add comments for PreCheckedTx

tx-pool/src/pool.rs

@@ -541,7 +541,7 @@ impl TxPool {
         assert!(!conflicts.is_empty());
 
         let short_id = rtx.transaction.proposal_short_id();
-        // Rule #4, new tx' fee need to higher than min_rbf_fee computed from the tx_pool configuration
+        // Rule #4, new tx's fee need to higher than min_rbf_fee computed from the tx_pool configuration
         // Rule #3, new tx's fee need to higher than conflicts, here we only check the root tx
         if let Some(min_replace_fee) = self.calculate_min_replace_fee(conflicts, tx_size) {
             if fee < min_replace_fee {

tx-pool/src/process.rs

@@ -1002,11 +1002,13 @@ impl TxPoolService {
 }
 
 type PreCheckedTx = (
-    Byte32,
-    Arc<ResolvedTransaction>,
-    TxStatus,
-    Capacity,
-    usize,
+    Byte32,                   // tip_hash
+    Arc<ResolvedTransaction>, // rtx
+    TxStatus,                 // status
+    Capacity,                 // tx fee
+    usize,                    // tx size
+    // the conflicted txs, used for latter `check_rbf`
+    // the root txs for removing from `tx-pool` when RBF is checked
     HashSet<ProposalShortId>,
 );