From 9374b6c2bc4a36cc96e6fa4e76398ef32edf7fbc Mon Sep 17 00:00:00 2001
From: Josh Lind <josh.lind@hotmail.com>
Date: Sun, 7 Jul 2024 10:54:02 -0400
Subject: [PATCH] [Consensus Observer] Add support for disabling QS.

---
 consensus/src/consensus_observer/observer.rs | 36 +++++++++++++-------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/consensus/src/consensus_observer/observer.rs b/consensus/src/consensus_observer/observer.rs
index 8aeac9d5003d14..b606a8f05f2552 100644
--- a/consensus/src/consensus_observer/observer.rs
+++ b/consensus/src/consensus_observer/observer.rs
@@ -76,6 +76,8 @@ pub struct ConsensusObserver {
 
     // The current epoch state
     epoch_state: Option<Arc<EpochState>>,
+    // Whether quorum store is enabled (updated on epoch changes)
+    quorum_store_enabled: bool,
     // The latest ledger info (updated via a callback)
     root: Arc<Mutex<LedgerInfoWithSignatures>>,
 
@@ -127,6 +129,7 @@ impl ConsensusObserver {
             consensus_observer_config,
             consensus_observer_client,
             epoch_state: None,
+            quorum_store_enabled: false, // Updated on epoch changes
             root: Arc::new(Mutex::new(root)),
             block_payload_store: BlockPayloadStore::new(),
             missing_block_store: MissingBlockStore::new(consensus_observer_config),
@@ -142,6 +145,17 @@ impl ConsensusObserver {
         }
     }
 
+    /// Returns true iff all payloads exist for the given blocks
+    fn all_payloads_exist(&self, blocks: &[Arc<PipelinedBlock>]) -> bool {
+        // If quorum store is disabled, all payloads exist (they're already in the blocks)
+        if !self.quorum_store_enabled {
+            return true;
+        }
+
+        // Otherwise, check if all the payloads exist in the payload store
+        self.block_payload_store.all_payloads_exist(blocks)
+    }
+
     /// Checks the progress of the consensus observer
     async fn check_progress(&mut self) {
         debug!(LogSchema::new(LogEntry::ConsensusObserver)
@@ -551,11 +565,8 @@ impl ConsensusObserver {
             .pending_ordered_blocks
             .get_verified_pending_block(commit_decision.epoch(), commit_decision.round());
         if let Some(pending_block) = pending_block {
-            // If the payload exists, add the commit decision to the pending blocks
-            if self
-                .block_payload_store
-                .all_payloads_exist(&pending_block.blocks)
-            {
+            // If all payloads exist, add the commit decision to the pending blocks
+            if self.all_payloads_exist(&pending_block.blocks) {
                 debug!(
                     LogSchema::new(LogEntry::ConsensusObserver).message(&format!(
                         "Adding decision to pending block: {}",
@@ -695,9 +706,9 @@ impl ConsensusObserver {
             return;
         };
 
-        // If all the payloads exist, process the ordered block.
-        // Otherwise, store the block in the missing block store.
-        if self.block_payload_store.all_payloads_exist(&blocks) {
+        // If all payloads exist, process the block. Otherwise, store it
+        // in the missing block store and wait for the payloads to arrive.
+        if self.all_payloads_exist(&blocks) {
             self.process_ordered_block(ordered_block).await;
         } else {
             self.missing_block_store.insert_missing_block(ordered_block);
@@ -1067,17 +1078,18 @@ impl ConsensusObserver {
             panic!("Reconfig events are required to wait for a new epoch to start! Something has gone wrong!")
         };
 
-        // Update the local epoch state
+        // Update the local epoch state and quorum store config
         self.epoch_state = Some(epoch_state.clone());
+        self.quorum_store_enabled = consensus_config.quorum_store_enabled();
         info!(
             LogSchema::new(LogEntry::ConsensusObserver).message(&format!(
-                "New epoch started: {}. Updated the epoch state!",
-                epoch_state.epoch
+                "New epoch started: {:?}. Updated the epoch state! Quorum store enabled: {:?}",
+                epoch_state.epoch, self.quorum_store_enabled,
             ))
         );
 
         // Create the payload manager
-        let payload_manager = if consensus_config.quorum_store_enabled() {
+        let payload_manager = if self.quorum_store_enabled {
             PayloadManager::ConsensusObserver(
                 self.block_payload_store.get_block_payloads(),
                 self.consensus_publisher.clone(),