Generalize over batch type; subscribe_{sync|async} methods; relays begin

CHANGELOG.md

@@ -1,4 +1,19 @@
-## MewssageBus changelog
+## MewssageBus pending changes:
+
+### 0.8.0
+#### new features:
+* Generator Handlers
+* Message Masking
+
+### 0.7.0
+#### new features:
+* Bus scopes (`enter` and `leave` methods) instead clone
+* Bus relays. Connect other message bus by IP address 
+
+#### breaking changes:
+* Batched handlers now require `InBatch` and `OutBatch` types 
+
+## MewssageBus changelog:
 
 ### 0.6.5
 #### new features:

Cargo.toml

@@ -19,6 +19,9 @@ smallvec = "1.6.1"
 log = "0.4.14"
 sharded-slab = "0.1.1"
 thiserror = "1.0.25"
+erased-serde = "0.3.16"
+serde = "1.0.126"
+serde_derive = "1.0.126"
 
 [dev-dependencies]
 anyhow = "1.0.41"

README.md

@@ -11,7 +11,7 @@ Inspired by Actix
 ### Basics
 1. Can deliver messages between actors using receivers (usually a queue implementations)
 2. Messages distincts and delivers by TypeId
-3. Messages delivers in a broadcast fashion to many receivers (Cloned)
+3. Messages delivers ether in a broadcast fashion to many receivers (Cloned) or addressed by recevier id, balanced (depends on queue load) or random
 4. There are different kind of receivers implemented:
   - BufferUnordered Receiver (sync and async)
   - Synchronized (sync and async)
@@ -21,9 +21,8 @@ Inspired by Actix
 
 Here are the list of implmented handler kinds:
 ```rust
-
 pub trait Handler<M: Message>: Send + Sync {
-    type Error: crate::Error;
+    type Error: StdSyncSendError;
     type Response: Message;
 
     fn handle(&self, msg: M, bus: &Bus) -> Result<Self::Response, Self::Error>;
@@ -34,7 +33,7 @@ pub trait Handler<M: Message>: Send + Sync {
 
 #[async_trait]
 pub trait AsyncHandler<M: Message>: Send + Sync {
-    type Error: crate::Error;
+    type Error: StdSyncSendError;
     type Response: Message;
 
     async fn handle(&self, msg: M, bus: &Bus) -> Result<Self::Response, Self::Error>;
@@ -44,7 +43,7 @@ pub trait AsyncHandler<M: Message>: Send + Sync {
 }
 
 pub trait SynchronizedHandler<M: Message>: Send {
-    type Error: crate::Error;
+    type Error: StdSyncSendError;
     type Response: Message;
 
     fn handle(&mut self, msg: M, bus: &Bus) -> Result<Self::Response, Self::Error>;
@@ -55,7 +54,7 @@ pub trait SynchronizedHandler<M: Message>: Send {
 
 #[async_trait]
 pub trait AsyncSynchronizedHandler<M: Message>: Send {
-    type Error: crate::Error;
+    type Error: StdSyncSendError;
     type Response: Message;
 
     async fn handle(&mut self, msg: M, bus: &Bus) -> Result<Self::Response, Self::Error>;
@@ -65,10 +64,12 @@ pub trait AsyncSynchronizedHandler<M: Message>: Send {
 }
 
 pub trait BatchHandler<M: Message>: Send + Sync {
-    type Error: crate::Error;
+    type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    fn handle(&self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    fn handle(&self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     fn sync(&self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -76,20 +77,24 @@ pub trait BatchHandler<M: Message>: Send + Sync {
 
 #[async_trait]
 pub trait AsyncBatchHandler<M: Message>: Send + Sync {
-    type Error: crate::Error;
+    type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    async fn handle(&self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    async fn handle(&self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     async fn sync(&self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
 }
 
 pub trait BatchSynchronizedHandler<M: Message>: Send {
-    type Error: crate::Error;
+    type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -97,10 +102,12 @@ pub trait BatchSynchronizedHandler<M: Message>: Send {
 
 #[async_trait]
 pub trait AsyncBatchSynchronizedHandler<M: Message>: Send {
-    type Error: crate::Error;
+    type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    async fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    async fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     async fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }

examples/demo_async.rs

@@ -1,11 +1,11 @@
 use async_trait::async_trait;
-use messagebus::{AsyncHandler, Bus, Handler, Message, error, receivers};
+use messagebus::{error, AsyncHandler, Bus, Handler, Message};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 enum Error {
     #[error("Error({0})")]
-    Error(anyhow::Error)
+    Error(anyhow::Error),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {
@@ -152,15 +152,15 @@ async fn main() {
 
     let (b, poller) = Bus::build()
         .register(TmpReceiver)
-        .subscribe::<f32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<f32>(8, Default::default())
-        .subscribe::<u16, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<u16>(8, Default::default())
-        .subscribe::<u32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<u32>(8, Default::default())
-        .subscribe::<i32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i32>(8, Default::default())
-        .subscribe::<i16, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i16>(8, Default::default())
         .done()
         .register(TmpReceiver2)
-        .subscribe::<i32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i32>(8, Default::default())
-        .subscribe::<i16, receivers::BufferUnorderedSync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_sync::<i16>(8, Default::default())
         .done()
         .build();
 

examples/demo_backpressure.rs

@@ -1,11 +1,11 @@
 use async_trait::async_trait;
-use messagebus::{receivers, AsyncHandler, Message, error, Bus};
+use messagebus::{error, receivers, AsyncHandler, Bus, Message};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 enum Error {
     #[error("Error({0})")]
-    Error(anyhow::Error)
+    Error(anyhow::Error),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {
@@ -35,13 +35,7 @@ impl AsyncHandler<f32> for TmpReceiver {
 async fn main() {
     let (b, poller) = Bus::build()
         .register(TmpReceiver)
-        .subscribe::<f32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(
+            .subscribe_async::<f32>(1, receivers::BufferUnorderedConfig { buffer_size: 1, max_parallel: 1 })
-            1,
-            receivers::BufferUnorderedConfig {
-                buffer_size: 1,
-                max_parallel: 1,
-            },
-        )
         .done()
         .build();
 

examples/demo_batch.rs

@@ -1,13 +1,13 @@
 use std::sync::Arc;
 
 use async_trait::async_trait;
-use messagebus::{receivers, AsyncBatchHandler, BatchHandler, Message, error, Bus};
+use messagebus::{error, AsyncBatchHandler, BatchHandler, Bus, Message};
 use thiserror::Error;
 
 #[derive(Debug, Error, Clone)]
 enum Error {
     #[error("Error({0})")]
-    Error(Arc<anyhow::Error>)
+    Error(Arc<anyhow::Error>),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {
@@ -21,6 +21,8 @@ struct TmpReceiver;
 impl AsyncBatchHandler<i32> for TmpReceiver {
     type Error = Error;
     type Response = ();
+    type InBatch = Vec<i32>;
+    type OutBatch = Vec<()>;
 
     async fn handle(&self, msg: Vec<i32>, _bus: &Bus) -> Result<Vec<Self::Response>, Self::Error> {
         println!("---> [i32; {}] {:?}", msg.len(), msg);
@@ -32,6 +34,8 @@ impl AsyncBatchHandler<i32> for TmpReceiver {
 impl BatchHandler<i16> for TmpReceiver {
     type Error = Error;
     type Response = ();
+    type InBatch = Vec<i16>;
+    type OutBatch = Vec<()>;
 
     fn handle(&self, msg: Vec<i16>, _bus: &Bus) -> Result<Vec<Self::Response>, Self::Error> {
         println!("---> [i16; {}] {:?}", msg.len(), msg);
@@ -43,8 +47,8 @@ impl BatchHandler<i16> for TmpReceiver {
 async fn main() {
     let (b, poller) = Bus::build()
         .register(TmpReceiver)
-        .subscribe::<i32, receivers::BufferUnorderedBatchedAsync<_, _, _>, _, _>(16, Default::default())
+            .subscribe_batch_async::<i32>(16, Default::default())
-        .subscribe::<i16, receivers::BufferUnorderedBatchedSync<_, _, _>, _, _>(16, Default::default())
+            .subscribe_batch_sync::<i16>(16, Default::default())
         .done()
         .build();
 

examples/demo_relay.rs

@@ -0,0 +1,51 @@
+use messagebus::{error, Bus, Handler, Message, Module};
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+enum Error {
+    #[error("Error({0})")]
+    Error(anyhow::Error),
+}
+
+impl<M: Message> From<error::Error<M>> for Error {
+    fn from(err: error::Error<M>) -> Self {
+        Self::Error(err.into())
+    }
+}
+
+struct TmpReceiver;
+
+impl Handler<u32> for TmpReceiver {
+    type Error = Error;
+    type Response = ();
+
+    fn handle(&self, msg: u32, _bus: &Bus) -> Result<Self::Response, Self::Error> {
+        println!("---> u32 {}", msg);
+        Ok(())
+    }
+}
+
+fn module() -> Module {
+    Module::new()
+        .register(TmpReceiver)
+            .subscribe_sync::<u32>(8, Default::default())
+        .done()
+}
+
+#[tokio::main]
+async fn main() {
+    let (b, poller) = Bus::build().add_module(module()).build();
+
+    // b.
+
+    println!("flush");
+    b.flush().await;
+
+    println!("close");
+    b.close().await;
+
+    println!("closed");
+
+    poller.await;
+    println!("[done]");
+}

examples/demo_req_resp.rs

@@ -1,13 +1,16 @@
 use core::f32;
 
 use async_trait::async_trait;
-use messagebus::{AsyncHandler, Bus, Message, error::{self, StdSyncSendError}, receivers};
+use messagebus::{
+    error::{self, StdSyncSendError},
+    AsyncHandler, Bus, Message,
+};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 enum Error {
     #[error("Error({0})")]
-    Error(anyhow::Error)
+    Error(anyhow::Error),
 }
 
 impl<M: Message, E: StdSyncSendError> From<error::Error<M, E>> for Error {
@@ -16,7 +19,6 @@ impl<M: Message, E: StdSyncSendError> From<error::Error<M, E>> for Error {
     }
 }
 
-
 struct TmpReceiver1;
 struct TmpReceiver2;
 
@@ -159,22 +161,23 @@ impl AsyncHandler<f32> for TmpReceiver2 {
 async fn main() {
     let (b, poller) = Bus::build()
         .register(TmpReceiver1)
-        .subscribe::<i32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i32>(8, Default::default())
-        .subscribe::<u32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<u32>(8, Default::default())
-        .subscribe::<i16, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i16>(8, Default::default())
-        .subscribe::<u16, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<u16>(8, Default::default())
-        .subscribe::<i8, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<i8>(8, Default::default())
-        .subscribe::<u8, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<u8>(8, Default::default())
         .done()
         .register(TmpReceiver2)
-        .subscribe::<f32, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<f32>(8, Default::default())
-        .subscribe::<f64, receivers::BufferUnorderedAsync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_async::<f64>(8, Default::default())
         .done()
         .build();
 
     println!(
         "{:?}",
-        b.request_we::<_, f64, Error>(1000f64, Default::default()).await
+        b.request_local_we::<_, f64, Error>(1000f64, Default::default())
+            .await
     );
 
     println!("flush");

examples/demo_slow.rs

@@ -1,10 +1,10 @@
-use messagebus::{Bus, Handler, Message, Module, error, receivers};
+use messagebus::{error, Bus, Handler, Message, Module};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 enum Error {
     #[error("Error({0})")]
-    Error(anyhow::Error)
+    Error(anyhow::Error),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {
@@ -53,17 +53,15 @@ impl Handler<u32> for TmpReceiver {
 fn module() -> Module {
     Module::new()
         .register(TmpReceiver)
-        .subscribe::<f32, receivers::BufferUnorderedSync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_sync::<f32>(8, Default::default())
-        .subscribe::<u16, receivers::BufferUnorderedSync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_sync::<u16>(8, Default::default())
-        .subscribe::<u32, receivers::BufferUnorderedSync<_, _, _>, _, _>(8, Default::default())
+            .subscribe_sync::<u32>(8, Default::default())
         .done()
 }
 
 #[tokio::main]
 async fn main() {
-    let (b, poller) = Bus::build()
+    let (b, poller) = Bus::build().add_module(module()).build();
-        .add_module(module())
-        .build();
 
     b.send(32f32).await.unwrap();
     b.send(11u16).await.unwrap();

examples/demo_sync_batch.rs

@@ -1,13 +1,15 @@
 use std::sync::Arc;
 
 use async_trait::async_trait;
-use messagebus::{receivers, AsyncBatchSynchronizedHandler, BatchSynchronizedHandler, Message, error, Bus};
+use messagebus::{
+    error, AsyncBatchSynchronizedHandler, BatchSynchronizedHandler, Bus, Message,
+};
 use thiserror::Error;
 
 #[derive(Debug, Error, Clone)]
 enum Error {
     #[error("Error({0})")]
-    Error(Arc<anyhow::Error>)
+    Error(Arc<anyhow::Error>),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {
@@ -22,8 +24,15 @@ struct TmpReceiver;
 impl AsyncBatchSynchronizedHandler<i32> for TmpReceiver {
     type Error = Error;
     type Response = ();
+    type InBatch = Vec<i32>;
+    type OutBatch = Vec<()>;
 
-    async fn handle(&mut self, msg: Vec<i32>, _bus: &Bus) -> Result<Vec<Self::Response>, Self::Error> {
+
+    async fn handle(
+        &mut self,
+        msg: Vec<i32>,
+        _bus: &Bus,
+    ) -> Result<Vec<Self::Response>, Self::Error> {
         println!("---> [i32; {}] {:?}", msg.len(), msg);
 
         Ok(vec![])
@@ -33,6 +42,8 @@ impl AsyncBatchSynchronizedHandler<i32> for TmpReceiver {
 impl BatchSynchronizedHandler<i16> for TmpReceiver {
     type Error = Error;
     type Response = ();
+    type InBatch = Vec<i16>;
+    type OutBatch = Vec<()>;
 
     fn handle(&mut self, msg: Vec<i16>, _bus: &Bus) -> Result<Vec<Self::Response>, Self::Error> {
         println!("---> [i16; {}] {:?}", msg.len(), msg);
@@ -44,8 +55,8 @@ impl BatchSynchronizedHandler<i16> for TmpReceiver {
 async fn main() {
     let (b, poller) = Bus::build()
         .register_unsync(TmpReceiver)
-        .subscribe::<i32, receivers::SynchronizedBatchedAsync<_, _, _>, _, _>(16, Default::default())
+            .subscribe_batch_async::<i32>(16, Default::default())
-        .subscribe::<i16, receivers::SynchronizedBatchedSync<_, _, _>, _, _>(16, Default::default())
+            .subscribe_batch_sync::<i16>(16, Default::default())
         .done()
         .build();
 

examples/non_sync.rs

@@ -1,11 +1,11 @@
 use async_trait::async_trait;
-use messagebus::{receivers, AsyncSynchronizedHandler, Bus, Message, error, SynchronizedHandler};
+use messagebus::{error, receivers, AsyncSynchronizedHandler, Bus, Message, SynchronizedHandler};
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 enum Error {
     #[error("Error({0})")]
-    Error(anyhow::Error)
+    Error(anyhow::Error),
 }
 
 impl<M: Message> From<error::Error<M>> for Error {

src/builder.rs

@@ -3,7 +3,7 @@ use std::{any::TypeId, collections::HashMap, marker::PhantomData, pin::Pin, sync
 use futures::{Future, FutureExt};
 use tokio::sync::Mutex;
 
-use crate::{Bus, BusInner, Message, Untyped, error::StdSyncSendError, receiver::{Receiver, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver}};
+use crate::{AsyncBatchHandler, AsyncBatchSynchronizedHandler, AsyncHandler, AsyncSynchronizedHandler, BatchHandler, BatchSynchronizedHandler, Bus, BusInner, Handler, Message, SynchronizedHandler, Untyped, error::StdSyncSendError, receiver::{Receiver, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver}, receivers};
 
 pub trait ReceiverSubscriberBuilder<T, M, R, E>:
     SendUntypedReceiver + SendTypedReceiver<M> + ReciveTypedReceiver<R, E>
@@ -52,7 +52,13 @@ pub struct RegisterEntry<K, T, F, B> {
 }
 
 impl<K, T: 'static, F, B> RegisterEntry<K, T, F, B>
-    where F: FnMut(&mut B, (TypeId, Receiver), Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>),
+where
+    F: FnMut(
+        &mut B,
+        (TypeId, Receiver),
+        Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+        Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+    ),
 {
     pub fn done(mut self) -> B {
         for (tid, v) in self.receivers {
@@ -87,6 +93,42 @@ impl<T, F, B> RegisterEntry<UnsyncEntry, T, F, B> {
 
         self
     }
+
+    #[inline]
+    pub fn subscribe_sync<M>(self, queue: u64, cfg: receivers::SynchronizedConfig) -> Self
+    where
+        T: SynchronizedHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::SynchronizedSync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+
+    #[inline]
+    pub fn subscribe_async<M>(self, queue: u64, cfg: receivers::SynchronizedConfig) -> Self
+    where
+        T: AsyncSynchronizedHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::SynchronizedAsync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+
+    #[inline]
+    pub fn subscribe_batch_sync<M>(self, queue: u64, cfg: receivers::SynchronizedBatchedConfig) -> Self
+    where
+        T: BatchSynchronizedHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::SynchronizedBatchedSync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+
+    #[inline]
+    pub fn subscribe_batch_async<M>(self, queue: u64, cfg: receivers::SynchronizedBatchedConfig) -> Self
+    where
+        T: AsyncBatchSynchronizedHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::SynchronizedBatchedAsync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
 }
 
 impl<T, F, B> RegisterEntry<SyncEntry, T, F, B> {
@@ -109,8 +151,45 @@ impl<T, F, B> RegisterEntry<SyncEntry, T, F, B> {
 
         self
     }
+
+    #[inline]
+    pub fn subscribe_sync<M>(self, queue: u64, cfg: receivers::BufferUnorderedConfig) -> Self
+    where
+        T: Handler<M> + Send + Sync + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::BufferUnorderedSync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
     }
 
+    #[inline]
+    pub fn subscribe_async<M>(self, queue: u64, cfg: receivers::BufferUnorderedConfig) -> Self
+    where
+        T: AsyncHandler<M> + Send + Sync + 'static,
+        M: Message,
+        T::Response: Message,
+        T::Error: StdSyncSendError,
+    {
+        self.subscribe::<M, receivers::BufferUnorderedAsync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+
+    #[inline]
+    pub fn subscribe_batch_sync<M>(self, queue: u64, cfg: receivers::BufferUnorderedBatchedConfig) -> Self
+    where
+        T: BatchHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::BufferUnorderedBatchedSync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+
+    #[inline]
+    pub fn subscribe_batch_async<M>(self, queue: u64, cfg: receivers::BufferUnorderedBatchedConfig) -> Self
+    where
+        T: AsyncBatchHandler<M> + Send + 'static,
+        M: Message,
+    {
+        self.subscribe::<M, receivers::BufferUnorderedBatchedAsync<M, T::Response, T::Error>, T::Response, T::Error>(queue, cfg)
+    }
+}
 
 pub struct Module {
     receivers: Vec<(TypeId, Receiver)>,
@@ -125,7 +204,20 @@ impl Module {
         }
     }
 
-    pub fn register<T: Send + Sync + 'static>(self, item: T) -> RegisterEntry<SyncEntry, T, impl FnMut(&mut Self, (TypeId, Receiver), Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>), Self> {
+    pub fn register<T: Send + Sync + 'static>(
+        self,
+        item: T,
+    ) -> RegisterEntry<
+        SyncEntry,
+        T,
+        impl FnMut(
+            &mut Self,
+            (TypeId, Receiver),
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+        ),
+        Self,
+    > {
         RegisterEntry {
             item: Arc::new(item) as Untyped,
             payload: self,
@@ -139,7 +231,20 @@ impl Module {
         }
     }
 
-    pub fn register_unsync<T: Send + 'static>(self, item: T) -> RegisterEntry<UnsyncEntry, T, impl FnMut(&mut Self, (TypeId, Receiver), Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>), Self> {
+    pub fn register_unsync<T: Send + 'static>(
+        self,
+        item: T,
+    ) -> RegisterEntry<
+        UnsyncEntry,
+        T,
+        impl FnMut(
+            &mut Self,
+            (TypeId, Receiver),
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+        ),
+        Self,
+    > {
         RegisterEntry {
             item: Arc::new(Mutex::new(item)) as Untyped,
             payload: self,
@@ -153,9 +258,11 @@ impl Module {
         }
     }
 
-    fn extend(&mut self, other: Module) {
+    pub fn add_module(mut self, module: Module) -> Self {
-        self.receivers.extend(other.receivers.into_iter());
+        self.receivers.extend(module.receivers);
-        self.pollings.extend(other.pollings.into_iter());
+        self.pollings.extend(module.pollings);
+
+        self
     }
 }
 
@@ -170,7 +277,20 @@ impl BusBuilder {
         }
     }
 
-    pub fn register<T: Send + Sync + 'static>(self, item: T) -> RegisterEntry<SyncEntry, T, impl FnMut(&mut Self, (TypeId, Receiver), Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>), Self> {
+    pub fn register<T: Send + Sync + 'static>(
+        self,
+        item: T,
+    ) -> RegisterEntry<
+        SyncEntry,
+        T,
+        impl FnMut(
+            &mut Self,
+            (TypeId, Receiver),
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+        ),
+        Self,
+    > {
         RegisterEntry {
             item: Arc::new(item) as Untyped,
             payload: self,
@@ -184,7 +304,20 @@ impl BusBuilder {
         }
     }
 
-    pub fn register_unsync<T: Send + 'static>(self, item: T) -> RegisterEntry<UnsyncEntry, T, impl FnMut(&mut Self, (TypeId, Receiver), Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>, Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>), Self> {
+    pub fn register_unsync<T: Send + 'static>(
+        self,
+        item: T,
+    ) -> RegisterEntry<
+        UnsyncEntry,
+        T,
+        impl FnMut(
+            &mut Self,
+            (TypeId, Receiver),
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+            Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>,
+        ),
+        Self,
+    > {
         RegisterEntry {
             item: Arc::new(Mutex::new(item)) as Untyped,
             payload: self,
@@ -199,7 +332,7 @@ impl BusBuilder {
     }
 
     pub fn add_module(mut self, module: Module) -> Self {
-        self.inner.extend(module);
+        self.inner = self.inner.add_module(module);
 
         self
     }

src/envelop.rs

@@ -1,6 +1,45 @@
-use core::any::Any;
+use core::any::{Any, type_name};
 use core::fmt;
-// use erased_serde::{Deserializer, Serialize};
+use serde::{de::DeserializeOwned, Serialize};
 
-pub trait Message: Any + fmt::Debug + Unpin + Send + Sync + 'static {}
+pub trait Message:
-impl<T: Any + fmt::Debug + Unpin + Send + Sync> Message for T {}
+    fmt::Debug + Unpin + Send + Sync + 'static
+{
+    fn type_name(&self) -> &str;
+}
+
+impl<T: fmt::Debug + Unpin + Send + Sync + 'static> Message for T {
+    fn type_name(&self) -> &str {
+        type_name::<T>()
+    }
+}
+
+pub trait TransferableMessage: Message + Serialize + DeserializeOwned
+{
+    fn into_boxed(self) -> BoxedMessage; 
+}
+impl<T: Message + Serialize + DeserializeOwned> TransferableMessage for T {
+    fn into_boxed(self) -> BoxedMessage {
+        BoxedMessage(Box::new(self) as _)
+    }
+}
+
+pub trait SafeMessage:
+    Any + fmt::Debug + erased_serde::Serialize + Unpin + Send + Sync + 'static
+{
+    fn type_name(&self) -> &str;
+}
+impl<T: Any + fmt::Debug + erased_serde::Serialize + Unpin + Send + Sync> SafeMessage for T {
+    fn type_name(&self) -> &str {
+        type_name::<T>()
+    }
+}
+
+#[derive(Debug)]
+pub struct BoxedMessage(Box<dyn SafeMessage>);
+
+impl<M: TransferableMessage> From<M> for BoxedMessage {
+    fn from(m: M) -> Self {
+        BoxedMessage(Box::new(m))
+    }
+}

src/error.rs

@@ -1,19 +1,18 @@
-use core::panic;
+use core::fmt;
 
 use thiserror::Error;
 use tokio::sync::oneshot;
 
-use crate::Message;
+use crate::{Message, envelop::{BoxedMessage, TransferableMessage}};
 
 pub trait StdSyncSendError: std::error::Error + Send + Sync + Unpin + 'static {}
 impl<T: std::error::Error + Send + Sync + Unpin + 'static> StdSyncSendError for T {}
 
-
 #[derive(Debug, Error)]
 pub enum VoidError {}
 
 #[derive(Debug, Error)]
-pub enum SendError<M: Message> {
+pub enum SendError<M: fmt::Debug> {
     #[error("Closed")]
     Closed(M),
 
@@ -21,8 +20,17 @@ pub enum SendError<M: Message> {
     Full(M),
 }
 
+impl<M: TransferableMessage> SendError<M> {
+    pub fn into_boxed(self) -> SendError<BoxedMessage> {
+        match self {
+            SendError::Closed(m) => SendError::Closed(BoxedMessage::from(m)),
+            SendError::Full(m) => SendError::Closed(BoxedMessage::from(m)),
+        }
+    }
+}
+
 #[derive(Debug, Error)]
-pub enum Error<M: Message = (), E: StdSyncSendError = VoidError> {
+pub enum Error<M: fmt::Debug + 'static = (), E: StdSyncSendError = VoidError> {
     #[error("Message Send Error: {0}")]
     SendError(#[from] SendError<M>),
 
@@ -35,6 +43,9 @@ pub enum Error<M: Message = (), E: StdSyncSendError = VoidError> {
     #[error("Other({0})")]
     Other(E),
 
+    #[error("Serialization({0})")]
+    Serialization(#[from] erased_serde::Error),
+
     #[error("Other({0})")]
     OtherBoxed(Box<dyn StdSyncSendError>),
 }
@@ -45,6 +56,7 @@ impl<M: Message, E: StdSyncSendError> Error<M, E> {
             Error::SendError(inner) => Error::SendError(inner),
             Error::NoResponse => Error::NoReceivers,
             Error::NoReceivers => Error::NoReceivers,
+            Error::Serialization(s) => Error::Serialization(s),
             Error::Other(inner) => Error::OtherBoxed(Box::new(inner) as _),
             Error::OtherBoxed(inner) => Error::OtherBoxed(inner),
         }
@@ -55,6 +67,7 @@ impl<M: Message, E: StdSyncSendError> Error<M, E> {
             Error::SendError(inner) => Error::SendError(inner),
             Error::NoResponse => Error::NoReceivers,
             Error::NoReceivers => Error::NoReceivers,
+            Error::Serialization(s) => Error::Serialization(s),
             Error::Other(_) => panic!("expected boxed error!"),
             Error::OtherBoxed(inner) => Error::Other(inner.into()),
         }
@@ -67,6 +80,7 @@ impl <E: StdSyncSendError> Error<(), E> {
             Error::SendError(_) => panic!("cannot specify type on typed error"),
             Error::NoResponse => Error::NoReceivers,
             Error::NoReceivers => Error::NoReceivers,
+            Error::Serialization(s) => Error::Serialization(s),
             Error::Other(inner) => Error::Other(inner),
             Error::OtherBoxed(inner) => Error::OtherBoxed(inner),
         }

src/handler.rs

@@ -1,4 +1,6 @@
-use crate::{Bus, Message, error::StdSyncSendError};
+use std::iter::FromIterator;
+
+use crate::{error::StdSyncSendError, Bus, Message};
 use async_trait::async_trait;
 
 pub trait Handler<M: Message>: Send + Sync {
@@ -46,8 +48,10 @@ pub trait AsyncSynchronizedHandler<M: Message>: Send {
 pub trait BatchHandler<M: Message>: Send + Sync {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    fn handle(&self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    fn handle(&self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     fn sync(&self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -57,8 +61,10 @@ pub trait BatchHandler<M: Message>: Send + Sync {
 pub trait AsyncBatchHandler<M: Message>: Send + Sync {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    async fn handle(&self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    async fn handle(&self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     async fn sync(&self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -67,8 +73,10 @@ pub trait AsyncBatchHandler<M: Message>: Send + Sync {
 pub trait BatchSynchronizedHandler<M: Message>: Send {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -78,8 +86,10 @@ pub trait BatchSynchronizedHandler<M: Message>: Send {
 pub trait AsyncBatchSynchronizedHandler<M: Message>: Send {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    async fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    async fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     async fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -109,8 +119,10 @@ pub trait LocalAsyncHandler<M: Message> {
 pub trait LocalBatchHandler<M: Message> {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }
@@ -120,8 +132,10 @@ pub trait LocalBatchHandler<M: Message> {
 pub trait LocalAsyncBatchHandler<M: Message> {
     type Error: StdSyncSendError + Clone;
     type Response: Message;
+    type InBatch: FromIterator<M> + Send;
+    type OutBatch: IntoIterator<Item = Self::Response> + Send;
 
-    async fn handle(&mut self, msg: Vec<M>, bus: &Bus) -> Result<Vec<Self::Response>, Self::Error>;
+    async fn handle(&mut self, msg: Self::InBatch, bus: &Bus) -> Result<Self::OutBatch, Self::Error>;
     async fn sync(&mut self, _bus: &Bus) -> Result<(), Self::Error> {
         Ok(())
     }

src/lib.rs

@@ -5,15 +5,18 @@ mod handler;
 mod receiver;
 pub mod receivers;
 mod trait_object;
+pub mod relay;
 
 #[macro_use]
 extern crate log;
 
 use crate::receiver::Permit;
 use builder::BusBuilder;
-use core::any::{Any, TypeId};
 pub use builder::Module;
-pub use envelop::Message;
+pub use relay::RelayTrait;
+use core::any::{Any, TypeId};
+pub use envelop::{BoxedMessage, TransferableMessage, Message};
+use error::{Error, SendError, StdSyncSendError};
 pub use handler::*;
 use receiver::Receiver;
 use smallvec::SmallVec;
@@ -25,7 +28,6 @@ use std::{
     },
 };
 use tokio::sync::oneshot;
-use error::{Error, SendError, StdSyncSendError};
 
 pub type Untyped = Arc<dyn Any + Send + Sync>;
 
@@ -134,11 +136,11 @@ impl BusInner {
     }
 
     #[inline]
-    pub fn try_send<M: Message + Clone>(&self, msg: M) -> Result<(), Error<M>> {
+    pub fn try_send<M: TransferableMessage + Clone>(&self, msg: M) -> Result<(), Error<M>> {
         self.try_send_ext(msg, SendOptions::Broadcast)
     }
 
-    pub fn try_send_ext<M: Message + Clone>(
+    pub fn try_send_ext<M: TransferableMessage + Clone>(
         &self,
         msg: M,
         _options: SendOptions,
@@ -163,13 +165,13 @@ impl BusInner {
 
             while counter < total {
                 let (p, r) = iter.next().unwrap();
-                let _ = r.send(mid, p, msg.clone());
+                let _ = r.send(mid, msg.clone(), p);
 
                 counter += 1;
             }
 
             if let Some((p, r)) = iter.next() {
-                let _ = r.send(mid, p, msg);
+                let _ = r.send(mid, msg, p);
                 return Ok(());
             }
         }
@@ -183,12 +185,12 @@ impl BusInner {
     }
 
     #[inline]
-    pub fn send_blocking<M: Message + Clone>(&self, msg: M) -> Result<(), Error<M>> {
+    pub fn send_blocking<M: TransferableMessage + Clone>(&self, msg: M) -> Result<(), Error<M>> {
         self.send_blocking_ext(msg, SendOptions::Broadcast)
     }
 
     #[inline]
-    pub fn send_blocking_ext<M: Message + Clone>(
+    pub fn send_blocking_ext<M: TransferableMessage + Clone>(
         &self,
         msg: M,
         options: SendOptions,
@@ -197,11 +199,11 @@ impl BusInner {
     }
 
     #[inline]
-    pub async fn send<M: Message + Clone>(&self, msg: M) -> core::result::Result<(), Error<M>> {
+    pub async fn send<M: TransferableMessage + Clone>(&self, msg: M) -> core::result::Result<(), Error<M>> {
         Ok(self.send_ext(msg, SendOptions::Broadcast).await?)
     }
 
-    pub async fn send_ext<M: Message + Clone>(
+    pub async fn send_ext<M: TransferableMessage + Clone>(
         &self,
         msg: M,
         _options: SendOptions,
@@ -216,10 +218,10 @@ impl BusInner {
         if let Some(rs) = self.receivers.get(&tid) {
             if let Some((last, head)) = rs.split_last() {
                 for r in head {
-                    let _ = r.send(mid, r.reserve().await, msg.clone());
+                    let _ = r.send(mid, msg.clone(), r.reserve().await);
                 }
 
-                let _ = last.send(mid, last.reserve().await, msg);
+                let _ = last.send(mid, msg, last.reserve().await);
 
                 return Ok(());
             }
@@ -234,11 +236,11 @@ impl BusInner {
     }
 
     #[inline]
-    pub fn force_send<M: Message + Clone>(&self, msg: M) -> Result<(), Error<M>> {
+    pub fn force_send<M: TransferableMessage + Clone>(&self, msg: M) -> Result<(), Error<M>> {
         self.force_send_ext(msg, SendOptions::Broadcast)
     }
 
-    pub fn force_send_ext<M: Message + Clone>(
+    pub fn force_send_ext<M: TransferableMessage + Clone>(
         &self,
         msg: M,
         _options: SendOptions,
@@ -271,7 +273,7 @@ impl BusInner {
     }
 
     #[inline]
-    pub fn try_send_one<M: Message>(&self, msg: M) -> Result<(), Error<M>> {
+    pub fn try_send_one<M: TransferableMessage>(&self, msg: M) -> Result<(), Error<M>> {
         if self.closed.load(Ordering::SeqCst) {
             return Err(SendError::Closed(msg).into());
         }
@@ -286,13 +288,13 @@ impl BusInner {
                 return Err(SendError::Full(msg).into());
             };
 
-            Ok(rs.send(mid, permits, msg)?)
+            Ok(rs.send(mid, msg, permits)?)
         } else {
             Err(Error::NoReceivers)
         }
     }
 
-    pub async fn send_one<M: Message>(&self, msg: M) -> Result<(), Error<M>> {
+    pub async fn send_one<M: TransferableMessage>(&self, msg: M) -> Result<(), Error<M>> {
         if self.closed.load(Ordering::SeqCst) {
             return Err(SendError::Closed(msg).into());
         }
@@ -301,18 +303,33 @@ impl BusInner {
         let tid = TypeId::of::<M>();
 
         if let Some(rs) = self.receivers.get(&tid).and_then(|rs| rs.first()) {
-            Ok(rs.send(mid, rs.reserve().await, msg)?)
+            Ok(rs.send(mid, msg, rs.reserve().await)?)
+        } else {
+            Err(Error::NoReceivers)
+        }
+    }
+
+    pub async fn send_local_one<M: Message>(&self, msg: M) -> Result<(), Error<M>> {
+        if self.closed.load(Ordering::SeqCst) {
+            return Err(SendError::Closed(msg).into());
+        }
+
+        let mid = ID_COUNTER.fetch_add(1, Ordering::Relaxed);
+        let tid = TypeId::of::<M>();
+
+        if let Some(rs) = self.receivers.get(&tid).and_then(|rs| rs.first()) {
+            Ok(rs.send(mid, msg, rs.reserve().await)?)
         } else {
             Err(Error::NoReceivers)
         }
     }
 
     #[inline]
-    pub fn send_one_blocking<M: Message>(&self, msg: M) -> Result<(), Error<M>> {
+    pub fn send_one_blocking<M: TransferableMessage>(&self, msg: M) -> Result<(), Error<M>> {
         futures::executor::block_on(self.send_one(msg))
     }
 
-    pub async fn request<M: Message, R: Message>(
+    pub async fn request<M: TransferableMessage, R: TransferableMessage>(
         &self,
         req: M,
         options: SendOptions,
@@ -324,7 +341,7 @@ impl BusInner {
         if let Some(rc) = iter.next() {
             let (tx, rx) = oneshot::channel();
             let mid = (rc.add_response_waiter(tx).unwrap() | 1 << (usize::BITS - 1)) as u64;
-            rc.send(mid, rc.reserve().await, req)?;
+            rc.send(mid, req, rc.reserve().await)?;
 
             rx.await?.map_err(|x| x.specify::<M>())
         } else {
@@ -332,15 +349,11 @@ impl BusInner {
         }
     }
 
-    pub async fn request_we<M, R, E>(
+    pub async fn request_local_we<M, R, E>(&self, req: M, options: SendOptions) -> Result<R, Error<M, E>>
-        &self,
-        req: M,
-        options: SendOptions,
-    ) -> Result<R, Error<M, E>> 
     where
         M: Message,
         R: Message,
-            E: StdSyncSendError
+        E: StdSyncSendError,
     {
         let tid = TypeId::of::<M>();
         let rid = TypeId::of::<R>();
@@ -350,10 +363,9 @@ impl BusInner {
         if let Some(rc) = iter.next() {
             let (tx, rx) = oneshot::channel();
             let mid = (rc.add_response_waiter_we(tx).unwrap() | 1 << (usize::BITS - 1)) as u64;
-            rc.send(mid, rc.reserve().await, req)?;
+            rc.send(mid, req, rc.reserve().await)?;
 
-            rx.await?
+            rx.await?.map_err(|x| x.specify::<M>())
-                .map_err(|x|x.specify::<M>())
         } else {
             Err(Error::NoReceivers)
         }

src/receiver.rs

@@ -1,4 +1,4 @@
-use crate::{Bus, Error, Message, error::{SendError, StdSyncSendError}, trait_object::TraitObject};
+use crate::{Bus, Error, Message, envelop::{BoxedMessage, TransferableMessage}, error::{SendError, StdSyncSendError}, trait_object::TraitObject};
 use core::{
     any::TypeId,
     fmt,
@@ -7,6 +7,7 @@ use core::{
     pin::Pin,
     task::{Context, Poll},
 };
+use erased_serde::Deserializer;
 use futures::future::poll_fn;
 use futures::Future;
 use std::{
@@ -52,6 +53,10 @@ pub trait ReceiverTrait: Send + Sync {
     fn flush(&self) -> Result<(), Error<Action>>;
 }
 
+pub trait TransferableReceiverTrait: Send + Sync {
+    fn send(&self, mid: u64, de: &mut dyn Deserializer) -> Result<(), Error<BoxedMessage>>;
+}
+
 pub trait ReceiverPollerBuilder {
     fn build(bus: Bus) -> Box<dyn Future<Output = ()>>;
 }
@@ -141,6 +146,19 @@ where
     }
 }
 
+impl<M, R, E, S> TransferableReceiverTrait for ReceiverWrapper<M, R, E, S>
+where
+    M: TransferableMessage,
+    R: TransferableMessage,
+    E: StdSyncSendError,
+    S: SendUntypedReceiver + SendTypedReceiver<M> + ReciveTypedReceiver<R, E> + 'static,
+{
+    fn send(&self, mid: u64, de: &mut dyn Deserializer) -> Result<(), Error<BoxedMessage>> {
+        unimplemented!()
+    }
+}
+
+
 pub struct Permit {
     pub(crate) fuse: bool,
     pub(crate) inner: Arc<dyn PermitDrop>,
@@ -301,8 +319,16 @@ impl Receiver {
                 inner,
                 _m: Default::default(),
             }),
-            waiters: Arc::new(sharded_slab::Slab::<oneshot::Sender<Result<R, Error<(), E>>>>::new_with_config::<SlabCfg>()),
+            waiters: Arc::new(
-            waiters_void: Arc::new(sharded_slab::Slab::<oneshot::Sender<Result<R, Error<()>>>>::new_with_config::<SlabCfg>()),
+                sharded_slab::Slab::<oneshot::Sender<Result<R, Error<(), E>>>>::new_with_config::<
+                    SlabCfg,
+                >(),
+            ),
+            waiters_void: Arc::new(
+                sharded_slab::Slab::<oneshot::Sender<Result<R, Error<()>>>>::new_with_config::<
+                    SlabCfg,
+                >(),
+            ),
         }
     }
 
@@ -374,8 +400,8 @@ impl Receiver {
     pub fn send<M: Message>(
         &self,
         mid: u64,
-        mut permit: Permit,
         msg: M,
+        mut permit: Permit,
     ) -> Result<(), SendError<M>> {
         let any_receiver = self.inner.typed();
         let receiver = any_receiver.dyn_typed_receiver::<M>();
@@ -416,13 +442,13 @@ impl Receiver {
         let waiters = self
             .waiters
             .clone()
-            .downcast::<Slab::<oneshot::Sender<Result<R, Error<(), E>>>>>()
+            .downcast::<Slab<oneshot::Sender<Result<R, Error<(), E>>>>>()
             .unwrap();
 
         let waiters_void = self
             .waiters_void
             .clone()
-            .downcast::<Slab::<oneshot::Sender<Result<R, Error<()>>>>>()
+            .downcast::<Slab<oneshot::Sender<Result<R, Error<()>>>>>()
             .unwrap();
 
         Box::new(move |_| {
@@ -454,7 +480,7 @@ impl Receiver {
                             } else if TypeId::of::<R>() != TypeId::of::<()>() {
                                 warn!("Non-void response has no waiters!");
                             }
-                        },
+                        }
 
                         _ => unimplemented!(),
                     }
@@ -491,6 +517,19 @@ impl Receiver {
         Some(idx)
     }
 
+    // #[inline]
+    // pub(crate) fn add_response_waiter_dyn(
+    //     &self,
+    //     waiter: oneshot::Sender<Result<R, Error<(), E>>>,
+    // ) -> Option<usize> {
+    //     let idx = self
+    //         .waiters
+    //         .downcast_ref::<Slab<oneshot::Sender<Result<R, Error<(), E>>>>>()
+    //         .unwrap()
+    //         .insert(waiter)?;
+
+    //     Some(idx)
+    // }
 
     #[inline]
     pub async fn close(&self) {

src/receivers/buffer_unordered/async.rs

@@ -10,8 +10,8 @@ use std::{
 use crate::{
     buffer_unordered_poller_macro,
     builder::ReceiverSubscriberBuilder,
-    error::{Error, StdSyncSendError, SendError}, 
+    error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver}, 
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
     receivers::{fix_type, Request},
     AsyncHandler, Bus, Message, Untyped,
 };

src/receivers/buffer_unordered/mod.rs

@@ -5,6 +5,7 @@ use std::sync::atomic::AtomicU64;
 
 pub use r#async::BufferUnorderedAsync;
 pub use sync::BufferUnorderedSync;
+use serde_derive::{Serialize, Deserialize};
 
 #[derive(Debug)]
 pub struct BufferUnorderedStats {
@@ -14,7 +15,7 @@ pub struct BufferUnorderedStats {
     pub parallel_total: AtomicU64,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
 pub struct BufferUnorderedConfig {
     pub buffer_size: usize,
     pub max_parallel: usize,
@@ -96,7 +97,8 @@ macro_rules! buffer_unordered_poller_macro {
                                 Poll::Pending => return Poll::Pending,
                                 Poll::Ready(Some((mid, resp))) => {
                                     let resp: Result<_, $t::Error> = resp;
-                                    stx.send(Event::Response(mid, resp.map_err(Error::Other))).ok();
+                                    stx.send(Event::Response(mid, resp.map_err(Error::Other)))
+                                        .ok();
                                 }
                                 Poll::Ready(None) => break,
                             }
@@ -114,7 +116,8 @@ macro_rules! buffer_unordered_poller_macro {
                                 Poll::Pending => return Poll::Pending,
                                 Poll::Ready(resp) => {
                                     let resp: Result<_, E> = resp;
-                                    stx.send(Event::Synchronized(resp.map_err(Error::Other))).ok();
+                                    stx.send(Event::Synchronized(resp.map_err(Error::Other)))
+                                        .ok();
                                 }
                             }
                             need_sync = false;

src/receivers/buffer_unordered/sync.rs

@@ -7,15 +7,15 @@ use std::{
     task::{Context, Poll},
 };
 
+use super::{BufferUnorderedConfig, BufferUnorderedStats};
 use crate::{
     buffer_unordered_poller_macro,
     builder::ReceiverSubscriberBuilder,
-    error::{Error, StdSyncSendError, SendError}, 
+    error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver}, 
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
     receivers::{fix_type, Request},
     Bus, Handler, Message, Untyped,
 };
-use super::{BufferUnorderedConfig, BufferUnorderedStats};
 
 use futures::{stream::FuturesUnordered, Future, StreamExt};
 use parking_lot::Mutex;

src/receivers/buffer_unordered_batched/async.rs

@@ -7,7 +7,14 @@ use std::{
     task::{Context, Poll},
 };
 
-use crate::{AsyncBatchHandler, Bus, Message, Untyped, buffer_unordered_batch_poller_macro, builder::ReceiverSubscriberBuilder, error::{Error, SendError, StdSyncSendError}, receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver}, receivers::{fix_type, Request}};
+use crate::{
+    buffer_unordered_batch_poller_macro,
+    builder::ReceiverSubscriberBuilder,
+    error::{Error, SendError, StdSyncSendError},
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receivers::{fix_type, Request},
+    AsyncBatchHandler, Bus, Message, Untyped,
+};
 
 use super::{BufferUnorderedBatchedConfig, BufferUnorderedBatchedStats};
 use futures::{stream::FuturesUnordered, Future, StreamExt};
@@ -39,7 +46,8 @@ where
     srx: Mutex<mpsc::UnboundedReceiver<Event<R, E>>>,
 }
 
-impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error> for BufferUnorderedBatchedAsync<M, R, T::Error>
+impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error>
+    for BufferUnorderedBatchedAsync<M, R, T::Error>
 where
     T: AsyncBatchHandler<M, Response = R> + 'static,
     T::Error: StdSyncSendError + Clone,

src/receivers/buffer_unordered_batched/mod.rs

@@ -5,6 +5,7 @@ use std::sync::atomic::AtomicU64;
 
 pub use r#async::BufferUnorderedBatchedAsync;
 pub use sync::BufferUnorderedBatchedSync;
+use serde_derive::{Serialize, Deserialize};
 
 #[derive(Debug)]
 pub struct BufferUnorderedBatchedStats {
@@ -16,7 +17,7 @@ pub struct BufferUnorderedBatchedStats {
     pub batch_size: AtomicU64,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
 pub struct BufferUnorderedBatchedConfig {
     pub buffer_size: usize,
     pub max_parallel: usize,
@@ -145,7 +146,11 @@ macro_rules! buffer_unordered_batch_poller_macro {
                                     }
                                     Err(er) => {
                                         for mid in mids {
-                                            stx.send(Event::Response(mid, Err(Error::Other(er.clone())))).ok();
+                                            stx.send(Event::Response(
+                                                mid,
+                                                Err(Error::Other(er.clone())),
+                                            ))
+                                            .ok();
                                         }
                                     }
                                 },
@@ -165,7 +170,8 @@ macro_rules! buffer_unordered_batch_poller_macro {
                                 Poll::Pending => return Poll::Pending,
                                 Poll::Ready(resp) => {
                                     let resp: Result<_, $t::Error> = resp;
-                                    stx.send(Event::Synchronized(resp.map_err(Error::Other))).ok();
+                                    stx.send(Event::Synchronized(resp.map_err(Error::Other)))
+                                        .ok();
                                 }
                             }
                             need_sync = false;

src/receivers/buffer_unordered_batched/sync.rs

@@ -7,8 +7,15 @@ use std::{
     task::{Context, Poll},
 };
 
-use crate::{BatchHandler, Bus, Message, Untyped, buffer_unordered_batch_poller_macro, builder::ReceiverSubscriberBuilder, error::{Error, SendError, StdSyncSendError}, receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver}, receivers::{fix_type, Request}};
 use super::{BufferUnorderedBatchedConfig, BufferUnorderedBatchedStats};
+use crate::{
+    buffer_unordered_batch_poller_macro,
+    builder::ReceiverSubscriberBuilder,
+    error::{Error, SendError, StdSyncSendError},
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receivers::{fix_type, Request},
+    BatchHandler, Bus, Message, Untyped,
+};
 
 use futures::{stream::FuturesUnordered, Future, StreamExt};
 use parking_lot::Mutex;
@@ -48,7 +55,8 @@ where
     srx: Mutex<mpsc::UnboundedReceiver<Event<R, E>>>,
 }
 
-impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error> for BufferUnorderedBatchedSync<M, R, T::Error>
+impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error>
+    for BufferUnorderedBatchedSync<M, R, T::Error>
 where
     T: BatchHandler<M, Response = R> + 'static,
     T::Error: StdSyncSendError,

src/receivers/mod.rs

@@ -28,6 +28,11 @@ where
     Pin::new_unchecked(x)
 }
 
+#[inline(always)]
+pub(crate) fn fix_into_iter<I, T: IntoIterator<Item = I> + Send>(x: T) -> impl IntoIterator<Item = I> + Send {
+    x
+}
+
 pub(crate) enum Request<M> {
     Action(Action),
     Request(u64, M),

src/receivers/synchronize_batched/async.rs

@@ -6,10 +6,10 @@ use std::{
 
 use crate::{
     batch_synchronized_poller_macro,
-    error::{Error, SendError, StdSyncSendError},
     builder::ReceiverSubscriberBuilder,
-    receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver},
+    error::{Error, SendError, StdSyncSendError},
-    receivers::{fix_type, Request},
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
+    receivers::{fix_type, fix_into_iter, Request},
     AsyncBatchSynchronizedHandler, Bus, Message, Untyped,
 };
 
@@ -40,7 +40,8 @@ where
     srx: parking_lot::Mutex<mpsc::UnboundedReceiver<Event<R, E>>>,
 }
 
-impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error> for SynchronizedBatchedAsync<M, R, T::Error>
+impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error>
+    for SynchronizedBatchedAsync<M, R, T::Error>
 where
     T: AsyncBatchSynchronizedHandler<M, Response = R> + 'static,
     T::Error: StdSyncSendError + Clone,
@@ -62,9 +63,8 @@ where
 
         let poller = Box::new(move |ut| {
             Box::new(move |bus| {
-                Box::pin(batch_synchronized_poller::<T, M, R>(
+                Box::pin(batch_synchronized_poller::<T, M, R>(rx, bus, ut, cfg, stx))
-                    rx, bus, ut, cfg, stx,
+                    as Pin<Box<dyn Future<Output = ()> + Send>>
-                )) as Pin<Box<dyn Future<Output = ()> + Send>>
             }) as Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>
         });
 

src/receivers/synchronize_batched/mod.rs

@@ -5,6 +5,8 @@ use std::sync::atomic::AtomicU64;
 
 pub use r#async::SynchronizedBatchedAsync;
 pub use sync::SynchronizedBatchedSync;
+use serde_derive::{Serialize, Deserialize};
+
 
 #[derive(Debug)]
 pub struct SynchronizedBatchedStats {
@@ -14,7 +16,7 @@ pub struct SynchronizedBatchedStats {
     pub batch_size: AtomicU64,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
 pub struct SynchronizedBatchedConfig {
     pub buffer_size: usize,
     pub batch_size: usize,
@@ -65,7 +67,7 @@ macro_rules! batch_synchronized_poller_macro {
                         Poll::Ready((mids, res)) => match res {
                             Ok(re) => {
                                 let mids: Vec<u64> = mids;
-                                let re: Vec<R> = re;
+                                let re = fix_into_iter::<R, _>(re);
 
                                 let mut mids = mids.into_iter();
                                 let mut re = re.into_iter();
@@ -74,11 +76,7 @@ macro_rules! batch_synchronized_poller_macro {
                                     if let Some(r) = re.next() {
                                         stx.send(Event::Response(mid, Ok(r))).ok();
                                     } else {
-                                        stx.send(Event::Response(
+                                        stx.send(Event::Response(mid, Err(Error::NoResponse))).ok();
-                                            mid,
-                                            Err(Error::NoResponse),
-                                        ))
-                                        .ok();
                                     }
                                 }
                             }
@@ -86,10 +84,11 @@ macro_rules! batch_synchronized_poller_macro {
                             Err(er) => {
                                 let er: $t::Error = er;
                                 for mid in mids {
-                                    stx.send(Event::Response(mid, Err(Error::Other(er.clone())))).ok();
+                                    stx.send(Event::Response(mid, Err(Error::Other(er.clone()))))
-                                }
+                                        .ok();
                                 }
                             }
+                        },
                     }
                 }
                 handle_future = None;
@@ -159,7 +158,8 @@ macro_rules! batch_synchronized_poller_macro {
                             Poll::Ready(resp) => {
                                 need_sync = false;
                                 let resp: Result<_, $t::Error> = resp;
-                                stx.send(Event::Synchronized(resp.map_err(Error::Other))).ok();
+                                stx.send(Event::Synchronized(resp.map_err(Error::Other)))
+                                    .ok();
                             }
                         }
                         sync_future = None;

src/receivers/synchronize_batched/sync.rs

@@ -7,9 +7,9 @@ use std::{
 use crate::{
     batch_synchronized_poller_macro,
     builder::ReceiverSubscriberBuilder,
-    error::{Error, StdSyncSendError, SendError}, 
+    error::{Error, SendError, StdSyncSendError},
-    receiver::{Action, Event, ReciveTypedReceiver, SendUntypedReceiver, SendTypedReceiver}, 
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
-    receivers::{fix_type, Request},
+    receivers::{fix_type, fix_into_iter, Request},
     BatchSynchronizedHandler, Bus, Message, Untyped,
 };
 
@@ -44,7 +44,8 @@ where
     srx: parking_lot::Mutex<mpsc::UnboundedReceiver<Event<R, E>>>,
 }
 
-impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error> for SynchronizedBatchedSync<M, R, T::Error>
+impl<T, M, R> ReceiverSubscriberBuilder<T, M, R, T::Error>
+    for SynchronizedBatchedSync<M, R, T::Error>
 where
     T: BatchSynchronizedHandler<M, Response = R> + 'static,
     T::Error: StdSyncSendError,
@@ -66,9 +67,8 @@ where
 
         let poller = Box::new(move |ut| {
             Box::new(move |bus| {
-                Box::pin(batch_synchronized_poller::<T, M, R>(
+                Box::pin(batch_synchronized_poller::<T, M, R>(rx, bus, ut, cfg, stx))
-                    rx, bus, ut, cfg, stx,
+                    as Pin<Box<dyn Future<Output = ()> + Send>>
-                )) as Pin<Box<dyn Future<Output = ()> + Send>>
             }) as Box<dyn FnOnce(Bus) -> Pin<Box<dyn Future<Output = ()> + Send>>>
         });
 

src/receivers/synchronized/async.rs

@@ -9,9 +9,9 @@ use futures::Future;
 
 use super::SynchronizedConfig;
 use crate::{
-    error::{Error, StdSyncSendError, SendError},
     builder::ReceiverSubscriberBuilder,
-    receiver::{SendTypedReceiver, Action, Event, ReciveTypedReceiver, SendUntypedReceiver},
+    error::{Error, SendError, StdSyncSendError},
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
     receivers::{fix_type, Request},
     AsyncSynchronizedHandler, Bus, Message, Untyped,
 };

src/receivers/synchronized/mod.rs

@@ -5,6 +5,7 @@ use std::sync::atomic::AtomicU64;
 
 pub use r#async::SynchronizedAsync;
 pub use sync::SynchronizedSync;
+use serde_derive::{Serialize, Deserialize};
 
 #[derive(Debug)]
 pub struct SynchronizedStats {
@@ -12,7 +13,7 @@ pub struct SynchronizedStats {
     pub buffer_total: AtomicU64,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct SynchronizedConfig {
     pub buffer_size: usize,
 }
@@ -51,7 +52,8 @@ macro_rules! synchronized_poller_macro {
                         Poll::Pending => return Poll::Pending,
                         Poll::Ready((mid, resp)) => {
                             let resp: Result<_, $t::Error> = resp;
-                            stx.send(Event::Response(mid, resp.map_err(Error::Other))).ok();
+                            stx.send(Event::Response(mid, resp.map_err(Error::Other)))
+                                .ok();
                         }
                     }
                 }
@@ -91,7 +93,8 @@ macro_rules! synchronized_poller_macro {
                             Poll::Ready(resp) => {
                                 need_sync = false;
                                 let resp: Result<_, $t::Error> = resp;
-                                stx.send(Event::Synchronized(resp.map_err(Error::Other))).ok();
+                                stx.send(Event::Synchronized(resp.map_err(Error::Other)))
+                                    .ok();
                             }
                         }
                         sync_future = None;

src/receivers/synchronized/sync.rs

@@ -5,15 +5,15 @@ use std::{
 };
 
 use crate::synchronized_poller_macro;
-use futures::{Future, executor::block_on};
+use futures::{executor::block_on, Future};
 
 use super::SynchronizedConfig;
 use crate::{
-    error::{Error, StdSyncSendError, SendError},
     builder::ReceiverSubscriberBuilder,
-    receiver::{SendTypedReceiver, Action, Event, ReciveTypedReceiver, SendUntypedReceiver},
+    error::{Error, SendError, StdSyncSendError},
+    receiver::{Action, Event, ReciveTypedReceiver, SendTypedReceiver, SendUntypedReceiver},
     receivers::{fix_type, Request},
-    SynchronizedHandler, Bus, Message, Untyped,
+    Bus, Message, SynchronizedHandler, Untyped,
 };
 use tokio::sync::{mpsc, Mutex};
 

src/relay.rs

@@ -0,0 +1,122 @@
+use std::{any::TypeId, borrow::Cow, collections::HashMap, sync::atomic::{AtomicU64, Ordering}};
+
+use tokio::sync::oneshot::Sender;
+use sharded_slab::Slab;
+
+use crate::{Bus, Message, envelop::SafeMessage, error::{Error, SendError}, receiver::Permit};
+
+pub trait RelayTrait {
+    // fn handle_message(&self, mid: u64, msg: &dyn SafeMessage, tx: Option<Sender<>>, bus: &Bus);
+    fn start_relay(&self, bus: &Bus) -> Result<(), Error> ;
+    fn stop_relay(&self);
+}
+
+pub struct Relay {
+    in_map: HashMap<Cow<'static, str>, TypeId>,
+    out_map: HashMap<TypeId, Cow<'static, str>>,
+    // waiters: Slab<Sender<Result<R, Error<(), E>>>>,
+    queue_size: AtomicU64,
+    limit: u64,
+}
+
+impl Relay {
+    // pub async fn reserve(&self) -> Permit {
+    //     loop {
+    //         let count = self.queue_size.load(Ordering::Relaxed);
+    //         if count < self.limit {
+    //             let res = self.processing.compare_exchange(
+    //                 count,
+    //                 count + 1,
+    //                 Ordering::SeqCst,
+    //                 Ordering::SeqCst,
+    //             );
+    //             if res.is_ok() {
+    //                 break Permit {
+    //                     fuse: false,
+    //                     inner: self.context.clone(),
+    //                 };
+    //             }
+
+    //             // continue
+    //         } else {
+    //             self.response.notified().await
+    //         }
+    //     }
+    // }
+
+    // pub fn try_reserve(&self) -> Option<Permit> {
+    //     loop {
+    //         let count = self.processing.load(Ordering::Relaxed);
+
+    //         if count < self.limit {
+    //             let res = self.processing.compare_exchange(
+    //                 count,
+    //                 count + 1,
+    //                 Ordering::SeqCst,
+    //                 Ordering::SeqCst,
+    //             );
+    //             if res.is_ok() {
+    //                 break Some(Permit {
+    //                     fuse: false,
+    //                     inner: self.context.clone(),
+    //                 });
+    //             }
+
+    //             // continue
+    //         } else {
+    //             break None;
+    //         }
+    //     }
+    // }
+
+    // #[inline]
+    // pub fn send<M: Message>(
+    //     &self,
+    //     mid: u64,
+    //     msg: M,
+    //     mut permit: Permit,
+    // ) -> Result<(), SendError<M>> {
+    //     unimplemented!()
+    // }
+
+    // #[inline]
+    // pub fn force_send<M: Message + Clone>(&self, mid: u64, msg: M) -> Result<(), SendError<M>> {
+    //     unimplemented!()
+    // }
+
+    // #[inline]
+    // pub fn need_flush(&self) -> bool {
+    //     self.context.need_flush.load(Ordering::SeqCst)
+    // }
+
+    // #[inline]
+    // pub async fn close(&self) {
+    //     let notified = self.context.closed.notified();
+    //     if self.inner.close().is_ok() {
+    //         notified.await;
+    //     } else {
+    //         warn!("close failed!");
+    //     }
+    // }
+
+    // #[inline]
+    // pub async fn sync(&self) {
+    //     let notified = self.context.synchronized.notified();
+    //     if self.inner.sync().is_ok() {
+    //         notified.await
+    //     } else {
+    //         warn!("sync failed!");
+    //     }
+    // }
+
+    // #[inline]
+    // pub async fn flush(&self) {
+    //     let notified = self.context.flushed.notified();
+    //     if self.inner.flush().is_ok() {
+    //         notified.await;
+    //         self.context.need_flush.store(false, Ordering::SeqCst);
+    //     } else {
+    //         warn!("flush failed!");
+    //     }
+    // }
+}