Here's a little update.
I'm currently working on a new mkctm.c and part of that project is to
get something better than "diff -n" as edit-generator. Technical
details at the end of this message.
This will mean that I must update the ctm program to understand the
new edit's and give you a fair warning to get your machines updated,
with the new ctm before I start to send the new format edits, so now
you know. I will send an email when that happens.
Next: I'm going to make a couple of "custom" CTM-deltas relative to
the 2.0.5 CDROM as soon as I get one.
Finally: Several people have expressed interest in improving ctm's
client side and I hope to see some results of this soon, in the
meantime you can send your ideas to email@example.com and they will
get to the right people.
Now the bad news: I'm going back to Denmark and I may not have too much
time to burn the next month and a half, and I may not be able to all of
the above before I go. Will keep you all posted.
The new edit format:
This is a "string reference" model, which means that it works by pointing
to strings in the old file, inserting new strings if needed, to generate
the new file.
The format is very compact and unreadable to the human eye, but seems
to be able to beat the diff -n on all conceiveable distances, and with
quite a fair margin on most of them.
It is more expensive to find this kind of edit-string than to do an
diff, but it has several advantages from a CTM point of view:
First: It works on binary files, the special casing of files which
had killer-characters in them is no longer needed.
Second: It works in memory, I save the fork/exec(diff) part. This
actually eliminates the window from I make the MD5 till the diff
is run, where a file-modification could sneak in, and make a mess
of the situation (This has only happened once, and my check found it,
but it is a stupid detail I'd like to get fixed.).
Third: The algorithm can be made to stop if the output would become
bigger than the entire contents of the file, where a CTMFS is more
Four: Error checking can be made much more water proof.
Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team.
http://www.freebsd.org/~phk | firstname.lastname@example.org Private mailbox.
whois: [PHK] | email@example.com TRW Financial Systems, Inc.
Just that: dried leaves in boiling water ?