Replace in-memory TTL cache with Redis

services/cache.py

@@ -1,29 +1,62 @@
-import time
+import json
+import logging
+import os
 from typing import Any
 
+import redis.asyncio as redis
 
-class TTLCache:
-    """Simple in-memory TTL cache."""
+logger = logging.getLogger(__name__)
 
-    def __init__(self, ttl_seconds: int = 60):
-        self._ttl = ttl_seconds
-        self._store: dict[str, tuple[float, Any]] = {}
+_redis: redis.Redis | None = None
 
-    def get(self, key: str) -> Any | None:
-        entry = self._store.get(key)
-        if entry is None:
+
+async def init_cache() -> None:
+    """Create Redis connection from environment variables."""
+    global _redis
+    host = os.environ.get("REDIS_HOST", "localhost")
+    port = int(os.environ.get("REDIS_PORT", "6379"))
+    db = int(os.environ.get("REDIS_DB", "0"))
+    try:
+        _redis = redis.Redis(host=host, port=port, db=db, decode_responses=True)
+        await _redis.ping()
+        logger.info("Redis connected at %s:%d/%d", host, port, db)
+    except Exception as e:
+        logger.warning("Redis connection failed: %s — running without cache", e)
+        _redis = None
+
+
+async def close_cache() -> None:
+    """Close Redis connection."""
+    global _redis
+    if _redis is not None:
+        await _redis.aclose()
+        _redis = None
+
+
+def redis_available() -> bool:
+    """Return whether Redis connection is live."""
+    return _redis is not None
+
+
+async def cache_get(key: str) -> Any | None:
+    """GET key from Redis, return deserialized value or None on miss/error."""
+    if _redis is None:
+        return None
+    try:
+        raw = await _redis.get(key)
+        if raw is None:
             return None
-        ts, value = entry
-        if time.monotonic() - ts > self._ttl:
-            del self._store[key]
-            return None
-        return value
-
-    def set(self, key: str, value: Any) -> None:
-        self._store[key] = (time.monotonic(), value)
-
-    def clear(self) -> None:
-        self._store.clear()
+        return json.loads(raw)
+    except Exception as e:
+        logger.warning("Redis GET %s failed: %s", key, e)
+        return None
 
 
-smart_cache = TTLCache(ttl_seconds=60)
+async def cache_set(key: str, value: Any, ttl: int = 120) -> None:
+    """SET key in Redis with expiry, silently catches errors."""
+    if _redis is None:
+        return
+    try:
+        await _redis.set(key, json.dumps(value), ex=ttl)
+    except Exception as e:
+        logger.warning("Redis SET %s failed: %s", key, e)