Add voting service (#18552)

core/src/voting_service.rs

@@ -0,0 +1,79 @@
+use solana_gossip::cluster_info::ClusterInfo;
+use solana_poh::poh_recorder::PohRecorder;
+use solana_sdk::{clock::Slot, transaction::Transaction};
+use std::{
+    sync::{mpsc::Receiver, Arc, Mutex},
+    thread::{self, Builder, JoinHandle},
+};
+
+pub enum VoteOp {
+    PushVote {
+        tx: Transaction,
+        tower_slots: Vec<Slot>,
+    },
+    RefreshVote {
+        tx: Transaction,
+        last_voted_slot: Slot,
+    },
+}
+
+impl VoteOp {
+    fn tx(&self) -> &Transaction {
+        match self {
+            VoteOp::PushVote { tx, tower_slots: _ } => tx,
+            VoteOp::RefreshVote {
+                tx,
+                last_voted_slot: _,
+            } => tx,
+        }
+    }
+}
+
+pub struct VotingService {
+    thread_hdl: JoinHandle<()>,
+}
+
+impl VotingService {
+    pub fn new(
+        vote_receiver: Receiver<VoteOp>,
+        cluster_info: Arc<ClusterInfo>,
+        poh_recorder: Arc<Mutex<PohRecorder>>,
+    ) -> Self {
+        let thread_hdl = Builder::new()
+            .name("sol-vote-service".to_string())
+            .spawn(move || {
+                for vote_op in vote_receiver.iter() {
+                    Self::handle_vote(&cluster_info, &poh_recorder, vote_op);
+                }
+            })
+            .unwrap();
+        Self { thread_hdl }
+    }
+
+    pub fn handle_vote(
+        cluster_info: &ClusterInfo,
+        poh_recorder: &Mutex<PohRecorder>,
+        vote_op: VoteOp,
+    ) {
+        let _ = cluster_info.send_transaction(
+            vote_op.tx(),
+            crate::banking_stage::next_leader_tpu(cluster_info, poh_recorder),
+        );
+
+        match vote_op {
+            VoteOp::PushVote { tx, tower_slots } => {
+                cluster_info.push_vote(&tower_slots, tx);
+            }
+            VoteOp::RefreshVote {
+                tx,
+                last_voted_slot,
+            } => {
+                cluster_info.refresh_vote(tx, last_voted_slot);
+            }
+        }
+    }
+
+    pub fn join(self) -> thread::Result<()> {
+        self.thread_hdl.join()
+    }
+}