-
Notifications
You must be signed in to change notification settings - Fork 1.9k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Introduce broadcast coroutine builder;
support `BroadcastChannel.cancel` method to drop the buffer; Introduce ReceiveChannel.broadcast() extension. Fixes #280
- Loading branch information
Showing
10 changed files
with
272 additions
and
20 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
140 changes: 140 additions & 0 deletions
140
...outines-core-common/src/main/kotlin/kotlinx/coroutines/experimental/channels/Broadcast.kt
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,140 @@ | ||
| /* | ||
| * Copyright 2016-2017 JetBrains s.r.o. | ||
| * | ||
| * Licensed under the Apache License, Version 2.0 (the "License"); | ||
| * you may not use this file except in compliance with the License. | ||
| * You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| package kotlinx.coroutines.experimental.channels | ||
|
|
||
| import kotlinx.coroutines.experimental.* | ||
| import kotlinx.coroutines.experimental.channels.Channel.Factory.CONFLATED | ||
| import kotlinx.coroutines.experimental.channels.Channel.Factory.UNLIMITED | ||
| import kotlinx.coroutines.experimental.intrinsics.* | ||
| import kotlin.coroutines.experimental.* | ||
|
|
||
| /** | ||
| * Broadcasts all elements of the channel. | ||
| * | ||
| * @param capacity capacity of the channel's buffer (1 by default). | ||
| * @param start coroutine start option. The default value is [CoroutineStart.LAZY]. | ||
| */ | ||
| fun <E> ReceiveChannel<E>.broadcast( | ||
| capacity: Int = 1, | ||
| start: CoroutineStart = CoroutineStart.LAZY | ||
| ) : BroadcastChannel<E> = | ||
| broadcast(Unconfined, capacity = capacity, start = start, onCompletion = consumes()) { | ||
| for (e in this@broadcast) { | ||
| send(e) | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Launches new coroutine to produce a stream of values by sending them to a broadcast channel | ||
| * and returns a reference to the coroutine as a [BroadcastChannel]. This resulting | ||
| * object can be used to [subscribe][BroadcastChannel.openSubscription] to elements produced by this coroutine. | ||
| * | ||
| * The scope of the coroutine contains [ProducerScope] interface, which implements | ||
| * both [CoroutineScope] and [SendChannel], so that coroutine can invoke | ||
| * [send][SendChannel.send] directly. The channel is [closed][SendChannel.close] | ||
| * when the coroutine completes. | ||
| * | ||
| * The [context] for the new coroutine can be explicitly specified. | ||
| * See [CoroutineDispatcher] for the standard context implementations that are provided by `kotlinx.coroutines`. | ||
| * The [coroutineContext] of the parent coroutine may be used, | ||
| * in which case the [Job] of the resulting coroutine is a child of the job of the parent coroutine. | ||
| * The parent job may be also explicitly specified using [parent] parameter. | ||
| * | ||
| * If the context does not have any dispatcher nor any other [ContinuationInterceptor], then [DefaultDispatcher] is used. | ||
| * | ||
| * Uncaught exceptions in this coroutine close the channel with this exception as a cause and | ||
| * the resulting channel becomes _failed_, so that any attempt to receive from such a channel throws exception. | ||
| * | ||
| * The kind of the resulting channel depends on the specified [capacity] parameter: | ||
| * * when `capacity` positive (1 by default), but less than [UNLIMITED] -- uses [ArrayBroadcastChannel] | ||
| * * when `capacity` is [CONFLATED] -- uses [ConflatedBroadcastChannel] that conflates back-to-back sends; | ||
| * * otherwise -- throws [IllegalArgumentException]. | ||
| * | ||
| * **Note:** By default, the coroutine does not start until the first subscriber appears via [BroadcastChannel.openSubscription] | ||
| * as [start] parameter has a value of [CoroutineStart.LAZY] by default. | ||
| * This ensures that the first subscriber does not miss any sent elements. | ||
| * However, later subscribers may miss elements. | ||
| * | ||
| * See [newCoroutineContext] for a description of debugging facilities that are available for newly created coroutine. | ||
| * | ||
| * @param context context of the coroutine. The default value is [DefaultDispatcher]. | ||
| * @param capacity capacity of the channel's buffer (1 by default). | ||
| * @param start coroutine start option. The default value is [CoroutineStart.LAZY]. | ||
| * @param parent explicitly specifies the parent job, overrides job from the [context] (if any).* | ||
| * @param onCompletion optional completion handler for the producer coroutine (see [Job.invokeOnCompletion]). | ||
| * @param block the coroutine code. | ||
| */ | ||
| public fun <E> broadcast( | ||
| context: CoroutineContext = DefaultDispatcher, | ||
| capacity: Int = 1, | ||
| start: CoroutineStart = CoroutineStart.LAZY, | ||
| parent: Job? = null, | ||
| onCompletion: CompletionHandler? = null, | ||
| block: suspend ProducerScope<E>.() -> Unit | ||
| ): BroadcastChannel<E> { | ||
| val channel = BroadcastChannel<E>(capacity) | ||
| val newContext = newCoroutineContext(context, parent) | ||
| val coroutine = if (start.isLazy) | ||
| LazyBroadcastCoroutine(newContext, channel, block) else | ||
| BroadcastCoroutine(newContext, channel, active = true) | ||
| if (onCompletion != null) coroutine.invokeOnCompletion(handler = onCompletion) | ||
| coroutine.start(start, coroutine, block) | ||
| return coroutine | ||
| } | ||
|
|
||
| private open class BroadcastCoroutine<E>( | ||
| parentContext: CoroutineContext, | ||
| protected val _channel: BroadcastChannel<E>, | ||
| active: Boolean | ||
| ) : AbstractCoroutine<Unit>(parentContext, active), ProducerScope<E>, BroadcastChannel<E> by _channel { | ||
| override val channel: SendChannel<E> | ||
| get() = this | ||
|
|
||
| @Suppress("RETURN_TYPE_MISMATCH_ON_OVERRIDE") | ||
| public override fun openSubscription(): ReceiveChannel<E> = _channel.openSubscription() | ||
|
|
||
| public override fun cancel(cause: Throwable?): Boolean = super.cancel(cause) | ||
|
|
||
| override fun onCancellationInternal(exceptionally: CompletedExceptionally?) { | ||
| val cause = exceptionally?.cause | ||
| val processed = when (exceptionally) { | ||
| is Cancelled -> _channel.cancel(cause) // producer coroutine was cancelled -- cancel channel | ||
| else -> _channel.close(cause) // producer coroutine has completed -- close channel | ||
| } | ||
| if (!processed && cause != null) | ||
| handleCoroutineException(context, cause) | ||
| } | ||
| } | ||
|
|
||
| private class LazyBroadcastCoroutine<E>( | ||
| parentContext: CoroutineContext, | ||
| channel: BroadcastChannel<E>, | ||
| private val block: suspend ProducerScope<E>.() -> Unit | ||
| ) : BroadcastCoroutine<E>(parentContext, channel, active = false) { | ||
| override fun openSubscription(): ReceiveChannel<E> { | ||
| // open subscription _first_ | ||
| val subscription = _channel.openSubscription() | ||
| // then start coroutine | ||
| start() | ||
| return subscription | ||
| } | ||
|
|
||
| override fun onStart() { | ||
| block.startCoroutineCancellable(this, this) | ||
| } | ||
| } | ||
|
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.