shopify / response_bank

Simple response caching for Ruby applications

ResponseBank

Features

• Serve gzip'd content
• Add ETag and 304 Not Modified headers
• Generational caching
• No explicit expiry

Support

This gem supports the following versions of Ruby and Rails:

• Ruby 2.7.0+
• Rails 6.0.0+

Usage

1. include the gem in your Gemfile

   gem 'response_bank'

2. add an initializer file. We need to configure the acquire_lock method, set the cache store and the logger

   require 'response_bank'
   
   module ResponseBank
     LOCK_TTL = 90
   
     class << self
       def acquire_lock(cache_key)
         cache_store.write("#{cache_key}:lock", '1', unless_exist: true, expires_in: LOCK_TTL, raw: true)
       end
     end
   end
   
   ResponseBank.cache_store = ActiveSupport::Cache.lookup_store(Rails.configuration.cache_store)
   ResponseBank.logger = Rails.logger

3. enables caching on your application

   config.action_controller.perform_caching = true

4. use #response_cache method to any desired controller's action

   class PostsController < ApplicationController
     def show
       response_cache do
         @post = @shop.posts.find(params[:id])
         respond_with(@post)
       end
     end
   end

5. (optional) set a custom TTL for the cache by overriding the write_to_backing_cache_store method in your initializer file

   module ResponseBank
     CACHE_TTL = 30.minutes
     def write_to_backing_cache_store(_env, key, payload, expires_in: nil)
       cache_store.write(key, payload, raw: true, expires_in: expires_in || CACHE_TTL)
     end
   end

6. (optional) override custom cache key data. For default, cache key is defined by URL and query string

   class PostsController < ApplicationController
     before_action :set_shop
   
     def index
       response_cache do
         @post = @shop.posts
         respond_with(@post)
       end
     end
   
     def show
       response_cache do
         @post = @shop.posts.find(params[:id])
         respond_with(@post)
       end
     end
   
     def another_action
       # custom cache key data
       cache_key = {
         action: action_name,
         format: request.format,
         shop_updated_at: @shop.updated_at
         # you may add more keys here
       }
       response_cache cache_key do
         @post = @shop.posts.find(params[:id])
         respond_with(@post)
       end
     end
   
     # override default cache key data globally per class
     def cache_key_data
       {
         action: action_name,
         format: request.format,
         params: params.slice(:id),
         shop_version: @shop.version
         # you may add more keys here
       }
     end
   
     def set_shop
       # @shop = ...
     end
   end

License

ResponseBank is released under the MIT License.