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

59 lines
2.1 KiB
Rust

use std::{io, collections::HashMap};
use crate::Id;
/// A description of a transaction which will eventually happen.
pub trait Eventuality: Sized + Send + Sync {
/// The type used to identify a received output.
type OutputId: Id;
/// The ID of the SignableTransaction this Eventuality is for.
///
/// This is an internal ID arbitrarily definable so long as it's unique.
fn id(&self) -> [u8; 32];
/// A unique byte sequence which can be used to identify potentially resolving transactions.
///
/// Both a transaction and an Eventuality are expected to be able to yield lookup sequences.
/// Lookup sequences MUST be unique to the Eventuality and identical to any transaction's which
/// satisfies this Eventuality. Transactions which don't satisfy this Eventuality MAY also have
/// an identical lookup sequence.
///
/// This is used to find the Eventuality a transaction MAY resolve so we don't have to check all
/// transactions against all Eventualities. Once the potential resolved Eventuality is
/// identified, the full check is performed.
fn lookup(&self) -> Vec<u8>;
/// The output the resolution of this Eventuality was supposed to spend.
///
/// If the resolution of this Eventuality has multiple inputs, there is no singular spent output
/// so this MUST return None.
fn singular_spent_output(&self) -> Option<Self::OutputId>;
/// Read an Eventuality.
fn read(reader: &mut impl io::Read) -> io::Result<Self>;
/// Write an Eventuality.
fn write(&self, writer: &mut impl io::Write) -> io::Result<()>;
}
/// A tracker of unresolved Eventualities.
#[derive(Debug)]
pub struct EventualityTracker<E: Eventuality> {
/// The active Eventualities.
///
/// These are keyed by their lookups.
pub active_eventualities: HashMap<Vec<u8>, E>,
}
impl<E: Eventuality> Default for EventualityTracker<E> {
fn default() -> Self {
EventualityTracker { active_eventualities: HashMap::new() }
}
}
impl<E: Eventuality> EventualityTracker<E> {
/// Insert an Eventuality into the tracker.
pub fn insert(&mut self, eventuality: E) {
self.active_eventualities.insert(eventuality.lookup(), eventuality);
}
}