fix(tmdb): 空结果缓存使用独立短 TTL，故障恢复后快速自愈，关闭 #6332

- cached 装饰器新增 empty_ttl/empty_if，空结果按独立短 TTL 写入
- TMDB request/async_request/discover 空结果快照 30 分钟过期
- TmdbCache 未识别负缓存(id=0)同步改用 30 分钟短 TTL，正缓存不变

app/modules/themoviedb/tmdbv3api/objs/discover.py

@@ -1,5 +1,5 @@
 from app.runtime.cache import cached
-from ..tmdb import TMDb
+from ..tmdb import TMDb, EMPTY_RESULT_CACHE_TTL
 
 try:
     from urllib import urlencode
@@ -13,7 +13,7 @@ class Discover(TMDb):
         "tv": "/discover/tv"
     }
 
-    @cached(maxsize=1, ttl=43200)
+    @cached(maxsize=1, ttl=43200, empty_ttl=EMPTY_RESULT_CACHE_TTL)
     def discover_movies(self, params_tuple):
         """
         Discover movies by different types of data like average rating, number of votes, genres and certifications.
@@ -23,7 +23,7 @@ class Discover(TMDb):
         params = dict(params_tuple)
         return self._request_obj(self._urls["movies"], urlencode(params), key="results", call_cached=False)
 
-    @cached(maxsize=1, ttl=43200)
+    @cached(maxsize=1, ttl=43200, empty_ttl=EMPTY_RESULT_CACHE_TTL)
     def discover_tv_shows(self, params_tuple):
         """
         Discover TV shows by different types of data like average rating, number of votes, genres,
@@ -33,7 +33,7 @@ class Discover(TMDb):
         """
         return self._request_obj(self._urls["tv"], urlencode(params_tuple), key="results", call_cached=False)
 
-    @cached(maxsize=1, ttl=43200)
+    @cached(maxsize=1, ttl=43200, empty_ttl=EMPTY_RESULT_CACHE_TTL)
     async def async_discover_movies(self, params_tuple):
         """
         Discover movies by different types of data like average rating, number of votes, genres and certifications.（异步版本）
@@ -43,7 +43,7 @@ class Discover(TMDb):
         params = dict(params_tuple)
         return await self._async_request_obj(self._urls["movies"], urlencode(params), key="results", call_cached=False)
 
-    @cached(maxsize=1, ttl=43200)
+    @cached(maxsize=1, ttl=43200, empty_ttl=EMPTY_RESULT_CACHE_TTL)
     async def async_discover_tv_shows(self, params_tuple):
         """
         Discover TV shows by different types of data like average rating, number of votes, genres,

app/modules/themoviedb/tmdbv3api/tmdb.py

@@ -22,6 +22,11 @@ logger = logging.getLogger(__name__)
 # 故取区间内的经验值。
 RETRY_BACKOFF_SECONDS = 2
 
+# 空结果缓存的独立过期时间（秒）。TMDB 代理故障期间「合法 JSON 但 results 为空」的
+# 响应会随默认 TTL（可达数十小时）固化，故障自愈后同 key 仍持续命中空结果；空结果
+# 改用 30 分钟短 TTL，既能拦住故障窗口内的重复回源，又能在故障恢复后较快自然失效。
+EMPTY_RESULT_CACHE_TTL = 30 * 60
+
 
 def _is_business_failure_snapshot(snapshot) -> bool:
     """
@@ -37,6 +42,23 @@ def _is_business_failure_snapshot(snapshot) -> bool:
     return isinstance(json_data, dict) and json_data.get("success") is False
 
 
+def _is_empty_result_snapshot(snapshot) -> bool:
+    """
+    判断响应快照是否为空结果（列表/搜索类接口的 results 为空列表）。
+
+    这类快照结构合法但无业务内容，常由代理瞬时故障产生；不能靠 skip_none/skip_empty
+    识别（快照本身是非空字典），需单独谓词判定后按 EMPTY_RESULT_CACHE_TTL 短 TTL
+    缓存。详情类接口无 results 字段，不属于空结果。
+    """
+    if not isinstance(snapshot, dict):
+        return False
+    json_data = snapshot.get("json")
+    if not isinstance(json_data, dict):
+        return False
+    results = json_data.get("results")
+    return isinstance(results, list) and not results
+
+
 class TMDb(object):
     _RESPONSE_SNAPSHOT_MARKER = "__mp_tmdb_response_snapshot__"
 
@@ -157,7 +179,8 @@ class TMDb(object):
         self._wait_on_rate_limit = bool(wait_on_rate_limit)
 
     @cached(maxsize=settings.CONF.tmdb, ttl=settings.CONF.meta, skip_none=True,
-            skip_if=_is_business_failure_snapshot)
+            skip_if=_is_business_failure_snapshot,
+            empty_ttl=EMPTY_RESULT_CACHE_TTL, empty_if=_is_empty_result_snapshot)
     def request(self, method, url, data, json, **kwargs):
         req = self._request_once(method, url, data, json)
         if req is None and method == "GET" and self._owns_session:
@@ -182,7 +205,8 @@ class TMDb(object):
         return self._req.post_res(url, data=data, json=json)
 
     @cached(maxsize=settings.CONF.tmdb, ttl=settings.CONF.meta, skip_none=True,
-            skip_if=_is_business_failure_snapshot)
+            skip_if=_is_business_failure_snapshot,
+            empty_ttl=EMPTY_RESULT_CACHE_TTL, empty_if=_is_empty_result_snapshot)
     async def async_request(self, method, url, data, json, **kwargs):
         req = await self._async_request_once(method, url, data, json)
         if req is None: