Class: ActiveFacts::Tracer

Inherits:
Object show all
Defined in:
lib/activefacts/tracer.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Tracer

Returns a new instance of Tracer.



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# File 'lib/activefacts/tracer.rb', line 52

def initialize
  @indent = 0	# Current nesting level of enabled trace blocks
  @nested = false   # Set when a block enables all enclosed tracing
  @available = {}	# Hash of available trace keys, accumulated during the run
  @delayed = nil	# A delayed message, emitted only if the enclosed block emits tracing

  @keys = {}
  if (e = ENV["TRACE"])
	e.split(/[^_a-zA-Z0-9]/).each{|k| enable(k) }
  end
end

Instance Method Details

#available_keys ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 74

def available_keys
  @available.keys
end

#disable(key) ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 92

def disable key
  !key.empty? and @keys.delete(key.to_sym)
end

#enable(key) ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 82

def enable key
  if !key.empty? && !@keys[s = key.to_sym]
	@keys[s] = true
	setup_help if s == :help
	setup_flame if s == :flame
  else
	true
  end
end

#enabled?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/activefacts/tracer.rb', line 78

def enabled? key
  !key.empty? && @keys[key.to_sym]
end

#setup_debugger ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 131

def setup_debugger
  begin
	require 'ruby-trace '
	Debugger.start # (:post_mortem => true)  # Some Ruby versions crash on post-mortem debugging
  rescue LoadError
	# Ok, no debugger, tough luck.
  end

  (
	[ENV["DEBUG_PREFERENCE"]].compact +
	[
	  'byebug',
	  'pry',
	  'debugger',
	  'ruby-trace '
	]
  ).each do |debugger|
	begin
	  require debugger
	  if debugger == 'byebug'
 Kernel.class_eval do
   alias_method :byebug, :debugger
 end
	  end
	  ::Debugger.start if (const_get(::Debugger) rescue nil)
	  break
	rescue LoadError => e
	  errors << e
	end
  end

  if trace :trap
	trap('SIGINT') do
	  puts "Stopped at:\n\t"+caller*"\n\t"
	  debugger
	  true	# Stopped on SIGINT
	end
  end
end

#setup_firstaid ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 171

def setup_firstaid
  if trace :firstaid
	puts "Preparing first aid kit"
	::Exception.class_eval do
	  alias_method :firstaid_initialize, :initialize

	  def initialize *args, &b
 send(:firstaid_initialize, *args, &b)
 return if NoMethodError === self && message =~ /^undefined method `to_ary' for \#<Gem::Specification/
 return if LoadError == self
 puts "Stopped due to #{self.class}: #{message} at "+caller*"\n\t"
 debugger
 true # Stopped in Exception constructor
	  end
	end
  end
end

#setup_flame ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 114

def setup_flame
  require 'ruby-prof'
  require 'ruby-prof-flamegraph'
  profile_result = RubyProf.start
  at_exit {
	profile_result2 = RubyProf.stop
	printer = RubyProf::FlameGraphPrinter.new(profile_result2)
	data_file = "/tmp/flamedata_#{Process.pid}.txt"
	svg_file = "/tmp/flamedata_#{Process.pid}.svg"
	flamegraph = File.dirname(__FILE__)+"/flamegraph.pl"
	File.popen("tee #{data_file} | perl #{flamegraph} --countname=ms --width=4800 > #{svg_file}", "w") { |f|
	  printer.print(f, {})
	}
	STDERR.puts("Flame graph dumped to file:///#{svg_file}")
  }
end

#setup_help ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 108

def setup_help
  at_exit {
	$stderr.puts "---\nTracing keys available: #{@available.keys.map{|s| s.to_s}.sort*", "}"
  }
end

#toggle(key) ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 96

def toggle key
  if !key.empty?
	if enabled?(key)
	  disable(key)
	  false
	else
	  enable(key)
	  true
	end
  end
end

#trace(*args, &block) ⇒ Object 



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# File 'lib/activefacts/tracer.rb', line 64

def trace(*args, &block)
  begin
	old_indent, old_nested, old_delayed, enabled = @indent, @nested, @delayed, show(*args)
	# This monstrosity reduces the steps when single-stepping:
	block ? yield : (args.size == 0 ? self : enabled)
  ensure
	@indent, @nested, @delayed = old_indent, old_nested, old_delayed
  end
end