module Rack::Reloader::Stat

def figure_path(file, paths)
  found = @cache[file]
  found = file if !found and Pathname.new(file).absolute?
  found, stat = safe_stat(found)
  return found, stat if found
  paths.find do |possible_path|
    path = ::File.join(possible_path, file)
    found, stat = safe_stat(path)
    return ::File.expand_path(found), stat if found
  end
  return false, false
end

def rotation
  files = [$0, *$LOADED_FEATURES].uniq
  paths = ['./', *$LOAD_PATH].uniq
  files.map{|file|
    next if /\.(so|bundle)$/.match?(file) # cannot reload compiled files
    found, stat = figure_path(file, paths)
    next unless found && stat && mtime = stat.mtime
    @cache[file] = found
    yield(found, mtime)
  }.compact
end

def safe_stat(file)
  return unless file
  stat = ::File.stat(file)
  return file, stat if stat.file?
rescue Errno::ENOENT, Errno::ENOTDIR, Errno::ESRCH
  @cache.delete(file) and false
end