[Awesome Ruby Gem] Use request_store gem to store pre request global data

Posted on 2019-12-21 Edited on 2023-09-02 In Programming Language , Ruby , Awesome Ruby Gem Views: Word count in article: 2k Reading time ≈ 2 mins.

request_store

request_store gives you per-request global storage.

Using request_store, the variables are stored in Thread.current, and that the storage is cleared after each request.

You can install it as a gem:

1	$ gem install request_store

or add it into a Gemfile (Bundler):

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# steveklabnik/request_store: Per-request global storage for Rack.
# https://github.com/steveklabnik/request_store
gem 'request_store', '1.5.0'

Then, run bundle install.

1	$ bundle install

And try the code to this:

def index
  RequestStore.store[:foo] ||= 0
  RequestStore.store[:foo] += 1

  render :text => RequestStore.store[:foo]
end

Now no matter what server you use, you’ll get 1 every time: the storage is local to that request.

This gem uses a Rack middleware to clear the store object after every request, but that doesn’t translate well to background processing with Sidekiq.

A companion library, madebylotus/request_store-sidekiq: Provides an easy integration between RequestStore and Sidekiq - https://github.com/madebylotus/request_store-sidekiq creates a Sidekiq middleware that will ensure the store is cleared after each job is processed, for security and consistency with how this is done in Rack.

request_store does not work when you need to use multiple threads per request, different threads access different stores. madebylotus/request_store-sidekiq: Provides an easy integration between RequestStore and Sidekiq - https://github.com/madebylotus/request_store-sidekiq may be a good alternative gem.