From ae9dcba6b49be90b5808814e0b42c7e6080ad540 Mon Sep 17 00:00:00 2001
From: Andrew Fitzgerald <apfitzge@gmail.com>
Date: Mon, 2 Oct 2023 20:58:00 +0000
Subject: [PATCH] ScannedLookupTableExtensions struct

---
 ledger/src/blockstore.rs                      | 14 ++++-----
 ...ransaction_address_lookup_table_scanner.rs | 29 +++++++------------
 2 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/ledger/src/blockstore.rs b/ledger/src/blockstore.rs
index 351159e91ec192..fccb0f4f7aaa44 100644
--- a/ledger/src/blockstore.rs
+++ b/ledger/src/blockstore.rs
@@ -21,7 +21,7 @@ use {
             Shred, ShredData, ShredId, ShredType, Shredder,
         },
         slot_stats::{ShredSource, SlotsStats},
-        transaction_address_lookup_table_scanner::{scan_transaction, ScanResult},
+        transaction_address_lookup_table_scanner::scan_transaction,
     },
     assert_matches::debug_assert_matches,
     bincode::{deserialize, serialize},
@@ -2958,14 +2958,10 @@ impl Blockstore {
                                 let tx = SanitizedVersionedTransaction::try_from(tx)
                                     .expect("transaction failed to sanitize");
 
-                                let alt_scan_result = scan_transaction(&tx);
-                                match alt_scan_result {
-                                    ScanResult::NotFound => {}
-                                    ScanResult::NativeUsed(keys) => add_to_set(&result, &keys),
-                                    ScanResult::NonNativeUsed(keys) => {
-                                        add_to_set(&result, &keys);
-                                        possible_cpi_alt_extend.store(true, Ordering::Relaxed);
-                                    }
+                                let alt_scan_extensions = scan_transaction(&tx);
+                                add_to_set(&result, &alt_scan_extensions.accounts);
+                                if alt_scan_extensions.possibly_incomplete {
+                                    possible_cpi_alt_extend.store(true, Ordering::Relaxed);
                                 }
                             }
                         });
diff --git a/ledger/src/transaction_address_lookup_table_scanner.rs b/ledger/src/transaction_address_lookup_table_scanner.rs
index f21a2c72ff6500..dd51c97f30b031 100644
--- a/ledger/src/transaction_address_lookup_table_scanner.rs
+++ b/ledger/src/transaction_address_lookup_table_scanner.rs
@@ -14,21 +14,15 @@ lazy_static! {
     static ref SDK_IDS_SET: HashSet<Pubkey> = SDK_IDS.iter().cloned().collect();
 }
 
-pub enum ScanResult {
-    /// The address lookup table program was not used
-    NotFound,
-    /// The address lookup table program was present, with non-native programs.
-    /// If instructions extending an account lookup table were found, the list
-    /// of Pubkeys will be returned. However, this may be incomplete due to the
-    /// possibility of non-native ixs CPIing to extend.
-    NonNativeUsed(Vec<Pubkey>),
-    /// The address lookup table program was present, with only native programs.
-    /// If instructions extending an account lookup table were found, the list
-    /// of Pubkeys will be returned.
-    NativeUsed(Vec<Pubkey>),
+#[derive(Default)]
+pub struct ScannedLookupTableExtensions {
+    pub possibly_incomplete: bool,
+    pub accounts: Vec<Pubkey>, // empty if no extensions found
 }
 
-pub fn scan_transaction(transaction: &SanitizedVersionedTransaction) -> ScanResult {
+pub fn scan_transaction(
+    transaction: &SanitizedVersionedTransaction,
+) -> ScannedLookupTableExtensions {
     // If the ALT program is not present in the account keys, it was not used
     if !transaction
         .get_message()
@@ -37,7 +31,7 @@ pub fn scan_transaction(transaction: &SanitizedVersionedTransaction) -> ScanResu
         .iter()
         .any(address_lookup_table::program::check_id)
     {
-        return ScanResult::NotFound;
+        return ScannedLookupTableExtensions::default();
     }
 
     // Accumulate accounts from account lookup table extension instructions
@@ -55,9 +49,8 @@ pub fn scan_transaction(transaction: &SanitizedVersionedTransaction) -> ScanResu
         }
     }
 
-    if native_only {
-        ScanResult::NativeUsed(accounts)
-    } else {
-        ScanResult::NonNativeUsed(accounts)
+    ScannedLookupTableExtensions {
+        possibly_incomplete: !native_only,
+        accounts,
     }
 }