Current File : /opt/cloudlinux/venv/lib/python3.11/site-packages/sentry_sdk//_lru_cache.py
"""
A fork of Python 3.6's stdlib lru_cache (found in Python's 'cpython/Lib/functools.py')
adapted into a data structure for single threaded uses.
https://github.com/python/cpython/blob/v3.6.12/Lib/functools.py
Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Python Software Foundation;
All Rights Reserved
PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
--------------------------------------------
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"""
SENTINEL = object()
# aliases to the entries in a node
PREV = 0
NEXT = 1
KEY = 2
VALUE = 3
class LRUCache(object):
def __init__(self, max_size):
assert max_size > 0
self.max_size = max_size
self.full = False
self.cache = {}
# root of the circularly linked list to keep track of
# the least recently used key
self.root = [] # type: ignore
# the node looks like [PREV, NEXT, KEY, VALUE]
self.root[:] = [self.root, self.root, None, None]
self.hits = self.misses = 0
def set(self, key, value):
link = self.cache.get(key, SENTINEL)
if link is not SENTINEL:
# have to move the node to the front of the linked list
link_prev, link_next, _key, _value = link
# first remove the node from the lsnked list
link_prev[NEXT] = link_next
link_next[PREV] = link_prev
# insert the node between the root and the last
last = self.root[PREV]
last[NEXT] = self.root[PREV] = link
link[PREV] = last
link[NEXT] = self.root
# update the value
link[VALUE] = value
elif self.full:
# reuse the root node, so update its key/value
old_root = self.root
old_root[KEY] = key
old_root[VALUE] = value
self.root = old_root[NEXT]
old_key = self.root[KEY]
self.root[KEY] = self.root[VALUE] = None
del self.cache[old_key]
self.cache[key] = old_root
else:
# insert new node after last
last = self.root[PREV]
link = [last, self.root, key, value]
last[NEXT] = self.root[PREV] = self.cache[key] = link
self.full = len(self.cache) >= self.max_size
def get(self, key, default=None):
link = self.cache.get(key, SENTINEL)
if link is SENTINEL:
self.misses += 1
return default
# have to move the node to the front of the linked list
link_prev, link_next, _key, _value = link
# first remove the node from the lsnked list
link_prev[NEXT] = link_next
link_next[PREV] = link_prev
# insert the node between the root and the last
last = self.root[PREV]
last[NEXT] = self.root[PREV] = link
link[PREV] = last
link[NEXT] = self.root
self.hits += 1
return link[VALUE]
