chore: more misc tracing (#9809)

crates/chain-state/src/in_memory.rs

@@ -515,6 +515,21 @@ pub enum NewCanonicalChain {
 }
 
 impl NewCanonicalChain {
+    /// Returns the length of the new chain.
+    pub fn new_block_count(&self) -> usize {
+        match self {
+            Self::Commit { new } | Self::Reorg { new, .. } => new.len(),
+        }
+    }
+
+    /// Returns the length of the reorged chain.
+    pub fn reorged_block_count(&self) -> usize {
+        match self {
+            Self::Commit { .. } => 0,
+            Self::Reorg { old, .. } => old.len(),
+        }
+    }
+
     /// Converts the new chain into a notification that will be emitted to listeners
     pub fn to_chain_notification(&self) -> CanonStateNotification {
         // TODO: do we need to merge execution outcome for multiblock commit or reorg?

crates/engine/tree/src/tree.rs

@@ -272,9 +272,6 @@ impl EngineApiTreeState {
 }
 
 /// The type responsible for processing engine API requests.
-///
-/// TODO: design: should the engine handler functions also accept the response channel or return the
-/// result and the caller redirects the response
 pub trait EngineApiTreeHandler {
     /// The engine type that this handler is for.
     type Engine: EngineTypes;
@@ -1473,7 +1470,7 @@ where
 
         // 2. ensure we can apply a new chain update for the head block
         if let Some(chain_update) = self.state.tree_state.on_new_head(state.head_block_hash) {
-            trace!(target: "engine", "applying new chain update");
+            trace!(target: "engine", new_blocks = %chain_update.new_block_count(), reorged_blocks =  %chain_update.reorged_block_count() ,"applying new chain update");
             // update the tracked canonical head
             self.state.tree_state.set_canonical_head(chain_update.tip().num_hash());