use crate::disktest::DisktestQuiet;
use std::collections::HashMap;
use std::sync::mpsc::{channel, Receiver, Sender};
pub struct BufCache {
snd: HashMap<u32, Sender<Vec<u8>>>,
quiet_level: DisktestQuiet,
}
impl BufCache {
pub fn new(quiet_level: DisktestQuiet) -> BufCache {
BufCache {
snd: HashMap::new(),
quiet_level,
}
}
pub fn new_consumer(&mut self, cons_id: u32) -> BufCacheCons {
let (snd, rcv) = channel();
self.snd.insert(cons_id, snd);
BufCacheCons { rcv }
}
pub fn push(&mut self, cons_id: u32, buf: Vec<u8>) {
let Some(snd) = self.snd.get(&cons_id) else {
panic!("BufCache: Consumer {} does not exist.", cons_id);
};
if let Err(e) = snd.send(buf) {
if self.quiet_level < DisktestQuiet::NoWarn {
eprintln!("BufCache: Failed to send: {}", e);
}
}
}
}
pub struct BufCacheCons {
rcv: Receiver<Vec<u8>>,
}
impl BufCacheCons {
pub fn pull(&mut self, buf_len: usize) -> Vec<u8> {
let mut buf = match self.rcv.try_recv() {
Ok(buf) => buf,
Err(_) => Vec::with_capacity(buf_len),
};
if buf.len() != buf_len {
buf.resize(buf_len, 0);
}
buf
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_bufcache() {
let mut cache = BufCache::new(DisktestQuiet::Normal);
let mut cons0 = cache.new_consumer(42);
let mut cons1 = cache.new_consumer(43);
let buf = cons0.pull(4);
assert_eq!(buf.len(), 4);
assert_eq!(buf, vec![0, 0, 0, 0]);
cache.push(42, vec![0xDE, 0xAD, 0xBE, 0xEF]);
let buf = cons0.pull(4);
assert_eq!(buf.len(), 4);
assert_eq!(buf, vec![0xDE, 0xAD, 0xBE, 0xEF]);
let buf = cons0.pull(4);
assert_eq!(buf.len(), 4);
assert_eq!(buf, vec![0, 0, 0, 0]);
cache.push(43, vec![0xCA, 0xFE, 0xAF, 0xFE]);
let buf = cons0.pull(4);
assert_eq!(buf.len(), 4);
assert_eq!(buf, vec![0, 0, 0, 0]);
let buf = cons1.pull(4);
assert_eq!(buf.len(), 4);
assert_eq!(buf, vec![0xCA, 0xFE, 0xAF, 0xFE]);
}
#[test]
#[should_panic(expected = "Consumer 42 does not exist")]
fn test_bufcache_cons_invalid() {
let mut cache = BufCache::new(DisktestQuiet::Normal);
cache.push(42, vec![]);
}
}