require 'securerandom' module ActiveSupport module Notifications # Instrumenters are stored in a thread local. class Instrumenter attr_reader :id def initialize(notifier) @id = unique_id @notifier = notifier end # Instrument the given block by measuring the time taken to execute it # and publish it. Notice that events get sent even if an error occurs # in the passed-in block. def instrument(name, payload={}) # some of the listeners might have state listeners_state = start name, payload begin yield payload rescue Exception => e payload[:exception] = [e.class.name, e.message] raise e ensure finish_with_state listeners_state, name, payload end end # Send a start notification with +name+ and +payload+. def start(name, payload) @notifier.start name, @id, payload end # Send a finish notification with +name+ and +payload+. def finish(name, payload) @notifier.finish name, @id, payload end def finish_with_state(listeners_state, name, payload) @notifier.finish name, @id, payload, listeners_state end private def unique_id SecureRandom.hex(10) end end class Event attr_reader :name, :time, :transaction_id, :payload, :children attr_accessor :end def initialize(name, start, ending, transaction_id, payload) @name = name @payload = payload.dup @time = start @transaction_id = transaction_id @end = ending @children = [] @duration = nil end # Returns the difference in milliseconds between when the execution of the # event started and when it ended. # # ActiveSupport::Notifications.subscribe('wait') do |*args| # @event = ActiveSupport::Notifications::Event.new(*args) # end # # ActiveSupport::Notifications.instrument('wait') do # sleep 1 # end # # @event.duration # => 1000.138 def duration @duration ||= 1000.0 * (self.end - time) end def <<(event) @children << event end def parent_of?(event) @children.include? event end end end end