Singleton LRUCache

Introduction

This class is a singleton class that stores data to memory.

This class is more of a dynamic singleton class. When the same parameter is passed to the constructor, the same instance is returned. If the parameter is different, a new instance is created. Custom key value pairs can be passed to the constructor to create a new instance. Custom key value pairs must be hashable.

This class is functionally the same as the Class LRUCache with the exception that it is a singleton class.

New in version 0.52.0.

Examples

This example creates an instance of the LRUCache class with a maximum size of 10.

Each time an item is accessed, it is moved to the front of the cache. If the cache is full, the least recently used item is removed and the new item is added to the front of the cache.

from ooodev.utils.cache.singleton import LRUCache

cache = LRUCache(max_size=10)

cache["key1"] = "value1"
cache["key2"] = "value2"
cache["key3"] = "value3"

print(cache["key1"]) # prints "value1"
print(cache["key2"]) # prints "value2"
print(cache["key3"]) # prints "value3"

del cache["key1"]
assert "key1" not in cache

cache2 = LRUCache(max_size=10)
assert cache is cache2 # True

This example demonstrates the use of custom key value pairs to create a new singleton instance of the LRUCache class.

from ooodev.utils.cache.singleton import LRUCache

cache = LRUCache(custom1="custom1", custom2="custom2")

cache["key1"] = "value1"
cache["key2"] = "value2"
cache["key3"] = "value3"

print(cache["key1"]) # prints "value1"
print(cache["key2"]) # prints "value2"
print(cache["key3"]) # prints "value3"

del cache["key1"]
assert "key1" not in cache

cache2 = LRUCache()
assert cache not is cache2 # True

cache3 = LRUCache(custom1="custom1", custom2="custom2")
assert cache is cache3 # True
print(cache3["key1"]) # prints "value1"

Class

class ooodev.utils.cache.singleton.LRUCache(*, capacity=128, **kwargs)[source]

Least Recently Used (LRU) singleton Cache