From 666c121bb32e1bbe835619586bc5fb000965007b Mon Sep 17 00:00:00 2001
From: rishflab <rishflab@hotmail.com>
Date: Fri, 9 Oct 2020 09:46:24 +1100
Subject: [PATCH] Implement transport traits with generics

---
 xmr-btc/src/alice.rs               |  4 +--
 xmr-btc/src/bob.rs                 |  4 +--
 xmr-btc/src/transport.rs           |  4 +--
 xmr-btc/tests/harness/transport.rs | 45 +++++++++---------------------
 4 files changed, 19 insertions(+), 38 deletions(-)

diff --git a/xmr-btc/src/alice.rs b/xmr-btc/src/alice.rs
index 8072f777..00eccfc5 100644
--- a/xmr-btc/src/alice.rs
+++ b/xmr-btc/src/alice.rs
@@ -3,7 +3,7 @@ use crate::{
     bitcoin::{BroadcastSignedTransaction, WatchForRawTransaction},
     bob, monero,
     monero::{CreateWalletForOutput, Transfer},
-    transport::{Receive, Send},
+    transport::{ReceiveMessage, SendMessage},
 };
 use anyhow::{anyhow, Result};
 use ecdsa_fun::{
@@ -21,7 +21,7 @@ pub async fn next_state<
     R: RngCore + CryptoRng,
     B: WatchForRawTransaction + BroadcastSignedTransaction,
     M: CreateWalletForOutput + Transfer,
-    T: Send<Message> + Receive<bob::Message>,
+    T: SendMessage<Message> + ReceiveMessage<bob::Message>,
 >(
     bitcoin_wallet: &B,
     monero_wallet: &M,
diff --git a/xmr-btc/src/bob.rs b/xmr-btc/src/bob.rs
index 8b73bf70..94b4f424 100644
--- a/xmr-btc/src/bob.rs
+++ b/xmr-btc/src/bob.rs
@@ -6,7 +6,7 @@ use crate::{
     },
     monero,
     monero::{CheckTransfer, CreateWalletForOutput},
-    transport::{Receive, Send},
+    transport::{ReceiveMessage, SendMessage},
 };
 use anyhow::{anyhow, Result};
 use ecdsa_fun::{
@@ -25,7 +25,7 @@ pub async fn next_state<
     R: RngCore + CryptoRng,
     B: WatchForRawTransaction + SignTxLock + BuildTxLockPsbt + BroadcastSignedTransaction,
     M: CreateWalletForOutput + CheckTransfer,
-    T: Send<Message> + Receive<alice::Message>,
+    T: SendMessage<Message> + ReceiveMessage<alice::Message>,
 >(
     bitcoin_wallet: &B,
     monero_wallet: &M,
diff --git a/xmr-btc/src/transport.rs b/xmr-btc/src/transport.rs
index 2a7db76a..f71992fb 100644
--- a/xmr-btc/src/transport.rs
+++ b/xmr-btc/src/transport.rs
@@ -2,11 +2,11 @@ use anyhow::Result;
 use async_trait::async_trait;
 
 #[async_trait]
-pub trait Send<SendMsg> {
+pub trait SendMessage<SendMsg> {
     async fn send_message(&mut self, message: SendMsg) -> Result<()>;
 }
 
 #[async_trait]
-pub trait Receive<RecvMsg> {
+pub trait ReceiveMessage<RecvMsg> {
     async fn receive_message(&mut self) -> Result<RecvMsg>;
 }
diff --git a/xmr-btc/tests/harness/transport.rs b/xmr-btc/tests/harness/transport.rs
index 6b7e007e..1c912b02 100644
--- a/xmr-btc/tests/harness/transport.rs
+++ b/xmr-btc/tests/harness/transport.rs
@@ -4,10 +4,7 @@ use tokio::{
     stream::StreamExt,
     sync::mpsc::{Receiver, Sender},
 };
-use xmr_btc::{
-    alice, bob,
-    transport::{Receive, Send},
-};
+use xmr_btc::transport::{ReceiveMessage, SendMessage};
 
 #[derive(Debug)]
 pub struct Transport<SendMsg, RecvMsg> {
@@ -16,32 +13,12 @@ pub struct Transport<SendMsg, RecvMsg> {
 }
 
 #[async_trait]
-impl Send<alice::Message> for Transport<alice::Message, bob::Message> {
-    async fn send_message(&mut self, message: alice::Message) -> Result<()> {
-        let _ = self
-            .sender
-            .send(message)
-            .await
-            .map_err(|_| anyhow!("failed to send message"))?;
-        Ok(())
-    }
-}
-
-#[async_trait]
-impl Receive<bob::Message> for Transport<alice::Message, bob::Message> {
-    async fn receive_message(&mut self) -> Result<bob::Message> {
-        let message = self
-            .receiver
-            .next()
-            .await
-            .ok_or_else(|| anyhow!("failed to receive message"))?;
-        Ok(message)
-    }
-}
-
-#[async_trait]
-impl Send<bob::Message> for Transport<bob::Message, alice::Message> {
-    async fn send_message(&mut self, message: bob::Message) -> Result<()> {
+impl<SendMsg, RecvMsg> SendMessage<SendMsg> for Transport<SendMsg, RecvMsg>
+where
+    SendMsg: Send + Sync,
+    RecvMsg: std::marker::Send,
+{
+    async fn send_message(&mut self, message: SendMsg) -> Result<()> {
         let _ = self
             .sender
             .send(message)
@@ -52,8 +29,12 @@ impl Send<bob::Message> for Transport<bob::Message, alice::Message> {
 }
 
 #[async_trait]
-impl Receive<alice::Message> for Transport<bob::Message, alice::Message> {
-    async fn receive_message(&mut self) -> Result<alice::Message> {
+impl<SendMsg, RecvMsg> ReceiveMessage<RecvMsg> for Transport<SendMsg, RecvMsg>
+where
+    SendMsg: std::marker::Send,
+    RecvMsg: Send + Sync,
+{
+    async fn receive_message(&mut self) -> Result<RecvMsg> {
         let message = self
             .receiver
             .next()