blob: 7ad2b7f5785b669edad18e0e0c22505cd3728b23 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
class LRUCache:
"""
A simple LRU cache for generated values.
"""
def __init__(self, size=100):
self.size = size
self.cache = {}
self.cacheList = []
def get(self, gen, *args):
"""
gen: A (presumably expensive) generator function. The identity of
gen is NOT taken into account by the cache.
*args: A list of immutable arguments, used to establish identiy by
*the cache, and passed to gen to generate values.
"""
if args in self.cache:
self.cacheList.remove(args)
self.cacheList.insert(0, args)
return self.cache[args]
else:
ret = gen(*args)
self.cacheList.insert(0, args)
self.cache[args] = ret
if len(self.cacheList) > self.size:
d = self.cacheList.pop()
self.cache.pop(d)
return ret
|
