Class: BuilderApm::Methods::Instrumenter

Inherits:
Object
  • Object
show all
Defined in:
lib/builder_apm/methods/instrumenter.rb

Instance Method Summary collapse

Constructor Details

#initialize(root_path: Rails.root.to_s) ⇒ Instrumenter

Returns a new instance of Instrumenter.



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# File 'lib/builder_apm/methods/instrumenter.rb', line 4

def initialize(root_path: Rails.root.to_s)
  @this_gem_path = File.expand_path("../../..", __dir__)
  @root_path = root_path
  @call_times = {}
end

Instance Method Details

#process_trace_point(tp) ⇒ Object 



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# File 'lib/builder_apm/methods/instrumenter.rb', line 41

def process_trace_point(tp)
  if tp.event == :call
    method_id = "#{tp.defined_class}##{tp.method_id}"
    (@call_times[method_id]||= []) << Process.clock_gettime(Process::CLOCK_MONOTONIC)
    caller_info = caller_locations(4,1).first
    calling_file_path = caller_info.absolute_path
    calling_line_number = caller_info.lineno
  
    method_call = { 
      method: method_id, 
      method_line: "#{tp.path.gsub(@root_path, '')}:#{tp.lineno}",
      triggering_line: "#{calling_file_path.gsub(@root_path, '')}:#{calling_line_number}", 
      children: [], 
      start_time: Time.now.to_f * 1000, 
      sql_events: [] 
    }
  
    (Thread.current[:stack] ||= []).push(method_call)
  else
    method_id = "#{tp.defined_class}##{tp.method_id}"
    
    if @call_times.key?(method_id)
      elapsed_time = Process.clock_gettime(Process::CLOCK_MONOTONIC) - @call_times[method_id].pop
      elapsed_time_in_ms = (elapsed_time * 1000).round(3)
      @call_times.delete(method_id)
  
      method_call = (Thread.current[:stack] ||= []).pop
      method_call[:end_time] = Time.now.to_f * 1000
      method_call[:duration] = elapsed_time_in_ms
  
      if Thread.current[:stack]&.any?
        Thread.current[:stack].last[:children].push(method_call) 
      else 
        Thread.current[:stack].push(method_call) 
      end
    end
  end
end

#setup_trace ⇒ Object 



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# File 'lib/builder_apm/methods/instrumenter.rb', line 20

def setup_trace
  me = self
  TracePoint.new(:call, :return, :end, :raise) do |tp|
    starttime = Time.now.to_f * 1000
    me.process_trace_point(tp) if Thread.current[:request_id] && me.valid_trace_point?(tp)
    duration = (Time.now.to_f * 1000) - starttime
    
    Thread.current[:method_tracing] = (Thread.current[:method_tracing] ||= 0) + duration
  end
end

#start ⇒ Object 



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# File 'lib/builder_apm/methods/instrumenter.rb', line 10

def start
  @trace = setup_trace
  @trace.enable
  Thread.current[:trace_point] = @trace
end

#stop ⇒ Object 



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# File 'lib/builder_apm/methods/instrumenter.rb', line 16

def stop
  @trace.disable unless @trace.nil?
end

#valid_trace_point?(tp) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/builder_apm/methods/instrumenter.rb', line 31

def valid_trace_point?(tp)
  return false unless tp.path.start_with?(@root_path)

  start_controller = Thread.current[:stack]&.first
  start_controller && "#{tp.defined_class}##{tp.method_id}" != start_controller[:method]

  # gems_to_track = BuilderApm.configuration.gems_to_track
  # gems_to_track.any? { |gem| tp.path.include?(File::SEPARATOR + gem) }
end