hook receive can return an IDisposable instead

pchalamet · Feb 12, 2021 · e5a7247 · e5a7247
1 parent 5ea4c03
commit e5a7247
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Showing 6 changed files with 12 additions and 22 deletions.
diff --git a/FBus.GenericHost.Tests/Container.fs b/FBus.GenericHost.Tests/Container.fs
@@ -40,12 +40,10 @@ let startServer<'t> (session: FBus.Testing.Session) name callback =
 
     let checkErrorHook = {
         new IBusHook with
-            member this.OnEnter ctx = null
+            member this.OnBeforeProcessing ctx = null
 
-            member this.OnError ctx msg exn state =
+            member this.OnError ctx msg exn =
                 failwithf "No error shall be raised: %A" exn
-
-            member this.OnLeave ctx state = ()
     }
 
     let svcCollection = ServiceCollection() :> IServiceCollection

diff --git a/FBus.Tests/Control.fs b/FBus.Tests/Control.fs
@@ -134,14 +134,13 @@ let ``Test bus control`` () =
     let mutable onError = 0
 
     let hook = { new FBus.IBusHook with
-                    member _.OnEnter ctx = null
-                    member this.OnError ctx msg exn state =
+                    member _.OnBeforeProcessing ctx = null
+                    member this.OnError ctx msg exn =
                         match msg with
                         | :? StringMessage as s when s.String = fatalString -> match exn with
                                                                                | :? TestBusException -> onError <- onError + 1
                                                                                | _ -> ()
                         | _ -> ()
-                    member _.OnLeave ctx state = ()
     }
 
     let bus = configure() |> withName client

diff --git a/FBus.Tests/Transports.fs b/FBus.Tests/Transports.fs
@@ -45,10 +45,8 @@ type InMemoryHandler2() =
 let startServer<'t> (session: FBus.Testing.Session) name =
     let checkErrorHook = {
         new IBusHook with
-            member _.OnEnter ctx = null
-            member _.OnError ctx msg exn state =
-                failwithf "No error shall be raised: %A" exn
-            member _.OnLeave ctx state = ()
+            member _.OnBeforeProcessing ctx = null
+            member _.OnError ctx msg exn = failwithf "No error shall be raised: %A" exn
     }
 
     let serverBus = FBus.Builder.configure() |> session.Use

diff --git a/FBus/Control.fs b/FBus/Control.fs
@@ -39,7 +39,7 @@ type Bus(busConfig: BusConfiguration) =
                     member _.Publish msg = conversationHeaders() |> publish msg
                     member _.Send client msg = conversationHeaders() |> send client msg }
 
-        let hookState = busConfig.Hook |> Option.map (fun hook -> hook.OnEnter ctx) |> Option.defaultValue null
+        use hookState = busConfig.Hook |> Option.map (fun hook -> hook.OnBeforeProcessing ctx) |> Option.defaultValue null
 
         try
             let handlerInfo = match busConfig.Handlers |> Map.tryFind msgType with
@@ -50,12 +50,10 @@ type Bus(busConfig: BusConfiguration) =
 
             msg <- busConfig.Serializer.Deserialize handlerInfo.MessageType content
             handlerInfo.CallSite.Invoke(handler, [| ctx; msg |]) |> ignore
-
-            busConfig.Hook |> Option.iter (fun hook -> hook.OnLeave ctx hookState)
         with
-            | :? Reflection.TargetInvocationException as tie -> busConfig.Hook |> Option.iter (fun hook -> hook.OnError ctx msg tie.InnerException hookState)
+            | :? Reflection.TargetInvocationException as tie -> busConfig.Hook |> Option.iter (fun hook -> hook.OnError ctx msg tie.InnerException)
                                                                 reraise()
-            | exn -> busConfig.Hook |> Option.iter (fun hook -> hook.OnError ctx msg exn hookState)
+            | exn -> busConfig.Hook |> Option.iter (fun hook -> hook.OnError ctx msg exn)
                      reraise()
 
     let newConversationHeaders () =

diff --git a/FBus/FBus.fs b/FBus/FBus.fs
@@ -46,10 +46,8 @@ type IBusSerializer =
     abstract Deserialize: Type -> ReadOnlyMemory<byte> -> obj
 
 type IBusHook =
-    abstract OnEnter: ctx:IBusConversation -> obj
-    abstract OnError: ctx:IBusConversation -> msg:obj -> exn: Exception -> state: obj -> unit
-    abstract OnLeave: ctx:IBusConversation -> state: obj -> unit
-
+    abstract OnBeforeProcessing: ctx:IBusConversation -> IDisposable
+    abstract OnError: ctx:IBusConversation -> msg:obj -> exn: Exception -> unit
 
 type BusConfiguration =
     { Name: string

diff --git a/README.md b/README.md
@@ -181,8 +181,7 @@ See `FBus.IBusHook`.
 
 FBus.IBusHook | Description | Comments
 --------------|-------------|---------
-`OnEnter` | Invoked before processing a message | Must not throw.
-`OnLeave` | Invoked after processing a message without error | Must not throw.
+`OnBeforeProcessing` | Invoked before processing a message | Must not throw - can return an IDisposable object released once processing is done.
 `OnError` | Invoked on error | Must not throw.
 
 ## Available extensions