Class: ScoutApm::Instruments::MiddlewareSummary::MiddlewareSummaryWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/scout_apm/instruments/middleware_summary.rb

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ MiddlewareSummaryWrapper

Returns a new instance of MiddlewareSummaryWrapper.



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# File 'lib/scout_apm/instruments/middleware_summary.rb', line 50

def initialize(app)
  @app = app
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *arguments, &block) ⇒ Object

Some code (found in resque_web initially) attempts to call methods directly on MyApplication.app, which is the middleware stack. If it hits our middleware instead of the object at the root of the app that it expected, then a method it expects will not be there, and an error thrown.

Specifically, resque_web assumes ResqueWeb::Engine.app.url_helpers is a method call on rails router for its own Engine, when in fact, we’ve added a middleware before it.

So method_missing just proxies anything to the nested @app object

While method_missing is not very performant, this is only here to handle edge-cases in other code, and should not be regularly called



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# File 'lib/scout_apm/instruments/middleware_summary.rb', line 77

def method_missing(sym, *arguments, &block)
  if @app.respond_to?(sym)
    @app.send(sym, *arguments, &block)
  else
    super
  end
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/scout_apm/instruments/middleware_summary.rb', line 54

def call(env)
  req = ScoutApm::RequestManager.lookup
  layer = ScoutApm::Layer.new("Middleware", "Summary")
  req.start_layer(layer)
  @app.call(env)
ensure
  req.stop_layer
end

#respond_to?(sym, include_private = false) ⇒ Boolean

Returns:



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# File 'lib/scout_apm/instruments/middleware_summary.rb', line 85

def respond_to?(sym, include_private = false)
  if @app.respond_to?(sym, include_private)
    true
  else
    super
  end
end