rack-mini-profiler

Middleware that displays speed badge for every html page. Designed to work both in production and in development.

Using rack-mini-profiler in your app

Install/add to Gemfile

gem 'rack-mini-profiler'

Using Rails:

All you have to do is include the Gem and you're good to go in development.

rack-mini-profiler is designed with production profiling in mind. To enable that just run Rack::MiniProfiler.authorize_request once you know a request is allowed to profile.

For example:

# A hook in your ApplicationController
def authorize
  if current_user.is_admin? 
    Rack::MiniProfiler.authorize_request
  end
end

Using Builder:

require 'rack-mini-profiler'
builder = Rack::Builder.new do
  use Rack::MiniProfiler

  map('/')    { run get }
end

Using Sinatra:

require 'rack-mini-profiler'
class MyApp < Sinatra::Base
  use Rack::MiniProfiler
end

Storage

By default, rack-mini-profiler stores its results in a memory store:

# our default
Rack::MiniProfiler.config.storage = Rack::MiniProfiler::MemoryStore

There are 2 other available storage engines, RedisStore and FileStore.

MemoryStore is stores results in a processes heap - something that does not work well in a multi process environment. FileStore stores results in the file system - something that may not work well in a multi machine environment.

Additionally you may implement an AbstractStore for your own provider.

Rails hooks up a FileStore for all environments.

Running the Specs

$ rake build
$ rake spec

Additionally you can also run autotest if you like.

Configuration Options

You can set configuration options using the configuration accessor on Rack::MiniProfiler:

# Have Mini Profiler show up on the right
Rack::MiniProfiler.config.position = 'right'

In a Rails app, this can be done conveniently in an initializer such as config/initializers/mini_profiler.rb.

Rails 2.X support

To get MiniProfiler working with Rails 2.3.X you need to do the initialization manually as well as monkey patch away an incompatibility between activesupport and json_pure.

Add the following code to your environment.rb (or just in a specific environment such as development.rb) for initialization and configuration of MiniProfiler.

# configure and initialize MiniProfiler
require 'rack-mini-profiler'
c = ::Rack::MiniProfiler.config
c.pre_authorize_cb = lambda { |env|
  Rails.env.development? || Rails.env.production?
}
tmp = Rails.root.to_s + "/tmp/miniprofiler"
FileUtils.mkdir_p(tmp) unless File.exists?(tmp)
c.storage_options = {:path => tmp}
c.storage = ::Rack::MiniProfiler::FileStore
config.middleware.use(::Rack::MiniProfiler)
::Rack::MiniProfiler.profile_method(ActionController::Base, :process) {|action| "Executing action: #{action}"}
::Rack::MiniProfiler.profile_method(ActionView::Template, :render) {|x,y| "Rendering: #{@virtual_path}"}

# monkey patch away an activesupport and json_pure incompatability
# http://pivotallabs.com/users/alex/blog/articles/1332-monkey-patch-of-the-day-activesupport-vs-json-pure-vs-ruby-1-8
if JSON.const_defined?(:Pure)
  class JSON::Pure::Generator::State
    include ActiveSupport::CoreExtensions::Hash::Except
  end
end

Available Options

• pre_authorize_cb - A lambda callback you can set to determine whether or not mini_profiler should be visible on a given request. Default in a Rails environment is only on in development mode. If in a Rack app, the default is always on.
• position - Can either be 'right' or 'left'. Default is 'left'.
• skip_schema_queries - Whether or not you want to log the queries about the schema of your tables. Default is 'false', 'true' in rails development.
• use_existing_jquery - Use the version of jQuery on the page as opposed to the self contained one
• auto_inject (default true) - when false the miniprofiler script is not injected in the page
• backtrace_filter - a regex you can use to filter out unwanted lines from the backtraces

Special query strings

If you include the query string pp=help at the end of your request you will see the various option you have. You can use these options to extend or contract the amount of diagnostics rack-mini-profiler gathers.