Redis expire returns a signed long, not uint

[alex88]

From my understanding redis uses msec_t which is a long when returning the value of GetExpire here

https://github.com/antirez/redis/blob/unstable/src/module.c#L1636

the problem is that since this library uses an uint64 it's impossible to do key.GetExpire() == rm.NO_EXPIRE because the first is a uint64 and the second a signed int (in this case also negative) and we have to either do int64(keyTTL) != rm.NO_EXPIRE or keyTTL == ^uint64(0)

Wouldn't be better to have GetExpire return a signed int so we can just compare them directly?

[wenerme]

pr is welcome, otherwise I will look into this later, maybe this weekend.