perf(pricebot): 透传复用共享 httpx 单例,免每请求重建 SSL 上下文 + 绕过进程代理

coupon/compare 透传原先每请求 async with httpx.AsyncClient(...) 新建:
每次重建 SSL 上下文(加载 certifi CA)实测 ~1s+,而 pricebot 是纯 HTTP
透传根本用不到 TLS;且 trust_env 默认 True 会把 http://localhost:8000
经进程代理(Clash)再绕几秒。

抽 app/core/pricebot_client.py 共享单例:trust_env=False 直连,lifespan
启动预热(SSL 一次性成本付在启动)、关停 aclose;timeout 下放到 .post()
保留 coupon 30s / compare 60s 差异。keep-alive 复用 TCP,每帧降到个位数 ms。

app/api/v1/compare.py

@@ -26,6 +26,7 @@ import httpx
 from fastapi import APIRouter, HTTPException, Request, status
 
 from app.core.config import settings
+from app.core.pricebot_client import get_pricebot_client
 from app.core.pricebot_router import pick_pricebot
 
 logger = logging.getLogger("shagua.compare")
@@ -65,10 +66,10 @@ async def _passthrough(request: Request, upstream_path: str) -> dict[str, Any]:
     )
 
     try:
-        async with httpx.AsyncClient(timeout=timeout) as client:
-            resp = await client.post(
-                url, content=raw, headers={"Content-Type": "application/json"}
-            )
+        client = get_pricebot_client()
+        resp = await client.post(
+            url, content=raw, headers={"Content-Type": "application/json"}, timeout=timeout
+        )
     except httpx.RequestError as e:
         logger.error("[pricebot] request failed: %s", e)
         raise HTTPException(

app/api/v1/coupon.py

@@ -20,6 +20,7 @@ from fastapi.concurrency import run_in_threadpool
 
 from app.api.deps import CurrentUser, DbSession
 from app.core.config import settings
+from app.core.pricebot_client import get_pricebot_client
 from app.core.pricebot_router import pick_pricebot
 from app.db.session import SessionLocal
 from app.repositories import coupon_state as coupon_repo
@@ -141,10 +142,10 @@ async def coupon_step(
     )
 
     try:
-        async with httpx.AsyncClient(timeout=timeout) as client:
-            resp = await client.post(
-                url, content=raw, headers={"Content-Type": "application/json"}
-            )
+        client = get_pricebot_client()
+        resp = await client.post(
+            url, content=raw, headers={"Content-Type": "application/json"}, timeout=timeout
+        )
     except httpx.RequestError as e:
         logger.error("[pricebot] request failed: %s", e)
         raise HTTPException(

app/core/pricebot_client.py

@@ -0,0 +1,35 @@
+"""透传到 pricebot 的共享 httpx.AsyncClient 单例。
+
+为什么不能每请求新建(coupon.py / compare.py 老写法 async with httpx.AsyncClient(...)):
+  ① 每次构造都重建一套 SSL 上下文(httpx.create_ssl_context 加载 certifi CA),实测
+     ~1s+/次;而 pricebot 是纯 http 透传,根本用不到 TLS → 纯浪费,且每帧重交一次。
+  ② trust_env 默认 True 会读进程 HTTP_PROXY,把 http://localhost:8000 这条本地透传整个
+     塞进本机代理(如 Clash 7897),恒定再多几秒。
+单例:启动只建一次(SSL/连接池一次性),keep-alive 复用 TCP,每帧降到个位数 ms。
+trust_env=False:对齐 integrations/meituan.py 的既有约定,不被进程代理误导,直连 pricebot。
+"""
+from __future__ import annotations
+
+import httpx
+
+_client: httpx.AsyncClient | None = None
+
+
+def get_pricebot_client() -> httpx.AsyncClient:
+    """取透传单例。lifespan 启动会预热;未预热(如测试态)懒建兜底。
+
+    超时不在此固化(coupon 30s / compare 60s 不同),由调用点 client.post(timeout=...) 传。
+    懒建无 await,asyncio 单线程下不会有并发竞态。
+    """
+    global _client
+    if _client is None:
+        _client = httpx.AsyncClient(trust_env=False)
+    return _client
+
+
+async def aclose_pricebot_client() -> None:
+    """lifespan 关停时调,优雅关连接池。"""
+    global _client
+    if _client is not None:
+        await _client.aclose()
+        _client = None

app/main.py

@@ -49,6 +49,7 @@ from app.core.daily_exchange_worker import (
     stop_daily_exchange_worker,
 )
 from app.core.logging import setup_logging
+from app.core.pricebot_client import aclose_pricebot_client, get_pricebot_client
 from app.core.withdraw_reconcile_worker import (
     start_withdraw_reconcile_worker,
     stop_withdraw_reconcile_worker,
@@ -68,6 +69,7 @@ async def lifespan(_: FastAPI) -> AsyncIterator[None]:
         settings.APP_DEBUG,
         settings.DATABASE_URL.split("://", 1)[0],
     )
+    get_pricebot_client()  # 预热透传 client:把建 SSL 上下文的一次性成本付在启动,首个领券请求即热
     reconcile_task = start_withdraw_reconcile_worker()
     heartbeat_task = start_heartbeat_monitor()
     daily_exchange_task = start_daily_exchange_worker()
@@ -77,6 +79,7 @@ async def lifespan(_: FastAPI) -> AsyncIterator[None]:
         await stop_heartbeat_monitor(heartbeat_task)
         await stop_withdraw_reconcile_worker(reconcile_task)
         await stop_daily_exchange_worker(daily_exchange_task)
+        await aclose_pricebot_client()
         logger.info("shutting down")