test: add suite of scenarios for txs topological order

Author: oleonardolima

crates/chain/src/canonical_iter.rs

@@ -14,7 +14,7 @@ type NotCanonicalSet = HashSet<Txid>;
 /// Modifies the canonicalization algorithm.
 #[derive(Debug, Default, Clone)]
 pub struct CanonicalizationParams {
-    /// Transactions that will supercede all other transactions.
+    /// Transactions that will supersede all other transactions.
     ///
     /// In case of conflicting transactions within `assume_canonical`, transactions that appear
     /// later in the list (have higher index) have precedence.
@@ -108,7 +108,7 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
                 .iter()
                 .last()
                 .expect(
-                    "tx taken from `unprocessed_txs_with_anchors` so it must atleast have an anchor",
+                    "tx taken from `unprocessed_txs_with_anchors` so it must at least have an anchor",
                 )
                 .confirmation_height_upper_bound(),
         ));
@@ -142,8 +142,9 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
         let staged_queue = TxAncestors::new_include_root(
             self.tx_graph,
             tx,
-            |_: usize, tx: Arc<Transaction>| -> Option<Txid> {
+            |depth: usize, tx: Arc<Transaction>| -> Option<Txid> {
                 let this_txid = tx.compute_txid();
+                println!("[canonical_iter] depth: {:?} ; txid: {:?}", depth, this_txid);
                 let this_reason = if is_starting_tx {
                     is_starting_tx = false;
                     reason.clone()
@@ -158,6 +159,8 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
                     Entry::Vacant(entry) => entry,
                 };
 
+                // TODO: should we also check that it's already been visited by the `self.not_canonical` ?
+
                 // Any conflicts with a canonical tx can be added to `not_canonical`. Descendants
                 // of `not_canonical` txs can also be added to `not_canonical`.
                 for (_, conflict_txid) in self.tx_graph.direct_conflicts(&tx) {
@@ -166,8 +169,8 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
                         conflict_txid,
                         |_: usize, txid: Txid| -> Option<()> {
                             if self.not_canonical.insert(txid) {
-                                undo_not_canonical.push(txid);
-                                Some(())
+                                undo_not_canonical.push(txid); 
+                               Some(())
                             } else {
                                 None
                             }
@@ -181,7 +184,8 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
                     detected_self_double_spend = true;
                     return None;
                 }
-                canonical_entry.insert((tx, this_reason));
+                canonical_entry.insert((tx.clone(), this_reason));
+                println!("mark_canonical: {:?}", tx.clone().compute_txid());
                 Some(this_txid)
             },
         )
@@ -196,6 +200,7 @@ impl<'g, A: Anchor, C: ChainOracle> CanonicalIter<'g, A, C> {
             }
         } else {
             self.queue.extend(staged_queue);
+            println!("staged_queue: {:?}", self.queue);
         }
     }
 }
@@ -205,7 +210,7 @@ impl<A: Anchor, C: ChainOracle> Iterator for CanonicalIter<'_, A, C> {
 
     fn next(&mut self) -> Option<Self::Item> {
         loop {
-            if let Some(txid) = self.queue.pop_front() {
+            if let Some(txid) = self.queue.pop_back() {
                 let (tx, reason) = self
                     .canonical
                     .get(&txid)
@@ -222,6 +227,7 @@ impl<A: Anchor, C: ChainOracle> Iterator for CanonicalIter<'_, A, C> {
 
             if let Some((txid, tx, anchors)) = self.unprocessed_anchored_txs.next() {
                 if !self.is_canonicalized(txid) {
+                    println!("{:?}", txid);
                     if let Err(err) = self.scan_anchors(txid, tx, anchors) {
                         return Some(Err(err));
                     }
@@ -266,7 +272,7 @@ pub enum ObservedIn {
 /// The reason why a transaction is canonical.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CanonicalReason<A> {
-    /// This transaction is explicitly assumed to be canonical by the caller, superceding all other
+    /// This transaction is explicitly assumed to be canonical by the caller, superseding all other
     /// canonicalization rules.
     Assumed {
         /// Whether it is a descendant that is assumed to be canonical.
@@ -312,7 +318,7 @@ impl<A: Clone> CanonicalReason<A> {
         }
     }
 
-    /// Contruct a new [`CanonicalReason`] from the original which is transitive to `descendant`.
+    /// Construct a new [`CanonicalReason`] from the original which is transitive to `descendant`.
     ///
     /// This signals that either the [`ObservedIn`] or [`Anchor`] value belongs to the transaction's
     /// descendant, but is transitively relevant.

crates/chain/src/tx_graph.rs

@@ -1641,7 +1641,7 @@ where
     F: FnMut(usize, Arc<Transaction>) -> Option<O>,
 {
     /// Creates a `TxAncestors` that includes the starting `Transaction` when iterating.
-    pub(crate) fn new_include_root(
+    pub fn new_include_root(
         graph: &'g TxGraph<A>,
         tx: impl Into<Arc<Transaction>>,
         filter_map: F,