Re: history

[Will P. <pa...@dc...>]

Rudolph Pereira asks:

> I'm wondering whether anyone has, or knows how to implement or have
> history in ark/arusha.

As far as I'm aware, not much has been done.  The main
reason I guess is that, while there are Twenty Cool Things
one can think of, no compelling need has arisen (at least
for me) that would put me in front of a keyboard for a week.

What we *do* do: Methods can be marked 'recordable' (and
lots are).  When they run, they record a few things about
themselves (who, when, what code, where parameter settings
came from...) in the "state directory".  This info is mainly
used to avoid re-doing such methods, but I have also been
known to go rooting around in there to see what happened N
months ago...

A few further developments of the "state directory" would (I
suspect) be not much work:

* Write some scripts to walk over the state info (it's all
  supposed to be well-formed XML), and tidy up any mess that
  is inadvertently there.

  An example script might be to find all the methods that
  used old versions of tools (e.g. an old GCC) and set up
  something for re-running them (with the new versions).

* Add to the state dir/stuff the stdout/stderr outputs from
  running the methods' code.  I do sometimes wish I could
  answer "Now, what the heck did 'make' do when I built
  libtiff on solaris8 back in March?"

* As you suggest, record the full (static) state of the
  object at time of a method invocation.  (In theory, this
  could be reconstructed just from CVS info.)

I would be interested in what you see as a compelling use
for "history" as you envision it.  ???

Will