Add input and output note counts

Address more review comments

Minor cleanup

Author: Mirko-von-Leipzig

crates/block-producer/src/domain/transaction.rs

@@ -99,6 +99,14 @@ impl AuthenticatedTransaction {
         self.inner.output_notes().iter().map(|note| note.id())
     }
 
+    pub fn output_note_count(&self) -> usize {
+        self.inner.output_notes().num_notes()
+    }
+
+    pub fn input_note_count(&self) -> usize {
+        self.inner.input_notes().num_notes()
+    }
+
     /// Notes which were unauthenticate in the transaction __and__ which were
     /// not authenticated by the store inputs.
     pub fn unauthenticated_notes(&self) -> impl Iterator<Item = NoteId> + '_ {

crates/block-producer/src/mempool/mod.rs

@@ -136,9 +136,8 @@ impl BatchBudget {
         let _: miden_objects::accounts::AccountId = tx.account_update().account_id();
         const ACCOUNT_UPDATES_PER_TX: usize = 1;
 
-        // TODO: This is inefficient and ProvenTransaction should provide len() access.
-        let output_notes = tx.output_notes().count();
-        let input_notes = tx.nullifiers().count();
+        let output_notes = tx.output_note_count();
+        let input_notes = tx.input_note_count();
 
         if self.transactions == 0
             || self.accounts < ACCOUNT_UPDATES_PER_TX