Rails boot allocations

boot_allocations.rb

def iter(n)
  if n > 0
    1.times{
      iter(n-1)
    }
  else
    # null code
  end
end

def gc
  3.times do
    iter(100)
    GC.start
    GC.start
  end
end

def start_objspace_trace
  require "objspace"
  ObjectSpace.trace_object_allocations_start
end

def stop_objspace_trace
  ObjectSpace.trace_object_allocations_stop
  gc
end

def log_retained_allocations(key = :file)
  current_file = File.basename(__FILE__)
  object_hash = {}
  ObjectSpace.each_object do |o|
    sourcefile = ObjectSpace.allocation_sourcefile(o) || ""
    next if sourcefile.include?(current_file)

    obj_key = "#{o.class.name}\t"
    obj_key << sourcefile if [:line, :file, :path].include?(key)
    obj_key << ":#{ObjectSpace.allocation_sourceline(o)}" if key == :line

    object_hash[obj_key] ||= Hash.new { |h, _| h[:count] = 0; h[:memsize] = 0 }
    object_hash[obj_key][:count] += 1
    object_hash[obj_key][:memsize] += ObjectSpace.memsize_of(o)
  end

  object_hash.sort_by {|k, v| -v[:memsize]}[0..1000].each do |k, v|
    puts "m: %11s | c: %7s | %s" %
    [v[:memsize].to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1,"),
     v[:count].to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1,"),
    k ]
  end
end

start_objspace_trace
require 'bundler/setup'
require './config/environment'

stop_objspace_trace
log_retained_allocations