59 lines
2.1 KiB
Rust
59 lines
2.1 KiB
Rust
|
//! Consumer ingest: reconstruct each node's stream from deliveries (spec
|
||
|
|
//! §8.1).
|
||
|
|
//!
|
||
|
|
//! The consumer receives frames from many nodes, in any order, some never
|
||
|
|
//! arriving, and reconstructs each node's stream — keyed by stream id,
|
||
|
|
//! ordered by position — into the [`Store`]. Ingest is deliberately thin:
|
||
|
|
//! it routes a delivery to its stream and records the frame whole. It MUST
|
||
|
|
//! NOT thin, aggregate, decode-and-discard, or truncate (spec §8.2), and it
|
||
|
|
//! never inspects a channel or a payload, so a channel it cannot decode is
|
||
|
|
//! retained exactly like any other (spec §8.3).
|
||
|
|
//!
|
||
|
|
//! Reconstruction is by position, not arrival: out-of-order deliveries land
|
||
|
|
//! in order in the store, and a position delivered twice collapses to one
|
||
|
|
//! (spec §7.5). Two lives of one node are different stream ids and never
|
||
|
|
//! merge (spec §8.4).
|
||
|
|
|
||
|
|
use super::store::Store;
|
||
|
|
use super::transport::Delivery;
|
||
|
|
|
||
|
|
/// The single consumer toward which all telemetry flows (spec §2). It owns
|
||
|
|
/// the stored streams and grows them as deliveries arrive.
|
||
|
|
#[derive(Debug, Default)]
|
||
|
|
pub struct Consumer {
|
||
|
|
store: Store,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl Consumer {
|
||
|
|
/// A consumer with an empty store.
|
||
|
|
pub fn new() -> Self {
|
||
|
|
Consumer::default()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Accept one delivery: route it to its stream and record the frame.
|
||
|
|
/// Returns `true` if the frame was new (a duplicate position is
|
||
|
|
/// ignored, keeping the first — the carrier cannot fabricate content,
|
||
|
|
/// spec §9).
|
||
|
|
pub fn accept(&mut self, delivery: Delivery) -> bool {
|
||
|
|
let Delivery { stream, frame } = delivery;
|
||
|
|
self.store.stream_mut(&stream).record(frame)
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Accept a batch of deliveries, in whatever order they arrive.
|
||
|
|
pub fn ingest(&mut self, deliveries: impl IntoIterator<Item = Delivery>) {
|
||
|
|
for delivery in deliveries {
|
||
|
|
self.accept(delivery);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// The stored streams — the source of truth for every view (spec §8.2).
|
||
|
|
pub fn store(&self) -> &Store {
|
||
|
|
&self.store
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Consume the consumer, yielding its store.
|
||
|
|
pub fn into_store(self) -> Store {
|
||
|
|
self.store
|
||
|
|
}
|
||
|
|
}
|