Add Rails Profiler

[simeonwillbanks]

Busted should wrap a Rails request and log cache invalidations.

# config/initializers/busted.rb
Busted.run profiler: :rails

[Cache Invalidations] method=0 constant=1
Completed 200 OK in 141.6ms (Views: 108.3ms | ActiveRecord: 2.2ms)

OR

method_cache_invalidations=0 constant_cache_invalidations=1
Completed 200 OK in 141.6ms (Views: 108.3ms | ActiveRecord: 2.2ms)

[spectralblu]

This looks abandoned. Have you started on this at all, and/or is there any source for this for me to look into? Currently investigating some cache invalidation performance issues and found this gem.

[simeonwillbanks]

@spectralblu First, thanks for stopping by! Second, I haven't worked on Busted; it is true. Sorry!

I think we can use middleware. Maybe something like this:

# lib/middleware/busted_tracer.rb
require "busted"

module Middleware
  class BustedTracer

    def initialize(app)
      @app = app
    end

    def call(env)
      Busted.start
      response = @app.call(env)
      Busted.finish
      #=> {:invalidations=>{:method=>0, :constant=>1}}
      response
    end
  end
end

# config/application.rb
require File.expand_path('../../lib/middleware/busted_tracer', __FILE__)

module MyApp
  class Application < Rails::Application
    # Maybe there is a better place to insert `Middleware::BustedTracer`?
    config.middleware.insert_after(ActionDispatch::Static, Middleware::BustedTracer)
  end
end

I borrowed this middleware configuration from a personal WIP/proof of concept project called rails-request-2-docs.

If I remember correctly, you'd have to curl a Rails action a few times before it "stabilized." By "stabilized", I mean the middleware output/trace was the same. I'm guessing, this would also be true for cache invalidations, but I haven't tried the above code.

If you get something working or need a bit of help, please let me know! Maybe you can craft a Pull Request? Thanks!

[simeonwillbanks]

@HParker and I tried this out, and Rails caused some confusing results, so we decided to keep Busted focused and not add a Rails profiler.

See full details in #16.