"""Non-asyncio Redis cache handler.""" # Standard Library import json import time import pickle import typing as t # Third Party from redis import Redis as SyncRedis from pydantic import SecretStr from redis.exceptions import RedisError # Project from hyperglass.cache.base import BaseCache from hyperglass.exceptions.private import DependencyError if t.TYPE_CHECKING: # Third Party from redis.client import PubSub as SyncPubsSub # Project from hyperglass.models.config.params import Params from hyperglass.models.config.devices import Devices class SyncCache(BaseCache): """Synchronous Redis cache handler.""" def __init__( self, *, db: int, host: str = "localhost", port: int = 6379, password: t.Optional[SecretStr] = None, decode_responses: bool = False, **kwargs: t.Any, ): """Initialize Redis connection.""" super().__init__( db=db, host=host, port=port, password=password, decode_responses=decode_responses, **kwargs, ) password = self.password if password is not None: password = password.get_secret_value() self.instance: SyncRedis = SyncRedis( db=self.db, host=self.host, port=self.port, password=password, decode_responses=self.decode_responses, **self.redis_args, ) def test(self): """Send an echo to Redis to ensure it can be reached.""" try: self.instance.echo("hyperglass test") except RedisError as err: err_msg = str(err) if not err_msg and hasattr(err, "__context__"): # Some Redis exceptions are raised without a message # even if they are raised from another exception that # does have a message. err_msg = str(err.__context__) if "auth" in err_msg.lower(): raise DependencyError( "Authentication to Redis server {s} failed with message: '{e}'", s=repr(self, e=err_msg), ) else: raise DependencyError( "Unable to connect to Redis server {s} due to error {e}", s=repr(self), e=err_msg, ) def get(self, *args: str, decode: bool = True) -> t.Any: """Get item(s) from cache.""" if len(args) == 1: raw = self.instance.get(args[0]) else: raw = self.instance.mget(args) if decode and isinstance(raw, bytes): raw = raw.decode() return self.parse_types(raw) GetObj = t.TypeVar("GetObj") def get_object(self, name: str, _type: t.Type[GetObj] = t.Any) -> GetObj: raw = self.instance.get(name) obj: _type = pickle.loads(raw) return obj def get_dict(self, key: str, field: str = "", *, decode: bool = True) -> t.Any: """Get hash map (dict) item(s).""" if not field: raw = self.instance.hgetall(key) else: raw = self.instance.hget(key, str(field)) return self.parse_types(raw) def set(self, key: str, value: str) -> bool: """Set cache values.""" return self.instance.set(key, str(value)) def set_dict(self, key: str, field: str, value: str) -> bool: """Set hash map (dict) values.""" success = False if isinstance(value, t.Dict): value = json.dumps(value) else: value = str(value) response = self.instance.hset(key, str(field), value) if response in (0, 1): success = True return success def wait(self, pubsub: "SyncPubsSub", timeout: int = 30, **kwargs) -> t.Any: """Wait for pub/sub messages & return posted message.""" now = time.time() timeout = now + timeout while now < timeout: message = pubsub.get_message(ignore_subscribe_messages=True, **kwargs) if message is not None and message["type"] == "message": data = message["data"] return self.parse_types(data) time.sleep(0.01) now = time.time() return None def pubsub(self) -> "SyncPubsSub": """Provide a redis.client.Pubsub instance.""" return self.instance.pubsub() def pub(self, key: str, value: str) -> None: """Publish a value.""" time.sleep(1) self.instance.publish(key, value) def clear(self) -> None: """Clear the cache.""" self.instance.flushdb() def delete(self, *keys: str) -> None: """Delete a cache key.""" self.instance.delete(*keys) def expire(self, *keys: str, seconds: int) -> None: """Set timeout of key in seconds.""" for key in keys: self.instance.expire(key, seconds) def get_params(self) -> "Params": """Get Params object from the cache.""" return self.get_object(self.CONFIG_KEY, "Params") # return pickle.loads(self.get(self.CONFIG_KEY, decode=False, parse=False)) def get_devices(self) -> "Devices": """Get Devices object from the cache.""" return self.get_object(self.DEVICES_KEY, "Devices") # return pickle.loads(self.get(self.DEVICES_KEY, decode=False, parse=False)) def set_config(self: "SyncCache", config: "Params") -> None: """Add a params instance to the cache.""" self.instance.set(self.CONFIG_KEY, pickle.dumps(config)) def set_devices(self: "SyncCache", devices: "Devices") -> None: """Add a devices instance to the cache.""" self.instance.set(self.DEVICES_KEY, pickle.dumps(devices))