PostgreSQL + async refactoring, WebSocket server, Redis caching, minified assets

cache.py

@@ -0,0 +1,67 @@
+import os
+import json
+import asyncio
+from typing import Optional, Any, Callable, Awaitable
+from datetime import timedelta
+
+REDIS_URL = os.getenv("REDIS_URL", "redis://localhost:6379/0")
+CACHE_TTL = int(os.getenv("CACHE_TTL", "300"))
+
+_redis_pool = None
+_lock = asyncio.Lock()
+
+
+async def get_redis():
+    global _redis_pool
+    if _redis_pool is None:
+        import aioredis
+        async with _lock:
+            if _redis_pool is None:
+                _redis_pool = await aioredis.from_url(REDIS_URL, decode_responses=True)
+    return _redis_pool
+
+
+async def cache_get(key: str) -> Optional[Any]:
+    try:
+        r = await get_redis()
+        val = await r.get(key)
+        if val:
+            return json.loads(val)
+    except Exception:
+        pass
+    return None
+
+
+async def cache_set(key: str, value: Any, ttl: int = CACHE_TTL):
+    try:
+        r = await get_redis()
+        await r.setex(key, ttl, json.dumps(value, default=str))
+    except Exception:
+        pass
+
+
+async def cache_delete(key: str):
+    try:
+        r = await get_redis()
+        await r.delete(key)
+    except Exception:
+        pass
+
+
+async def cache_get_or_set(key: str, factory: Callable[[], Awaitable[Any]], ttl: int = CACHE_TTL) -> Any:
+    cached = await cache_get(key)
+    if cached is not None:
+        return cached
+    value = await factory()
+    await cache_set(key, value, ttl)
+    return value
+
+
+async def cache_invalidate_pattern(pattern: str):
+    try:
+        r = await get_redis()
+        keys = await r.keys(pattern)
+        if keys:
+            await r.delete(*keys)
+    except Exception:
+        pass