Message.kt
/*
* Copyright 2022 The Android Open Source Project
*
* 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 androidx.datastore.core
import kotlin.coroutines.CoroutineContext
import kotlinx.coroutines.CompletableDeferred
/** The actions for the actor. */
internal sealed class Message<T> {
abstract val lastState: State<T>?
/**
* Represents a read operation. If the data is already cached, this is a no-op. If data
* has not been cached, it triggers a new read to the specified dataChannel.
*/
class Read<T>(
override val lastState: State<T>?
) : Message<T>()
/** Represents an update operation. */
class Update<T>(
val transform: suspend (t: T) -> T,
/**
* Used to signal (un)successful completion of the update to the caller.
*/
val ack: CompletableDeferred<T>,
override val lastState: State<T>?,
val callerContext: CoroutineContext
) : Message<T>()
}