use crate::StreamId;
pub trait IdGen: Default {
fn next(&mut self) -> StreamId;
fn id(&self) -> StreamId;
fn seed(&mut self, _seed: usize) {}
}
#[derive(Default, Copy, Clone, PartialEq, Debug)]
pub struct IncrementIdGen {
id: StreamId,
}
impl Unpin for IncrementIdGen {}
impl IdGen for IncrementIdGen {
#[tracing::instrument(level = "trace", skip(self))]
fn next(&mut self) -> StreamId {
self.id = self.id.wrapping_add(1);
self.id
}
fn id(&self) -> StreamId {
self.id
}
#[tracing::instrument(level = "trace", skip(self))]
fn seed(&mut self, seed: StreamId) {
self.id = seed;
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn increment() {
let mut id = IncrementIdGen::default();
id.seed(usize::max_value());
assert_eq!(usize::max_value(), id.id());
let zero = id.next();
assert_eq!(0, zero);
let one = id.next();
assert_eq!(1, one);
assert_eq!(one, id.id());
}
}