GNU bug report logs - #2756
move SCCS later in vc-handled-backends

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Message #3 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Dan Nicolaescu <dann <at> ics.uci.edu>
To: bug-gnu-emacs <bug-gnu-emacs <at> gnu.org>
Subject: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 10:25:21 -0700 (PDT)

SCCS should be moved after later in the vc-handled-backends list, after
the modern VCs.  

Opening any file costs a call to vc-sccs-registered
vc-sccs-search-project-dir (and whatever they call).

SCCS is not really popular nowadays, and that should be reflected on the
vc-handled-backends list.

Message #8 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> IRO.UMontreal.CA>
To: Dan Nicolaescu <dann <at> ics.uci.edu>
Cc: 2756 <at> debbugs.gnu.org, bug-gnu-emacs <bug-gnu-emacs <at> gnu.org>
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 16:16:49 -0400

> SCCS should be moved after later in the vc-handled-backends list, after
> the modern VCs.
> Opening any file costs a call to vc-sccs-registered
> vc-sccs-search-project-dir (and whatever they call).

No matter where SCCS is in the vc-handled-backends list, those functions
will be run for any file that is not version controlled, which is likely
to be a very common case.

> SCCS is not really popular nowadays,

Same thing for RCS, indeed.

> and that should be reflected on the vc-handled-backends list.

We could remove backends from the list based on the presence/absence of
the corresponding executable(s).


        Stefan

Message #16 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Dan Nicolaescu <dann <at> ics.uci.edu>
To: Stefan Monnier <monnier <at> IRO.UMontreal.CA>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 14:51:56 -0700 (PDT)

Stefan Monnier <monnier <at> IRO.UMontreal.CA> writes:

  > > SCCS should be moved after later in the vc-handled-backends list, after
  > > the modern VCs.
  > > Opening any file costs a call to vc-sccs-registered
  > > vc-sccs-search-project-dir (and whatever they call).
  > 
  > No matter where SCCS is in the vc-handled-backends list, those functions
  > will be run for any file that is not version controlled, which is likely
  > to be a very common case.
  >
  > > SCCS is not really popular nowadays,
  > 
  > Same thing for RCS, indeed.
  > 
  > > and that should be reflected on the vc-handled-backends list.
  > 
  > We could remove backends from the list based on the presence/absence of
  > the corresponding executable(s).

Would that be acceptable for 23.1?
If not, let's go for fixing the easier problem: moving SCCS later in the
list of backends.

Message #21 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Dan Nicolaescu <dann <at> ics.uci.edu>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 18:15:00 -0400

>> > SCCS should be moved after later in the vc-handled-backends list, after
>> > the modern VCs.
>> > Opening any file costs a call to vc-sccs-registered
>> > vc-sccs-search-project-dir (and whatever they call).
>> 
>> No matter where SCCS is in the vc-handled-backends list, those functions
>> will be run for any file that is not version controlled, which is likely
>> to be a very common case.
>> 
>> > SCCS is not really popular nowadays,
>> 
>> Same thing for RCS, indeed.
>> 
>> > and that should be reflected on the vc-handled-backends list.
>> 
>> We could remove backends from the list based on the presence/absence of
>> the corresponding executable(s).

> Would that be acceptable for 23.1?

No.

> If not, let's go for fixing the easier problem: moving SCCS later in the
> list of backends.

What problem?  And in what way is it a fix for it?


        Stefan

Message #24 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Dan Nicolaescu <dann <at> ics.uci.edu>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 15:22:46 -0700 (PDT)

Stefan Monnier <monnier <at> iro.umontreal.ca> writes:

  > What problem?  And in what way is it a fix for it?

The fact that SCCS generates unnecessary work for all files managed by
bzr, git, hg (which is a good number nowadays).

Message #29 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Dan Nicolaescu <dann <at> ics.uci.edu>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Mon, 23 Mar 2009 19:50:14 -0400

>> What problem?  And in what way is it a fix for it?
> The fact that SCCS generates unnecessary work for all files managed by
> bzr, git, hg (which is a good number nowadays).

Unnecessary work is not a problem in and of itself.
And, if this unnecessary work is a problem for Bzr, Git, or Hg files,
it's even more problematic for all the non-revision controlled files
which additionally need to do unnecessary work to determine that they're
neither under Git, Bzr, nor Hg control.  So changing the order won't
make much of a difference, other than hide the problem in the particular
case where you're lucky enough to access a file under the right VCS.


        Stefan

Message #32 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Dan Nicolaescu <dann <at> ics.uci.edu>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Wed, 1 Apr 2009 08:44:38 -0700 (PDT)

Stefan Monnier <monnier <at> iro.umontreal.ca> writes:

  > >> What problem?  And in what way is it a fix for it?
  > > The fact that SCCS generates unnecessary work for all files managed by
  > > bzr, git, hg (which is a good number nowadays).
  > 
  > Unnecessary work is not a problem in and of itself.

No, but given that it's unnecessary, and that it will be unnecessary in
the future too, why not get rid of it?

  > And, if this unnecessary work is a problem for Bzr, Git, or Hg files,
  > it's even more problematic for all the non-revision controlled files
  > which additionally need to do unnecessary work to determine that they're
  > neither under Git, Bzr, nor Hg control.  So changing the order won't
  > make much of a difference, other than hide the problem in the particular
  > case where you're lucky enough to access a file under the right VCS.

Yes, the thing is, what you are talking about above is a separate problem
that cannot be solved at this point.  
Even more, the solution for that problem would not solve the problem or
unnecessary checking for SCCS for systems that have sccs installed by
default (i.e. about all commercial unixes and free ones that install
cssc).  So why not just move SCCS to the end of the list?

Message #37 received at 2756 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Dan Nicolaescu <dann <at> ics.uci.edu>
Cc: 2756 <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Wed, 01 Apr 2009 11:55:24 -0400

>> >> What problem?  And in what way is it a fix for it?
>> > The fact that SCCS generates unnecessary work for all files managed by
>> > bzr, git, hg (which is a good number nowadays).
>> Unnecessary work is not a problem in and of itself.
> No, but given that it's unnecessary, and that it will be unnecessary in
> the future too, why not get rid of it?
>> And, if this unnecessary work is a problem for Bzr, Git, or Hg files,
>> it's even more problematic for all the non-revision controlled files
>> which additionally need to do unnecessary work to determine that they're
>> neither under Git, Bzr, nor Hg control.  So changing the order won't
>> make much of a difference, other than hide the problem in the particular
>> case where you're lucky enough to access a file under the right VCS.
> Yes, the thing is, what you are talking about above is a separate problem
> that cannot be solved at this point.  
> Even more, the solution for that problem would not solve the problem or
> unnecessary checking for SCCS for systems that have sccs installed by
> default (i.e. about all commercial unixes and free ones that install
> cssc).  So why not just move SCCS to the end of the list?

Because we're in prestest so we limit ourselves to bug-fixes.


        Stefan

Message #40 received at 2756-quiet <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Glenn Morris <rgm <at> gnu.org>
To: 2756-quiet <at> debbugs.gnu.org
Subject: Re: Bug#2756
Date: Tue, 23 Jun 2009 15:05:23 -0400

Some discussion at

http://lists.gnu.org/archive/html/emacs-devel/2009-06/msg00421.html

Message #45 received at 2756-done <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Dan Nicolaescu <dann <at> ics.uci.edu>
To: 2756-done <at> debbugs.gnu.org
Subject: Re: bug#2756: move SCCS later in vc-handled-backends
Date: Wed, 26 Aug 2009 11:34:43 -0700 (PDT)

Dan Nicolaescu <dann <at> ics.uci.edu> writes:

  > SCCS should be moved after later in the vc-handled-backends list, after
  > the modern VCs.  
  > 
  > Opening any file costs a call to vc-sccs-registered
  > vc-sccs-search-project-dir (and whatever they call).
  > 
  > SCCS is not really popular nowadays, and that should be reflected on the
  > vc-handled-backends list.

Closing, this request has been rejected.

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