optionally pass plugin conf path to persistence plugins, #19822

akka-docs/rst/java/lambda-persistence.rst

@@ -870,15 +870,21 @@ A journal plugin can be activated with the following minimal configuration:
 
 .. includecode:: ../scala/code/docs/persistence/PersistencePluginDocSpec.scala#journal-plugin-config
 
-The specified plugin ``class`` must have a no-arg constructor. The ``plugin-dispatcher`` is the dispatcher
-used for the plugin actor. If not specified, it defaults to ``akka.persistence.dispatchers.default-plugin-dispatcher``.
-
 The journal plugin instance is an actor so the methods corresponding to requests from persistent actors
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The journal plugin class must have a constructor without parameters or a constructor with one ``com.typesafe.config.Config``
+The journal plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
+The ``plugin-dispatcher`` is the dispatcher used for the plugin actor. If not specified, it defaults to 
+``akka.persistence.dispatchers.default-plugin-dispatcher``.
 
 Don't run journal tasks/futures on the system default dispatcher, since that might starve other tasks.
 
@@ -893,15 +899,21 @@ A snapshot store plugin can be activated with the following minimal configuratio
 
 .. includecode:: ../scala/code/docs/persistence/PersistencePluginDocSpec.scala#snapshot-store-plugin-config
 
-The specified plugin ``class`` must have a no-arg constructor. The ``plugin-dispatcher`` is the dispatcher
-used for the plugin actor. If not specified, it defaults to ``akka.persistence.dispatchers.default-plugin-dispatcher``.
-
 The snapshot store instance is an actor so the methods corresponding to requests from persistent actors
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The snapshot store plugin class must have a constructor without parameters or constructor with one ``com.typesafe.config.Config``
+The snapshot store plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
+The ``plugin-dispatcher`` is the dispatcher used for the plugin actor. If not specified, it defaults to 
+``akka.persistence.dispatchers.default-plugin-dispatcher``.
 
 Don't run snapshot store tasks/futures on the system default dispatcher, since that might starve other tasks.
 

akka-docs/rst/java/persistence-query.rst

@@ -255,6 +255,16 @@ And the ``EventsByTag`` could be backed by such an Actor for example:
 
 .. includecode:: code/docs/persistence/query/MyEventsByTagJavaPublisher.java#events-by-tag-publisher
 
+The ``ReadJournalProvider`` class must have a constructor with one of these signatures:
+
+* constructor with a ``ExtendedActorSystem`` parameter, a ``com.typesafe.config.Config`` parameter, and a ``String`` parameter for the config path
+* constructor with a ``ExtendedActorSystem`` parameter, and a ``com.typesafe.config.Config`` parameter
+* constructor with one ``ExtendedActorSystem`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
 If the underlying datastore only supports queries that are completed when they reach the
 end of the "result set", the journal has to submit new queries after a while in order
 to support "infinite" event streams that include events stored after the initial query

akka-docs/rst/java/persistence.rst

@@ -874,8 +874,14 @@ The journal plugin instance is an actor so the methods corresponding to requests
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The journal plugin class must have a constructor without parameters or a constructor with one ``com.typesafe.config.Config``
+The journal plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
 
 Don't run journal tasks/futures on the system default dispatcher, since that might starve other tasks.
 
@@ -890,15 +896,21 @@ A snapshot store plugin can be activated with the following minimal configuratio
 
 .. includecode:: ../scala/code/docs/persistence/PersistencePluginDocSpec.scala#snapshot-store-plugin-config
 
-The specified plugin ``class`` must have a no-arg constructor. The ``plugin-dispatcher`` is the dispatcher
-used for the plugin actor. If not specified, it defaults to ``akka.persistence.dispatchers.default-plugin-dispatcher``.
-
 The snapshot store instance is an actor so the methods corresponding to requests from persistent actors
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The snapshot store plugin class must have a constructor without parameters or constructor with one ``com.typesafe.config.Config``
+The snapshot store plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
+The ``plugin-dispatcher`` is the dispatcher used for the plugin actor. If not specified, it defaults to 
+``akka.persistence.dispatchers.default-plugin-dispatcher``.
 
 Don't run snapshot store tasks/futures on the system default dispatcher, since that might starve other tasks.
 

akka-docs/rst/scala/persistence-query.rst

@@ -250,6 +250,16 @@ And the ``eventsByTag`` could be backed by such an Actor for example:
 
 .. includecode:: code/docs/persistence/query/MyEventsByTagPublisher.scala#events-by-tag-publisher
 
+The ``ReadJournalProvider`` class must have a constructor with one of these signatures:
+
+* constructor with a ``ExtendedActorSystem`` parameter, a ``com.typesafe.config.Config`` parameter, and a ``String`` parameter for the config path
+* constructor with a ``ExtendedActorSystem`` parameter, and a ``com.typesafe.config.Config`` parameter
+* constructor with one ``ExtendedActorSystem`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
 If the underlying datastore only supports queries that are completed when they reach the
 end of the "result set", the journal has to submit new queries after a while in order
 to support "infinite" event streams that include events stored after the initial query

akka-docs/rst/scala/persistence.rst

@@ -937,15 +937,21 @@ A journal plugin can be activated with the following minimal configuration:
 
 .. includecode:: code/docs/persistence/PersistencePluginDocSpec.scala#journal-plugin-config
 
-The specified plugin ``class`` must have a no-arg constructor. The ``plugin-dispatcher`` is the dispatcher
-used for the plugin actor. If not specified, it defaults to ``akka.persistence.dispatchers.default-plugin-dispatcher``.
-
 The journal plugin instance is an actor so the methods corresponding to requests from persistent actors
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The journal plugin class must have a constructor without parameters or a constructor with one ``com.typesafe.config.Config``
+The journal plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
+The ``plugin-dispatcher`` is the dispatcher used for the plugin actor. If not specified, it defaults to 
+``akka.persistence.dispatchers.default-plugin-dispatcher``.
 
 Don't run journal tasks/futures on the system default dispatcher, since that might starve other tasks.
 
@@ -960,15 +966,21 @@ A snapshot store plugin can be activated with the following minimal configuratio
 
 .. includecode:: code/docs/persistence/PersistencePluginDocSpec.scala#snapshot-store-plugin-config
 
-The specified plugin ``class`` must have a no-arg constructor. The ``plugin-dispatcher`` is the dispatcher
-used for the plugin actor. If not specified, it defaults to ``akka.persistence.dispatchers.default-plugin-dispatcher``.
-
 The snapshot store instance is an actor so the methods corresponding to requests from persistent actors
 are executed sequentially. It may delegate to asynchronous libraries, spawn futures, or delegate to other
 actors to achive parallelism.
 
-The snapshot store plugin class must have a constructor without parameters or a constructor with one ``com.typesafe.config.Config``
+The snapshot store plugin class must have a constructor with one of these signatures:
-parameter. The plugin section of the actor system's config will be passed in the config constructor parameter.
+
+* constructor with one ``com.typesafe.config.Config`` parameter and a ``String`` parameter for the config path
+* constructor with one ``com.typesafe.config.Config`` parameter
+* constructor without parameters
+
+The plugin section of the actor system's config will be passed in the config constructor parameter. The config path
+of the plugin is passed in the ``String`` parameter.
+
+The ``plugin-dispatcher`` is the dispatcher used for the plugin actor. If not specified, it defaults to 
+``akka.persistence.dispatchers.default-plugin-dispatcher``.
 
 Don't run snapshot store tasks/futures on the system default dispatcher, since that might starve other tasks.
 

akka-persistence-query/src/main/scala/akka/persistence/query/PersistenceQuery.scala

@@ -82,11 +82,18 @@ class PersistenceQuery(system: ExtendedActorSystem) extends Extension {
     def instantiate(args: collection.immutable.Seq[(Class[_], AnyRef)]) =
       system.dynamicAccess.createInstanceFor[ReadJournalProvider](pluginClass, args)
 
-    instantiate((classOf[ExtendedActorSystem], system) :: (classOf[Config], pluginConfig) :: Nil)
+    instantiate((classOf[ExtendedActorSystem], system) :: (classOf[Config], pluginConfig) ::
+      (classOf[String], configPath) :: Nil)
+      .recoverWith {
+        case x: NoSuchMethodException ⇒ instantiate(
+          (classOf[ExtendedActorSystem], system) :: (classOf[Config], pluginConfig) :: Nil)
+      }
       .recoverWith { case x: NoSuchMethodException ⇒ instantiate((classOf[ExtendedActorSystem], system) :: Nil) }
       .recoverWith { case x: NoSuchMethodException ⇒ instantiate(Nil) }
       .recoverWith {
-        case ex: Exception ⇒ Failure.apply(new IllegalArgumentException(s"Unable to create read journal plugin instance for path [$configPath], class [$pluginClassName]!", ex))
+        case ex: Exception ⇒ Failure.apply(
+          new IllegalArgumentException("Unable to create read journal plugin instance for path " +
+            s"[$configPath], class [$pluginClassName]!", ex))
       }.get
   }
 

akka-persistence-query/src/test/scala/akka/persistence/query/DummyReadJournal.scala

@@ -7,6 +7,7 @@ package akka.persistence.query
 import akka.NotUsed
 import akka.stream.scaladsl.Source
 import com.typesafe.config.{ Config, ConfigFactory }
+import akka.actor.ExtendedActorSystem
 
 /**
  * Use for tests only!
@@ -29,10 +30,19 @@ class DummyReadJournalForJava(readJournal: DummyReadJournal) extends javadsl.Rea
 object DummyReadJournalProvider {
   final val config: Config = ConfigFactory.parseString(
     s"""
-      |${DummyReadJournal.Identifier} {
+      ${DummyReadJournal.Identifier} {
-      |  class = "${classOf[DummyReadJournalProvider].getCanonicalName}"
+        class = "${classOf[DummyReadJournalProvider].getCanonicalName}"
-      |}
+      }
-    """.stripMargin)
+      ${DummyReadJournal.Identifier}2 {
+        class = "${classOf[DummyReadJournalProvider2].getCanonicalName}"
+      }
+      ${DummyReadJournal.Identifier}3 {
+        class = "${classOf[DummyReadJournalProvider3].getCanonicalName}"
+      }
+      ${DummyReadJournal.Identifier}4 {
+        class = "${classOf[DummyReadJournalProvider4].getCanonicalName}"
+      }
+    """)
 }
 
 class DummyReadJournalProvider extends ReadJournalProvider {
@@ -43,3 +53,10 @@ class DummyReadJournalProvider extends ReadJournalProvider {
   override val javadslReadJournal: DummyReadJournalForJava =
     new DummyReadJournalForJava(scaladslReadJournal)
 }
+
+class DummyReadJournalProvider2(sys: ExtendedActorSystem) extends DummyReadJournalProvider
+
+class DummyReadJournalProvider3(sys: ExtendedActorSystem, conf: Config) extends DummyReadJournalProvider
+
+class DummyReadJournalProvider4(sys: ExtendedActorSystem, conf: Config, confPath: String) extends DummyReadJournalProvider
+

akka-persistence-query/src/test/scala/akka/persistence/query/PersistenceQuerySpec.scala

@@ -28,6 +28,10 @@ class PersistenceQuerySpec extends WordSpecLike with Matchers with BeforeAndAfte
     "be found by full config key" in {
       withActorSystem() { system ⇒
         PersistenceQuery.get(system).readJournalFor[DummyReadJournal](DummyReadJournal.Identifier)
+        // other combinations of constructor parameters
+        PersistenceQuery.get(system).readJournalFor[DummyReadJournal](DummyReadJournal.Identifier + "2")
+        PersistenceQuery.get(system).readJournalFor[DummyReadJournal](DummyReadJournal.Identifier + "3")
+        PersistenceQuery.get(system).readJournalFor[DummyReadJournal](DummyReadJournal.Identifier + "4")
       }
     }
 

akka-persistence/src/main/scala/akka/persistence/Persistence.scala

@@ -289,9 +289,15 @@ class Persistence(val system: ExtendedActorSystem) extends Extension {
     val pluginClass = system.dynamicAccess.getClassFor[Any](pluginClassName).get
     val pluginDispatcherId = pluginConfig.getString("plugin-dispatcher")
     val pluginActorArgs = try {
-      Reflect.findConstructor(pluginClass, List(pluginConfig)) // will throw if not found
+      Reflect.findConstructor(pluginClass, List(pluginConfig, configPath)) // will throw if not found
-      List(pluginConfig)
+      List(pluginConfig, configPath)
-    } catch { case NonFatal(_) ⇒ Nil } // otherwise use empty constructor
+    } catch {
+      case NonFatal(_) ⇒
+        try {
+          Reflect.findConstructor(pluginClass, List(pluginConfig)) // will throw if not found
+          List(pluginConfig)
+        } catch { case NonFatal(_) ⇒ Nil } // otherwise use empty constructor
+    }
     val pluginActorProps = Props(Deploy(dispatcher = pluginDispatcherId), pluginClass, pluginActorArgs)
     system.systemActorOf(pluginActorProps, pluginActorName)
   }