CouchRest Instrumentation for Rails 3

instrumentation.rb

# add to config/initializers/instrumentation.rb


module CouchRest

  class Database
    alias_method :old_get, :get
    alias_method :old_view, :view
    alias_method :old_update_doc, :update_doc
    alias_method :old_delete_doc, :delete_doc
    alias_method :old_save_doc, :save_doc

    def get(id, params = {})
      ActiveSupport::Notifications.instrument("query.couchdb", :params => {:id => id, :params => params}) do
        old_get id, params
      end
    end

    def view(name, params = {}, payload = {}, &block)
      ActiveSupport::Notifications.instrument("view.couchdb", :params => {:name => name, :params => params, :payload => payload}) do
        old_view name, params, payload, &block
      end

    end

    def save_doc(doc, bulk = false, batch = false)
      ActiveSupport::Notifications.instrument("save.couchdb", :params => {:doc => doc, :bulk => bulk, :batch => batch}) do
        old_save_doc doc, bulk, batch
      end

    end

    def update_doc(doc_id, params = {}, update_limit = 10) 
      ActiveSupport::Notifications.instrument("update.couchdb", :params => {:doc_id => doc_id, :params => params, :update_limit => update_limit}) do
        old_update_doc doc_id, params, update_limit
      end

    end

    def delete_doc(doc, bulk = false)
      ActiveSupport::Notifications.instrument("delete.couchdb", :params => {:doc => doc}) do
        old_delete_doc doc, bulk
      end
    end
  end
end


module CouchInstrumentation
  class LogSubscriber < ActiveSupport::LogSubscriber

    def initialize
      super
      @odd_or_even = false
    end

    def query(event)
      logit("Get",event)
    end

    def view(event)
      logit("View", event)
    end

    def save(event)
      logit("Save", event)
    end

    def update(event)
      logit("Update", event)
    end

    def delete(event)
      logit("Delete", event)
    end


    private
    def logit(type, event)
    #return unless logger.debug?

      name = '%s (%.1fms)' % ["COUCHDB #{type}", event.duration]

      query = event.payload[:params].map{ |k, v| "#{k}: #{color(v, BOLD, true)}" }.join(', ')


      if odd?
        debug "  #{color(name, YELLOW, true)} [ #{query} ]"
      else
        debug "  #{color(name, BLUE, true)} [ #{query} ]"
      end
    end

    def odd?
      @odd_or_even = !@odd_or_even
    end
  end
end

CouchInstrumentation::LogSubscriber.attach_to :couchdb