Behaviors.logMessages implementation

akka-actor-typed-tests/src/test/java/akka/actor/typed/javadsl/ActorLoggingTest.java

@@ -4,6 +4,7 @@
 
 package akka.actor.typed.javadsl;
 
+import akka.actor.typed.ActorRef;
 import akka.actor.typed.Behavior;
 import akka.event.Logging;
 import akka.japi.pf.PFBuilder;
@@ -72,4 +73,22 @@ public void loggingProvidesMDC() {
     testKit.spawn(behavior);
     eventFilter.awaitDone(FiniteDuration.create(3, TimeUnit.SECONDS));
   }
+
+  @Test
+  public void logMessagesBehavior() {
+    Behavior<String> behavior = Behaviors.logMessages(Behaviors.empty());
+
+    CustomEventFilter eventFilter =
+        new CustomEventFilter(
+            new PFBuilder<Logging.LogEvent, Object>()
+                .match(
+                    Logging.LogEvent.class,
+                    (event) -> event.message().equals("received message Hello"))
+                .build(),
+            1);
+
+    ActorRef<String> ref = testKit.spawn(behavior);
+    ref.tell("Hello");
+    eventFilter.awaitDone(FiniteDuration.create(3, TimeUnit.SECONDS));
+  }
 }

akka-actor-typed-tests/src/test/scala/akka/actor/typed/LogMessagesSpec.scala

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2009-2019 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package akka.actor.typed
+
+import akka.actor
+import akka.actor.testkit.typed.scaladsl.ScalaTestWithActorTestKit
+import akka.actor.typed.scaladsl.Behaviors
+import akka.actor.typed.scaladsl.adapter._
+import akka.event.Logging
+import akka.testkit.EventFilter
+import org.scalatest.WordSpecLike
+
+class LogMessagesSpec extends ScalaTestWithActorTestKit("""
+    akka.loglevel = DEBUG # test verifies debug
+    akka.loggers = ["akka.testkit.TestEventListener"]
+    """) with WordSpecLike {
+
+  implicit val untyped: actor.ActorSystem = system.toUntyped
+
+  "The log messages behavior" should {
+    "log signals" in {
+      val behavior: Behavior[Signal] = Behaviors.logMessages(Behaviors.empty)
+
+      val ref: ActorRef[Signal] = spawn(behavior)
+
+      EventFilter.debug("received signal PostStop", source = ref.path.toString, occurrences = 1).intercept {
+        testKit.stop(ref)
+      }
+    }
+
+    "log messages" in {
+      val behavior: Behavior[String] = Behaviors.logMessages(Behaviors.empty)
+
+      val ref: ActorRef[String] = spawn(behavior)
+
+      EventFilter.debug("received message Hello", source = ref.path.toString, occurrences = 1).intercept {
+        ref ! "Hello"
+      }
+    }
+
+    "log messages with provided log level" in {
+      val opts = LogOptions().withLevel(Logging.InfoLevel)
+      val behavior: Behavior[String] = Behaviors.logMessages(opts, Behaviors.empty)
+
+      val ref: ActorRef[String] = spawn(behavior)
+
+      EventFilter.info("received message Hello", source = ref.path.toString, occurrences = 1).intercept {
+        ref ! "Hello"
+      }
+    }
+
+    "log messages with provided logger" in {
+      val logger = system.log
+      val opts = LogOptions().withLogger(logger)
+      val behavior: Behavior[String] = Behaviors.logMessages(opts, Behaviors.empty)
+
+      val ref: ActorRef[String] = spawn(behavior)
+
+      EventFilter.debug("received message Hello", source = "LogMessagesSpec", occurrences = 1).intercept {
+        ref ! "Hello"
+      }
+    }
+
+    "not log messages when not enabled" in {
+      val opts = LogOptions().withEnabled(false)
+      val behavior: Behavior[String] = Behaviors.logMessages(opts, Behaviors.empty)
+
+      val ref: ActorRef[String] = spawn(behavior)
+
+      EventFilter.debug("received message Hello", source = ref.path.toString, occurrences = 0).intercept {
+        ref ! "Hello"
+      }
+    }
+
+    "log messages with decorated MDC values" in {
+      val behavior = Behaviors.withMdc[String](Map("mdc" -> true))(Behaviors.logMessages(Behaviors.empty))
+
+      val ref = spawn(behavior)
+      EventFilter.custom({
+        case logEvent if logEvent.level == Logging.DebugLevel ⇒
+          logEvent.message should ===("received message Hello")
+          logEvent.mdc should ===(Map("mdc" -> true))
+          true
+        case other ⇒ system.log.error(s"Unexpected log event: {}", other); false
+      }, occurrences = 1).intercept {
+        ref ! "Hello"
+      }
+    }
+  }
+}

akka-actor-typed/src/main/scala/akka/actor/typed/Logger.scala

@@ -4,7 +4,10 @@
 
 package akka.actor.typed
 
+import java.util.Optional
+
 import akka.annotation.{ DoNotInherit, InternalApi }
+import akka.event.Logging
 import akka.event.Logging._
 
 /**
@@ -41,6 +44,75 @@ object LogMarker {
 
 }
 
+/**
+ * Logging options when using `Behaviors.logMessages`.
+ */
+@DoNotInherit
+abstract sealed class LogOptions {
+  /**
+   * User control whether messages are logged or not.  This is useful when you want to have an application configuration
+   * to control when to log messages.
+   */
+  def withEnabled(enabled: Boolean): LogOptions
+
+  /**
+   * The [[akka.event.Logging.LogLevel]] to use when logging messages.
+   */
+  def withLevel(level: LogLevel): LogOptions
+
+  /**
+   * A [[akka.actor.typed.Logger]] to use when logging messages.
+   */
+  def withLogger(logger: Logger): LogOptions
+
+  def enabled: Boolean
+  def level: LogLevel
+  def logger: Option[Logger]
+  /** Java API */
+  def getLogger: Optional[Logger]
+}
+
+/**
+ * Factories for log options
+ */
+object LogOptions {
+  /**
+   * INTERNAL API
+   */
+  @InternalApi
+  private[akka] final case class LogOptionsImpl(enabled: Boolean, level: LogLevel, logger: Option[Logger])
+    extends LogOptions {
+    /**
+     * User control whether messages are logged or not.  This is useful when you want to have an application configuration
+     * to control when to log messages.
+     */
+    override def withEnabled(enabled: Boolean): LogOptions = this.copy(enabled = enabled)
+
+    /**
+     * The [[akka.event.Logging.LogLevel]] to use when logging messages.
+     */
+    override def withLevel(level: LogLevel): LogOptions = this.copy(level = level)
+
+    /**
+     * A [[akka.actor.typed.Logger]] to use when logging messages.
+     */
+    override def withLogger(logger: Logger): LogOptions = this.copy(logger = Option(logger))
+
+    /** Java API */
+    override def getLogger: Optional[Logger] = Optional.ofNullable(logger.orNull)
+  }
+
+  /**
+   * Scala API: Create a new log options with defaults.
+   */
+  def apply(): LogOptions = LogOptionsImpl(enabled = true, Logging.DebugLevel, None)
+
+  /**
+   * Java API: Create a new log options.
+   */
+  def create(): LogOptions = apply()
+}
+
 /**
  * Logging API provided inside of actors through the actor context.
  *

akka-actor-typed/src/main/scala/akka/actor/typed/internal/InterceptorImpl.scala

@@ -6,8 +6,9 @@ package akka.actor.typed.internal
 
 import akka.actor.typed
 import akka.actor.typed.Behavior.{ SameBehavior, UnhandledBehavior }
+import akka.actor.typed.LogOptions.LogOptionsImpl
 import akka.actor.typed.internal.TimerSchedulerImpl.TimerMsg
-import akka.actor.typed.{ ActorRef, Behavior, BehaviorInterceptor, ExtensibleBehavior, PreRestart, Signal, TypedActorContext }
+import akka.actor.typed.{ LogOptions, _ }
 import akka.annotation.InternalApi
 import akka.util.LineNumbers
 
@@ -126,6 +127,35 @@ private[akka] final case class MonitorInterceptor[T](actorRef: ActorRef[T]) exte
 
 }
 
+/**
+ * Log all messages for this decorated ReceiveTarget[T] to logger before receiving it ourselves.
+ *
+ * INTERNAL API
+ */
+@InternalApi
+private[akka] final case class LogMessagesInterceptor[T](opts: LogOptions) extends BehaviorInterceptor[T, T] {
+
+  import BehaviorInterceptor._
+
+  override def aroundReceive(ctx: TypedActorContext[T], msg: T, target: ReceiveTarget[T]): Behavior[T] = {
+    if (opts.enabled)
+      opts.logger.getOrElse(ctx.asScala.log).log(opts.level, "received message {}", msg)
+    target(ctx, msg)
+  }
+
+  override def aroundSignal(ctx: TypedActorContext[T], signal: Signal, target: SignalTarget[T]): Behavior[T] = {
+    if (opts.enabled)
+      opts.logger.getOrElse(ctx.asScala.log).log(opts.level, "received signal {}", signal)
+    target(ctx, signal)
+  }
+
+  // only once in the same behavior stack
+  override def isSame(other: BehaviorInterceptor[Any, Any]): Boolean = other match {
+    case LogMessagesInterceptor(`opts`) ⇒ true
+    case _                              ⇒ false
+  }
+}
+
 /**
  * INTERNAL API
  */

akka-actor-typed/src/main/scala/akka/actor/typed/javadsl/Behaviors.scala

@@ -7,9 +7,8 @@ package akka.actor.typed.javadsl
 import java.util.Collections
 import java.util.function.{ Function ⇒ JFunction }
 
-import akka.actor.typed.{ ActorRef, Behavior, BehaviorInterceptor, Signal, SupervisorStrategy }
+import akka.actor.typed._
 import akka.actor.typed.internal.{ BehaviorImpl, Supervisor, TimerSchedulerImpl, WithMdcBehaviorInterceptor }
-import akka.actor.typed.scaladsl
 import akka.annotation.ApiMayChange
 import akka.japi.function.{ Function2 ⇒ JapiFunction2 }
 import akka.japi.pf.PFBuilder
@@ -185,6 +184,22 @@ object Behaviors {
   def monitor[T](monitor: ActorRef[T], behavior: Behavior[T]): Behavior[T] =
     scaladsl.Behaviors.monitor(monitor, behavior)
 
+  /**
+   * Behavior decorator that logs all messages to the [[akka.actor.typed.Behavior]] using the provided
+   * [[akka.actor.typed.LogOptions]] default configuration before invoking the wrapped behavior.
+   * To include an MDC context then first wrap `logMessages` with `withMDC`.
+   */
+  def logMessages[T](behavior: Behavior[T]): Behavior[T] =
+    scaladsl.Behaviors.logMessages(behavior)
+
+  /**
+   * Behavior decorator that logs all messages to the [[akka.actor.typed.Behavior]] using the provided
+   * [[akka.actor.typed.LogOptions]] configuration before invoking the wrapped behavior.
+   * To include an MDC context then first wrap `logMessages` with `withMDC`.
+   */
+  def logMessages[T](logOptions: LogOptions, behavior: Behavior[T]): Behavior[T] =
+    scaladsl.Behaviors.logMessages(logOptions, behavior)
+
   /**
    * Wrap the given behavior such that it is restarted (i.e. reset to its
    * initial state) whenever it throws an exception of the given class or a

akka-actor-typed/src/main/scala/akka/actor/typed/scaladsl/Behaviors.scala

@@ -157,6 +157,22 @@ object Behaviors {
   def monitor[T](monitor: ActorRef[T], behavior: Behavior[T]): Behavior[T] =
     BehaviorImpl.intercept(new MonitorInterceptor[T](monitor))(behavior)
 
+  /**
+   * Behavior decorator that logs all messages to the [[akka.actor.typed.Behavior]] using the provided
+   * [[akka.actor.typed.LogOptions]] default configuration before invoking the wrapped behavior.
+   * To include an MDC context then first wrap `logMessages` with `withMDC`.
+   */
+  def logMessages[T](behavior: Behavior[T]): Behavior[T] =
+    BehaviorImpl.intercept(new LogMessagesInterceptor[T](LogOptions()))(behavior)
+
+  /**
+   * Behavior decorator that logs all messages to the [[akka.actor.typed.Behavior]] using the provided
+   * [[akka.actor.typed.LogOptions]] configuration before invoking the wrapped behavior.
+   * To include an MDC context then first wrap `logMessages` with `withMDC`.
+   */
+  def logMessages[T](logOptions: LogOptions, behavior: Behavior[T]): Behavior[T] =
+    BehaviorImpl.intercept(new LogMessagesInterceptor[T](logOptions))(behavior)
+
   /**
    * Wrap the given behavior with the given [[SupervisorStrategy]] for
    * the given exception.