From 35d2a0fd69729001f99781e65831e9187258c4c3 Mon Sep 17 00:00:00 2001
From: Ashwin Sekar <ashwin@solana.com>
Date: Sat, 14 May 2022 10:57:51 -0700
Subject: [PATCH] Serialize lamports per signature in snapshots (#25181)

* Serialize lamports per signature

* pr comments
---
 runtime/src/serde_snapshot/newer.rs | 11 ++++++++++-
 runtime/src/serde_snapshot/tests.rs |  2 +-
 sdk/program/src/fee_calculator.rs   |  7 +++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/runtime/src/serde_snapshot/newer.rs b/runtime/src/serde_snapshot/newer.rs
index ccdb32c9cb..9b370e6f02 100644
--- a/runtime/src/serde_snapshot/newer.rs
+++ b/runtime/src/serde_snapshot/newer.rs
@@ -60,6 +60,8 @@ struct DeserializableVersionedBank {
     unused_accounts: UnusedAccounts,
     epoch_stakes: HashMap<Epoch, EpochStakes>,
     is_delta: bool,
+    #[serde(deserialize_with = "default_on_eof")]
+    lamports_per_signature: u64,
 }
 
 impl From<DeserializableVersionedBank> for BankFieldsToDeserialize {
@@ -88,7 +90,9 @@ impl From<DeserializableVersionedBank> for BankFieldsToDeserialize {
             collector_id: dvb.collector_id,
             collector_fees: dvb.collector_fees,
             fee_calculator: dvb.fee_calculator,
-            fee_rate_governor: dvb.fee_rate_governor,
+            fee_rate_governor: dvb
+                .fee_rate_governor
+                .clone_with_lamports_per_signature(dvb.lamports_per_signature),
             collected_rent: dvb.collected_rent,
             rent_collector: dvb.rent_collector,
             epoch_schedule: dvb.epoch_schedule,
@@ -137,10 +141,12 @@ struct SerializableVersionedBank<'a> {
     unused_accounts: UnusedAccounts,
     epoch_stakes: &'a HashMap<Epoch, EpochStakes>,
     is_delta: bool,
+    lamports_per_signature: u64,
 }
 
 impl<'a> From<crate::bank::BankFieldsToSerialize<'a>> for SerializableVersionedBank<'a> {
     fn from(rhs: crate::bank::BankFieldsToSerialize<'a>) -> Self {
+        let lamports_per_signature = rhs.fee_rate_governor.lamports_per_signature;
         Self {
             blockhash_queue: rhs.blockhash_queue,
             ancestors: rhs.ancestors,
@@ -174,6 +180,7 @@ impl<'a> From<crate::bank::BankFieldsToSerialize<'a>> for SerializableVersionedB
             unused_accounts: UnusedAccounts::default(),
             epoch_stakes: rhs.epoch_stakes,
             is_delta: rhs.is_delta,
+            lamports_per_signature,
         }
     }
 }
@@ -311,6 +318,7 @@ impl<'a> TypeContext<'a> for Context {
         let rhs = bank_fields;
         let blockhash_queue = RwLock::new(rhs.blockhash_queue.clone());
         let hard_forks = RwLock::new(rhs.hard_forks.clone());
+        let lamports_per_signature = rhs.fee_rate_governor.lamports_per_signature;
         let bank = SerializableVersionedBank {
             blockhash_queue: &blockhash_queue,
             ancestors: &rhs.ancestors,
@@ -344,6 +352,7 @@ impl<'a> TypeContext<'a> for Context {
             unused_accounts: UnusedAccounts::default(),
             epoch_stakes: &rhs.epoch_stakes,
             is_delta: rhs.is_delta,
+            lamports_per_signature,
         };
 
         bincode::serialize_into(stream_writer, &(bank, accounts_db_fields))
diff --git a/runtime/src/serde_snapshot/tests.rs b/runtime/src/serde_snapshot/tests.rs
index 1ac1a55ce2..28e51eb033 100644
--- a/runtime/src/serde_snapshot/tests.rs
+++ b/runtime/src/serde_snapshot/tests.rs
@@ -367,7 +367,7 @@ 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 = "HT9yewU4zJ6ZAgJ7aDSbHPtzZGZqASpq6rkq6ET42Kki")]
+    #[frozen_abi(digest = "3PiYioYfEPzm2u64FZLsLx1SUTGE3NUvALXvwqhxZuRF")]
     #[derive(Serialize, AbiExample)]
     pub struct BankAbiTestWrapperNewer {
         #[serde(serialize_with = "wrapper_newer")]
diff --git a/sdk/program/src/fee_calculator.rs b/sdk/program/src/fee_calculator.rs
index 3dd8078bf1..62d952b660 100644
--- a/sdk/program/src/fee_calculator.rs
+++ b/sdk/program/src/fee_calculator.rs
@@ -165,6 +165,13 @@ impl FeeRateGovernor {
         me
     }
 
+    pub fn clone_with_lamports_per_signature(&self, lamports_per_signature: u64) -> Self {
+        Self {
+            lamports_per_signature,
+            ..*self
+        }
+    }
+
     /// calculate unburned fee from a fee total, returns (unburned, burned)
     pub fn burn(&self, fees: u64) -> (u64, u64) {
         let burned = fees * u64::from(self.burn_percent) / 100;