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
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
import time, typing, uuid
class Cache(object):
def __init__(self):
self._items = {}
self._item_to_id = {}
def cache(self, item: typing.Any) -> str:
return self._cache(item, None)
def temporary_cache(self, item: typing.Any, timeout: float)-> str:
return self._cache(item, time.monotonic()+timeout)
def _cache(self, item: typing.Any, timeout: typing.Optional[float]) -> str:
id = str(uuid.uuid4())
self._items[id] = [item, timeout]
self._item_to_id[item] = id
return id
def next_expiration(self) -> typing.Optional[float]:
expirations = [self._items[id][1] for id in self._items]
expirations = list(filter(None, expirations))
if not expirations:
return None
expirations = [e-time.monotonic() for e in expirations]
return max(min(expirations), 0)
def expire(self):
now = time.monotonic()
expired = []
for id in self._items:
item, expiration = self._items[id]
if expiration and expiration <= now:
expired.append(id)
for id in expired:
item, expiration = self._items[id]
del self._items[id]
del self._item_to_id[item]
def has_item(self, item: typing.Any) -> bool:
return item in self._item_to_id
def get(self, id: str) -> typing.Any:
item, expiration = self._items[id]
return item
def get_expiration(self, item: typing.Any) -> float:
id = self._item_to_id[item]
item, expiration = self._items[id]
return expiration
def until_expiration(self, item: typing.Any) -> float:
expiration = self.get_expiration(item)
return expiration-time.monotonic()
|
