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use serde::{Deserialize, Serialize};
#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
pub enum Status {
Available,
Transit,
}
impl Default for Status {
fn default() -> Status {
Status::Available
}
}
#[derive(Serialize, Deserialize, Debug, Clone)]
pub struct State {
status: Status,
tries: u32,
max_tries: u32,
}
impl State {
pub(crate) fn new(max_tries: u32) -> State {
State {
status: Status::default(),
tries: 0,
max_tries,
}
}
pub(crate) fn has_tries(&self) -> bool {
self.tries < self.max_tries
}
pub(crate) fn requeue(&mut self) {
self.status = Status::Available;
}
pub(crate) fn reserve(&mut self) {
self.status = Status::Transit;
self.tries += 1;
}
pub(crate) fn requeueable(&self) -> bool {
self.status == Status::Transit
}
pub(crate) fn reservable(&self) -> bool {
self.status == Status::Available && self.has_tries()
}
pub(crate) fn requires_gc(&self) -> bool {
self.tries == self.max_tries && self.status == Status::Available
}
pub fn status(&self) -> &Status {
&self.status
}
pub fn tries(&self) -> &u32 {
&self.tries
}
pub fn max_tries(&self) -> &u32 {
&self.max_tries
}
}
#[cfg(test)]
mod tests {
use super::State;
#[test]
fn create_valid_state() {
let state = State::new(1);
assert!(state.reservable());
assert!(!state.requeueable());
assert!(!state.requires_gc());
}
#[test]
fn create_useless_state() {
let state = State::new(0);
assert!(state.requires_gc());
}
#[test]
fn lifecycle() {
let mut state = State::new(1);
assert!(state.reservable());
state.reserve();
assert!(state.requeueable());
state.requeue();
assert!(state.requires_gc());
}
}