Remove unnecessary channels

`alice::swap::run_until` will be called once the execution setup is
done. The steps before are directly handled by the event loop,
hence no channels are needed for said steps: connection established,
swap request/response & execution setup.

swap/src/protocol/alice/event_loop.rs

@@ -4,7 +4,7 @@ use crate::{
     protocol::{
         alice::{
             behaviour::{Behaviour, OutEvent},
-            State0, State3, SwapResponse, TransferProof,
+            State3, SwapResponse, TransferProof,
         },
         bob::{EncryptedSignature, SwapRequest},
     },
@@ -17,7 +17,7 @@ use tokio::{
     sync::mpsc::{Receiver, Sender},
     time::timeout,
 };
-use tracing::{error, trace};
+use tracing::{debug, error, trace};
 
 #[allow(missing_debug_implementations)]
 pub struct Channels<T> {
@@ -34,36 +34,12 @@ impl<T> Default for Channels<T> {
 
 #[derive(Debug)]
 pub struct EventLoopHandle {
-    done_execution_setup: Receiver<State3>,
     recv_encrypted_signature: Receiver<EncryptedSignature>,
-    recv_swap_request: Receiver<(SwapRequest, ResponseChannel<SwapResponse>)>,
-    conn_established: Receiver<PeerId>,
-    send_swap_response: Sender<(ResponseChannel<SwapResponse>, SwapResponse)>,
-    start_execution_setup: Sender<(PeerId, State0)>,
     send_transfer_proof: Sender<(PeerId, TransferProof)>,
     recv_transfer_proof_ack: Receiver<()>,
 }
 
 impl EventLoopHandle {
-    pub async fn recv_conn_established(&mut self) -> Result<PeerId> {
-        self.conn_established
-            .recv()
-            .await
-            .ok_or_else(|| anyhow!("Failed to receive connection established from Bob"))
-    }
-
-    pub async fn execution_setup(&mut self, bob_peer_id: PeerId, state0: State0) -> Result<State3> {
-        let _ = self
-            .start_execution_setup
-            .send((bob_peer_id, state0))
-            .await?;
-
-        self.done_execution_setup
-            .recv()
-            .await
-            .ok_or_else(|| anyhow!("Failed to setup execution with Bob"))
-    }
-
     pub async fn recv_encrypted_signature(&mut self) -> Result<EncryptedSignature> {
         self.recv_encrypted_signature
             .recv()
@@ -71,27 +47,6 @@ impl EventLoopHandle {
             .ok_or_else(|| anyhow!("Failed to receive Bitcoin encrypted signature from Bob"))
     }
 
-    pub async fn recv_swap_request(
-        &mut self,
-    ) -> Result<(SwapRequest, ResponseChannel<SwapResponse>)> {
-        self.recv_swap_request
-            .recv()
-            .await
-            .ok_or_else(|| anyhow!("Failed to receive amounts request from Bob"))
-    }
-
-    pub async fn send_swap_response(
-        &mut self,
-        channel: ResponseChannel<SwapResponse>,
-        swap_response: SwapResponse,
-    ) -> Result<()> {
-        let _ = self
-            .send_swap_response
-            .send((channel, swap_response))
-            .await?;
-        Ok(())
-    }
-
     pub async fn send_transfer_proof(
         &mut self,
         bob: PeerId,
@@ -120,12 +75,7 @@ impl EventLoopHandle {
 #[allow(missing_debug_implementations)]
 pub struct EventLoop {
     swarm: libp2p::Swarm<Behaviour>,
-    start_execution_setup: Receiver<(PeerId, State0)>,
-    done_execution_setup: Sender<State3>,
     recv_encrypted_signature: Sender<EncryptedSignature>,
-    recv_swap_request: Sender<(SwapRequest, ResponseChannel<SwapResponse>)>,
-    conn_established: Sender<PeerId>,
-    send_swap_response: Receiver<(ResponseChannel<SwapResponse>, SwapResponse)>,
     send_transfer_proof: Receiver<(PeerId, TransferProof)>,
     recv_transfer_proof_ack: Sender<()>,
 }
@@ -148,34 +98,19 @@ impl EventLoop {
         Swarm::listen_on(&mut swarm, listen.clone())
             .with_context(|| format!("Address is not supported: {:#}", listen))?;
 
-        let start_execution_setup = Channels::default();
-        let done_execution_setup = Channels::default();
         let recv_encrypted_signature = Channels::default();
-        let request = Channels::default();
-        let conn_established = Channels::default();
-        let send_swap_response = Channels::default();
         let send_transfer_proof = Channels::default();
         let recv_transfer_proof_ack = Channels::default();
 
         let driver = EventLoop {
             swarm,
-            start_execution_setup: start_execution_setup.receiver,
-            done_execution_setup: done_execution_setup.sender,
             recv_encrypted_signature: recv_encrypted_signature.sender,
-            recv_swap_request: request.sender,
-            conn_established: conn_established.sender,
-            send_swap_response: send_swap_response.receiver,
             send_transfer_proof: send_transfer_proof.receiver,
             recv_transfer_proof_ack: recv_transfer_proof_ack.sender,
         };
 
         let handle = EventLoopHandle {
-            start_execution_setup: start_execution_setup.sender,
-            done_execution_setup: done_execution_setup.receiver,
             recv_encrypted_signature: recv_encrypted_signature.receiver,
-            recv_swap_request: request.receiver,
-            conn_established: conn_established.receiver,
-            send_swap_response: send_swap_response.sender,
             send_transfer_proof: send_transfer_proof.sender,
             recv_transfer_proof_ack: recv_transfer_proof_ack.receiver,
         };
@@ -189,13 +124,13 @@ impl EventLoop {
                 swarm_event = self.swarm.next().fuse() => {
                     match swarm_event {
                         OutEvent::ConnectionEstablished(alice) => {
-                            let _ = self.conn_established.send(alice).await;
+                            debug!("Connection Established with {}", alice);
                         }
                         OutEvent::SwapRequest { msg, channel } => {
-                            let _ = self.recv_swap_request.send((msg, channel)).await;
+                            let _ = self.handle_swap_request(msg, channel).await;
                         }
                         OutEvent::ExecutionSetupDone(state3) => {
-                            let _ = self.done_execution_setup.send(*state3).await;
+                            let _ = self.handle_execution_setup_done(*state3).await;
                         }
                         OutEvent::TransferProofAcknowledged => {
                             trace!("Bob acknowledged transfer proof");
@@ -214,21 +149,6 @@ impl EventLoop {
                         }
                     }
                 },
-                swap_response = self.send_swap_response.recv().fuse() => {
-                    if let Some((channel, swap_response)) = swap_response  {
-                        let _ = self
-                            .swarm
-                            .send_swap_response(channel, swap_response)
-                            .map_err(|err|error!("Failed to send swap response: {:#}", err));
-                    }
-                },
-                option = self.start_execution_setup.recv().fuse() => {
-                    if let Some((bob_peer_id, state0)) = option {
-                        let _ = self
-                            .swarm
-                            .start_execution_setup(bob_peer_id, state0);
-                    }
-                },
                 transfer_proof = self.send_transfer_proof.recv().fuse() => {
                     if let Some((bob_peer_id, msg)) = transfer_proof  {
                       self.swarm.send_transfer_proof(bob_peer_id, msg);
@@ -237,4 +157,13 @@ impl EventLoop {
             }
         }
     }
+
+    async fn handle_swap_request(
+        &self,
+        _msg: SwapRequest,
+        _channel: ResponseChannel<SwapResponse>,
+    ) {
+    }
+
+    async fn handle_execution_setup_done(&self, _state3: State3) {}
 }

swap/src/protocol/alice/steps.rs

@@ -12,7 +12,7 @@ use crate::{
     monero::Transfer,
     protocol::{
         alice,
-        alice::{event_loop::EventLoopHandle, SwapResponse, TransferProof},
+        alice::{event_loop::EventLoopHandle, TransferProof},
         SwapAmounts,
     },
 };
@@ -26,43 +26,7 @@ use libp2p::PeerId;
 use sha2::Sha256;
 use std::sync::Arc;
 use tokio::time::timeout;
-use tracing::{info, trace};
-
-pub async fn negotiate(
-    state0: alice::State0,
-    xmr_amount: monero::Amount,
-    event_loop_handle: &mut EventLoopHandle,
-    execution_params: ExecutionParams,
-) -> Result<(PeerId, alice::State3)> {
-    trace!("Starting negotiate");
-
-    // todo: we can move this out, we dont need to timeout here
-    let bob_peer_id = timeout(
-        execution_params.bob_time_to_act,
-        event_loop_handle.recv_conn_established(),
-    )
-    .await
-    .context("Failed to receive dial connection from Bob")??;
-
-    let event = timeout(
-        execution_params.bob_time_to_act,
-        event_loop_handle.recv_swap_request(),
-    )
-    .await
-    .context("Failed to receive swap request from Bob")??;
-
-    event_loop_handle
-        .send_swap_response(event.1, SwapResponse { xmr_amount })
-        .await?;
-
-    let state3 = timeout(
-        execution_params.bob_time_to_act,
-        event_loop_handle.execution_setup(bob_peer_id, state0),
-    )
-    .await??;
-
-    Ok((bob_peer_id, state3))
-}
+use tracing::info;
 
 // TODO(Franck): Use helper functions from xmr-btc instead of re-writing them
 // here

swap/src/protocol/alice/swap.rs

@@ -17,10 +17,10 @@ use crate::{
             event_loop::EventLoopHandle,
             steps::{
                 build_bitcoin_punish_transaction, build_bitcoin_redeem_transaction,
-                extract_monero_private_key, lock_xmr, negotiate,
-                publish_bitcoin_punish_transaction, publish_bitcoin_redeem_transaction,
-                publish_cancel_transaction, wait_for_bitcoin_encrypted_signature,
-                wait_for_bitcoin_refund, wait_for_locked_bitcoin,
+                extract_monero_private_key, lock_xmr, publish_bitcoin_punish_transaction,
+                publish_bitcoin_redeem_transaction, publish_cancel_transaction,
+                wait_for_bitcoin_encrypted_signature, wait_for_bitcoin_refund,
+                wait_for_locked_bitcoin,
             },
             AliceState,
         },
@@ -92,18 +92,10 @@ async fn run_until_internal(
     } else {
         match state {
             AliceState::Started { amounts, state0 } => {
-                let (bob_peer_id, state3) = negotiate(
-                    state0,
-                    amounts.xmr,
-                    &mut event_loop_handle,
-                    execution_params,
-                )
-                .await?;
-
                 let state = AliceState::Negotiated {
-                    bob_peer_id,
+                    bob_peer_id: todo!(),
                     amounts,
-                    state3: Box::new(state3),
+                    state3: todo!(),
                 };
 
                 let db_state = (&state).into();