46 lines
1.3 KiB
Python
46 lines
1.3 KiB
Python
import collections
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import datetime
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from datetime import timedelta, timezone
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from typing import Any, Optional
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from pydantic import BaseModel, Field
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class CachedItem(BaseModel):
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timestamp: datetime.datetime = Field(
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default_factory=lambda: datetime.datetime.now(tz=timezone.utc)
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)
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value: Any
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class LRUCache:
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def __init__(self, capacity: int, expiration_time: timedelta):
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self.capacity: int = capacity
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self.expiration_time: timedelta = expiration_time
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self.cache: collections.OrderedDict = collections.OrderedDict()
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def get(self, key) -> Optional[CachedItem]:
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try:
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item: CachedItem = self.cache.pop(key)
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if (
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datetime.datetime.now(tz=timezone.utc) - item.timestamp
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> self.expiration_time
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):
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return None
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self.cache[key] = item
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return item.value
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except KeyError:
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return None
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def set(self, key, value) -> None:
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try:
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self.cache.pop(key)
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except KeyError:
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if len(self.cache) >= self.capacity:
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self.cache.popitem(last=False)
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self.cache[key] = CachedItem(value=value)
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@staticmethod
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def create_key(*args):
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return str(args) # TODO think about this
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