obj_space.rb

require "objspace"
ObjectSpace.trace_object_allocations_start

def log_object_space
  ObjectSpace.trace_object_allocations_stop

  object_hash = {}
  ObjectSpace.each_object do |o|
    key = "#{ObjectSpace.allocation_sourcefile(o)}" #:#{ObjectSpace.allocation_sourceline(o)}"
    object_hash[key] ||= Hash.new { |h, _| h[:count] = 0; h[:memsize] = 0 }
    object_hash[key][:count] += 1
    object_hash[key][:memsize] += ObjectSpace.memsize_of(o)
  end

  #object_hash.sort_by {|k, v| -v[:count]}.each {|k, v| puts "count: #{v[:count]}, #{k}, memsize: #{v[:memsize]}"}
  object_hash.sort_by {|k, v| -v[:memsize]}[0..20].each do |k, v|
    k = k.gsub(/.*[y\/]gems\//,'')
    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
  nil
ensure
  ObjectSpace.trace_object_allocations_start
end