Add negative config key cache

botto/storage/config_storage.py

@@ -8,6 +8,7 @@
 log = logging.getLogger(__name__)
 
 ConfigCache = dict[str, dict[str, ConfigEntry]]
+NegativeConfigKeyCache = dict[str, set[str]]
 
 
 class ConfigStorage(Storage):
@@ -19,6 +20,8 @@ def __init__(self, airtable_base: str, airtable_key: str):
         )
         self.config_lock = asyncio.Lock()
         self.config_cache: ConfigCache = {}
+        self.config_key_negative_cache_lock = asyncio.Lock()
+        self.config_key_negative_cache: NegativeConfigKeyCache = {}
         self.auth_header = {"Authorization": f"Bearer {self.airtable_key}"}
 
     async def clear_server_cache(self, server_id: str):
@@ -64,9 +67,18 @@ async def retrieve_config(
                 return server_config if not key else server_config[key]
         except (StopIteration, StopAsyncIteration, KeyError):
             log.info(f"No config found for Key {key} with Server ID {server_id}")
+            async with self.config_key_negative_cache_lock:
+                self.config_key_negative_cache.setdefault(str(server_id), set()).add(
+                    key
+                )
             return None
 
     async def get_config(self, server_id: str | int, key: str) -> Optional[ConfigEntry]:
+        if (
+            not self.config_key_negative_cache_lock.locked()
+            and self.config_key_negative_cache.get(str(server_id), {}).get(key)
+        ):
+            return None
         await self.config_lock.acquire()
         if (server_config := self.config_cache.get(str(server_id))) and (
             config := server_config.get(key)
@@ -82,6 +94,21 @@ async def refresh_cache(self):
         await self.config_lock.acquire()
         current_cache = self.config_cache
         self.config_lock.release()
-        for key in current_cache:
+        for key, entries in current_cache.items():
             log.debug(f"Refreshing config for server {key}")
-            await self.retrieve_config(server_id=key, key=None)
+            for entry in entries.values():
+                await self.retrieve_config(server_id=key, key=entry.config_key)
+
+        log.info("Refreshing negative config key cache")
+        for server_id, keys in self.config_key_negative_cache.items():
+            keys_to_remove = []
+            for key in keys:
+                async with self.config_key_negative_cache_lock:
+                    if await self.retrieve_config(server_id, key):
+                        keys_to_remove.append(key)
+                        log.debug(
+                            f"Previously non-existent key {key} now exists for {server_id}"
+                        )
+            for key in keys_to_remove:
+                self.config_key_negative_cache[server_id].remove(key)
+        log.info("Config cache refreshed")