Class: ScoutApm::Instruments::ActiveRecord

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context) ⇒ ActiveRecord

Returns a new instance of ActiveRecord.



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# File 'lib/scout_apm/instruments/active_record.rb', line 40

def initialize(context)
  @context = context
  @installed = false
end

Instance Attribute Details

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/scout_apm/instruments/active_record.rb', line 38

def context
  @context
end

Instance Method Details

#add_instruments ⇒ Object 



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# File 'lib/scout_apm/instruments/active_record.rb', line 73

def add_instruments
  # Setup Tracer on AR::Base
  if Utils::KlassHelper.defined?("ActiveRecord::Base")
    @installed = true

    ::ActiveRecord::Base.class_eval do
      include ::ScoutApm::Tracer
    end
  end

  # Install #log tracing
  if Utils::KlassHelper.defined?("ActiveRecord::ConnectionAdapters::AbstractAdapter")
    if Module.respond_to?(:prepend)
      ::ActiveRecord::ConnectionAdapters::AbstractAdapter.prepend(ActiveRecordInstruments)
      ::ActiveRecord::ConnectionAdapters::AbstractAdapter.include(Tracer)
    else
      ::ActiveRecord::ConnectionAdapters::AbstractAdapter.module_eval do
        include ::ScoutApm::Instruments::ActiveRecordAliasMethodInstruments
        include ::ScoutApm::Tracer
      end
    end
  end

  if Utils::KlassHelper.defined?("ActiveRecord::Base")
    ::ActiveRecord::Base.class_eval do
      include ::ScoutApm::Instruments::ActiveRecordUpdateInstruments
    end
  end

  # Disabled until we can determine how to use Module#prepend in the
  # agent. Otherwise, this will cause infinite loops if NewRelic is
  # installed. We can't just use normal Module#include, since the
  # original methods don't call super the way Base#save does
  #
  #if Utils::KlassHelper.defined?("ActiveRecord::Relation")
  #  ::ActiveRecord::Relation.class_eval do
  #    include ::ScoutApm::Instruments::ActiveRecordRelationInstruments
  #  end
  #end

  if Utils::KlassHelper.defined?("ActiveRecord::Querying")
    ::ActiveRecord::Querying.module_eval do
      include ::ScoutApm::Tracer
      include ::ScoutApm::Instruments::ActiveRecordQueryingInstruments
    end
  end

  rails_3_2_or_above = defined?(::ActiveRecord::VERSION::MAJOR) &&
    defined?(::ActiveRecord::VERSION::MINOR) &&
    (::ActiveRecord::VERSION::MAJOR.to_i > 3 ||
     (::ActiveRecord::VERSION::MAJOR.to_i == 3 && ::ActiveRecord::VERSION::MINOR.to_i >= 2))
  if rails_3_2_or_above
    if Utils::KlassHelper.defined?("ActiveRecord::Relation")
      if @context.environment.supports_module_prepend?
        ::ActiveRecord::Relation.module_eval do
          prepend ::ScoutApm::Instruments::ActiveRecordRelationQueryInstruments
        end
      else
        ::ActiveRecord::Relation.module_eval do
          include ::ScoutApm::Instruments::ActiveRecordRelationQueryInstruments
        end
      end
    end
  else
    if Utils::KlassHelper.defined?("ActiveRecord::FinderMethods")
      ::ActiveRecord::FinderMethods.module_eval do
        include ::ScoutApm::Tracer
        include ::ScoutApm::Instruments::ActiveRecordFinderMethodsInstruments
      end
    end
  end

  if Utils::KlassHelper.defined?("ActiveSupport::Notifications")
    ActiveSupport::Notifications.subscribe("instantiation.active_record") do |event_name, start, stop, uuid, payload|
      req = ScoutApm::RequestManager.lookup
      layer = req.current_layer
      if layer && layer.type == "ActiveRecord"
        layer.annotate_layer({
          :class_name => payload[:class_name],
          :record_count => payload[:record_count]
        })
      elsif layer
        logger.debug("Expected layer type: ActiveRecord, got #{layer && layer.type}")
      else
        # noop, no layer at all. We're probably ignoring this req.
      end
    end
  end
rescue
  logger.warn "ActiveRecord instrumentation exception: #{$!.message}"
end

#install ⇒ Object 



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# File 'lib/scout_apm/instruments/active_record.rb', line 53

def install
  if install_via_after_initialize?
    Rails.configuration.after_initialize do
      add_instruments
    end
  else
    add_instruments
  end
end

#install_via_after_initialize? ⇒ Boolean

If we have the right version of rails, we should use the hooks provided to install these instruments

Returns:

  • (Boolean) 


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# File 'lib/scout_apm/instruments/active_record.rb', line 65

def install_via_after_initialize?
  defined?(::Rails) &&
    defined?(::Rails::VERSION) &&
    defined?(::Rails::VERSION::MAJOR) &&
    ::Rails::VERSION::MAJOR.to_i == 3 &&
    ::Rails.respond_to?(:configuration)
end

#installed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/scout_apm/instruments/active_record.rb', line 49

def installed?
  @installed
end

#logger ⇒ Object 



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# File 'lib/scout_apm/instruments/active_record.rb', line 45

def logger
  context.logger
end