perf(api-server): tune gallery load shedding

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

@@ -6,6 +6,7 @@ use std::{
     time::{SystemTime, UNIX_EPOCH},
 };
 
+use axum::extract::FromRef;
 use module_ai::{AiTaskService, InMemoryAiTaskStore};
 use module_auth::{
     AuthUserService, InMemoryAuthStore, PasswordEntryService, PhoneAuthService,
@@ -39,13 +40,113 @@ const ADMIN_ROLE: &str = "admin";
 
 pub type HttpRequestPermitPool = Semaphore;
 
-// 当前阶段先保留最小共享状态壳，后续逐步接入配置、客户端与平台适配。
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum HttpRequestPermitPoolKind {
+    Default,
+    Gallery,
+    Detail,
+    Admin,
+}
+
+impl HttpRequestPermitPoolKind {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Default => "default",
+            Self::Gallery => "gallery",
+            Self::Detail => "detail",
+            Self::Admin => "admin",
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
-pub struct AppState {
+pub struct HttpRequestPermitPools {
+    default: Option<Arc<HttpRequestPermitPool>>,
+    gallery: Option<Arc<HttpRequestPermitPool>>,
+    detail: Option<Arc<HttpRequestPermitPool>>,
+    admin: Option<Arc<HttpRequestPermitPool>>,
+}
+
+impl HttpRequestPermitPools {
+    fn from_config(config: &AppConfig) -> Self {
+        Self {
+            default: config
+                .max_concurrent_requests
+                .map(HttpRequestPermitPool::new)
+                .map(Arc::new),
+            gallery: config
+                .gallery_max_concurrent_requests
+                .map(HttpRequestPermitPool::new)
+                .map(Arc::new),
+            detail: config
+                .detail_max_concurrent_requests
+                .map(HttpRequestPermitPool::new)
+                .map(Arc::new),
+            admin: config
+                .admin_max_concurrent_requests
+                .map(HttpRequestPermitPool::new)
+                .map(Arc::new),
+        }
+    }
+
+    pub fn pool(
+        &self,
+        kind: HttpRequestPermitPoolKind,
+    ) -> Option<(HttpRequestPermitPoolKind, Arc<HttpRequestPermitPool>)> {
+        let selected = match kind {
+            HttpRequestPermitPoolKind::Default => self.default.clone(),
+            HttpRequestPermitPoolKind::Gallery => self.gallery.clone(),
+            HttpRequestPermitPoolKind::Detail => self.detail.clone(),
+            HttpRequestPermitPoolKind::Admin => self.admin.clone(),
+        };
+        selected.map(|pool| (kind, pool)).or_else(|| {
+            self.default
+                .clone()
+                .map(|pool| (HttpRequestPermitPoolKind::Default, pool))
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct BackpressureState {
+    permit_pools: HttpRequestPermitPools,
+}
+
+impl BackpressureState {
+    pub fn request_permit_pool(
+        &self,
+        kind: HttpRequestPermitPoolKind,
+    ) -> Option<(HttpRequestPermitPoolKind, Arc<HttpRequestPermitPool>)> {
+        self.permit_pools.pool(kind)
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct AppState(Arc<AppStateInner>);
+
+impl std::ops::Deref for AppState {
+    type Target = AppStateInner;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl FromRef<AppState> for BackpressureState {
+    fn from_ref(state: &AppState) -> Self {
+        Self {
+            permit_pools: state.http_request_permit_pools(),
+        }
+    }
+}
+
+// Axum/Hyper 会在路由树和连接 service 上频繁 clone state；AppState 外层必须保持浅拷贝。
+#[derive(Debug)]
+pub struct AppStateInner {
     // 配置会在后续中间件、路由和平台适配接入时逐步消费。
     #[allow(dead_code)]
     pub config: AppConfig,
-    http_request_permit_pool: Option<Arc<HttpRequestPermitPool>>,
+    http_request_permit_pools: HttpRequestPermitPools,
     auth_jwt_config: JwtConfig,
     admin_runtime: Option<AdminRuntime>,
     refresh_cookie_config: RefreshCookieConfig,
@@ -198,14 +299,11 @@ impl AppState {
         });
         let llm_client = build_llm_client(&config)?;
         let creative_agent_gpt5_client = build_creative_agent_gpt5_client(&config)?;
-        let http_request_permit_pool = config
-            .max_concurrent_requests
-            .map(HttpRequestPermitPool::new)
-            .map(Arc::new);
+        let http_request_permit_pools = HttpRequestPermitPools::from_config(&config);
 
-        Ok(Self {
+        Ok(Self(Arc::new(AppStateInner {
             config,
-            http_request_permit_pool,
+            http_request_permit_pools,
             auth_jwt_config,
             admin_runtime,
             refresh_cookie_config,
@@ -232,7 +330,7 @@ impl AppState {
             creative_agent_sessions: Arc::new(Mutex::new(HashMap::new())),
             #[cfg(test)]
             test_runtime_snapshot_store: Arc::new(Mutex::new(HashMap::new())),
-        })
+        })))
     }
 
     pub fn auth_jwt_config(&self) -> &JwtConfig {
@@ -247,8 +345,8 @@ impl AppState {
         &self.refresh_cookie_config
     }
 
-    pub fn http_request_permit_pool(&self) -> Option<Arc<HttpRequestPermitPool>> {
-        self.http_request_permit_pool.clone()
+    pub fn http_request_permit_pools(&self) -> HttpRequestPermitPools {
+        self.http_request_permit_pools.clone()
     }
 
     pub async fn upsert_creation_entry_type_config(