runtime: transpose `VoteAccount::vote_state()` return to improve ergonomics (#31256)

core/src/consensus.rs

@@ -302,7 +302,7 @@ impl Tower {
                 continue;
             }
             trace!("{} {} with stake {}", vote_account_pubkey, key, voted_stake);
-            let mut vote_state = match account.vote_state().as_ref() {
+            let mut vote_state = match account.vote_state().cloned() {
                 Err(_) => {
                     datapoint_warn!(
                         "tower_warn",
@@ -314,7 +314,7 @@ impl Tower {
                     );
                     continue;
                 }
-                Ok(vote_state) => vote_state.clone(),
+                Ok(vote_state) => vote_state,
             };
             for vote in &vote_state.votes {
                 lockout_intervals
@@ -1284,9 +1284,8 @@ impl Tower {
         if let Some(vote_account) = bank.get_vote_account(vote_account_pubkey) {
             self.vote_state = vote_account
                 .vote_state()
-                .as_ref()
-                .expect("vote_account isn't a VoteState?")
-                .clone();
+                .cloned()
+                .expect("vote_account isn't a VoteState?");
             self.initialize_root(root);
             self.initialize_lockouts(|v| v.slot() > root);
             trace!(

core/src/replay_stage.rs

@@ -2894,9 +2894,7 @@ impl ReplayStage {
                         Tower::is_direct_vote_state_update_enabled(bank),
                         bank.get_vote_account(my_vote_pubkey),
                     ) {
-                        if let Some(mut bank_vote_state) =
-                            vote_account.vote_state().as_ref().ok().cloned()
-                        {
+                        if let Ok(mut bank_vote_state) = vote_account.vote_state().cloned() {
                             if bank_vote_state.last_voted_slot()
                                 > tower.vote_state.last_voted_slot()
                             {

ledger-tool/src/main.rs

@@ -520,7 +520,7 @@ fn graph_forks(bank_forks: &BankForks, config: &GraphConfig) -> String {
             .sum();
         for (stake, vote_account) in bank.vote_accounts().values() {
             let vote_state = vote_account.vote_state();
-            let vote_state = vote_state.as_ref().unwrap_or(&default_vote_state);
+            let vote_state = vote_state.unwrap_or(&default_vote_state);
             if let Some(last_vote) = vote_state.votes.iter().last() {
                 let entry = last_votes.entry(vote_state.node_pubkey).or_insert((
                     last_vote.slot(),
@@ -561,7 +561,7 @@ fn graph_forks(bank_forks: &BankForks, config: &GraphConfig) -> String {
         loop {
             for (_, vote_account) in bank.vote_accounts().values() {
                 let vote_state = vote_account.vote_state();
-                let vote_state = vote_state.as_ref().unwrap_or(&default_vote_state);
+                let vote_state = vote_state.unwrap_or(&default_vote_state);
                 if let Some(last_vote) = vote_state.votes.iter().last() {
                     let validator_votes = all_votes.entry(vote_state.node_pubkey).or_default();
                     validator_votes

rpc/src/rpc.rs

@@ -939,7 +939,7 @@ impl JsonRpcRequestProcessor {
                 }
 
                 let vote_state = account.vote_state();
-                let vote_state = vote_state.as_ref().unwrap_or(&default_vote_state);
+                let vote_state = vote_state.unwrap_or(&default_vote_state);
                 let last_vote = if let Some(vote) = vote_state.votes.iter().last() {
                     vote.slot()
                 } else {

runtime/src/bank.rs

@@ -171,7 +171,7 @@ use {
         collections::{HashMap, HashSet},
         convert::{TryFrom, TryInto},
         fmt, mem,
-        ops::{AddAssign, Deref, RangeInclusive},
+        ops::{AddAssign, RangeInclusive},
         path::PathBuf,
         rc::Rc,
         sync::{
@@ -2740,8 +2740,8 @@ impl Bank {
                 invalid_vote_keys.insert(vote_pubkey, InvalidCacheEntryReason::WrongOwner);
                 return None;
             }
-            let vote_state = match vote_account.vote_state().deref() {
-                Ok(vote_state) => vote_state.clone(),
+            let vote_state = match vote_account.vote_state().cloned() {
+                Ok(vote_state) => vote_state,
                 Err(_) => {
                     invalid_vote_keys.insert(vote_pubkey, InvalidCacheEntryReason::BadState);
                     return None;

runtime/src/vote_account.rs

@@ -65,12 +65,13 @@ impl VoteAccount {
         self.0.account.owner()
     }
 
-    pub fn vote_state(&self) -> &Result<VoteState, Error> {
+    pub fn vote_state(&self) -> Result<&VoteState, &Error> {
         // VoteState::deserialize deserializes a VoteStateVersions and then
         // calls VoteStateVersions::convert_to_current.
         self.0
             .vote_state
             .get_or_init(|| VoteState::deserialize(self.0.account.data()).map_err(Error::from))
+            .as_ref()
     }
 
     pub(crate) fn is_deserialized(&self) -> bool {
@@ -79,7 +80,7 @@ impl VoteAccount {
 
     /// VoteState.node_pubkey of this vote-account.
     pub fn node_pubkey(&self) -> Option<Pubkey> {
-        Some(self.vote_state().as_ref().ok()?.node_pubkey)
+        Some(self.vote_state().ok()?.node_pubkey)
     }
 }
 
@@ -395,9 +396,9 @@ mod tests {
         let lamports = account.lamports();
         let vote_account = VoteAccount::try_from(account).unwrap();
         assert_eq!(lamports, vote_account.lamports());
-        assert_eq!(vote_state, *vote_account.vote_state().as_ref().unwrap());
+        assert_eq!(vote_state, *vote_account.vote_state().unwrap());
         // 2nd call to .vote_state() should return the cached value.
-        assert_eq!(vote_state, *vote_account.vote_state().as_ref().unwrap());
+        assert_eq!(vote_state, *vote_account.vote_state().unwrap());
     }
 
     #[test]
@@ -405,7 +406,7 @@ mod tests {
         let mut rng = rand::thread_rng();
         let (account, vote_state) = new_rand_vote_account(&mut rng, None);
         let vote_account = VoteAccount::try_from(account.clone()).unwrap();
-        assert_eq!(vote_state, *vote_account.vote_state().as_ref().unwrap());
+        assert_eq!(vote_state, *vote_account.vote_state().unwrap());
         // Assert than VoteAccount has the same wire format as Account.
         assert_eq!(
             bincode::serialize(&account).unwrap(),
@@ -419,13 +420,10 @@ mod tests {
         let (account, vote_state) = new_rand_vote_account(&mut rng, None);
         let data = bincode::serialize(&account).unwrap();
         let vote_account = VoteAccount::try_from(account).unwrap();
-        assert_eq!(vote_state, *vote_account.vote_state().as_ref().unwrap());
+        assert_eq!(vote_state, *vote_account.vote_state().unwrap());
         let other_vote_account: VoteAccount = bincode::deserialize(&data).unwrap();
         assert_eq!(vote_account, other_vote_account);
-        assert_eq!(
-            vote_state,
-            *other_vote_account.vote_state().as_ref().unwrap()
-        );
+        assert_eq!(vote_state, *other_vote_account.vote_state().unwrap());
     }
 
     #[test]
@@ -433,15 +431,12 @@ mod tests {
         let mut rng = rand::thread_rng();
         let (account, vote_state) = new_rand_vote_account(&mut rng, None);
         let vote_account = VoteAccount::try_from(account).unwrap();
-        assert_eq!(vote_state, *vote_account.vote_state().as_ref().unwrap());
+        assert_eq!(vote_state, *vote_account.vote_state().unwrap());
         let data = bincode::serialize(&vote_account).unwrap();
         let other_vote_account: VoteAccount = bincode::deserialize(&data).unwrap();
         // Assert that serialize->deserialized returns the same VoteAccount.
         assert_eq!(vote_account, other_vote_account);
-        assert_eq!(
-            vote_state,
-            *other_vote_account.vote_state().as_ref().unwrap()
-        );
+        assert_eq!(vote_state, *other_vote_account.vote_state().unwrap());
     }
 
     #[test]