var TimeKey = "cachetime"
TimeKey specifies the memcache entity that keeps the logical datastore time.
Get fetches data for name at time now from memcache and unmarshals it into value. It reports whether it found the cache record and logs any errors to the admin console.
Now returns the current logical datastore time to use for cache lookups.
Set puts value into memcache under name at time now. It logs any errors to the admin console.
Tick sets the current logical datastore time to a never-before-used time and returns that time. It should be called to invalidate the cache.