Simple Redis Cache
src takes one hash parameter with url and expiry defined. Expiry is the number of seconds a value is non expired in Redis.
var src = ;var cache =;
Callbacks for set are optional
get requires a callback
If the key has expired, err will not be used to determine this. Err will only be a non null value when an error is thrown from Redis.
If you want to delete a key from the cache explicity src provides this
Callbacks are optional for del