serai/processor/scheduler/primitives/src/lib.rs
2024-09-19 23:36:32 -07:00

77 lines
2.5 KiB
Rust

#![cfg_attr(docsrs, feature(doc_auto_cfg))]
#![doc = include_str!("../README.md")]
#![deny(missing_docs)]
use core::marker::PhantomData;
use std::io;
use ciphersuite::{group::GroupEncoding, Ciphersuite};
use frost::{dkg::ThresholdKeys, sign::PreprocessMachine};
use serai_db::DbTxn;
/// A transaction.
pub trait Transaction: Sized + Send {
/// Read a `Transaction`.
fn read(reader: &mut impl io::Read) -> io::Result<Self>;
/// Write a `Transaction`.
fn write(&self, writer: &mut impl io::Write) -> io::Result<()>;
}
/// A signable transaction.
pub trait SignableTransaction: 'static + Sized + Send + Sync + Clone {
/// The underlying transaction type.
type Transaction: Transaction;
/// The ciphersuite used to sign this transaction.
type Ciphersuite: Ciphersuite;
/// The preprocess machine for the signing protocol for this transaction.
type PreprocessMachine: Clone + PreprocessMachine<Signature: Send + Into<Self::Transaction>>;
/// Read a `SignableTransaction`.
fn read(reader: &mut impl io::Read) -> io::Result<Self>;
/// Write a `SignableTransaction`.
fn write(&self, writer: &mut impl io::Write) -> io::Result<()>;
/// The ID for this transaction.
///
/// This is an internal ID arbitrarily definable so long as it's unique.
///
/// This same ID MUST be returned by the Eventuality for this transaction.
fn id(&self) -> [u8; 32];
/// Sign this transaction.
fn sign(self, keys: ThresholdKeys<Self::Ciphersuite>) -> Self::PreprocessMachine;
}
/// The transaction type for a SignableTransaction.
pub type TransactionFor<ST> = <ST as SignableTransaction>::Transaction;
mod db {
use serai_db::{Get, DbTxn, create_db, db_channel};
db_channel! {
SchedulerPrimitives {
TransactionsToSign: (key: &[u8]) -> Vec<u8>,
}
}
}
/// The transactions to sign, as scheduled by a Scheduler.
pub struct TransactionsToSign<T>(PhantomData<T>);
impl<T: SignableTransaction> TransactionsToSign<T> {
/// Send a transaction to sign.
pub fn send(txn: &mut impl DbTxn, key: &impl GroupEncoding, tx: &T) {
let mut buf = Vec::with_capacity(128);
tx.write(&mut buf).unwrap();
db::TransactionsToSign::send(txn, key.to_bytes().as_ref(), &buf);
}
/// Try to receive a transaction to sign.
pub fn try_recv(txn: &mut impl DbTxn, key: &impl GroupEncoding) -> Option<T> {
let tx = db::TransactionsToSign::try_recv(txn, key.to_bytes().as_ref())?;
let mut tx = tx.as_slice();
let res = T::read(&mut tx).unwrap();
assert!(tx.is_empty());
Some(res)
}
}