From d4d42ae3ae8e19d0e2e185b2a19c5eb1aabd437f Mon Sep 17 00:00:00 2001
From: rishflab <rishflab@hotmail.com>
Date: Wed, 10 Feb 2021 12:31:16 +1100
Subject: [PATCH] Debugging: Checked sub to calculate tx confirmation

---
 swap/src/bitcoin/timelocks.rs | 13 ++-----------
 swap/src/bitcoin/wallet.rs    | 12 +++++++-----
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/swap/src/bitcoin/timelocks.rs b/swap/src/bitcoin/timelocks.rs
index c850906a..c0c8da4e 100644
--- a/swap/src/bitcoin/timelocks.rs
+++ b/swap/src/bitcoin/timelocks.rs
@@ -1,6 +1,5 @@
-use std::ops::{Add, Sub};
-
 use serde::{Deserialize, Serialize};
+use std::ops::Add;
 
 /// Represent a timelock, expressed in relative block height as defined in
 /// [BIP68](https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki).
@@ -27,7 +26,7 @@ impl From<Timelock> for u32 {
 /// after the genesis block.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Ord, PartialOrd, Serialize, Deserialize)]
 #[serde(transparent)]
-pub struct BlockHeight(u32);
+pub struct BlockHeight(pub u32);
 
 impl From<BlockHeight> for u32 {
     fn from(height: BlockHeight) -> Self {
@@ -49,14 +48,6 @@ impl Add<Timelock> for BlockHeight {
     }
 }
 
-impl Sub<BlockHeight> for BlockHeight {
-    type Output = BlockHeight;
-
-    fn sub(self, rhs: BlockHeight) -> Self::Output {
-        BlockHeight(self.0 - rhs.0)
-    }
-}
-
 #[derive(Debug, Clone, Copy)]
 pub enum ExpiredTimelocks {
     None,
diff --git a/swap/src/bitcoin/wallet.rs b/swap/src/bitcoin/wallet.rs
index 7873b7ac..1d75d404 100644
--- a/swap/src/bitcoin/wallet.rs
+++ b/swap/src/bitcoin/wallet.rs
@@ -264,13 +264,15 @@ impl WaitForTransactionFinality for Wallet {
         let mut interval = interval(execution_params.bitcoin_avg_block_time / 4);
 
         loop {
-            tracing::debug!("syncing wallet");
             let tx_block_height = self.transaction_block_height(txid).await;
+            tracing::debug!("tx_block_height: {}", tx_block_height.0);
             let block_height = self.get_block_height().await;
-            let confirmations = block_height - tx_block_height;
-            tracing::debug!("confirmations: {:?}", confirmations);
-            if confirmations >= BlockHeight::new(execution_params.bitcoin_finality_confirmations) {
-                break;
+            tracing::debug!("block_height: {}", block_height.0);
+            if let Some(confirmations) = block_height.0.checked_sub(tx_block_height.0) {
+                tracing::debug!("confirmations: {:?}", confirmations);
+                if confirmations >= execution_params.bitcoin_finality_confirmations {
+                    break;
+                }
             }
             interval.tick().await;
         }