feat(api-server): add container loadtest observability

server-rs/crates/api-server/src/puzzle_gallery_cache.rs

@@ -3,8 +3,8 @@ use std::{
     time::{Duration, Instant},
 };
 
-use axum::Json;
-use serde_json::Value;
+use axum::response::Response;
+use bytes::Bytes;
 use shared_contracts::{
     puzzle_gallery::{PuzzleGalleryResponse, PuzzleGalleryWorkRefResponse},
     puzzle_works::PuzzleWorkSummaryResponse,
@@ -14,7 +14,7 @@ use tokio::{
     time,
 };
 
-use crate::{api_response::json_success_body, request_context::RequestContext};
+use crate::{api_response::json_success_data_bytes_response, request_context::RequestContext};
 
 const PUZZLE_GALLERY_PRIMARY_ITEM_COUNT: usize = 10;
 const PUZZLE_GALLERY_PREVIEW_REF_COUNT: usize = 10;
@@ -30,10 +30,21 @@ pub struct PuzzleGalleryCache {
 
 #[derive(Clone, Debug)]
 struct PuzzleGalleryCacheEntry {
-    response: PuzzleGalleryResponse,
+    data_json: Bytes,
     built_at: Instant,
 }
 
+#[derive(Clone, Debug)]
+pub struct PuzzleGalleryCachedResponse {
+    data_json: Bytes,
+}
+
+impl PuzzleGalleryCachedResponse {
+    pub fn data_json_len(&self) -> usize {
+        self.data_json.len()
+    }
+}
+
 impl PuzzleGalleryCache {
     pub fn new() -> Self {
         Self {
@@ -46,22 +57,31 @@ impl PuzzleGalleryCache {
         self.rebuild_lock.lock().await
     }
 
-    pub async fn read_fresh_response(&self) -> Option<PuzzleGalleryResponse> {
+    pub async fn read_fresh_response(&self) -> Option<PuzzleGalleryCachedResponse> {
         let guard = self.inner.read().await;
         let entry = guard.as_ref()?;
         let now = Instant::now();
         if now.duration_since(entry.built_at) > PUZZLE_GALLERY_CACHE_TTL {
             return None;
         }
-        Some(entry.response.clone())
+        Some(PuzzleGalleryCachedResponse {
+            data_json: entry.data_json.clone(),
+        })
     }
 
-    pub async fn store_response(&self, response: PuzzleGalleryResponse) {
+    pub async fn store_response(
+        &self,
+        response: PuzzleGalleryResponse,
+    ) -> Result<PuzzleGalleryCachedResponse, serde_json::Error> {
         let now = Instant::now();
+        let cached = PuzzleGalleryCachedResponse {
+            data_json: Bytes::from(serde_json::to_vec(&response)?),
+        };
         *self.inner.write().await = Some(PuzzleGalleryCacheEntry {
-            response,
+            data_json: cached.data_json.clone(),
             built_at: now,
         });
+        Ok(cached)
     }
 
     pub fn spawn_cleanup_task(&self) {
@@ -118,9 +138,9 @@ pub fn build_puzzle_gallery_window_response(
 
 pub fn puzzle_gallery_cached_json(
     request_context: &RequestContext,
-    response: PuzzleGalleryResponse,
-) -> Json<Value> {
-    json_success_body(Some(request_context), response)
+    response: PuzzleGalleryCachedResponse,
+) -> Response {
+    json_success_data_bytes_response(Some(request_context), response.data_json)
 }
 
 #[cfg(test)]