Merge pull request #628 from square/zachklipp/tracing-v2

Rewrite the tracing infrastructure to use a listener-based approach.

Author: zach-klippenstein

kotlin/build.gradle

@@ -149,9 +149,8 @@ subprojects {
     project.tasks.findByName('check')?.dependsOn 'detekt'
 
     project.configurations.configureEach {
-      // No module depends on on Kotlin Reflect directly, but there could be transitive dependencies
-      // in tests with a lower version. This could cause problems with a newer Kotlin version that
-      // we use.
+      // There could be transitive dependencies in tests with a lower version. This could cause
+      // problems with a newer Kotlin version that we use.
       resolutionStrategy.force "org.jetbrains.kotlin:kotlin-reflect:${versions.kotlin}"
     }
   }

kotlin/samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/MainActivity.kt

@@ -17,6 +17,7 @@ package com.squareup.sample.dungeon
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
+import com.squareup.workflow.diagnostic.SimpleLoggingDiagnosticListener
 import com.squareup.workflow.ui.WorkflowRunner
 import com.squareup.workflow.ui.setContentWorkflow
 
@@ -34,7 +35,8 @@ class MainActivity : AppCompatActivity() {
       WorkflowRunner.Config(
           workflow = component.appWorkflow,
           viewRegistry = component.viewRegistry,
-          props = "simple_maze.txt"
+          props = "simple_maze.txt",
+          diagnosticListener = SimpleLoggingDiagnosticListener()
       )
     }
   }

kotlin/samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt

@@ -223,6 +223,8 @@ private class TickerWorker(private val ticksPerSecond: Int) : Worker<Long> {
       delay(periodMs)
     }
   }
+
+  override fun toString(): String = "TickerWorker(ticksPerSecond=$ticksPerSecond)"
 }
 
 private data class MoveResult(

kotlin/samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflowFragment.kt

@@ -15,6 +15,7 @@
  */
 package com.squareup.sample.helloworkflowfragment
 
+import com.squareup.workflow.diagnostic.SimpleLoggingDiagnosticListener
 import com.squareup.workflow.ui.ViewRegistry
 import com.squareup.workflow.ui.WorkflowFragment
 import com.squareup.workflow.ui.WorkflowRunner
@@ -23,6 +24,8 @@ private val viewRegistry = ViewRegistry(HelloFragmentLayoutRunner)
 
 class HelloWorkflowFragment : WorkflowFragment<Unit, Unit>() {
   override fun onCreateWorkflow(): WorkflowRunner.Config<Unit, Unit> {
-    return WorkflowRunner.Config(HelloWorkflow, viewRegistry)
+    return WorkflowRunner.Config(HelloWorkflow, viewRegistry,
+        diagnosticListener = SimpleLoggingDiagnosticListener()
+    )
   }
 }

kotlin/samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflowActivity.kt

@@ -17,6 +17,7 @@ package com.squareup.sample.helloworkflow
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
+import com.squareup.workflow.diagnostic.SimpleLoggingDiagnosticListener
 import com.squareup.workflow.ui.ViewRegistry
 import com.squareup.workflow.ui.WorkflowRunner
 import com.squareup.workflow.ui.setContentWorkflow
@@ -29,7 +30,10 @@ class HelloWorkflowActivity : AppCompatActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     runner = setContentWorkflow(savedInstanceState) {
-      WorkflowRunner.Config(HelloWorkflow, viewRegistry)
+      WorkflowRunner.Config(
+          HelloWorkflow, viewRegistry,
+          diagnosticListener = SimpleLoggingDiagnosticListener()
+      )
     }
   }
 

kotlin/samples/tictactoe/app/src/main/java/com/squareup/sample/mainactivity/MainActivity.kt

@@ -21,10 +21,11 @@ import androidx.test.espresso.IdlingResource
 import com.squareup.sample.authworkflow.AuthViewBindings
 import com.squareup.sample.gameworkflow.TicTacToeViewBindings
 import com.squareup.sample.panel.PanelContainer
+import com.squareup.workflow.VeryExperimentalWorkflow
+import com.squareup.workflow.diagnostic.SimpleLoggingDiagnosticListener
 import com.squareup.workflow.ui.ViewRegistry
 import com.squareup.workflow.ui.WorkflowRunner
 import com.squareup.workflow.ui.setContentWorkflow
-import io.reactivex.disposables.CompositeDisposable
 import io.reactivex.disposables.Disposables
 import timber.log.Timber
 
@@ -36,6 +37,7 @@ class MainActivity : AppCompatActivity() {
 
   lateinit var idlingResource: IdlingResource
 
+  @UseExperimental(VeryExperimentalWorkflow::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
 
@@ -48,15 +50,17 @@ class MainActivity : AppCompatActivity() {
 
     workflowRunner = setContentWorkflow(
         savedInstanceState,
-        { WorkflowRunner.Config(component.mainWorkflow, viewRegistry) }
+        {
+          WorkflowRunner.Config(
+              component.mainWorkflow, viewRegistry,
+              diagnosticListener = SimpleLoggingDiagnosticListener()
+          )
+        }
     ) {
       finish()
     }
 
-    loggingSub = CompositeDisposable(
-        workflowRunner.renderings.subscribe { Timber.d("rendering: %s", it) },
-        workflowRunner.debugInfo.subscribe { Timber.v("debug snapshot: %s", it) }
-    )
+    loggingSub = workflowRunner.renderings.subscribe { Timber.d("rendering: %s", it) }
   }
 
   override fun onSaveInstanceState(outState: Bundle) {

kotlin/samples/todo-android/app/src/main/java/com/squareup/sample/mainactivity/MainActivity.kt

@@ -18,6 +18,7 @@ package com.squareup.sample.mainactivity
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.squareup.sample.todo.TodoListsAppWorkflow
+import com.squareup.workflow.diagnostic.SimpleLoggingDiagnosticListener
 import com.squareup.workflow.ui.ViewRegistry
 import com.squareup.workflow.ui.WorkflowRunner
 import com.squareup.workflow.ui.setContentWorkflow
@@ -36,7 +37,10 @@ class MainActivity : AppCompatActivity() {
         ?: TodoListsAppWorkflow()
 
     workflowRunner = setContentWorkflow(savedInstanceState) {
-      WorkflowRunner.Config(rootWorkflow, viewRegistry)
+      WorkflowRunner.Config(
+          rootWorkflow, viewRegistry,
+          diagnosticListener = SimpleLoggingDiagnosticListener()
+      )
     }
   }
 

kotlin/workflow-core/src/main/java/com/squareup/workflow/Worker.kt

@@ -359,11 +359,14 @@ private class TimerWorker(
 
   override fun doesSameWorkAs(otherWorker: Worker<*>): Boolean =
     otherWorker is TimerWorker && otherWorker.key == key
+
+  override fun toString(): String = "TimerWorker(delayMs=$delayMs)"
 }
 
 private object FinishedWorker : Worker<Nothing> {
   override fun run(): Flow<Nothing> = emptyFlow()
   override fun doesSameWorkAs(otherWorker: Worker<*>): Boolean = otherWorker === FinishedWorker
+  override fun toString(): String = "FinishedWorker"
 }
 
 private class WorkerWrapper<T, R>(
@@ -374,4 +377,6 @@ private class WorkerWrapper<T, R>(
   override fun doesSameWorkAs(otherWorker: Worker<*>): Boolean =
     otherWorker is WorkerWrapper<*, *> &&
         wrapped.doesSameWorkAs(otherWorker.wrapped)
+
+  override fun toString(): String = "WorkerWrapper($wrapped)"
 }

kotlin/workflow-runtime/build.gradle

@@ -31,4 +31,5 @@ dependencies {
   api deps.kotlin.coroutines.core
 
   testImplementation deps.kotlin.test.jdk
+  testImplementation "org.jetbrains.kotlin:kotlin-reflect:${versions.kotlin}"
 }

kotlin/workflow-runtime/src/main/java/com/squareup/workflow/LaunchWorkflow.kt

@@ -15,7 +15,6 @@
  */
 package com.squareup.workflow
 
-import com.squareup.workflow.debugging.WorkflowDebugInfo
 import com.squareup.workflow.internal.RealWorkflowLoop
 import com.squareup.workflow.internal.WorkflowLoop
 import com.squareup.workflow.internal.unwrapCancellationCause
@@ -140,7 +139,12 @@ fun <PropsT, StateT, OutputT : Any, RenderingT, RunnerT> launchWorkflowForTestFr
     beforeStart = beforeStart
 )
 
-@UseExperimental(ExperimentalCoroutinesApi::class, FlowPreview::class)
+@UseExperimental(
+    ExperimentalCoroutinesApi::class,
+    FlowPreview::class,
+    VeryExperimentalWorkflow::class
+)
+@Suppress("LongParameterList")
 internal fun <PropsT, StateT, OutputT : Any, RenderingT, RunnerT> launchWorkflowImpl(
   scope: CoroutineScope,
   workflowLoop: WorkflowLoop,
@@ -152,28 +156,31 @@ internal fun <PropsT, StateT, OutputT : Any, RenderingT, RunnerT> launchWorkflow
 ): RunnerT {
   val renderingsAndSnapshots = ConflatedBroadcastChannel<RenderingAndSnapshot<RenderingT>>()
   val outputs = BroadcastChannel<OutputT>(capacity = 1)
-  val debugSnapshots = ConflatedBroadcastChannel<WorkflowDebugInfo>()
   val workflowScope = scope + Job(parent = scope.coroutineContext[Job])
 
   // Give the caller a chance to start collecting outputs.
-  val session = WorkflowSession(
-      renderingsAndSnapshots.asFlow(),
-      outputs.asFlow(),
-      debugSnapshots.asFlow()
-  )
+  val session = WorkflowSession(renderingsAndSnapshots.asFlow(), outputs.asFlow())
   val result = beforeStart(workflowScope, session)
+  val visitor = session.diagnosticListener
 
   val workflowJob = workflowScope.launch {
-    // Run the workflow processing loop forever, or until it fails or is cancelled.
-    workflowLoop.runWorkflowLoop(
-        workflow,
-        props,
-        initialSnapshot = initialSnapshot,
-        initialState = initialState,
-        onRendering = renderingsAndSnapshots::send,
-        onOutput = outputs::send,
-        onDebugSnapshot = debugSnapshots::send
-    )
+    visitor?.onRuntimeStarted(this)
+    try {
+      // Run the workflow processing loop forever, or until it fails or is cancelled.
+      workflowLoop.runWorkflowLoop(
+          workflow,
+          props,
+          initialSnapshot = initialSnapshot,
+          initialState = initialState,
+          onRendering = renderingsAndSnapshots::send,
+          onOutput = outputs::send,
+          diagnosticListener = visitor
+      )
+    } finally {
+      // Only emit the runtime stopped debug event after all child coroutines have completed.
+      // coroutineScope does an implicit join on all its children.
+      visitor?.onRuntimeStopped()
+    }
   }
 
   // Ensure we close the channels when we're done, so that they propagate errors.
@@ -183,7 +190,6 @@ internal fun <PropsT, StateT, OutputT : Any, RenderingT, RunnerT> launchWorkflow
     val realCause = cause?.unwrapCancellationCause()
     renderingsAndSnapshots.close(realCause)
     outputs.close(realCause)
-    debugSnapshots.close(realCause)
 
     // If the cancellation came from inside the workflow loop, the outer runtime scope needs to be
     // explicitly cancelled. See https://github.com/square/workflow/issues/464.

kotlin/workflow-runtime/src/main/java/com/squareup/workflow/WorkflowSession.kt

@@ -15,18 +15,21 @@
  */
 package com.squareup.workflow
 
-import com.squareup.workflow.debugging.WorkflowDebugInfo
+import com.squareup.workflow.diagnostic.WorkflowDiagnosticListener
 import kotlinx.coroutines.flow.Flow
 
 /**
  * A tuple of [Flow]s representing all the emissions from the workflow runtime.
  *
- * Passed to the function taken by [launchWorkflowIn].
+ * Passed to [launchWorkflowIn]'s `beforeStart` function.
  *
- * @param debugInfo A stream of [diagnostic information][WorkflowDebugInfo] about the runtime.
+ * @param diagnosticListener Null by default. If set to a non-null value before `beforeStart`
+ * returns, that [WorkflowDiagnosticListener] will receive all diagnostic events from the runtime.
+ * Setting this property after `beforeStart` returns will have no effect.
  */
+@UseExperimental(VeryExperimentalWorkflow::class)
 class WorkflowSession<out OutputT : Any, out RenderingT>(
   val renderingsAndSnapshots: Flow<RenderingAndSnapshot<RenderingT>>,
   val outputs: Flow<OutputT>,
-  val debugInfo: Flow<WorkflowDebugInfo>
+  var diagnosticListener: WorkflowDiagnosticListener? = null
 )