fix: Fix bug in the publisher confirmations

core/src/main/scala/com/avast/clients/rabbitmq/DefaultRabbitMQClientFactory.scala

@@ -1,7 +1,6 @@
 package com.avast.clients.rabbitmq
 
 import cats.effect._
-import cats.effect.concurrent.{Deferred, Ref}
 import cats.implicits.{catsSyntaxFlatMapOps, toFunctorOps, toTraverseOps}
 import com.avast.bytes.Bytes
 import com.avast.clients.rabbitmq.DefaultRabbitMQClientFactory.startConsumingQueue
@@ -270,41 +269,42 @@ private[rabbitmq] class DefaultRabbitMQClientFactory[F[_]: ConcurrentEffect: Tim
     producerConfig.properties.confirms match {
       case Some(PublisherConfirmsConfig(true, sendAttempts)) =>
         prepareProducer(producerConfig, connection) { (defaultProperties, channel, logger) =>
-          Ref.of(Map.empty[Long, Deferred[F, Either[NotAcknowledgedPublish, Unit]]])
-            .map {
-              new PublishConfirmsRabbitMQProducer[F, A](
-                producerConfig.name,
-                producerConfig.exchange,
-                channel,
-                defaultProperties,
-                _,
-                sendAttempts,
-                producerConfig.reportUnroutable,
-                producerConfig.sizeLimitBytes,
-                blocker,
-                logger,
-                monitor)
-            }
+          F.pure {
+            new PublishConfirmsRabbitMQProducer[F, A](
+              producerConfig.name,
+              producerConfig.exchange,
+              channel,
+              defaultProperties,
+              sendAttempts,
+              producerConfig.reportUnroutable,
+              producerConfig.sizeLimitBytes,
+              blocker,
+              logger,
+              monitor
+            )
+          }
         }
       case _ =>
         prepareProducer(producerConfig, connection) { (defaultProperties, channel, logger) =>
           F.pure {
-            new DefaultRabbitMQProducer[F, A](producerConfig.name,
-                                              producerConfig.exchange,
-                                              channel,
-                                              defaultProperties,
-                                              producerConfig.reportUnroutable,
-                                              producerConfig.sizeLimitBytes,
-                                              blocker,
-                                              logger,
-                                              monitor)
+            new DefaultRabbitMQProducer[F, A](
+              producerConfig.name,
+              producerConfig.exchange,
+              channel,
+              defaultProperties,
+              producerConfig.reportUnroutable,
+              producerConfig.sizeLimitBytes,
+              blocker,
+              logger,
+              monitor
+            )
           }
         }
     }
   }
 
   private def prepareProducer[T: ClassTag, A: ProductConverter](producerConfig: ProducerConfig, connection: RabbitMQConnection[F])(
-    createProducer: (MessageProperties, ServerChannel, ImplicitContextLogger[F]) => F[T]) = {
+      createProducer: (MessageProperties, ServerChannel, ImplicitContextLogger[F]) => F[T]) = {
     val logger: ImplicitContextLogger[F] = ImplicitContextLogger.createLogger[F, T]
 
     connection
@@ -319,7 +319,7 @@ private[rabbitmq] class DefaultRabbitMQClientFactory[F[_]: ConcurrentEffect: Tim
           contentType = producerConfig.properties.contentType,
           contentEncoding = producerConfig.properties.contentEncoding,
           priority = producerConfig.properties.priority.map(Integer.valueOf)
-          )
+        )
         createProducer(defaultProperties, channel, logger)
       }
   }

core/src/main/scala/com/avast/clients/rabbitmq/publisher/BaseRabbitMQProducer.scala

@@ -9,7 +9,7 @@ import com.avast.clients.rabbitmq.JavaConverters._
 import com.avast.clients.rabbitmq.api.CorrelationIdStrategy.FromPropertiesOrRandomNew
 import com.avast.clients.rabbitmq.api._
 import com.avast.clients.rabbitmq.logging.ImplicitContextLogger
-import com.avast.clients.rabbitmq.{CorrelationId, ProductConverter, ServerChannel, startAndForget}
+import com.avast.clients.rabbitmq.{startAndForget, CorrelationId, ProductConverter, ServerChannel}
 import com.avast.metrics.scalaeffectapi.Monitor
 import com.rabbitmq.client.AMQP.BasicProperties
 import com.rabbitmq.client.{AlreadyClosedException, ReturnListener}
@@ -63,17 +63,21 @@ abstract class BaseRabbitMQProducer[F[_], A: ProductConverter](name: String,
     }
   }
 
-  protected def basicSend(routingKey: String, body: Bytes, properties: MessageProperties)(implicit correlationId: CorrelationId): F[Unit] = {
+  protected def basicSend(routingKey: String, body: Bytes, properties: MessageProperties, preSendAction: Long => Unit = (_: Long) => ())(
+      implicit correlationId: CorrelationId): F[Long] = {
     for {
       _ <- logger.debug(s"Sending message with ${body.size()} B to exchange $exchangeName with routing key '$routingKey' and $properties")
-      _ <- blocker.delay {
+      sequenceNumber <- blocker.delay {
         sendLock.synchronized {
           // see https://www.rabbitmq.com/api-guide.html#channel-threads
+          val sequenceNumber = channel.getNextPublishSeqNo
+          preSendAction(sequenceNumber)
           channel.basicPublish(exchangeName, routingKey, properties.asAMQP, body.toByteArray)
+          sequenceNumber
         }
       }
       _ <- sentMeter.mark
-    } yield ()
+    } yield sequenceNumber
   }
 
   private def processErrors(from: F[Unit], routingKey: String)(implicit correlationId: CorrelationId): F[Unit] = {

core/src/main/scala/com/avast/clients/rabbitmq/publisher/DefaultRabbitMQProducer.scala

@@ -1,6 +1,7 @@
 package com.avast.clients.rabbitmq.publisher
 
 import cats.effect.{Blocker, ConcurrentEffect, ContextShift}
+import cats.implicits.toFunctorOps
 import com.avast.bytes.Bytes
 import com.avast.clients.rabbitmq.api.MessageProperties
 import com.avast.clients.rabbitmq.logging.ImplicitContextLogger
@@ -26,5 +27,5 @@ class DefaultRabbitMQProducer[F[_], A: ProductConverter](name: String,
                                        logger,
                                        monitor) {
   override def sendMessage(routingKey: String, body: Bytes, properties: MessageProperties)(implicit correlationId: CorrelationId): F[Unit] =
-    basicSend(routingKey, body, properties)
+    basicSend(routingKey, body, properties).void
 }

core/src/main/scala/com/avast/clients/rabbitmq/publisher/PublishConfirmsRabbitMQProducer.scala

@@ -1,22 +1,22 @@
 package com.avast.clients.rabbitmq.publisher
 
-import cats.effect.concurrent.{Deferred, Ref}
+import cats.effect.concurrent.Deferred
 import cats.effect.{Blocker, ConcurrentEffect, ContextShift}
 import cats.syntax.flatMap._
 import cats.syntax.functor._
 import com.avast.bytes.Bytes
 import com.avast.clients.rabbitmq.api.{MaxAttemptsReached, MessageProperties, NotAcknowledgedPublish}
 import com.avast.clients.rabbitmq.logging.ImplicitContextLogger
-import com.avast.clients.rabbitmq.publisher.PublishConfirmsRabbitMQProducer.SentMessages
-import com.avast.clients.rabbitmq.{CorrelationId, ProductConverter, ServerChannel, startAndForget}
+import com.avast.clients.rabbitmq.{startAndForget, CorrelationId, ProductConverter, ServerChannel}
 import com.avast.metrics.scalaeffectapi.Monitor
 import com.rabbitmq.client.ConfirmListener
 
+import java.util.concurrent.ConcurrentHashMap
+import scala.collection.JavaConverters._
 class PublishConfirmsRabbitMQProducer[F[_], A: ProductConverter](name: String,
                                                                  exchangeName: String,
                                                                  channel: ServerChannel,
                                                                  defaultProperties: MessageProperties,
-                                                                 sentMessages: SentMessages[F],
                                                                  sendAttempts: Int,
                                                                  reportUnroutable: Boolean,
                                                                  sizeLimitBytes: Option[Int],
@@ -39,6 +39,10 @@ class PublishConfirmsRabbitMQProducer[F[_], A: ProductConverter](name: String,
   private val acked = monitor.meter("acked")
   private val nacked = monitor.meter("nacked")
 
+  private[rabbitmq] val confirmationCallbacks = {
+    new ConcurrentHashMap[Long, Deferred[F, Either[NotAcknowledgedPublish, Unit]]]().asScala
+  }
+
   override def sendMessage(routingKey: String, body: Bytes, properties: MessageProperties)(implicit correlationId: CorrelationId): F[Unit] =
     sendWithAck(routingKey, body, properties, 1)
 
@@ -48,34 +52,29 @@ class PublishConfirmsRabbitMQProducer[F[_], A: ProductConverter](name: String,
     if (attemptCount > sendAttempts) {
       F.raiseError(MaxAttemptsReached("Exhausted max number of attempts"))
     } else {
-      val messageId = channel.getNextPublishSeqNo
       for {
-        defer <- Deferred.apply[F, Either[NotAcknowledgedPublish, Unit]]
-        _ <- sentMessages.update(_ + (messageId -> defer))
-        _ <- basicSend(routingKey, body, properties)
-        result <- defer.get
+        confirmationCallback <- Deferred.apply[F, Either[NotAcknowledgedPublish, Unit]]
+        sequenceNumber <- basicSend(routingKey, body, properties, (sequenceNumber: Long) => {
+          confirmationCallbacks += sequenceNumber -> confirmationCallback
+        })
+        result <- confirmationCallback.get
+        _ <- F.delay(confirmationCallbacks -= sequenceNumber)
         _ <- result match {
           case Left(err) =>
             val sendResult = if (sendAttempts > 1) {
-              clearProcessedMessage(messageId) >> sendWithAck(routingKey, body, properties, attemptCount + 1)
+              sendWithAck(routingKey, body, properties, attemptCount + 1)
             } else {
               F.raiseError(err)
             }
-
             nacked.mark >> sendResult
           case Right(_) =>
-            acked.mark >> clearProcessedMessage(messageId)
+            acked.mark
         }
       } yield ()
     }
   }
 
-  private def clearProcessedMessage(messageId: Long): F[Unit] = {
-    sentMessages.update(_ - messageId)
-  }
-
   private object DefaultConfirmListener extends ConfirmListener {
-    import cats.syntax.foldable._
 
     override def handleAck(deliveryTag: Long, multiple: Boolean): Unit = {
       startAndForget {
@@ -92,12 +91,10 @@ class PublishConfirmsRabbitMQProducer[F[_], A: ProductConverter](name: String,
     }
 
     private def completeDefer(deliveryTag: Long, result: Either[NotAcknowledgedPublish, Unit]): F[Unit] = {
-      sentMessages.get.flatMap(_.get(deliveryTag).traverse_(_.complete(result)))
+      confirmationCallbacks.get(deliveryTag) match {
+        case Some(callback) => callback.complete(result)
+        case None => logger.plainWarn("Received confirmation for unknown delivery tag. That is unexpected state.")
+      }
     }
   }
-
-}
-
-object PublishConfirmsRabbitMQProducer {
-  type SentMessages[F[_]] = Ref[F, Map[Long, Deferred[F, Either[NotAcknowledgedPublish, Unit]]]]
 }

core/src/test/scala/com/avast/clients/rabbitmq/PublisherConfirmsRabbitMQProducerTest.scala

@@ -1,33 +1,33 @@
 package com.avast.clients.rabbitmq
 
-import cats.effect.concurrent.{Deferred, Ref}
-import cats.syntax.parallel._
+import cats.implicits.catsSyntaxParallelAp
 import com.avast.bytes.Bytes
 import com.avast.clients.rabbitmq.api.{MessageProperties, NotAcknowledgedPublish}
 import com.avast.clients.rabbitmq.logging.ImplicitContextLogger
 import com.avast.clients.rabbitmq.publisher.PublishConfirmsRabbitMQProducer
-import com.avast.clients.rabbitmq.publisher.PublishConfirmsRabbitMQProducer.SentMessages
 import com.avast.metrics.scalaeffectapi.Monitor
 import com.rabbitmq.client.impl.recovery.AutorecoveringChannel
 import monix.eval.Task
 import monix.execution.Scheduler.Implicits.global
+import org.junit.runner.manipulation.InvalidOrderingException
 import org.mockito.Matchers
 import org.mockito.Matchers.any
 import org.mockito.Mockito.{times, verify, when}
 
+import scala.concurrent.Await
+import scala.concurrent.duration.DurationInt
 import scala.util.Random
 
 class PublisherConfirmsRabbitMQProducerTest extends TestBase {
-  test("message is acked after one retry") {
+
+  test("Message is acked after one retry") {
     val exchangeName = Random.nextString(10)
     val routingKey = Random.nextString(10)
     val seqNumber = 1L
     val seqNumber2 = 2L
 
     val channel = mock[AutorecoveringChannel]
-    val ref = Ref.of[Task, Map[Long, Deferred[Task, Either[NotAcknowledgedPublish, Unit]]]](Map.empty).await
-    val updatedState1 = updateMessageState(ref, seqNumber)(Left(NotAcknowledgedPublish("abcd", messageId = seqNumber)))
-    val updatedState2 = updateMessageState(ref, seqNumber2)(Right())
+    when(channel.getNextPublishSeqNo).thenReturn(seqNumber, seqNumber2)
 
     val producer = new PublishConfirmsRabbitMQProducer[Task, Bytes](
       name = "test",
@@ -39,15 +39,21 @@ class PublisherConfirmsRabbitMQProducerTest extends TestBase {
       sizeLimitBytes = None,
       blocker = TestBase.testBlocker,
       logger = ImplicitContextLogger.createLogger,
-      sentMessages = ref,
       sendAttempts = 2
     )
-    when(channel.getNextPublishSeqNo).thenReturn(seqNumber, seqNumber2)
 
-    producer.send(routingKey, Bytes.copyFrom(Array.fill(499)(32.toByte))).parProduct(updatedState1.parProduct(updatedState2)).await
+    val body = Bytes.copyFrom(Array.fill(499)(32.toByte))
+
+    val publishTask = producer.send(routingKey, body).runToFuture
+
+    updateMessageState(producer, seqNumber)(Left(NotAcknowledgedPublish("abcd", messageId = seqNumber))).parProduct {
+      updateMessageState(producer, seqNumber2)(Right())
+    }.await
+
+    Await.result(publishTask, 10.seconds)
 
     verify(channel, times(2))
-      .basicPublish(Matchers.eq(exchangeName), Matchers.eq(routingKey), any(), Matchers.eq(Bytes.copyFrom(Array.fill(499)(32.toByte)).toByteArray))
+      .basicPublish(Matchers.eq(exchangeName), Matchers.eq(routingKey), any(), Matchers.eq(body.toByteArray))
   }
 
   test("Message not acked returned if number of attempts exhausted") {
@@ -56,8 +62,7 @@ class PublisherConfirmsRabbitMQProducerTest extends TestBase {
     val seqNumber = 1L
 
     val channel = mock[AutorecoveringChannel]
-    val ref = Ref.of[Task, Map[Long, Deferred[Task, Either[NotAcknowledgedPublish, Unit]]]](Map.empty).await
-    val updatedState = updateMessageState(ref, seqNumber)(Left(NotAcknowledgedPublish("abcd", messageId = seqNumber)))
+    when(channel.getNextPublishSeqNo).thenReturn(seqNumber)
 
     val producer = new PublishConfirmsRabbitMQProducer[Task, Bytes](
       name = "test",
@@ -69,22 +74,76 @@ class PublisherConfirmsRabbitMQProducerTest extends TestBase {
       sizeLimitBytes = None,
       blocker = TestBase.testBlocker,
       logger = ImplicitContextLogger.createLogger,
-      sentMessages = ref,
       sendAttempts = 1
     )
-    when(channel.getNextPublishSeqNo).thenReturn(seqNumber)
+
+    val body = Bytes.copyFrom(Array.fill(499)(32.toByte))
+
+    val publishTask = producer.send(routingKey, body).runToFuture
 
     assertThrows[NotAcknowledgedPublish] {
-      producer.send(routingKey, Bytes.copyFrom(Array.fill(499)(32.toByte))).parProduct(updatedState).await
+      updateMessageState(producer, seqNumber)(Left(NotAcknowledgedPublish("abcd", messageId = seqNumber))).await
+      Await.result(publishTask, 10.seconds)
     }
 
-    verify(channel).basicPublish(Matchers.eq(exchangeName), Matchers.eq(routingKey), any(), Matchers.eq(Bytes.copyFrom(Array.fill(499)(32.toByte)).toByteArray))
+    verify(channel).basicPublish(Matchers.eq(exchangeName), Matchers.eq(routingKey), any(), Matchers.eq(body.toByteArray))
+  }
+
+  test("Multiple messages are fully acked") {
+    val exchangeName = Random.nextString(10)
+    val routingKey = Random.nextString(10)
+
+    val channel = mock[AutorecoveringChannel]
+
+    val seqNumbers = 1 to 500
+    val iterator = seqNumbers.iterator
+    when(channel.getNextPublishSeqNo).thenAnswer(_ => { iterator.next() })
+
+    val producer = new PublishConfirmsRabbitMQProducer[Task, Bytes](
+      name = "test",
+      exchangeName = exchangeName,
+      channel = channel,
+      monitor = Monitor.noOp(),
+      defaultProperties = MessageProperties.empty,
+      reportUnroutable = false,
+      sizeLimitBytes = None,
+      blocker = TestBase.testBlocker,
+      logger = ImplicitContextLogger.createLogger,
+      sendAttempts = 2
+    )
+
+    val body = Bytes.copyFrom(Array.fill(499)(32.toByte))
+
+    val publishTasks = Task.parSequenceUnordered {
+      seqNumbers.map { _ =>
+        producer.send(routingKey, body)
+      }
+    }.runToFuture
+
+    Task
+      .parSequenceUnordered(seqNumbers.map { seqNumber =>
+        updateMessageState(producer, seqNumber)(Right())
+      })
+      .await(15.seconds)
+
+    Await.result(publishTasks, 15.seconds)
+
+    verify(channel, times(seqNumbers.length))
+      .basicPublish(Matchers.eq(exchangeName), Matchers.eq(routingKey), any(), Matchers.eq(body.toByteArray))
   }
 
-  private def updateMessageState(ref: SentMessages[Task], messageId: Long)(result: Either[NotAcknowledgedPublish, Unit]): Task[Unit] = {
-    ref.get.flatMap(map => map.get(messageId) match {
-      case Some(value) => value.complete(result)
-      case None => updateMessageState(ref, messageId)(result)
-    })
+  private def updateMessageState(producer: PublishConfirmsRabbitMQProducer[Task, Bytes], messageId: Long, attempt: Int = 1)(
+      result: Either[NotAcknowledgedPublish, Unit]): Task[Unit] = {
+    Task
+      .delay(producer.confirmationCallbacks.get(messageId))
+      .flatMap {
+        case Some(value) => value.complete(result)
+        case None =>
+          if (attempt < 90) {
+            Task.sleep(100.millis) >> updateMessageState(producer, messageId, attempt + 1)(result)
+          } else {
+            throw new InvalidOrderingException(s"The message ID $messageId is not present in the list of callbacks")
+          }
+      }
   }
 }