rails: how to get all key-values from Rails.cache

Question

I want to maintain an user online/offline list with Rails.cache(memory_store).

Basically if a request /user/heartbeat?name=John reached Rails server, it will simply:

def update_status
  name = params.require(:name)
  Rails.cache.write(name, Time.now.utc.iso8601, expires_in: 6.seconds)
end

But how could I get all the data stored in Rails.cache similarly as following?

def get_status
  # wrong codes, as Rails.cache.read doesn't have :all option.
  ary = Rails.cache.read(:all)
  # deal with array ...
end

I googled for a while, it seems Rails.cache doesn't provide the method to get all the data directly. Or there is better way to store the data?

I'm using Rails 5.0.2.

Thanks for your time!

Answer 1

You can get all keys with code:

keys = Rails.cache.instance_variable_get(:@data).keys

Answer 2

If you have redis you can use sth like Rails.cache.redis.keys