Fix authorized voter ahead of time

cli/src/vote.rs

@@ -457,7 +457,7 @@ pub fn process_show_vote_account(
         build_balance_message(vote_account.lamports, use_lamports_unit, true)
     );
     println!("Validator Identity: {}", vote_state.node_pubkey);
-    println!("Authorized Voter: {}", vote_state.authorized_voter);
+    println!("Authorized Voter: {:?}", vote_state.authorized_voters());
     println!(
         "Authorized Withdrawer: {}",
         vote_state.authorized_withdrawer

core/src/validator.rs

@@ -35,6 +35,7 @@ use solana_metrics::datapoint_info;
 use solana_runtime::bank::Bank;
 use solana_sdk::{
     clock::{Slot, DEFAULT_SLOTS_PER_TURN},
+    epoch_schedule::MAX_LEADER_SCHEDULE_EPOCH_OFFSET,
     genesis_config::GenesisConfig,
     hash::Hash,
     pubkey::Pubkey,
@@ -562,6 +563,14 @@ fn new_banks_from_blockstore(
         error!("Failed to load genesis from {:?}: {}", blockstore_path, err);
         process::exit(1);
     });
+
+    // This needs to be limited otherwise the state in the VoteAccount data
+    // grows too large
+    let leader_schedule_slot_offset = genesis_config.epoch_schedule.leader_schedule_slot_offset;
+    let slots_per_epoch = genesis_config.epoch_schedule.slots_per_epoch;
+    let leader_epoch_offset = (leader_schedule_slot_offset + slots_per_epoch - 1) / slots_per_epoch;
+    assert!(leader_epoch_offset <= MAX_LEADER_SCHEDULE_EPOCH_OFFSET);
+
     let genesis_hash = genesis_config.hash();
     info!("genesis hash: {}", genesis_hash);
 

programs/vote/src/authorized_voters.rs

@@ -0,0 +1,102 @@
+use log::*;
+use serde_derive::{Deserialize, Serialize};
+use solana_sdk::pubkey::Pubkey;
+use std::collections::BTreeMap;
+
+#[derive(Debug, Default, Serialize, Deserialize, PartialEq, Eq, Clone)]
+pub struct AuthorizedVoters {
+    authorized_voters: BTreeMap<u64, Pubkey>,
+}
+
+impl AuthorizedVoters {
+    pub fn new(epoch: u64, pubkey: Pubkey) -> Self {
+        let mut authorized_voters = BTreeMap::new();
+        authorized_voters.insert(epoch, pubkey);
+        Self { authorized_voters }
+    }
+
+    pub fn get_authorized_voter(&self, epoch: u64) -> Option<Pubkey> {
+        self.get_or_calculate_authorized_voter_for_epoch(epoch)
+            .map(|(pubkey, _)| pubkey)
+    }
+
+    pub fn get_and_cache_authorized_voter_for_epoch(&mut self, epoch: u64) -> Option<Pubkey> {
+        let res = self.get_or_calculate_authorized_voter_for_epoch(epoch);
+
+        res.map(|(pubkey, existed)| {
+            if !existed {
+                self.authorized_voters.insert(epoch, pubkey);
+            }
+            pubkey
+        })
+    }
+
+    pub fn insert(&mut self, epoch: u64, authorized_voter: Pubkey) {
+        self.authorized_voters.insert(epoch, authorized_voter);
+    }
+
+    pub fn purge_authorized_voters(&mut self, current_epoch: u64) -> bool {
+        // Iterate through the keys in order, filtering out the ones
+        // less than the current epoch
+        let expired_keys: Vec<_> = self
+            .authorized_voters
+            .range(0..current_epoch)
+            .map(|(authorized_epoch, _)| *authorized_epoch)
+            .collect();
+
+        for key in expired_keys {
+            self.authorized_voters.remove(&key);
+        }
+
+        // Have to uphold this invariant b/c this is
+        // 1) The check for whether the vote state is initialized
+        // 2) How future authorized voters for uninitialized epochs are set
+        //    by this function
+        assert!(!self.authorized_voters.is_empty());
+        true
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.authorized_voters.is_empty()
+    }
+
+    pub fn first(&self) -> Option<(&u64, &Pubkey)> {
+        self.authorized_voters.iter().next()
+    }
+
+    pub fn last(&self) -> Option<(&u64, &Pubkey)> {
+        self.authorized_voters.iter().next_back()
+    }
+
+    pub fn len(&self) -> usize {
+        self.authorized_voters.len()
+    }
+
+    pub fn contains(&self, epoch: u64) -> bool {
+        self.authorized_voters.get(&epoch).is_some()
+    }
+
+    // Returns the authorized voter at the given epoch if the epoch is >= the
+    // current epoch, and a bool indicating whether the entry for this epoch
+    // exists in the self.authorized_voter map
+    fn get_or_calculate_authorized_voter_for_epoch(&self, epoch: u64) -> Option<(Pubkey, bool)> {
+        let res = self.authorized_voters.get(&epoch);
+        if res.is_none() {
+            // If no authorized voter has been set yet for this epoch,
+            // this must mean the authorized voter remains unchanged
+            // from the latest epoch before this one
+            let res = self.authorized_voters.range(0..epoch).next_back();
+
+            if res.is_none() {
+                warn!(
+                    "Tried to query for the authorized voter of an epoch earlier
+                    than the current epoch. Earlier epochs have been purged"
+                );
+            }
+
+            res.map(|(_, pubkey)| (*pubkey, false))
+        } else {
+            res.map(|pubkey| (*pubkey, true))
+        }
+    }
+}

programs/vote/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod authorized_voters;
 pub mod vote_instruction;
 pub mod vote_state;
 

programs/vote/src/vote_instruction.rs

@@ -138,8 +138,11 @@ pub fn update_node(
     authorized_voter_pubkey: &Pubkey,
     node_pubkey: &Pubkey,
 ) -> Instruction {
-    let account_metas =
-        vec![AccountMeta::new(*vote_pubkey, false)].with_signer(authorized_voter_pubkey);
+    let account_metas = vec![
+        AccountMeta::new(*vote_pubkey, false),
+        AccountMeta::new_readonly(sysvar::clock::id(), false),
+    ]
+    .with_signer(authorized_voter_pubkey);
 
     Instruction::new(
         id(),
@@ -205,9 +208,12 @@ pub fn process_instruction(
             &signers,
             &Clock::from_keyed_account(next_keyed_account(keyed_accounts)?)?,
         ),
-        VoteInstruction::UpdateNode(node_pubkey) => {
-            vote_state::update_node(me, &node_pubkey, &signers)
-        }
+        VoteInstruction::UpdateNode(node_pubkey) => vote_state::update_node(
+            me,
+            &node_pubkey,
+            &signers,
+            &Clock::from_keyed_account(next_keyed_account(keyed_accounts)?)?,
+        ),
         VoteInstruction::Vote(vote) => {
             inc_new_counter_info!("vote-native", 1);
             vote_state::process_vote(