1
0
Fork 0
mirror of https://github.com/rails/rails.git synced 2022-11-09 12:12:34 -05:00
rails--rails/activesupport/lib/active_support/notifications.rb

81 lines
2.3 KiB
Ruby

require 'active_support/core_ext/module/delegation'
module ActiveSupport
# Notifications provides an instrumentation API for Ruby. To instrument an
# action in Ruby you just need to do:
#
# ActiveSupport::Notifications.instrument(:render, :extra => :information) do
# render :text => "Foo"
# end
#
# You can consume those events and the information they provide by registering
# a log subscriber. For instance, let's store all instrumented events in an array:
#
# @events = []
#
# ActiveSupport::Notifications.subscribe do |*args|
# @events << ActiveSupport::Notifications::Event.new(*args)
# end
#
# ActiveSupport::Notifications.instrument(:render, :extra => :information) do
# render :text => "Foo"
# end
#
# event = @events.first
# event.name #=> :render
# event.duration #=> 10 (in miliseconds)
# event.result #=> "Foo"
# event.payload #=> { :extra => :information }
#
# When subscribing to Notifications, you can pass a pattern, to only consume
# events that match the pattern:
#
# ActiveSupport::Notifications.subscribe(/render/) do |event|
# @render_events << event
# end
#
# Notifications ships with a queue implementation that consumes and publish events
# to log subscribers in a thread. You can use any queue implementation you want.
#
module Notifications
autoload :Instrumenter, 'active_support/notifications/instrumenter'
autoload :Event, 'active_support/notifications/instrumenter'
autoload :Fanout, 'active_support/notifications/fanout'
class << self
attr_writer :notifier
delegate :publish, :subscribe, :unsubscribe, :to => :notifier
delegate :instrument, :to => :instrumenter
def notifier
@notifier ||= Notifier.new
end
def instrumenter
Thread.current[:"instrumentation_#{notifier.object_id}"] ||= Instrumenter.new(notifier)
end
end
class Notifier
def initialize(queue = Fanout.new)
@queue = queue
end
def publish(*args)
@queue.publish(*args)
end
def subscribe(pattern = nil, &block)
@queue.bind(pattern).subscribe(&block)
end
def unsubscribe(subscriber)
@queue.unsubscribe(subscriber)
end
def wait
@queue.wait
end
end
end
end