perf: reduce webapp and admin cache stampedes

backend/bot/app/web/webapp/cache_helpers.py

@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+from typing import Any, Awaitable, Callable, Optional
+
+from bot.infra.redis import cache_delete, redis_key
+from bot.utils.ttl_cache import AsyncTTLCache
+from config.settings import Settings
+
+_WEBAPP_USER_PAYLOAD_CACHES: dict[tuple[int, str, int], AsyncTTLCache] = {}
+
+
+def _webapp_user_payload_cache(
+    settings: Settings,
+    namespace: str,
+    ttl_seconds: int,
+) -> Optional[AsyncTTLCache]:
+    ttl = max(0, int(ttl_seconds or 0))
+    if ttl <= 0:
+        return None
+    cache_key = (id(settings), namespace, ttl)
+    cache = _WEBAPP_USER_PAYLOAD_CACHES.get(cache_key)
+    if cache is None:
+        cache = AsyncTTLCache(
+            ttl_seconds=ttl,
+            settings=settings,
+            namespace=f"webapp:{namespace}",
+        )
+        _WEBAPP_USER_PAYLOAD_CACHES[cache_key] = cache
+    return cache
+
+
+async def webapp_cached_user_payload(
+    settings: Settings,
+    namespace: str,
+    user_id: int,
+    ttl_seconds: int,
+    loader: Callable[[], Awaitable[Any]],
+) -> Any:
+    cache = _webapp_user_payload_cache(settings, namespace, ttl_seconds)
+    if cache is None:
+        return await loader()
+    return await cache.get_or_load(str(int(user_id)), loader)
+
+
+def invalidate_local_webapp_user_payload(
+    settings: Settings,
+    namespace: str,
+    user_id: int,
+) -> None:
+    key = str(int(user_id))
+    for (settings_id, cache_namespace, _ttl), cache in tuple(
+        _WEBAPP_USER_PAYLOAD_CACHES.items()
+    ):
+        if settings_id == id(settings) and cache_namespace == namespace:
+            cache.invalidate(key)
+
+
+async def invalidate_webapp_user_caches(
+    settings: Settings,
+    *user_ids: Optional[int],
+    include_devices: bool = False,
+) -> None:
+    keys: list[str] = []
+    seen: set[int] = set()
+    for raw_user_id in user_ids:
+        if raw_user_id is None:
+            continue
+        try:
+            user_id = int(raw_user_id)
+        except (TypeError, ValueError):
+            continue
+        if user_id in seen:
+            continue
+        seen.add(user_id)
+        keys.append(redis_key(settings, "cache", "webapp", "me", user_id))
+        invalidate_local_webapp_user_payload(settings, "me", user_id)
+        if include_devices:
+            keys.append(redis_key(settings, "cache", "webapp", "devices", user_id))
+            invalidate_local_webapp_user_payload(settings, "devices", user_id)
+    if keys:
+        await cache_delete(settings, *keys)