Marshalling error when caching models with date prior to 1900

问题

I have some active record models which have a "published_on" attribute. When I attempt to cache models with a published_on date prior to 1/1/1900, I get an error such as:

Marshalling error for key 'popular_products': year too big to marshal: 1300 UTC
You are trying to cache a Ruby object which cannot be serialized to memcached.

I can reproduce a similar error with ruby:

irb(main)> Marshal.dump( Time.parse("1/1/1900") )
ArgumentError: year too big to marshal: 1899 UTC

What's the right approach for caching models with dates prior to 1900?

回答1:

As @j03w commented, this is a limitation of the Time type. I chose to change the type to Date, which resolved the problem.

回答2:

You can also overload the _dump and _load methods of Time class, as follow:

require 'time' # Time extension to have xmlschema method
class Time
  def _dump(level)
    xmlschema(9) # store nsec
  end
  def self._load(str)
    Time.parse(str)
  end
end

irb(main):013:0> t=Time.new(1515,1,1)
=> 1515-01-01 00:00:00 +0100
irb(main):014:0> a=Marshal.dump(t)
=> "\x04\bIu:\tTime(1515-01-01T00:00:00.000000000+01:00\x06:\x06ET"
irb(main):015:0> t==Marshal.load(a)
=> true

来源：https://stackoverflow.com/questions/18247465/marshalling-error-when-caching-models-with-date-prior-to-1900