Add support for ContextView in Reactor integration

Author: dkhalanskyjb

reactive/kotlinx-coroutines-reactor/api/kotlinx-coroutines-reactor.api

@@ -33,14 +33,16 @@ public final class kotlinx/coroutines/reactor/MonoKt {
 public final class kotlinx/coroutines/reactor/ReactorContext : kotlin/coroutines/AbstractCoroutineContextElement {
 	public static final field Key Lkotlinx/coroutines/reactor/ReactorContext$Key;
 	public fun <init> (Lreactor/util/context/Context;)V
+	public fun <init> (Lreactor/util/context/ContextView;)V
 	public final fun getContext ()Lreactor/util/context/Context;
 }
 
 public final class kotlinx/coroutines/reactor/ReactorContext$Key : kotlin/coroutines/CoroutineContext$Key {
 }
 
 public final class kotlinx/coroutines/reactor/ReactorContextKt {
-	public static final fun asCoroutineContext (Lreactor/util/context/Context;)Lkotlinx/coroutines/reactor/ReactorContext;
+	public static final synthetic fun asCoroutineContext (Lreactor/util/context/Context;)Lkotlinx/coroutines/reactor/ReactorContext;
+	public static final fun asCoroutineContext (Lreactor/util/context/ContextView;)Lkotlinx/coroutines/reactor/ReactorContext;
 }
 
 public final class kotlinx/coroutines/reactor/ReactorFlowKt {

reactive/kotlinx-coroutines-reactor/src/Flux.kt

@@ -50,7 +50,7 @@ private fun <T> reactorPublish(
         return@onSubscribe
     }
     val currentContext = subscriber.currentContext()
-    val reactorContext = (context[ReactorContext]?.context?.putAll(currentContext) ?: currentContext).asCoroutineContext()
+    val reactorContext = context.extendReactorContext(currentContext)
     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

reactive/kotlinx-coroutines-reactor/src/Mono.kt

@@ -83,7 +83,7 @@ private fun <T> monoInternal(
     context: CoroutineContext,
     block: suspend CoroutineScope.() -> T?
 ): Mono<T> = Mono.create { sink ->
-    val reactorContext = (context[ReactorContext]?.context?.putAll(sink.currentContext()) ?: sink.currentContext()).asCoroutineContext()
+    val reactorContext = context.extendReactorContext(sink.currentContext())
     val newContext = scope.newCoroutineContext(context + reactorContext)
     val coroutine = MonoCoroutine(newContext, sink)
     sink.onDispose(coroutine)

reactive/kotlinx-coroutines-reactor/src/ReactorContext.kt

@@ -5,9 +5,9 @@
 package kotlinx.coroutines.reactor
 
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import reactor.util.context.Context
 import kotlin.coroutines.*
 import kotlinx.coroutines.reactive.*
+import reactor.util.context.*
 
 /**
  * Wraps Reactor's [Context] into a [CoroutineContext] element for seamless integration between
@@ -51,12 +51,29 @@ import kotlinx.coroutines.reactive.*
  */
 @ExperimentalCoroutinesApi
 public class ReactorContext(public val context: Context) : AbstractCoroutineContextElement(ReactorContext) {
+
+    public constructor(contextView: ContextView): this(Context.of(contextView))
+
     public companion object Key : CoroutineContext.Key<ReactorContext>
 }
 
 /**
- * Wraps the given [Context] into [ReactorContext], so it can be added to coroutine's context
+ * Wraps the given [ContextView] into [ReactorContext], so it can be added to the coroutine's context
+ * and later used via `coroutineContext[ReactorContext]`.
+ */
+@ExperimentalCoroutinesApi
+public fun ContextView.asCoroutineContext(): ReactorContext = ReactorContext(this)
+
+/**
+ * Wraps the given [Context] into [ReactorContext], so it can be added to the coroutine's context
  * and later used via `coroutineContext[ReactorContext]`.
  */
 @ExperimentalCoroutinesApi
-public fun Context.asCoroutineContext(): ReactorContext = ReactorContext(this)
+@Deprecated("Use the more general version for ContextView instead", level = DeprecationLevel.HIDDEN)
+public fun Context.asCoroutineContext(): ReactorContext = readOnly().asCoroutineContext()
+
+/**
+ * Updates the Reactor context in this [CoroutineContext], adding (or possibly replacing) some values.
+ */
+internal fun CoroutineContext.extendReactorContext(extensions: ContextView): CoroutineContext =
+    (this[ReactorContext]?.context?.putAll(extensions) ?: extensions).asCoroutineContext()