ignoring any exceptions that are thrown.

Parameters:

cancellable - The Cancellable to cancel.