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mirror of https://github.com/checktheroads/hyperglass synced 2024-05-11 05:55:08 +00:00

147 lines
4.5 KiB
Python

"""Asyncio Redis cache handler."""
# Standard Library
import json
import time
import pickle
import asyncio
from typing import Any, Dict
# Third Party
from aredis import StrictRedis as AsyncRedis # type: ignore
from aredis.pubsub import PubSub as AsyncPubSub # type: ignore
from aredis.exceptions import RedisError # type: ignore
# Project
from hyperglass.cache.base import BaseCache
from hyperglass.exceptions.private import DependencyError
class AsyncCache(BaseCache):
"""Asynchronous Redis cache handler."""
def __init__(self, *args, **kwargs):
"""Initialize Redis connection."""
super().__init__(*args, **kwargs)
password = self.password
if password is not None:
password = password.get_secret_value()
self.instance: AsyncRedis = AsyncRedis(
db=self.db,
host=self.host,
port=self.port,
password=password,
decode_responses=self.decode_responses,
**self.redis_args,
)
async def test(self):
"""Send an echo to Redis to ensure it can be reached."""
try:
await 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,
)
async def get(self, *args: str) -> Any:
"""Get item(s) from cache."""
if len(args) == 1:
raw = await self.instance.get(args[0])
else:
raw = await self.instance.mget(args)
return self.parse_types(raw)
async def get_dict(self, key: str, field: str = "") -> Any:
"""Get hash map (dict) item(s)."""
if not field:
raw = await self.instance.hgetall(key)
else:
raw = await self.instance.hget(key, field)
return self.parse_types(raw)
async def set(self, key: str, value: str) -> bool:
"""Set cache values."""
return await self.instance.set(key, value)
async def set_dict(self, key: str, field: str, value: str) -> bool:
"""Set hash map (dict) values."""
success = False
if isinstance(value, Dict):
value = json.dumps(value)
else:
value = str(value)
response = await self.instance.hset(key, field, value)
if response in (0, 1):
success = True
return success
async def wait(self, pubsub: AsyncPubSub, timeout: int = 30, **kwargs) -> Any:
"""Wait for pub/sub messages & return posted message."""
now = time.time()
timeout = now + timeout
while now < timeout:
message = await 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)
await asyncio.sleep(0.01)
now = time.time()
return None
async def pubsub(self) -> AsyncPubSub:
"""Provide an aredis.pubsub.Pubsub instance."""
return self.instance.pubsub()
async def pub(self, key: str, value: str) -> None:
"""Publish a value."""
await asyncio.sleep(1)
await self.instance.publish(key, value)
async def clear(self) -> None:
"""Clear the cache."""
await self.instance.flushdb()
async def delete(self, *keys: str) -> None:
"""Delete a cache key."""
await self.instance.delete(*keys)
async def expire(self, *keys: str, seconds: int) -> None:
"""Set timeout of key in seconds."""
for key in keys:
await self.instance.expire(key, seconds)
async def get_config(self) -> Dict:
"""Get picked config object from cache."""
pickled = await self.instance.get("HYPERGLASS_CONFIG")
return pickle.loads(pickled)