1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* Copyright 2016-2019 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.Publisher
import reactor.core.CoreSubscriber
import reactor.core.publisher.*
import kotlin.coroutines.*
import kotlin.internal.LowPriorityInOverloadResolution
/**
* 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 items with `send`. Unsubscribing cancels running coroutine.
*
* Coroutine context can be specified with [context] argument.
* If the context does not have any dispatcher nor any other [ContinuationInterceptor], then [Dispatchers.Default] is used.
*
* Invocations of `send` are suspended appropriately when subscribers apply back-pressure and to ensure that
* `onNext` is not invoked concurrently.
*
* | **Coroutine action** | **Signal to subscriber**
* | -------------------------------------------- | ------------------------
* | `send` | `onNext`
* | Normal completion or `close` without cause | `onComplete`
* | Failure with exception or `close` with cause | `onError`
*
* 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)
subscriber.onSubscribe(coroutine) // do it first (before starting coroutine), to avoid unnecessary suspensions
coroutine.start(CoroutineStart.DEFAULT, coroutine, block)
}
|
