mirror of
https://github.com/open-metadata/OpenMetadata.git
synced 2025-08-25 09:28:23 +00:00
44 lines
1.1 KiB
Python
44 lines
1.1 KiB
Python
|
"""
|
||
|
|
LRU cache
|
||
|
|
"""
|
||
|
|
|
||
|
|
from collections import OrderedDict
|
||
|
|
|
||
|
|
|
||
|
|
class LRUCache:
|
||
|
|
"""Least Recently Used cache"""
|
||
|
|
|
||
|
|
def __init__(self, capacity: int) -> None:
|
||
|
|
self._cache = OrderedDict()
|
||
|
|
self.capacity = capacity
|
||
|
|
|
||
|
|
def get(self, key):
|
||
|
|
"""
|
||
|
|
Returns the value associated to `key` if it exists,
|
||
|
|
updating the cache usage.
|
||
|
|
Raises `KeyError` if `key doesn't exist in the cache.
|
||
|
|
"""
|
||
|
|
self._cache.move_to_end(key)
|
||
|
|
return self._cache[key]
|
||
|
|
|
||
|
|
def put(self, key, value) -> None:
|
||
|
|
"""
|
||
|
|
Assigns `value` to `key`, overwriting `key` if it already exists
|
||
|
|
in the cache and updating the cache usage.
|
||
|
|
If the size of the cache grows above capacity, pops the least used
|
||
|
|
element.
|
||
|
|
"""
|
||
|
|
self._cache[key] = value
|
||
|
|
self._cache.move_to_end(key)
|
||
|
|
if len(self._cache) > self.capacity:
|
||
|
|
self._cache.popitem(last=False)
|
||
|
|
|
||
|
|
def __contains__(self, key) -> bool:
|
||
|
|
if key not in self._cache:
|
||
|
|
return False
|
||
|
|
self._cache.move_to_end(key)
|
||
|
|
return True
|
||
|
|
|
||
|
|
def __len__(self) -> int:
|
||
|
|
return len(self._cache)
|