yoi/crates/pod/src/notification_buffer.rs
2026-04-19 08:20:07 +09:00

125 lines
4.0 KiB
Rust

//! Pending-notification buffer for `Method::Notify`.
//!
//! Notifications are queued here by the Controller and drained by
//! `PodInterceptor::pre_llm_request` into the per-request context
//! (never into the Worker's persistent history). Each queued entry
//! becomes one `Item::system_message` in the outgoing request.
use std::collections::VecDeque;
use std::sync::{Arc, Mutex};
use llm_worker::Item;
use tracing::warn;
/// Maximum queued notifications. Oldest entries are dropped beyond this.
const CAPACITY: usize = 128;
/// One pending notification awaiting injection into the next LLM request.
#[derive(Debug, Clone)]
pub struct PendingNotification {
pub message: String,
}
/// Shared, mutex-guarded buffer of pending notifications.
///
/// Cloned between the Pod (producer) and PodInterceptor (consumer).
#[derive(Clone, Default)]
pub struct NotificationBuffer {
inner: Arc<Mutex<VecDeque<PendingNotification>>>,
}
impl NotificationBuffer {
pub fn new() -> Self {
Self::default()
}
/// Push a notification onto the queue. If the queue is full, the
/// oldest entry is dropped and a `tracing::warn` is emitted — the
/// caller should never hit this in normal operation.
pub fn push(&self, message: String) {
let mut q = self.inner.lock().expect("notification buffer poisoned");
if q.len() >= CAPACITY {
let dropped = q.pop_front();
warn!(
capacity = CAPACITY,
dropped_message = dropped.as_ref().map(|n| n.message.as_str()),
"notification buffer overflow; dropped oldest"
);
}
q.push_back(PendingNotification { message });
}
/// Remove and return all pending notifications in FIFO order.
pub fn drain(&self) -> Vec<PendingNotification> {
let mut q = self.inner.lock().expect("notification buffer poisoned");
q.drain(..).collect()
}
/// Number of pending notifications. Primarily for tests.
pub fn len(&self) -> usize {
self.inner
.lock()
.expect("notification buffer poisoned")
.len()
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
}
/// Format a single pending notification into the `Item::system_message`
/// that gets injected into the per-request context.
pub(crate) fn format_notification(n: &PendingNotification) -> Item {
let text = format!(
"[Notification]\n{message}\n\n\
This is a notification, not a blocking request. \
If you are in the middle of a task, continue your current work \
and address this at a natural stopping point.",
message = n.message,
);
Item::system_message(text)
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn push_then_drain_preserves_order() {
let buf = NotificationBuffer::new();
buf.push("one".into());
buf.push("two".into());
let drained = buf.drain();
assert_eq!(drained.len(), 2);
assert_eq!(drained[0].message, "one");
assert_eq!(drained[1].message, "two");
assert!(buf.is_empty());
}
#[test]
fn capacity_drops_oldest() {
let buf = NotificationBuffer::new();
for i in 0..(CAPACITY + 5) {
buf.push(format!("msg{i}"));
}
let drained = buf.drain();
assert_eq!(drained.len(), CAPACITY);
// Oldest 5 were dropped; first retained is msg5.
assert_eq!(drained[0].message, "msg5");
assert_eq!(drained[CAPACITY - 1].message, format!("msg{}", CAPACITY + 4));
}
#[test]
fn format_notification_includes_message_and_nonblocking_hint() {
let n = PendingNotification {
message: "hello".into(),
};
let item = format_notification(&n);
let text = item.as_text().unwrap_or_default().to_string();
assert!(text.contains("[Notification]"));
assert!(text.contains("hello"));
assert!(text.contains("not a blocking request"));
}
}