Clean up some logs and comments

swap/src/alice.rs

@@ -12,8 +12,7 @@ use libp2p::{
 use rand::rngs::OsRng;
 use std::{sync::Arc, time::Duration};
 use tokio::sync::Mutex;
-use tracing::{info, warn};
-use xmr_btc::alice;
+use tracing::{debug, info, warn};
 
 mod amounts;
 mod message0;
@@ -34,14 +33,12 @@ use crate::{
     SwapAmounts, PUNISH_TIMELOCK, REFUND_TIMELOCK,
 };
 use xmr_btc::{
-    alice::{action_generator, Action, ReceiveBitcoinRedeemEncsig, State0},
+    alice::{self, action_generator, Action, ReceiveBitcoinRedeemEncsig, State0},
     bitcoin::BroadcastSignedTransaction,
     bob,
     monero::{CreateWalletForOutput, Transfer},
 };
 
-pub type Swarm = libp2p::Swarm<Alice>;
-
 pub async fn swap(
     bitcoin_wallet: Arc<bitcoin::Wallet>,
     monero_wallet: Arc<monero::Wallet>,
@@ -55,15 +52,14 @@ pub async fn swap(
 
     impl Network {
         pub async fn send_message2(&mut self, proof: monero::TransferProof) {
-            tracing::debug!("Sending transfer proof");
-
             match self.channel.take() {
                 None => warn!("Channel not found, did you call this twice?"),
                 Some(channel) => {
                     let mut guard = self.swarm.lock().await;
                     guard.send_message2(channel, alice::Message2 {
                         tx_lock_proof: proof,
-                    })
+                    });
+                    info!("Sent transfer proof");
                 }
             }
         }
@@ -78,17 +74,12 @@ pub async fn swap(
             #[derive(Debug)]
             struct UnexpectedMessage;
 
-            tracing::debug!("Receiving bitcoin redeem encsig");
-
-            (|| async {
+            let encsig = (|| async {
                 let mut guard = self.swarm.lock().await;
                 let encsig = match guard.next().await {
-                    OutEvent::Message3(msg) => {
-                        tracing::debug!("Got redeem encsig from Bob");
-                        msg.tx_redeem_encsig
-                    }
+                    OutEvent::Message3(msg) => msg.tx_redeem_encsig,
                     other => {
-                        warn!("Expected Bob's Message3, got: {:?}", other);
+                        warn!("Expected Bob's Bitcoin redeem encsig, got: {:?}", other);
                         return Err(backoff::Error::Transient(UnexpectedMessage));
                     }
                 };
@@ -97,33 +88,35 @@ pub async fn swap(
             })
             .retry(ConstantBackoff::new(Duration::from_secs(1)))
             .await
-            .expect("transient errors to be retried")
+            .expect("transient errors to be retried");
+
+            info!("Received Bitcoin redeem encsig");
+
+            encsig
         }
     }
 
-    tracing::debug!("swapping ...");
-
     let mut swarm = new_swarm(listen, local_port)?;
     let message0: bob::Message0;
     let mut state0: Option<alice::State0> = None;
     let mut last_amounts: Option<SwapAmounts> = None;
 
+    // TODO: This loop is a neat idea for local development, as it allows us to keep
+    // Alice up and let Bob keep trying to connect, request amounts and/or send the
+    // first message of the handshake, but it comes at the cost of needing to handle
+    // mutable state, which has already been the source of a bug at one point. This
+    // is an obvious candidate for refactoring
     loop {
         match swarm.next().await {
-            OutEvent::ConnectionEstablished(id) => {
-                info!("Connection established with: {}", id);
+            OutEvent::ConnectionEstablished(bob) => {
+                info!("Connection established with: {}", bob);
             }
             OutEvent::Request(amounts::OutEvent::Btc { btc, channel }) => {
                 let amounts = calculate_amounts(btc);
-                // TODO: We cache the last amounts returned, this needs improving along with
-                // verification of message 0.
                 last_amounts = Some(amounts);
                 swarm.send_amounts(channel, amounts);
 
-                let (xmr, btc) = match last_amounts {
-                    Some(p) => (p.xmr, p.btc),
-                    None => unreachable!("should have amounts by here"),
-                };
+                let SwapAmounts { btc, xmr } = amounts;
 
                 let redeem_address = bitcoin_wallet.as_ref().new_address().await?;
                 let punish_address = redeem_address.clone();
@@ -139,6 +132,8 @@ pub async fn swap(
                     redeem_address,
                     punish_address,
                 );
+
+                info!("Commencing handshake");
                 swarm.set_state0(state.clone());
 
                 state0 = Some(state)
@@ -156,10 +151,7 @@ pub async fn swap(
         };
     }
 
-    let state1 = state0
-        .expect("to be set")
-        .receive(message0)
-        .expect("failed to receive msg 0");
+    let state1 = state0.expect("to be set").receive(message0)?;
 
     let (state2, channel) = match swarm.next().await {
         OutEvent::Message1 { msg, channel } => {
@@ -197,7 +189,7 @@ pub async fn swap(
     loop {
         let state = action_generator.async_resume().await;
 
-        tracing::info!("resumed execution of alice generator, got: {:?}", state);
+        tracing::info!("Resumed execution of generator, got: {:?}", state);
 
         match state {
             GeneratorState::Yielded(Action::LockXmr {
@@ -211,6 +203,7 @@ pub async fn swap(
 
                 let mut guard = network.as_ref().lock().await;
                 guard.send_message2(transfer_proof).await;
+                info!("Sent transfer proof");
             }
 
             GeneratorState::Yielded(Action::RedeemBtc(tx)) => {
@@ -235,6 +228,8 @@ pub async fn swap(
     }
 }
 
+pub type Swarm = libp2p::Swarm<Alice>;
+
 fn new_swarm(listen: Multiaddr, port: Option<u16>) -> Result<Swarm> {
     use anyhow::Context as _;
 
@@ -366,11 +361,12 @@ impl Alice {
     pub fn send_amounts(&mut self, channel: ResponseChannel<AliceToBob>, amounts: SwapAmounts) {
         let msg = AliceToBob::Amounts(amounts);
         self.amounts.send(channel, msg);
+        info!("Sent amounts response");
     }
 
     /// Message0 gets sent within the network layer using this state0.
     pub fn set_state0(&mut self, state: State0) {
-        info!("Set state 0");
+        debug!("Set state 0");
         let _ = self.message0.set_state(state);
     }
 
@@ -380,7 +376,8 @@ impl Alice {
         channel: ResponseChannel<AliceToBob>,
         msg: xmr_btc::alice::Message1,
     ) {
-        self.message1.send(channel, msg)
+        self.message1.send(channel, msg);
+        debug!("Sent Message1");
     }
 
     /// Send Message2 to Bob in response to receiving his Message2.
@@ -389,7 +386,8 @@ impl Alice {
         channel: ResponseChannel<AliceToBob>,
         msg: xmr_btc::alice::Message2,
     ) {
-        self.message2.send(channel, msg)
+        self.message2.send(channel, msg);
+        debug!("Sent Message2");
     }
 }
 
@@ -410,11 +408,11 @@ impl Default for Alice {
 }
 
 fn calculate_amounts(btc: ::bitcoin::Amount) -> SwapAmounts {
-    const XMR_PER_BTC: u64 = 100; // TODO: Get this from an exchange.
+    // TODO: Get this from an exchange.
+    // This value corresponds to 100 XMR per BTC
+    const PICONERO_PER_SAT: u64 = 1_000_000;
 
-    // TODO: Check that this is correct.
-    // XMR uses 12 zerose BTC uses 8.
-    let picos = (btc.as_sat() * 10000) * XMR_PER_BTC;
+    let picos = btc.as_sat() * PICONERO_PER_SAT;
     let xmr = monero::Amount::from_piconero(picos);
 
     SwapAmounts { btc, xmr }