class LRUCache(FIFOCache):
'''Least recently used object cache.
Args:
max_items: The maximum number of items to keep
time_to_live: The time in seconds of how long to keep the item
'''
def __init__(self, max_items=None, time_to_live=None):
super().__init__(max_items=max_items, time_to_live=time_to_live)
self._seq = LinkedList()
def __getitem__(self, key):
self.trim()
self.touch(key)
return self._map[key].value
def __setitem__(self, key, value):
if key in self._map:
self._map[key].value = value
self.touch(key)
else:
item = CacheItem(key, value, self._time_to_live)
self._map[key] = item
self._seq.append(item)
self.trim()
def touch(self, key):
self._map[key].access_time = time.time()
self._seq.remove(self._map[key])
self._seq.append(self._map[key])
class LRUCache(FIFOCache):
'''Least recently used object cache.
Args:
max_items: The maximum number of items to keep
time_to_live: The time in seconds of how long to keep the item
'''
def __init__(self, max_items=None, time_to_live=None):
super().__init__(max_items=max_items, time_to_live=time_to_live)
self._seq = LinkedList()
def __getitem__(self, key):
self.trim()
self.touch(key)
return self._map[key].value
def __setitem__(self, key, value):
if key in self._map:
self._map[key].value = value
self.touch(key)
else:
item = CacheItem(key, value, self._time_to_live)
self._map[key] = item
self._seq.append(item)
self.trim()
def touch(self, key):
self._map[key].access_time = time.time()
self._seq.remove(self._map[key])
self._seq.append(self._map[key])
def test_linked_list(self):
linked_list = LinkedList()
for dummy in range(2):
self.assertEqual(0, len(linked_list))
linked_list.append('a')
self.assertEqual(1, len(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.append('b')
self.assertEqual(2, len(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('b', linked_list.tail.value)
linked_list.append('c')
self.assertEqual(3, len(linked_list))
self.assertEqual(('a', 'b', 'c'), tuple(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
self.assertEqual('a', linked_list[0])
self.assertEqual('b', linked_list[1])
self.assertEqual('c', linked_list[2])
linked_list.appendleft('d')
self.assertEqual(4, len(linked_list))
self.assertEqual(('d', 'a', 'b', 'c'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('a')
self.assertEqual(3, len(linked_list))
self.assertEqual(('d', 'b', 'c'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.append('a')
self.assertEqual(4, len(linked_list))
self.assertEqual(('d', 'b', 'c', 'a'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.remove('d')
self.assertEqual(3, len(linked_list))
self.assertEqual(('b', 'c', 'a'), tuple(linked_list))
self.assertEqual('b', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.remove('a')
self.assertEqual(2, len(linked_list))
self.assertEqual(('b', 'c'), tuple(linked_list))
self.assertEqual('b', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('b')
self.assertEqual(1, len(linked_list))
self.assertEqual(('c', ), tuple(linked_list))
self.assertEqual('c', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('c')
self.assertEqual(0, len(linked_list))
self.assertEqual((), tuple(linked_list))
self.assertRaises(ValueError, linked_list.remove, 'asdf')
linked_list.appendleft('a')
linked_list.append('b')
linked_list.appendleft('c')
linked_list.append('d')
self.assertEqual(4, len(linked_list))
self.assertEqual(('c', 'a', 'b', 'd'), tuple(linked_list))
self.assertEqual('c', linked_list.popleft())
self.assertEqual('d', linked_list.pop())
self.assertEqual(2, len(linked_list))
self.assertEqual(('a', 'b'), tuple(linked_list))
linked_list.clear()
def test_linked_list(self):
linked_list = LinkedList()
for dummy in range(2):
self.assertEqual(0, len(linked_list))
linked_list.append('a')
self.assertEqual(1, len(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.append('b')
self.assertEqual(2, len(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('b', linked_list.tail.value)
linked_list.append('c')
self.assertEqual(3, len(linked_list))
self.assertEqual(('a', 'b', 'c'), tuple(linked_list))
self.assertEqual('a', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
self.assertEqual('a', linked_list[0])
self.assertEqual('b', linked_list[1])
self.assertEqual('c', linked_list[2])
linked_list.appendleft('d')
self.assertEqual(4, len(linked_list))
self.assertEqual(('d', 'a', 'b', 'c'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('a')
self.assertEqual(3, len(linked_list))
self.assertEqual(('d', 'b', 'c'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.append('a')
self.assertEqual(4, len(linked_list))
self.assertEqual(('d', 'b', 'c', 'a'), tuple(linked_list))
self.assertEqual('d', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.remove('d')
self.assertEqual(3, len(linked_list))
self.assertEqual(('b', 'c', 'a'), tuple(linked_list))
self.assertEqual('b', linked_list.head.value)
self.assertEqual('a', linked_list.tail.value)
linked_list.remove('a')
self.assertEqual(2, len(linked_list))
self.assertEqual(('b', 'c'), tuple(linked_list))
self.assertEqual('b', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('b')
self.assertEqual(1, len(linked_list))
self.assertEqual(('c',), tuple(linked_list))
self.assertEqual('c', linked_list.head.value)
self.assertEqual('c', linked_list.tail.value)
linked_list.remove('c')
self.assertEqual(0, len(linked_list))
self.assertEqual((), tuple(linked_list))
self.assertRaises(ValueError, linked_list.remove, 'asdf')
linked_list.appendleft('a')
linked_list.append('b')
linked_list.appendleft('c')
linked_list.append('d')
self.assertEqual(4, len(linked_list))
self.assertEqual(('c', 'a', 'b', 'd'), tuple(linked_list))
self.assertEqual('c', linked_list.popleft())
self.assertEqual('d', linked_list.pop())
self.assertEqual(2, len(linked_list))
self.assertEqual(('a', 'b'), tuple(linked_list))
linked_list.clear()
def __init__(self, max_items=None, time_to_live=None):
super().__init__(max_items=max_items, time_to_live=time_to_live)
self._seq = LinkedList()
def __init__(self, max_items=None, time_to_live=None):
super().__init__(max_items=max_items, time_to_live=time_to_live)
self._seq = LinkedList()
