Source code for maestral.utils.caches
"""Module containing cache implementations."""
from __future__ import annotations
from collections import OrderedDict
from threading import RLock
from typing import Any, Hashable
[docs]
class LRUCache:
"""A simple LRU cache implementation
:param capacity: Maximum number of entries to keep.
"""
def __init__(self, capacity: int) -> None:
self._lock = RLock()
self._cache: OrderedDict[Hashable, Any] = OrderedDict()
self.capacity = capacity
[docs]
def get(self, key: Hashable) -> Any:
"""
Get the cached value for a key. Mark as most recently used.
:param key: Key to query.
:returns: Cached value or None.
"""
with self._lock:
try:
self._cache.move_to_end(key)
return self._cache[key]
except KeyError:
return None
[docs]
def put(self, key: Hashable, value: Any) -> None:
"""
Set the cached value for a key. Mark as most recently used.
:param key: Key to use. Must be hashable.
:param value: Value to cache.
"""
with self._lock:
self._cache[key] = value
self._cache.move_to_end(key)
if len(self._cache) > self.capacity:
self._cache.popitem(last=False)