Re: Idea for reducing disk IO on tagging operations

[Dr. David Alan Gilbert]

* Doug Lee (address@hidden) wrote:
> I followed this discussion only loosely and kept silent because I
> suspect someone will shoot me to pieces for the complaint I'm about to
> make, but now that we're to the stage of actual implementation, I
> guess I'd like to say this anyway...

Hey that's OK.

> I have reservations about any system that makes whitespace significant
> in a text file.  I can make an exception for indent levels, as used by
> Python, because these are visible and errors are obvious without
> resorting to odd tactics like hex editors, vi's :list command, etc.

Let me make it clear that this patch *in no way* makes whitespace
significant; in actual fact it only works because it isn't
significant.

What it does is put a glob of whitespace in when it is convenient;
nothing changes in the parsing or anything - so just like before
that whitespace is completely ignored.

The trick is that when it comes to add a tag it checks to see if there
is spare white space and if so overwrites it; if you removed
the white space or otherwise fettled with the file that is fine;
it won't perform the optimisation.

Indeed this means that an existing cvs client can quite happily
read a repository which has had my patch inflicted on it.

(The existing cvs code that rewrites the file will remove any
excess white space you added up there anyway.)

Dave
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