Hydrator is traceable. (d6161f27) · Commits · e / os / android_frameworks_base

packages/SystemUI/src/com/android/systemui/lifecycle/Hydrator.kt

+51 −12

Original line number	Diff line number	Diff line
		@@ -19,6 +19,8 @@ package com.android.systemui.lifecycle
		import androidx.compose.runtime.State
		import androidx.compose.runtime.mutableStateOf
		import androidx.compose.runtime.snapshots.StateFactoryMarker
		import com.android.app.tracing.coroutines.launch
		import com.android.app.tracing.coroutines.traceCoroutine
		import kotlinx.coroutines.awaitCancellation
		import kotlinx.coroutines.coroutineScope
		import kotlinx.coroutines.flow.Flow
		@@ -37,35 +39,55 @@ import kotlinx.coroutines.launch
		* }
		* ```
		*/
		class Hydrator : ExclusiveActivatable() {
		class Hydrator(
		/**
		* A name for performance tracing purposes.
		*
		* Please use a short string literal that's easy to find in code search. Try to avoid
		* concatenation or templating.
		*/
		private val traceName: String,
		) : ExclusiveActivatable() {

		private val children = mutableListOf<Activatable>()
		private val children = mutableListOf<NamedActivatable>()

		/**
		* Returns a snapshot [State] that's kept up-to-date as long as the [SysUiViewModel] is active.
		* Returns a snapshot [State] that's kept up-to-date as long as its owner is active.
		*
		* @param traceName Used for coroutine performance tracing purposes. Please try to use a label
		* that's unique enough and easy enough to find in code search; this should help correlate
		* performance findings with actual code. One recommendation: prefer whole string literals
		* instead of some complex concatenation or templating scheme.
		* @param source The upstream [StateFlow] to collect from; values emitted to it will be
		* automatically set on the returned [State].
		*/
		@StateFactoryMarker
		fun <T> hydratedStateOf(
		traceName: String,
		source: StateFlow<T>,
		): State<T> {
		return hydratedStateOf(
		traceName = traceName,
		initialValue = source.value,
		source = source,
		)
		}

		/**
		* Returns a snapshot [State] that's kept up-to-date as long as the [SysUiViewModel] is active.
		* Returns a snapshot [State] that's kept up-to-date as long as its owner is active.
		*
		* @param traceName Used for coroutine performance tracing purposes. Please try to use a label
		* that's unique enough and easy enough to find in code search; this should help correlate
		* performance findings with actual code. One recommendation: prefer whole string literals
		* instead of some complex concatenation or templating scheme. Use `null` to disable
		* performance tracing for this state.
		* @param initialValue The first value to place on the [State]
		* @param source The upstream [Flow] to collect from; values emitted to it will be automatically
		* set on the returned [State].
		*/
		@StateFactoryMarker
		fun <T> hydratedStateOf(
		traceName: String?,
		initialValue: T,
		source: Flow<T>,
		): State<T> {
		@@ -73,18 +95,35 @@ class Hydrator : ExclusiveActivatable() {

		val mutableState = mutableStateOf(initialValue)
		children.add(
		NamedActivatable(
		traceName = traceName,
		activatable =
		object : ExclusiveActivatable() {
		override suspend fun onActivated(): Nothing {
		source.collect { mutableState.value = it }
		awaitCancellation()
		}
		}
		},
		)
		)
		return mutableState
		}

		override suspend fun onActivated() = coroutineScope {
		children.forEach { child -> launch { child.activate() } }
		traceCoroutine(traceName) {
		children.forEach { child ->
		if (child.traceName != null) {
		launch(spanName = child.traceName) { child.activatable.activate() }
		} else {
		launch { child.activatable.activate() }
		}
		}
		awaitCancellation()
		}
		}

		private data class NamedActivatable(
		val traceName: String?,
		val activatable: Activatable,
		)
		}

packages/SystemUI/src/com/android/systemui/scene/ui/viewmodel/SceneContainerViewModel.kt

+2 −2

Original line number	Diff line number	Diff line
		@@ -51,10 +51,10 @@ constructor(
		/** The scene that should be rendered. */
		val currentScene: StateFlow<SceneKey> = sceneInteractor.currentScene

		private val hydrator = Hydrator()
		private val hydrator = Hydrator("SceneContainerViewModel.hydrator")

		/** Whether the container is visible. */
		val isVisible: Boolean by hydrator.hydratedStateOf(sceneInteractor.isVisible)
		val isVisible: Boolean by hydrator.hydratedStateOf("isVisible", sceneInteractor.isVisible)

		override suspend fun onActivated(): Nothing {
		try {

packages/SystemUI/tests/utils/src/com/android/systemui/lifecycle/FakeSysUiViewModel.kt

+11 −3

Original line number	Diff line number	Diff line
		@@ -33,10 +33,18 @@ class FakeSysUiViewModel(
		var activationCount = 0
		var cancellationCount = 0

		private val hydrator = Hydrator()
		private val hydrator = Hydrator("test")
		val stateBackedByFlow: Boolean by
		hydrator.hydratedStateOf(initialValue = true, source = upstreamFlow)
		val stateBackedByStateFlow: Boolean by hydrator.hydratedStateOf(source = upstreamStateFlow)
		hydrator.hydratedStateOf(
		traceName = "test",
		initialValue = true,
		source = upstreamFlow,
		)
		val stateBackedByStateFlow: Boolean by
		hydrator.hydratedStateOf(
		traceName = "test",
		source = upstreamStateFlow,
		)

		override suspend fun onActivated(): Nothing {
		activationCount++