ModelObserver

A rails plugin to count the model object creations between each request, and help to find out the duplication.

Installation

Add to your Gemfile

group :development do
  gem 'model_observer'
end

and bundle

bundle

Query Log

The duration include instantiate models will be logged after each sql log like this:

Author Load (0.5ms)  SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1 LIMIT 1
Author Instantiate (1.5ms)  SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1 LIMIT 1

1.5ms == 0.5ms(DB query) + 1.0ms(model instantiation)

Summary Log

The summary of each request will be added to the end like this:

===== Model Observer Start =====
Author: 1 sum(10.6ms) avg(10.6ms)
Book: 27 sum(25.7ms) avg(1.0ms)
  id(319): 3
  id(377): 3
  id(487): 3
  id(489): 3
  id(493): 3
  id(496): 3
  id(499): 3
  id(507): 3
  id(536): 3
===== Model Observer End =======

id(319): 3 means the models with same class(Book) and same id(319) have been instantiated three times.