# encoding: utf-8
if ENV["PROFILE_BAD_LOG_CALLS"] || ($DEBUGLIST || []).include?("log")
  # Set PROFILE_BAD_LOG_CALLS=1 in your environment if you want
  # to track down logger calls that cause performance problems
  #
  # Related research here:
  #   https://github.com/jordansissel/experiments/tree/master/ruby/logger-string-vs-block
  #
  # Basically, the following is wastes tons of effort creating objects that are
  # never used if the log level hides the log:
  #
  #     logger.debug("something happened", :what => Happened)
  #
  # This is shown to be 4x faster:
  #
  #     logger.debug(...) if logger.debug?
  #
  # I originally intended to use RubyParser and SexpProcessor to
  # process all the logstash ruby code offline, but it was much
  # faster to write this monkeypatch to warn as things are called.
  require "cabin/mixins/logger"
  module Cabin::Mixins::Logger
    LEVELS.keys.each do |level|
      m = "original_#{level}".to_sym
      predicate = "#{level}?".to_sym
      alias_method m, level
      define_method(level) do |*args|
        if !send(predicate)
          warn("Unconditional log call", :location => caller[0])
        end
        send(m, *args)
      end
    end
  end
end # PROFILE_BAD_LOG_CALLS
