mirror of https://github.com/borgbackup/borg.git
77 lines
2.1 KiB
Python
77 lines
2.1 KiB
Python
from UserDict import DictMixin
|
|
from heapq import heappush, heapify, heapreplace, heappop
|
|
import unittest
|
|
|
|
|
|
class LRUCache(dict):
|
|
|
|
def __init__(self, capacity):
|
|
super(LRUCache, self).__init__()
|
|
self._lru = []
|
|
self._capacity = capacity
|
|
|
|
def __setitem__(self, key, value):
|
|
try:
|
|
self._lru.remove(key)
|
|
except ValueError:
|
|
pass
|
|
self._lru.append(key)
|
|
while len(self._lru) > self._capacity:
|
|
del self[self._lru[0]]
|
|
return super(LRUCache, self).__setitem__(key, value)
|
|
|
|
def __getitem__(self, key):
|
|
try:
|
|
self._lru.remove(key)
|
|
self._lru.append(key)
|
|
except ValueError:
|
|
pass
|
|
return super(LRUCache, self).__getitem__(key)
|
|
|
|
def __delitem__(self, key):
|
|
try:
|
|
self._lru.remove(key)
|
|
except ValueError:
|
|
pass
|
|
return super(LRUCache, self).__delitem__(key)
|
|
|
|
|
|
class LRUCacheTestCase(unittest.TestCase):
|
|
|
|
def test(self):
|
|
c = LRUCache(2)
|
|
self.assertEqual(len(c), 0)
|
|
for i, x in enumerate('abc'):
|
|
c[x] = i
|
|
self.assertEqual(len(c), 2)
|
|
self.assertEqual(set(c), set(['b', 'c']))
|
|
self.assertEqual(set(c.iteritems()), set([('b', 1), ('c', 2)]))
|
|
self.assertEqual(False, 'a' in c)
|
|
self.assertEqual(True, 'b' in c)
|
|
self.assertRaises(KeyError, lambda: c['a'])
|
|
self.assertEqual(c['b'], 1)
|
|
self.assertEqual(c['c'], 2)
|
|
c['d'] = 3
|
|
self.assertEqual(len(c), 2)
|
|
self.assertEqual(c['c'], 2)
|
|
self.assertEqual(c['d'], 3)
|
|
c['c'] = 22
|
|
c['e'] = 4
|
|
self.assertEqual(len(c), 2)
|
|
self.assertRaises(KeyError, lambda: c['d'])
|
|
self.assertEqual(c['c'], 22)
|
|
self.assertEqual(c['e'], 4)
|
|
del c['c']
|
|
self.assertEqual(len(c), 1)
|
|
self.assertRaises(KeyError, lambda: c['c'])
|
|
self.assertEqual(c['e'], 4)
|
|
|
|
|
|
def suite():
|
|
return unittest.TestLoader().loadTestsFromTestCase(LRUCacheTestCase)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
unittest.main()
|
|
|