[Python-Dev] proposal: add basic time type to the standard library

Jeremy Hylton jeremy@alum.mit.edu
Thu, 7 Feb 2002 20:04:23 -0500

>>>>> "TP" == Tim Peters <tim.one@comcast.net> writes:

  TP> [Guido]
  >> I'm notoriously bad at channeling Jim.  Nevertheless, I do recall
  >> him saying he wanted a lightweight time object.

  TP> Given that most mallocs align to 8-byte boundaries these days
  TP> (also true of pymalloc), it's impossible in reality to define a
  TP> smaller object than TimeStamp, provided it needs at least one
  TP> byte of info beyond PyObject_HEAD.

Also, it may not be necessary to have a TimeStamp object in ZODB 4.
There are three uses for the timestamp: tracking how recently an
object was used for cache evication, providing a last modified time to
users, and as a simple version number.  

In ZODB 4, the cache eviction may be done quite differently.  The
version number may be a simple int.  The last mod time will not be
provided for each object; instead, users will need to define this
themselves if they care about it.  If they define it themselves,
they'd probably use a DateTime object, but we'd care much less about
how small it is.