Mailbox Processor in Cloud Agent with automatic dead lettering and at-least-once processing.

CloudAgent-3.fs

let CreateActor (ActorKey name) =
    MailboxProcessor.Start(fun mailbox ->
        let messageStore = GetMessageStore name
        let rec loop data =
            async {
                // Wait asynchronously until we get a message + reply channel
                let! message, replyWith = mailbox.Receive()

                match message with
                | Clear ->
                    messageStore.DeleteIfExists()
                    replyWith Completed // confirm processing!
                    return! loop { Count = 0; Messages = [] }
                | Record message when data.Count < 5 ->
                    let updatedData =
                        { data with
                            Count = data.Count + 1
                            Messages = data.Messages @ [ message ] }
                    messageStore.SetData(updatedData)
                    replyWith Completed // confirm processing!
                    return! (loop updatedData)
                  | Record message ->
                    // bad data - max limit of messages is 5
                    replyWith Abandoned
            }

        let data = defaultArg (messageStore.GetData()) { Count = 0; Messages = [] }
        loop data)

// Change how we start listening to the pool as well - ResilientCloudAgent instead of BasicCloudAgent
let disposable = ConnectionFactory.StartListening(cloudConnection, CreateActor >> ResilientCloudAgent)