67 lines
2.1 KiB
Rust
67 lines
2.1 KiB
Rust
//! WebSocket upgrade and per-connection handler. Serves cached JSON quickly.
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use axum::{
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extract::{
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ws::{Message, WebSocket, WebSocketUpgrade},
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Query, State,
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},
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http::StatusCode,
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response::{IntoResponse, Response},
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};
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use futures_util::stream::StreamExt;
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use crate::metrics::collect_metrics;
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use crate::state::AppState;
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use std::collections::HashMap;
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use std::sync::atomic::Ordering;
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pub async fn ws_handler(
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ws: WebSocketUpgrade,
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State(state): State<AppState>,
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Query(q): Query<HashMap<String, String>>,
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) -> Response {
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if let Some(expected) = state.auth_token.as_ref() {
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match q.get("token") {
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Some(t) if t == expected => {}
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_ => return StatusCode::UNAUTHORIZED.into_response(),
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}
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}
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ws.on_upgrade(move |socket| handle_socket(socket, state))
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}
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async fn handle_socket(mut socket: WebSocket, state: AppState) {
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// Bump client count on connect and wake the sampler.
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state.client_count.fetch_add(1, Ordering::Relaxed);
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state.wake_sampler.notify_waiters();
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// Ensure we decrement on disconnect (drop).
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struct ClientGuard(AppState);
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impl Drop for ClientGuard {
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fn drop(&mut self) {
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self.0.client_count.fetch_sub(1, Ordering::Relaxed);
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self.0.wake_sampler.notify_waiters();
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}
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}
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let _guard = ClientGuard(state.clone());
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while let Some(Ok(msg)) = socket.next().await {
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match msg {
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Message::Text(text) if text == "get_metrics" => {
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// Serve the cached JSON quickly; if empty (cold start), collect once.
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let cached = state.last_json.read().await.clone();
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if !cached.is_empty() {
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let _ = socket.send(Message::Text(cached)).await;
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} else {
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let metrics = collect_metrics(&state).await;
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if let Ok(js) = serde_json::to_string(&metrics) {
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let _ = socket.send(Message::Text(js)).await;
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}
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}
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}
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Message::Close(_) => break,
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_ => {}
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}
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}
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}
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