module Sprockets::DigestUtils

def digest(obj)

Returns a String digest of the object.

obj - A JSON serializable object.

wicked fast. Microbenchmarks away!
This is used for generating cache keys, so its pretty important its

Internal: Generate a hexdigest for a nested JSON serializable object. 
def digest(obj)
  digest = digest_class.new
  queue  = [obj]
  while queue.length > 0
    obj = queue.shift
    klass = obj.class
    if klass == String
      digest << obj
    elsif klass == Symbol
      digest << 'Symbol'
      digest << obj.to_s
    elsif klass == Fixnum
      digest << 'Fixnum'
      digest << obj.to_s
    elsif klass == Bignum
      digest << 'Bignum'
      digest << obj.to_s
    elsif klass == TrueClass
      digest << 'TrueClass'
    elsif klass == FalseClass
      digest << 'FalseClass'
    elsif klass == NilClass
      digest << 'NilClass'
    elsif klass == Array
      digest << 'Array'
      queue.concat(obj)
    elsif klass == Hash
      digest << 'Hash'
      queue.concat(obj.sort)
    elsif klass == Set
      digest << 'Set'
      queue.concat(obj.to_a)
    elsif klass == Encoding
      digest << 'Encoding'
      digest << obj.name
    else
      raise TypeError, "couldn't digest #{klass}"
    end
  end
  digest.digest
end