Start saving/loading prior_roots(_with_hash) to snapshot (#23844)

* Start saving/loading prior_roots(_with_hash) to snapshot

* Update runtime/src/accounts_index.rs

Co-authored-by: Michael Vines <mvines@gmail.com>

* Update runtime/src/accounts_index.rs

Co-authored-by: Michael Vines <mvines@gmail.com>

* update comment

Co-authored-by: Michael Vines <mvines@gmail.com>

runtime/src/accounts_index.rs

@@ -652,7 +652,7 @@ impl RollingBitField {
 
 #[derive(Debug)]
 pub struct RootsTracker {
-    roots: RollingBitField,
+    pub(crate) roots: RollingBitField,
     uncleaned_roots: HashSet<Slot>,
     previous_uncleaned_roots: HashSet<Slot>,
 }
@@ -869,7 +869,7 @@ pub struct AccountsIndex<T: IndexValue> {
     program_id_index: SecondaryIndex<DashMapSecondaryIndexEntry>,
     spl_token_mint_index: SecondaryIndex<DashMapSecondaryIndexEntry>,
     spl_token_owner_index: SecondaryIndex<RwLockSecondaryIndexEntry>,
-    roots_tracker: RwLock<RootsTracker>,
+    pub(crate) roots_tracker: RwLock<RootsTracker>,
     ongoing_scan_roots: RwLock<BTreeMap<Slot, u64>>,
     // Each scan has some latest slot `S` that is the tip of the fork the scan
     // is iterating over. The unique id of that slot `S` is recorded here (note we don't use

runtime/src/serde_snapshot.rs

@@ -23,6 +23,7 @@ use {
     solana_measure::measure::Measure,
     solana_sdk::{
         clock::{Epoch, Slot, UnixTimestamp},
+        deserialize_utils::default_on_eof,
         epoch_schedule::EpochSchedule,
         fee_calculator::{FeeCalculator, FeeRateGovernor},
         genesis_config::GenesisConfig,
@@ -67,6 +68,12 @@ struct AccountsDbFields<T>(
     StoredMetaWriteVersion,
     Slot,
     BankHashInfo,
+    /// all slots that were roots within the last epoch
+    #[serde(deserialize_with = "default_on_eof")]
+    Vec<Slot>,
+    /// slots that were roots within the last epoch for which we care about the hash value
+    #[serde(deserialize_with = "default_on_eof")]
+    Vec<(Slot, Hash)>,
 );
 
 /// Helper type to wrap BufReader streams when deserializing and reconstructing from either just a
@@ -86,9 +93,9 @@ struct SnapshotAccountsDbFields<T> {
 
 impl<T> SnapshotAccountsDbFields<T> {
     /// Collapse the SnapshotAccountsDbFields into a single AccountsDbFields.  If there is no
-    /// incremental snapshot, this returns the AccountsDbFields from the full snapshot.  Otherwise
+    /// incremental snapshot, this returns the AccountsDbFields from the full snapshot.
-    /// this uses the version, slot, and bank hash info from the incremental snapshot, then the
+    /// Otherwise, use the AccountsDbFields from the incremental snapshot, and a combination
-    /// combination of the storages from both the full and incremental snapshots.
+    /// of the storages from both the full and incremental snapshots.
     fn collapse_into(self) -> Result<AccountsDbFields<T>, Error> {
         match self.incremental_snapshot_accounts_db_fields {
             None => Ok(self.full_snapshot_accounts_db_fields),
@@ -97,6 +104,8 @@ impl<T> SnapshotAccountsDbFields<T> {
                 incremental_snapshot_version,
                 incremental_snapshot_slot,
                 incremental_snapshot_bank_hash_info,
+                incremental_snapshot_prior_roots,
+                incremental_snapshot_prior_roots_with_hash,
             )) => {
                 let full_snapshot_storages = self.full_snapshot_accounts_db_fields.0;
                 let full_snapshot_slot = self.full_snapshot_accounts_db_fields.2;
@@ -119,6 +128,8 @@ impl<T> SnapshotAccountsDbFields<T> {
                     incremental_snapshot_version,
                     incremental_snapshot_slot,
                     incremental_snapshot_bank_hash_info,
+                    incremental_snapshot_prior_roots,
+                    incremental_snapshot_prior_roots_with_hash,
                 ))
             }
         }
@@ -418,6 +429,8 @@ where
         snapshot_version,
         snapshot_slot,
         snapshot_bank_hash_info,
+        _snapshot_prior_roots,
+        _snapshot_prior_roots_with_hash,
     ) = snapshot_accounts_db_fields.collapse_into()?;
 
     let snapshot_storages = snapshot_storages.into_iter().collect::<Vec<_>>();

runtime/src/serde_snapshot/newer.rs

@@ -238,8 +238,27 @@ impl<'a> TypeContext<'a> for Context {
             .unwrap_or_else(|| panic!("No bank_hashes entry for slot {}", serializable_db.slot))
             .clone();
 
+        // for now, prior_roots is the same as 'roots' and is redundant with the storages we persist in the snapshot
+        let prior_roots = serializable_db
+            .accounts_db
+            .accounts_index
+            .roots_tracker
+            .read()
+            .unwrap()
+            .roots
+            .get_all();
+        let prior_roots_with_hash = Vec::<(Slot, Hash)>::default();
+
         let mut serialize_account_storage_timer = Measure::start("serialize_account_storage_ms");
-        let result = (entries, version, slot, hash).serialize(serializer);
+        let result = (
+            entries,
+            version,
+            slot,
+            hash,
+            prior_roots,
+            prior_roots_with_hash,
+        )
+            .serialize(serializer);
         serialize_account_storage_timer.stop();
         datapoint_info!(
             "serialize_account_storage_ms",

runtime/src/serde_snapshot/tests.rs

@@ -305,7 +305,7 @@ mod test_bank_serialize {
 
     // This some what long test harness is required to freeze the ABI of
     // Bank's serialization due to versioned nature
-    #[frozen_abi(digest = "ERbJJzaQD39td9tiE4FPAud374S2Hvk6pvsxejm6quWf")]
+    #[frozen_abi(digest = "H2XtVdhokwLMTbjXh4Lh3Mw8m7PYQDMh4Ha5ojuxip9Z")]
     #[derive(Serialize, AbiExample)]
     pub struct BankAbiTestWrapperNewer {
         #[serde(serialize_with = "wrapper_newer")]

sdk/src/deserialize_utils.rs

@@ -12,6 +12,7 @@ where
     let result = T::deserialize(d);
     match result {
         Err(err) if err.to_string() == "io error: unexpected end of file" => Ok(T::default()),
+        Err(err) if err.to_string() == "io error: failed to fill whole buffer" => Ok(T::default()),
         result => result,
     }
 }