Re: simple performance question on CVS

[Eric Siegerman]

On Sun, Aug 03, 2003 at 08:23:38PM -0400, Larry Jones wrote:
> The trade-off is that you have to read the entire file in order to
> verify the checksum.  Since SCCS has to read the entire file anyway,
> there's no additional overhead.  RCS, on the other hand, doesn't have to
> read all of the diffs, particularly if you're just checking out the head
> revision which, in the RCS philosophy, is by far the most common
> operation.

True, but an RCS-like format could checksum each individual
section, instead of the file as a whole; e.g. one checksum
covering the <admin> and all the <delta>'s, and then a checksum
for each individual <deltatext>.  This still wouldn't catch
errors in <deltatext>'s you weren't reading at the moment, but
when it did finally catch an error, it'd know right off what was
wrong -- none of this random-file-format-error stuff.

(No, I'm not suggesting this for RCS or CVS!  Just
hypothesizing.)

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        address@hidden
|  |  /
When I came back around from the dark side, there in front of me would
be the landing area where the crew was, and the Earth, all in the view
of my window. I couldn't help but think that there in front of me was
all of humanity, except me.
        - Michael Collins, Apollo 11 Command Module Pilot