Add redeem_vote_credits to runtime (#7910)

* Move redeem_vote_credits into runtime

* fixup

* test

* move stake manipulation to stake program

* chugga for less indentation

programs/stake/src/stake_state.rs

@@ -365,13 +365,28 @@ impl Stake {
     pub fn stake(&self, epoch: Epoch, history: Option<&StakeHistory>) -> u64 {
         self.delegation.stake(epoch, history)
     }
+
+    pub fn redeem_rewards(
+        &mut self,
+        point_value: f64,
+        vote_state: &VoteState,
+        stake_history: Option<&StakeHistory>,
+    ) -> Option<(u64, u64)> {
+        self.calculate_rewards(point_value, vote_state, stake_history)
+            .map(|(voters_reward, stakers_reward, credits_observed)| {
+                self.credits_observed = credits_observed;
+                self.delegation.stake += stakers_reward;
+                (voters_reward, stakers_reward)
+            })
+    }
+
     /// for a given stake and vote_state, calculate what distributions and what updates should be made
     /// returns a tuple in the case of a payout of:
     ///   * voter_rewards to be distributed
     ///   * staker_rewards to be distributed
     ///   * new value for credits_observed in the stake
     //  returns None if there's no payout or if any deserved payout is < 1 lamport
-    fn calculate_rewards(
+    pub fn calculate_rewards(
         &self,
         point_value: f64,
         vote_state: &VoteState,
@@ -805,6 +820,33 @@ impl<'a> StakeAccount for KeyedAccount<'a> {
     }
 }
 
+// utility function, used by runtime
+pub fn redeem_rewards(
+    stake_account: &mut Account,
+    vote_account: &mut Account,
+    point_value: f64,
+    stake_history: Option<&StakeHistory>,
+) -> Result<u64, InstructionError> {
+    if let StakeState::Stake(meta, mut stake) = stake_account.state()? {
+        let vote_state = vote_account.state()?;
+
+        if let Some((voters_reward, stakers_reward)) =
+            stake.redeem_rewards(point_value, &vote_state, stake_history)
+        {
+            stake_account.lamports += stakers_reward;
+            vote_account.lamports += voters_reward;
+
+            stake_account.set_state(&StakeState::Stake(meta, stake))?;
+
+            Ok(stakers_reward + voters_reward)
+        } else {
+            Err(StakeError::NoCreditsToRedeem.into())
+        }
+    } else {
+        Err(InstructionError::InvalidAccountData)
+    }
+}
+
 // utility function, used by runtime::Stakes, tests
 pub fn new_stake_history_entry<'a, I>(
     epoch: Epoch,
@@ -1924,6 +1966,43 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_stake_state_redeem_rewards() {
+        let mut vote_state = VoteState::default();
+        // assume stake.stake() is right
+        // bootstrap means fully-vested stake at epoch 0
+        let stake_lamports = 1;
+        let mut stake = Stake::new(
+            stake_lamports,
+            &Pubkey::default(),
+            &vote_state,
+            std::u64::MAX,
+            &Config::default(),
+        );
+
+        // this one can't collect now, credits_observed == vote_state.credits()
+        assert_eq!(
+            None,
+            stake.redeem_rewards(1_000_000_000.0, &vote_state, None)
+        );
+
+        // put 2 credits in at epoch 0
+        vote_state.increment_credits(0);
+        vote_state.increment_credits(0);
+
+        // this one should be able to collect exactly 2
+        assert_eq!(
+            Some((0, stake_lamports * 2)),
+            stake.redeem_rewards(1.0, &vote_state, None)
+        );
+
+        assert_eq!(
+            stake.delegation.stake,
+            stake_lamports + (stake_lamports * 2)
+        );
+        assert_eq!(stake.credits_observed, 2);
+    }
+
     #[test]
     fn test_stake_state_calculate_rewards() {
         let mut vote_state = VoteState::default();

runtime/src/bank.rs

@@ -48,7 +48,7 @@ use solana_sdk::{
     timing::years_as_slots,
     transaction::{Result, Transaction, TransactionError},
 };
-use solana_stake_program::stake_state::Delegation;
+use solana_stake_program::stake_state::{self, Delegation};
 use solana_vote_program::vote_state::VoteState;
 use std::{
     cell::RefCell,
@@ -630,12 +630,50 @@ impl Bank {
             &sysvar::rewards::create_account(1, validator_point_value, storage_point_value),
         );
 
+        let validator_rewards = self.pay_validator_rewards(validator_point_value);
+
         self.capitalization.fetch_add(
-            (validator_rewards + storage_rewards) as u64,
+            validator_rewards + storage_rewards as u64,
             Ordering::Relaxed,
         );
     }
 
+    /// iterate over all stakes, redeem vote credits for each stake we can
+    ///   successfully load and parse, return total payout
+    fn pay_validator_rewards(&self, point_value: f64) -> u64 {
+        let stake_history = self.stakes.read().unwrap().history().clone();
+        self.stake_delegations()
+            .iter()
+            .map(|(stake_pubkey, delegation)| {
+                match (
+                    self.get_account(&stake_pubkey),
+                    self.get_account(&delegation.voter_pubkey),
+                ) {
+                    (Some(mut stake_account), Some(mut vote_account)) => {
+                        let rewards = stake_state::redeem_rewards(
+                            &mut stake_account,
+                            &mut vote_account,
+                            point_value,
+                            Some(&stake_history),
+                        );
+                        if let Ok(rewards) = rewards {
+                            self.store_account(&stake_pubkey, &stake_account);
+                            self.store_account(&delegation.voter_pubkey, &vote_account);
+                            rewards
+                        } else {
+                            debug!(
+                                "stake_state::redeem_rewards() failed for {}: {:?}",
+                                stake_pubkey, rewards
+                            );
+                            0
+                        }
+                    }
+                    (_, _) => 0,
+                }
+            })
+            .sum()
+    }
+
     pub fn update_recent_blockhashes(&self) {
         let blockhash_queue = self.blockhash_queue.read().unwrap();
         let recent_blockhash_iter = blockhash_queue.get_recent_blockhashes();
@@ -2920,14 +2958,14 @@ mod tests {
         }));
         assert_eq!(bank.capitalization(), 42 * 1_000_000_000);
 
-        let ((vote_id, mut vote_account), stake) =
+        let ((vote_id, mut vote_account), (stake_id, stake_account)) =
             crate::stakes::tests::create_staked_node_accounts(1_0000);
 
         let ((validator_id, validator_account), (archiver_id, archiver_account)) =
             crate::storage_utils::tests::create_storage_accounts_with_credits(100);
 
         // set up stakes, vote, and storage accounts
-        bank.store_account(&stake.0, &stake.1);
+        bank.store_account(&stake_id, &stake_account);
         bank.store_account(&validator_id, &validator_account.borrow());
         bank.store_account(&archiver_id, &archiver_account.borrow());
 
@@ -2960,6 +2998,16 @@ mod tests {
             .map(|account| Rewards::from_account(&account).unwrap())
             .unwrap();
 
+        // verify the stake and vote accounts are the right size
+        assert!(
+            ((bank1.get_balance(&stake_id) - stake_account.lamports + bank1.get_balance(&vote_id)
+                - vote_account.lamports) as f64
+                - rewards.validator_point_value * validator_points as f64)
+                .abs()
+                < 1.0
+        );
+
+        // verify the rewards are the right size
         assert!(
             ((rewards.validator_point_value * validator_points as f64
                 + rewards.storage_point_value * storage_points as f64)

runtime/tests/stake.rs

@@ -1,4 +1,3 @@
-use assert_matches::assert_matches;
 use solana_runtime::{
     bank::Bank,
     bank_client::BankClient,
@@ -11,7 +10,7 @@ use solana_sdk::{
     pubkey::Pubkey,
     signature::{Keypair, KeypairUtil},
     system_instruction::create_address_with_seed,
-    sysvar::{self, rewards::Rewards, stake_history::StakeHistory, Sysvar},
+    sysvar::{self, stake_history::StakeHistory, Sysvar},
 };
 use solana_stake_program::{
     stake_instruction::{self},
@@ -241,6 +240,14 @@ fn test_stake_account_lifetime() {
         assert!(false, "wrong account type found")
     }
 
+    loop {
+        if warmed_up(&bank, &stake_pubkey) {
+            break;
+        }
+        // Cycle thru banks until we're fully warmed up
+        bank = next_epoch(&bank);
+    }
+
     // Reward redemption
     // Submit enough votes to generate rewards
     bank = fill_epoch_with_votes(&bank, &vote_keypair, &mint_keypair);
@@ -251,35 +258,14 @@ fn test_stake_account_lifetime() {
 
     // 1 less vote, as the first vote should have cleared the lockout
     assert_eq!(vote_state.votes.len(), 31);
-    assert_eq!(vote_state.credits(), 1);
+    // one vote per slot, might be more slots than 32 in the epoch
+    assert!(vote_state.credits() >= 1);
     bank = fill_epoch_with_votes(&bank, &vote_keypair, &mint_keypair);
 
-    loop {
-        if warmed_up(&bank, &stake_pubkey) {
-            break;
-        }
-        // Cycle thru banks until we're fully warmed up
-        bank = next_epoch(&bank);
-    }
-
-    // Test that rewards are there
-    let rewards_account = bank
-        .get_account(&sysvar::rewards::id())
-        .expect("account not found");
-    assert_matches!(Rewards::from_account(&rewards_account), Some(_));
-
     let pre_staked = get_staked(&bank, &stake_pubkey);
 
-    // Redeem the credit
-    let bank_client = BankClient::new_shared(&bank);
-    let message = Message::new_with_payer(
-        vec![stake_instruction::redeem_vote_credits(
-            &stake_pubkey,
-            &vote_pubkey,
-        )],
-        Some(&mint_pubkey),
-    );
-    assert_matches!(bank_client.send_message(&[&mint_keypair], message), Ok(_));
+    // next epoch bank should pay rewards
+    bank = next_epoch(&bank);
 
     // Test that balance increased, and that the balance got staked
     let staked = get_staked(&bank, &stake_pubkey);
@@ -290,6 +276,8 @@ fn test_stake_account_lifetime() {
     // split the stake
     let split_stake_keypair = Keypair::new();
     let split_stake_pubkey = split_stake_keypair.pubkey();
+
+    let bank_client = BankClient::new_shared(&bank);
     // Test split
     let message = Message::new_with_payer(
         stake_instruction::split(

sdk/src/account_utils.rs

@@ -1,6 +1,8 @@
 //! useful extras for Account state
-use crate::account::{Account, KeyedAccount};
-use crate::instruction::InstructionError;
+use crate::{
+    account::{Account, KeyedAccount},
+    instruction::InstructionError,
+};
 use bincode::ErrorKind;
 
 /// Convenience trait to covert bincode errors to instruction errors.