mirror of
https://github.com/lnbits/lnbits-legend.git
synced 2025-02-25 07:07:48 +01:00
2577ce7f81
* add simple caching utility * test cache * remove prefix, default on get * check expiry in pop aswell * remove unnecessary type * improve invalidation task increase default interval to 10 seconds - doesnt have to check that often. instead of recreating the dict everytime mutate the existing one
65 lines
1.8 KiB
Python
65 lines
1.8 KiB
Python
from __future__ import annotations
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import asyncio
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from time import time
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from typing import Any, NamedTuple, Optional
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from loguru import logger
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class Cached(NamedTuple):
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value: Any
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expiry: float
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class Cache:
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"""
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Small caching utility providing simple get/set interface (very much like redis)
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"""
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def __init__(self):
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self._values: dict[Any, Cached] = {}
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def get(self, key: str, default=None) -> Optional[Any]:
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cached = self._values.get(key)
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if cached is not None:
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if cached.expiry > time():
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return cached.value
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else:
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self._values.pop(key)
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return default
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def set(self, key: str, value: Any, expiry: float = 10):
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self._values[key] = Cached(value, time() + expiry)
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def pop(self, key: str, default=None) -> Optional[Any]:
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cached = self._values.pop(key, None)
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if cached and cached.expiry > time():
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return cached.value
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return default
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async def save_result(self, coro, key: str, expiry: float = 10):
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"""
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If `key` exists, return its value, otherwise call coro and cache its result
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"""
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cached = self.get(key)
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if cached:
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return cached
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else:
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value = await coro()
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self.set(key, value, expiry=expiry)
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return value
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async def invalidate_forever(self, interval: float = 10):
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while True:
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try:
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await asyncio.sleep(interval)
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ts = time()
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expired = [k for k, v in self._values.items() if v.expiry < ts]
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for k in expired:
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self._values.pop(k)
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except Exception:
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logger.error("Error invalidating cache")
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cache = Cache()
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