def test_key_is_none(self):
cache = Cache("LRU", 4)
self.assertRaises(ValueError, cache.put, None, 1)
cache = Cache("MRU", 4)
self.assertRaises(ValueError, cache.put, None, 1)
cache = Cache("SF", 4)
self.assertRaises(ValueError, cache.put, None, 1)
def test_smallest_first_system_str_input(self):
cache = Cache("SF", 3)
cache.put("a", 1)
cache.put("b", 2)
cache.put("c", 3)
self.assertEqual(cache.get("a"), 1)
self.assertEqual(cache.get("b"), 2)
cache.put("d", 4)
self.assertEqual(cache.get("a"), None) # evicted ("a",1)
self.assertEqual(cache.get("d"), 4)
def test_lru_system_int_input(self):
cache = Cache("LRU", 3)
cache.put(1, 1)
cache.put(2, 2)
cache.put(3, 3)
self.assertEqual(cache.get(1), 1)
cache.put(4, 4)
self.assertEqual(cache.get(2), None) # evicted (2,2)
self.assertEqual(cache.get(4), 4)
def __init__(self, eviction_strategy, num_caches, cache_size, key_type,
value_type):
"""
Smallest First strategy implemented as custom strategy.
:param eviction_strategy: One of ["LRU", "MRU", "SF"] by default.
:param num_caches: Number of caches.
:param cache_size: Size of each cache.
:param key_type: Type of keys. Once chosen, every key has to be of
this type.
:param value_type: Type of values. Once chose, every value has to be of
this type.
"""
self.eviction_strategy = eviction_strategy
self.num_caches = num_caches
self.cache_size = cache_size
self.check_key_type_immutable(key_type)
self.key_type = key_type
self.value_type = value_type
self.caches = [
Cache(eviction_strategy, cache_size) for _ in range(num_caches)
]
def test_mru_system_tuple_input(self):
cache = Cache("MRU", 3)
cache.put((1, 2), 1)
cache.put((1, 1), 2)
cache.put((2, 5), 3)
self.assertEqual(cache.get((1,1)), 2)
cache.put((5, 6), 4)
self.assertEqual(cache.get((1, 1)), None) # evicted ((1,1), 2)
self.assertEqual(cache.get((0, 0)), None) # never added
self.assertEqual(cache.get((5, 6)), 4)
def test_smallest_first_system_int_input(self):
cache = Cache("SF", 3)
cache.put(1, 1)
cache.put(2, 2)
cache.put(3, 3)
self.assertEqual(cache.get(1), 1)
self.assertEqual(cache.get(2), 2)
cache.put(4, 4)
self.assertEqual(cache.get(1), None) # evicted (1,1)
self.assertEqual(cache.get(4), 4)
cache.put(4, 5)
self.assertEqual(cache.get(4), 5) # update key 4
def test_evicts_smallest(self):
cache = Cache("SF", 2)
cache.put((1, 1), 1)
cache.put((1, 2), 2)
cache.put((1, 3), 3)
self.assertEqual(cache.get((1, 1)), None)