Files
solana/sdk/src/vote_program.rs
2019-02-05 14:24:49 -07:00

140 lines
4.1 KiB
Rust

//! Vote program
//! Receive and processes votes from validators
use crate::native_program::ProgramError;
use crate::pubkey::Pubkey;
use bincode::{deserialize, serialize_into, serialized_size, ErrorKind};
use std::collections::VecDeque;
pub const VOTE_PROGRAM_ID: [u8; 32] = [
132, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0,
];
pub fn check_id(program_id: &Pubkey) -> bool {
program_id.as_ref() == VOTE_PROGRAM_ID
}
pub fn id() -> Pubkey {
Pubkey::new(&VOTE_PROGRAM_ID)
}
// Maximum number of votes to keep around
const MAX_VOTE_HISTORY: usize = 32;
#[derive(Serialize, Default, Deserialize, Debug, PartialEq, Eq, Clone)]
pub struct Vote {
// TODO: add signature of the state here as well
/// A vote for height tick_height
pub tick_height: u64,
}
impl Vote {
pub fn new(tick_height: u64) -> Self {
Self { tick_height }
}
}
#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
pub enum VoteInstruction {
/// Register a new "vote account" to represent a particular validator in the Vote Contract,
/// and initialize the VoteState for this "vote account"
/// * Transaction::keys[0] - the validator id
/// * Transaction::keys[1] - the new "vote account" to be associated with the validator
/// identified by keys[0] for voting
RegisterAccount,
Vote(Vote),
}
#[derive(Debug, Default, Serialize, Deserialize, PartialEq, Eq)]
pub struct VoteState {
pub votes: VecDeque<Vote>,
pub node_id: Pubkey,
pub staker_id: Pubkey,
credits: u64,
}
pub fn get_max_size() -> usize {
// Upper limit on the size of the Vote State. Equal to
// sizeof(VoteState) when votes.len() is MAX_VOTE_HISTORY
let mut vote_program = VoteState::default();
vote_program.votes = VecDeque::from(vec![Vote::default(); MAX_VOTE_HISTORY]);
serialized_size(&vote_program).unwrap() as usize
}
impl VoteState {
pub fn new(node_id: Pubkey, staker_id: Pubkey) -> Self {
let votes = VecDeque::new();
let credits = 0;
Self {
votes,
node_id,
staker_id,
credits,
}
}
pub fn deserialize(input: &[u8]) -> Result<Self, ProgramError> {
deserialize(input).map_err(|_| ProgramError::InvalidUserdata)
}
pub fn serialize(&self, output: &mut [u8]) -> Result<(), ProgramError> {
serialize_into(output, self).map_err(|err| match *err {
ErrorKind::SizeLimit => ProgramError::UserdataTooSmall,
_ => ProgramError::GenericError,
})
}
pub fn process_vote(&mut self, vote: Vote) {
// TODO: Integrity checks
// a) Verify the vote's bank hash matches what is expected
// b) Verify vote is older than previous votes
// Only keep around the most recent MAX_VOTE_HISTORY votes
if self.votes.len() == MAX_VOTE_HISTORY {
self.votes.pop_front();
self.credits += 1;
}
self.votes.push_back(vote);
}
/// Number of "credits" owed to this account from the mining pool. Submit this
/// VoteState to the Rewards program to trade credits for lamports.
pub fn credits(&self) -> u64 {
self.credits
}
/// Clear any credits.
pub fn clear_credits(&mut self) {
self.credits = 0;
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_vote_serialize() {
let mut buffer: Vec<u8> = vec![0; get_max_size()];
let mut vote_state = VoteState::default();
vote_state.votes.resize(MAX_VOTE_HISTORY, Vote::default());
vote_state.serialize(&mut buffer).unwrap();
assert_eq!(VoteState::deserialize(&buffer).unwrap(), vote_state);
}
#[test]
fn test_vote_credits() {
let mut vote_state = VoteState::default();
vote_state.votes.resize(MAX_VOTE_HISTORY, Vote::default());
assert_eq!(vote_state.credits(), 0);
vote_state.process_vote(Vote::new(42));
assert_eq!(vote_state.credits(), 1);
vote_state.process_vote(Vote::new(43));
assert_eq!(vote_state.credits(), 2);
vote_state.clear_credits();
assert_eq!(vote_state.credits(), 0);
}
}