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/*
* Copyright 2016-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
*/
@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
package kotlinx.coroutines.reactor
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*
import kotlinx.coroutines.reactive.*
import org.reactivestreams.*
import reactor.core.*
import reactor.core.publisher.*
import reactor.util.context.*
import kotlin.coroutines.*
import kotlin.internal.*
/**
* Creates cold reactive [Flux] that runs a given [block] in a coroutine.
* Every time the returned flux is subscribed, it starts a new coroutine in the specified [context].
* Coroutine emits ([Subscriber.onNext]) values with `send`, completes ([Subscriber.onComplete])
* when the coroutine completes or channel is explicitly closed and emits error ([Subscriber.onError])
* if coroutine throws an exception or closes channel with a cause.
* Unsubscribing cancels running coroutine.
*
* Invocations of `send` are suspended appropriately when subscribers apply back-pressure and to ensure that
* `onNext` is not invoked concurrently.
*
* Method throws [IllegalArgumentException] if provided [context] contains a [Job] instance.
*
* **Note: This is an experimental api.** Behaviour of publishers that work as children in a parent scope with respect
* to cancellation and error handling may change in the future.
*/
@ExperimentalCoroutinesApi
public fun <T> flux(
context: CoroutineContext = EmptyCoroutineContext,
@BuilderInference block: suspend ProducerScope<T>.() -> Unit
): Flux<T> {
require(context[Job] === null) { "Flux context cannot contain job in it." +
"Its lifecycle should be managed via Disposable handle. Had $context" }
return Flux.from(reactorPublish(GlobalScope, context, block))
}
@Deprecated(
message = "CoroutineScope.flux is deprecated in favour of top-level flux",
level = DeprecationLevel.ERROR,
replaceWith = ReplaceWith("flux(context, block)")
) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0. Binary compatibility with Spring
@LowPriorityInOverloadResolution
public fun <T> CoroutineScope.flux(
context: CoroutineContext = EmptyCoroutineContext,
@BuilderInference block: suspend ProducerScope<T>.() -> Unit
): Flux<T> =
Flux.from(reactorPublish(this, context, block))
private fun <T> reactorPublish(
scope: CoroutineScope,
context: CoroutineContext = EmptyCoroutineContext,
@BuilderInference block: suspend ProducerScope<T>.() -> Unit
): Publisher<T> = Publisher { subscriber ->
// specification requires NPE on null subscriber
if (subscriber == null) throw NullPointerException("Subscriber cannot be null")
require(subscriber is CoreSubscriber) { "Subscriber is not an instance of CoreSubscriber, context can not be extracted." }
val currentContext = subscriber.currentContext()
val reactorContext = (context[ReactorContext]?.context?.putAll(currentContext) ?: currentContext).asCoroutineContext()
val newContext = scope.newCoroutineContext(context + reactorContext)
val coroutine = PublisherCoroutine(newContext, subscriber, REACTOR_HANDLER)
subscriber.onSubscribe(coroutine) // do it first (before starting coroutine), to avoid unnecessary suspensions
coroutine.start(CoroutineStart.DEFAULT, coroutine, block)
}
private val REACTOR_HANDLER: (Throwable, CoroutineContext) -> Unit = { e, ctx ->
if (e !is CancellationException) {
try {
Operators.onOperatorError(e, ctx[ReactorContext]?.context ?: Context.empty())
} catch (e: Throwable) {
handleCoroutineException(ctx, e)
}
}
}
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