ActiveSupport::Notifications (original) (raw)

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
event.duration
event.payload

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.

Namespace

• CLASS ActiveSupport::Notifications::Event
• CLASS ActiveSupport::Notifications::Fanout
• CLASS ActiveSupport::Notifications::Instrumenter

Methods

I

• instrument,
• instrumenter

P

• publish

S

• subscribe

U

• unsubscribe

Attributes

Class Public methods

instrument(name, payload = {})

Source: show

def instrument(name, payload = {}) if @instrumenters[name] instrumenter.instrument(name, payload) { yield payload if block_given? } else yield payload if block_given? end end

instrumenter()

Source: show

def instrumenter Thread.current[:"instrumentation_#{notifier.object_id}"] ||= Instrumenter.new(notifier) end

publish(name, *args)

Source: show

def publish(name, *args) notifier.publish(name, *args) end

subscribe(*args, &block)

Source: show

def subscribe(*args, &block) notifier.subscribe(*args, &block).tap do @instrumenters.clear end end

unsubscribe(args)

Source: show

def unsubscribe(args) notifier.unsubscribe(args) @instrumenters.clear end