v1.3 persistent tower

core/benches/consensus.rs

@@ -0,0 +1,36 @@
+#![feature(test)]
+
+extern crate solana_core;
+extern crate test;
+
+use solana_core::consensus::Tower;
+use solana_runtime::bank::Bank;
+use solana_runtime::bank_forks::BankForks;
+use solana_sdk::{
+    pubkey::Pubkey,
+    signature::{Keypair, Signer},
+};
+use std::sync::Arc;
+use tempfile::TempDir;
+use test::Bencher;
+
+#[bench]
+fn bench_save_tower(bench: &mut Bencher) {
+    let dir = TempDir::new().unwrap();
+    let path = dir.path();
+
+    let vote_account_pubkey = &Pubkey::default();
+    let node_keypair = Arc::new(Keypair::new());
+    let heaviest_bank = BankForks::new(Bank::default()).working_bank();
+    let tower = Tower::new(
+        &node_keypair.pubkey(),
+        &vote_account_pubkey,
+        0,
+        &heaviest_bank,
+        &path,
+    );
+
+    bench.iter(move || {
+        tower.save(&node_keypair).unwrap();
+    });
+}

core/src/bank_weight_fork_choice.rs

@@ -60,7 +60,7 @@ impl ForkChoice for BankWeightForkChoice {
         trace!("frozen_banks {}", frozen_banks.len());
         let num_old_banks = frozen_banks
             .iter()
-            .filter(|b| b.slot() < tower.root().unwrap_or(0))
+            .filter(|b| b.slot() < tower.root())
             .count();
 
         let last_voted_slot = tower.last_voted_slot();