Supports deserializing accounts lt hash in snapshots

accounts-db/src/accounts_hash.rs

@@ -1265,6 +1265,10 @@ pub struct AccountLtHash(pub LtHash);
 pub const ZERO_LAMPORT_ACCOUNT_LT_HASH: AccountLtHash =
     AccountLtHash(LtHash([0; LtHash::NUM_ELEMENTS]));
 
+/// Lattice hash of all accounts
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct AccountsLtHash(pub LtHash);
+
 /// Hash of accounts
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub enum AccountsHashKind {

runtime/Cargo.toml

@@ -46,6 +46,7 @@ regex = { workspace = true }
 serde = { workspace = true, features = ["rc"] }
 serde_derive = { workspace = true }
 serde_json = { workspace = true }
+serde_with = { workspace = true }
 solana-accounts-db = { workspace = true }
 solana-address-lookup-table-program = { workspace = true }
 solana-bpf-loader-program = { workspace = true }
@@ -63,6 +64,7 @@ solana-frozen-abi-macro = { workspace = true, optional = true, features = [
     "frozen-abi",
 ] }
 solana-inline-spl = { workspace = true }
+solana-lattice-hash = { workspace = true }
 solana-loader-v4-program = { workspace = true }
 solana-measure = { workspace = true }
 solana-metrics = { workspace = true }

runtime/src/serde_snapshot.rs

@@ -57,10 +57,12 @@ use {
         thread::Builder,
     },
     storage::SerializableStorage,
+    types::SerdeAccountsLtHash,
 };
 
 mod storage;
 mod tests;
+mod types;
 mod utils;
 
 pub(crate) use {
@@ -400,6 +402,9 @@ struct ExtraFieldsToDeserialize {
     epoch_accounts_hash: Option<Hash>,
     #[serde(deserialize_with = "default_on_eof")]
     versioned_epoch_stakes: HashMap<u64, VersionedEpochStakes>,
+    #[serde(deserialize_with = "default_on_eof")]
+    #[allow(dead_code)]
+    accounts_lt_hash: Option<SerdeAccountsLtHash>,
 }
 
 /// Extra fields that are serialized at the end of snapshots.
@@ -441,6 +446,7 @@ where
         incremental_snapshot_persistence,
         epoch_accounts_hash,
         versioned_epoch_stakes,
+        accounts_lt_hash: _,
     } = extra_fields;
 
     bank_fields.fee_rate_governor = bank_fields

runtime/src/serde_snapshot/types.rs

@@ -0,0 +1,22 @@
+use {solana_accounts_db::accounts_hash::AccountsLtHash, solana_lattice_hash::lt_hash::LtHash};
+
+/// Snapshot serde-safe AccountsLtHash
+#[cfg_attr(feature = "frozen-abi", derive(AbiExample))]
+#[serde_with::serde_as]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+pub struct SerdeAccountsLtHash(
+    // serde only has array support up to 32 elements; anything larger needs to be handled manually
+    // see https://github.com/serde-rs/serde/issues/1937 for more information
+    #[serde_as(as = "[_; LtHash::NUM_ELEMENTS]")] pub [u16; LtHash::NUM_ELEMENTS],
+);
+
+impl From<SerdeAccountsLtHash> for AccountsLtHash {
+    fn from(accounts_lt_hash: SerdeAccountsLtHash) -> Self {
+        Self(LtHash(accounts_lt_hash.0))
+    }
+}
+impl From<AccountsLtHash> for SerdeAccountsLtHash {
+    fn from(accounts_lt_hash: AccountsLtHash) -> Self {
+        Self(accounts_lt_hash.0 .0)
+    }
+}