47 lines
1.2 KiB
Python
47 lines
1.2 KiB
Python
from typing import TYPE_CHECKING
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if TYPE_CHECKING:
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from typing import Any
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_SENTINEL = object()
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class LRUCache:
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def __init__(self, max_size):
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# type: (int) -> None
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if max_size <= 0:
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raise AssertionError(f"invalid max_size: {max_size}")
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self.max_size = max_size
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self._data = {} # type: dict[Any, Any]
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self.hits = self.misses = 0
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self.full = False
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def set(self, key, value):
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# type: (Any, Any) -> None
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current = self._data.pop(key, _SENTINEL)
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if current is not _SENTINEL:
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self._data[key] = value
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elif self.full:
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self._data.pop(next(iter(self._data)))
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self._data[key] = value
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else:
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self._data[key] = value
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self.full = len(self._data) >= self.max_size
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def get(self, key, default=None):
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# type: (Any, Any) -> Any
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try:
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ret = self._data.pop(key)
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except KeyError:
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self.misses += 1
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ret = default
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else:
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self.hits += 1
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self._data[key] = ret
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return ret
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def get_all(self):
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# type: () -> list[tuple[Any, Any]]
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return list(self._data.items())
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