From d940c6ede0477cd38d559c546a75d1e2437f4761 Mon Sep 17 00:00:00 2001
From: apfitzge <apfitzge@users.noreply.github.com>
Date: Fri, 19 Aug 2022 09:33:50 -0500
Subject: [PATCH] slots_connected: check if the range is connected (>=
 ending_slot) (#27152)

---
 ledger-tool/src/main.rs  |  4 ++--
 ledger/src/blockstore.rs | 27 +++++++++++++--------------
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/ledger-tool/src/main.rs b/ledger-tool/src/main.rs
index e2b6fdc2e7609a..ce3d42a06a0a9a 100644
--- a/ledger-tool/src/main.rs
+++ b/ledger-tool/src/main.rs
@@ -955,9 +955,9 @@ fn load_bank_forks(
     };
 
     if let Some(halt_slot) = process_options.halt_at_slot {
-        // Check if we have the slot data necessary to replay from starting_slot to halt_slot.
+        // Check if we have the slot data necessary to replay from starting_slot to >= halt_slot.
         //  - This will not catch the case when loading from genesis without a full slot 0.
-        if !blockstore.slots_connected(starting_slot, halt_slot) {
+        if !blockstore.slot_range_connected(starting_slot, halt_slot) {
             eprintln!(
                 "Unable to load bank forks at slot {} due to disconnected blocks.",
                 halt_slot,
diff --git a/ledger/src/blockstore.rs b/ledger/src/blockstore.rs
index 2c0913a5ab8cfb..5c246b5ab8045c 100644
--- a/ledger/src/blockstore.rs
+++ b/ledger/src/blockstore.rs
@@ -546,9 +546,9 @@ impl Blockstore {
         self.prepare_rooted_slot_iterator(slot, IteratorDirection::Reverse)
     }
 
-    /// Determines if `starting_slot` and `ending_slot` are connected by full slots
+    /// Determines if we can iterate from `starting_slot` to >= `ending_slot` by full slots
     /// `starting_slot` is excluded from the `is_full()` check
-    pub fn slots_connected(&self, starting_slot: Slot, ending_slot: Slot) -> bool {
+    pub fn slot_range_connected(&self, starting_slot: Slot, ending_slot: Slot) -> bool {
         if starting_slot == ending_slot {
             return true;
         }
@@ -562,8 +562,7 @@ impl Blockstore {
                 if slot_meta.is_full() {
                     match slot.cmp(&ending_slot) {
                         cmp::Ordering::Less => next_slots.extend(slot_meta.next_slots),
-                        cmp::Ordering::Equal => return true,
-                        cmp::Ordering::Greater => {} // slot is greater than the ending slot, so all its children would be as well
+                        _ => return true,
                     }
                 }
             }
@@ -5502,7 +5501,7 @@ pub mod tests {
         }
     */
     #[test]
-    fn test_slots_connected_chain() {
+    fn test_slot_range_connected_chain() {
         let ledger_path = get_tmp_ledger_path_auto_delete!();
         let blockstore = Blockstore::open(ledger_path.path()).unwrap();
 
@@ -5511,12 +5510,12 @@ pub mod tests {
             make_and_insert_slot(&blockstore, slot, slot.saturating_sub(1));
         }
 
-        assert!(blockstore.slots_connected(1, 3));
-        assert!(!blockstore.slots_connected(1, 4)); // slot 4 does not exist
+        assert!(blockstore.slot_range_connected(1, 3));
+        assert!(!blockstore.slot_range_connected(1, 4)); // slot 4 does not exist
     }
 
     #[test]
-    fn test_slots_connected_disconnected() {
+    fn test_slot_range_connected_disconnected() {
         let ledger_path = get_tmp_ledger_path_auto_delete!();
         let blockstore = Blockstore::open(ledger_path.path()).unwrap();
 
@@ -5524,20 +5523,20 @@ pub mod tests {
         make_and_insert_slot(&blockstore, 2, 1);
         make_and_insert_slot(&blockstore, 4, 2);
 
-        assert!(!blockstore.slots_connected(1, 3)); // Slot 3 does not exit
-        assert!(blockstore.slots_connected(1, 4));
+        assert!(blockstore.slot_range_connected(1, 3)); // Slot 3 does not exist, but we can still replay this range to slot 4
+        assert!(blockstore.slot_range_connected(1, 4));
     }
 
     #[test]
-    fn test_slots_connected_same_slot() {
+    fn test_slot_range_connected_same_slot() {
         let ledger_path = get_tmp_ledger_path_auto_delete!();
         let blockstore = Blockstore::open(ledger_path.path()).unwrap();
 
-        assert!(blockstore.slots_connected(54, 54));
+        assert!(blockstore.slot_range_connected(54, 54));
     }
 
     #[test]
-    fn test_slots_connected_starting_slot_not_full() {
+    fn test_slot_range_connected_starting_slot_not_full() {
         let ledger_path = get_tmp_ledger_path_auto_delete!();
         let blockstore = Blockstore::open(ledger_path.path()).unwrap();
 
@@ -5545,7 +5544,7 @@ pub mod tests {
         make_and_insert_slot(&blockstore, 6, 5);
 
         assert!(!blockstore.meta(4).unwrap().unwrap().is_full());
-        assert!(blockstore.slots_connected(4, 6));
+        assert!(blockstore.slot_range_connected(4, 6));
     }
 
     #[test]