31 Mar
2016
31 Mar
'16
9:54 a.m.
On Thu, Mar 31, 2016 at 01:42:23AM +0200, Joerg Schilling wrote:
Larry McVoy <lm(a)mcvoy.com> wrote:
We talked about this before: You are the only person who does not attack me
when I write that SCCS is much faster than RCS, just because you know ;-)
You can thank Walter Tichy, who got a PhD for RCS if I recall, can you
believe that? He tried to paint SCCS as bad and everyone believed him.
SCCS is brilliant in how it stores the changes, it's a weave rather than
diff and patch. Which means it can get 1.1 as fast as it can get the tip.
Or better put, in a big tree, it is way way faster than git for some things:
What BK GIT How much faster is BK?
----------------------------------------------------------------------------
annotate/blame 0.01 seconds 32.3 seconds 3230 times faster
search history 0.01 seconds 138.9 seconds 13890 times faster
That's a 1M changeset tree with 230,000 files (4GB of history). You all
know what annotate/blame are, the search history is answering the question
"did the string 'those bastards at $COMPANY' ever occur in our source
code?"
so it's searching all versions. The SCCS weave is instant for stuff like
that; diff and patch have to tons more work.
Given
that using git enforces a loss of meta data, is there a chance to get
the SCCS history for older UNIX versions?
You are the first person outside of BitMover that I've ever seen
recognize that. Go you! It's very annoying, we can write a perfect BK
to Git exporter but going the other way is a research project. The first system to implement something based on
previous good ideas was BK and
We took the weave and turbo charged it. Recent BK versions are crazy fast.
AFAIK, GIT was implemented originally as an empty
shelf that aimed to imitate
the CLI from BK.
No, Git, credit to Linus, was his own ideas. Yeah, he took the basic model
of clone/pull/commit/push, but the storage format is all his (and retarded,
it doesn't scale, it's all content addressable data by hash, works when it
fits in memory, thrashes like hell when it doesn't).
Anyhoo, we should take this private, this is a Unix list, not an SCM list.
Though I am loving the work to get a repo, even if it is git, with all
the history. That's awesome!