server: fix slow profanity filter

server/reflector/redis_cache.py

@@ -0,0 +1,50 @@
+import functools
+import json
+
+import redis
+from reflector.settings import settings
+
+redis_clients = {}
+
+
+def get_redis_client(db=0):
+    """
+    Get a Redis client for the specified database.
+    """
+    if db not in redis_clients:
+        redis_clients[db] = redis.StrictRedis(
+            host=settings.REDIS_HOST,
+            port=settings.REDIS_PORT,
+            db=db,
+        )
+    return redis_clients[db]
+
+
+def redis_cache(prefix="cache", duration=3600, db=settings.REDIS_CACHE_DB, argidx=1):
+    """
+    Cache the result of a function in Redis.
+    """
+
+    def decorator(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            # Check if the first argument is a string
+            if len(args) < (argidx + 1) or not isinstance(args[argidx], str):
+                return func(*args, **kwargs)
+
+            # Compute the cache key based on the arguments and prefix
+            cache_key = prefix + ":" + args[argidx]
+            redis_client = get_redis_client(db=db)
+            cached_result = redis_client.get(cache_key)
+
+            if cached_result:
+                return json.loads(cached_result.decode("utf-8"))
+
+            # If the result is not cached, call the original function
+            result = func(*args, **kwargs)
+            redis_client.setex(cache_key, duration, json.dumps(result))
+            return result
+
+        return wrapper
+
+    return decorator