support config for jackson buffer recycler pool (#1192)

* support config for jackson buffer recycler pool

* Update JacksonFactorySpec.scala

* Update JacksonFactorySpec.scala

* add blank lines

serialization-jackson/src/main/resources/reference.conf

@@ -35,6 +35,17 @@ pekko.serialization.jackson {
   migrations {
   }
 
+  # Controls the Buffer Recycler Pool implementation used by Jackson.
+  # https://javadoc.io/static/com.fasterxml.jackson.core/jackson-core/2.16.2/com/fasterxml/jackson/core/util/JsonRecyclerPools.html
+  # The default is "thread-local" which is the same as the default in Jackson 2.16.
+  buffer-recycler {
+    # the supported values are "thread-local", "lock-free", "shared-lock-free", "concurrent-deque",
+    # "shared-concurrent-deque", "bounded"
+    pool-instance = "thread-local"
+    # the maximum size of bounded recycler pools - must be >=1 or an IllegalArgumentException will occur
+    # only applies to pool-instance type "bounded"
+    bounded-pool-size = 100
+  }
 }
 
 #//#stream-read-constraints

serialization-jackson/src/main/scala/org/apache/pekko/serialization/jackson/JacksonObjectMapperProvider.scala

@@ -30,6 +30,7 @@ import com.fasterxml.jackson.core.{
   StreamWriteFeature
 }
 import com.fasterxml.jackson.core.json.{ JsonReadFeature, JsonWriteFeature }
+import com.fasterxml.jackson.core.util.{ BufferRecycler, JsonRecyclerPools, RecyclerPool }
 import com.fasterxml.jackson.databind.{
   DeserializationFeature,
   MapperFeature,
@@ -103,10 +104,12 @@ object JacksonObjectMapperProvider extends ExtensionId[JacksonObjectMapperProvid
         // instead of using JsonFactoryBuilder (new in Jackson 2.10.0).
         factory.setStreamReadConstraints(streamReadConstraints)
         factory.setStreamWriteConstraints(streamWriteConstraints)
+        factory.setRecyclerPool(getBufferRecyclerPool(config))
       case None =>
         new JsonFactoryBuilder()
           .streamReadConstraints(streamReadConstraints)
           .streamWriteConstraints(streamWriteConstraints)
+          .recyclerPool(getBufferRecyclerPool(config))
           .build()
     }
 
@@ -153,6 +156,18 @@ object JacksonObjectMapperProvider extends ExtensionId[JacksonObjectMapperProvid
     jsonFactory
   }
 
+  private def getBufferRecyclerPool(cfg: Config): RecyclerPool[BufferRecycler] = {
+    cfg.getString("buffer-recycler.pool-instance") match {
+      case "thread-local"            => JsonRecyclerPools.threadLocalPool()
+      case "lock-free"               => JsonRecyclerPools.newLockFreePool()
+      case "shared-lock-free"        => JsonRecyclerPools.sharedLockFreePool()
+      case "concurrent-deque"        => JsonRecyclerPools.newConcurrentDequePool()
+      case "shared-concurrent-deque" => JsonRecyclerPools.sharedConcurrentDequePool()
+      case "bounded"                 => JsonRecyclerPools.newBoundedPool(cfg.getInt("buffer-recycler.bounded-pool-size"))
+      case other                     => throw new IllegalArgumentException(s"Unknown recycler-pool: $other")
+    }
+  }
+
   @nowarn("msg=deprecated")
   private def configureObjectMapperFeatures(
       bindingName: String,

serialization-jackson/src/test/scala/org/apache/pekko/serialization/jackson/JacksonFactorySpec.scala

@@ -17,6 +17,7 @@
 
 package org.apache.pekko.serialization.jackson
 
+import com.fasterxml.jackson.core.util.JsonRecyclerPools.BoundedPool
 import com.typesafe.config.ConfigFactory
 import org.scalatest.BeforeAndAfterAll
 import org.scalatest.matchers.should.Matchers
@@ -60,6 +61,7 @@ class JacksonFactorySpec extends TestKit(ActorSystem("JacksonFactorySpec"))
       streamReadConstraints.getMaxDocumentLength shouldEqual maxDocLen
       streamReadConstraints.getMaxNestingDepth shouldEqual maxNestingDepth
     }
+
     "support StreamWriteConstraints" in {
       val bindingName = "testJackson"
       val maxNestingDepth = 54321
@@ -72,5 +74,31 @@ class JacksonFactorySpec extends TestKit(ActorSystem("JacksonFactorySpec"))
       val streamWriteConstraints = mapper.getFactory.streamWriteConstraints()
       streamWriteConstraints.getMaxNestingDepth shouldEqual maxNestingDepth
     }
+
+    "support BufferRecycler (default)" in {
+      val bindingName = "testJackson"
+      val jacksonConfig = JacksonObjectMapperProvider.configForBinding(bindingName, defaultConfig)
+      val mapper = JacksonObjectMapperProvider.createObjectMapper(
+        bindingName, None, objectMapperFactory, jacksonConfig, dynamicAccess, None)
+      val recyclerPool = mapper.getFactory._getRecyclerPool()
+      recyclerPool.getClass.getSimpleName shouldEqual "ThreadLocalPool"
+    }
+
+    "support BufferRecycler with config override" in {
+      val bindingName = "testJackson"
+      val poolInstance = "bounded"
+      val boundedPoolSize = 1234
+      val config = ConfigFactory.parseString(
+        s"""pekko.serialization.jackson.buffer-recycler.pool-instance=$poolInstance
+           |pekko.serialization.jackson.buffer-recycler.bounded-pool-size=$boundedPoolSize
+           |""".stripMargin)
+        .withFallback(defaultConfig)
+      val jacksonConfig = JacksonObjectMapperProvider.configForBinding(bindingName, config)
+      val mapper = JacksonObjectMapperProvider.createObjectMapper(
+        bindingName, None, objectMapperFactory, jacksonConfig, dynamicAccess, None)
+      val recyclerPool = mapper.getFactory._getRecyclerPool()
+      recyclerPool.getClass.getSimpleName shouldEqual "BoundedPool"
+      recyclerPool.asInstanceOf[BoundedPool].capacity() shouldEqual boundedPoolSize
+    }
   }
 }