我们知道,缓存有其过期时间,具体到 memcached 中,我们来分析它是怎么处理过期时间的。
#define REALTIME_MAXDELTA 60*60*24*30
/*
* given time value that's either unix time or delta from current unix time, return
* unix time. Use the fact that delta can't exceed one month (and real time value can't
* be that low).