class LRUCache(object):
def __init__(self, size):
if size < 1:
raise ValueException('Value for cache size should be positive, '
'provided: {0}'.format(size))
self.size = size
self.value_map = {}
self.recents = LinkedList()
def get(self, key):
try:
node, value = self.value_map[key]
self.recents.remove_node(node)
self.recents.push_front(node)
return value
except KeyError as k:
raise CacheMissException(key)
def put(self, key, value):
try:
node, old_value = self.value_map[key]
self.recents.remove_node(node)
except KeyError as k: # not in map
if len(self.recents) >= self.size:
back_node = self.recents.pop_back()
del self.value_map[back_node.data]
node = LinkedListNode(key)
self.recents.push_front(node)
self.value_map[key] = node, value
def __init__(self, size):
if size < 1:
raise ValueException('Value for cache size should be positive, '
'provided: {0}'.format(size))
self.size = size
self.value_map = {}
self.recents = LinkedList()
