Module: ScoutApm::Tracer::ClassMethods

Defined in:
lib/scout_apm/tracer.rb

Instance Method Summary collapse

Instance Method Details

#instrument(type, name, options = {}) ⇒ Object

Type: the Layer type - “View” or similar Name: specific name - “users/_gravatar”. The object must respond to “#to_s”. This allows us to be more efficient - in most cases, the metric name isn’t needed unless we are processing a slow transaction. A Block: The code to be instrumented

Options:

  • :ignore_children - will not instrument any method calls beneath this call. Example use case: InfluxDB uses Net::HTTP, which is instrumented. However, we can provide more specific data if we know we’re doing an influx call, so we’d rather just instrument the Influx call and ignore Net::HTTP. when rendering the transaction tree in the UI.

  • :desc - Additional capture, SQL, or HTTP url or similar

  • :scope - set to true if you want to make this layer a subscope



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# File 'lib/scout_apm/tracer.rb', line 25

def instrument(type, name, options={}) # Takes a block
  layer = ScoutApm::Layer.new(type, name)
  layer.desc = options[:desc] if options[:desc]
  layer.subscopable!          if options[:scope]

  req = ScoutApm::RequestManager.lookup
  req.start_layer(layer)
  req.ignore_children! if options[:ignore_children]

  begin
    yield
  ensure
    req.acknowledge_children! if options[:ignore_children]
    req.stop_layer
  end
end

#instrument_method(method_name, options = {}) ⇒ Object

Wraps a method in a call to #instrument via aggressive monkey patching.

Options: type - “View” or “ActiveRecord” and similar name - “users/show”, “App#find”



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# File 'lib/scout_apm/tracer.rb', line 47

def instrument_method(method_name, options = {})
  ScoutApm::Agent.instance.logger.info "Instrumenting #{method_name}"
  type = options[:type] || "Custom"
  name = options[:name] || "#{self.name}/#{method_name.to_s}"

  instrumented_name, uninstrumented_name = _determine_instrumented_name(method_name, type)

  ScoutApm::Agent.instance.logger.info "Instrumenting #{instrumented_name}, #{uninstrumented_name}"

  return if !_instrumentable?(method_name) or _instrumented?(instrumented_name, method_name)

  class_eval(
    _instrumented_method_string(instrumented_name, uninstrumented_name, type, name, {:scope => options[:scope] }),
    __FILE__, __LINE__
  )

  alias_method uninstrumented_name, method_name
  alias_method method_name, instrumented_name
end