File LOCK methods

[David Dyer-Bennet]

On 23-May-10 16:57, Greg Ward wrote:
> On Tue, May 18, 2010 at 11:22 AM, David Dyer-Bennet<dd-b at dd-b.net>  wrote:
>> Then I was going to use a pre-commit hook to verify that they had the file
>> locked before they could commit changes.  I'd write a standalone command
>> to lock files when needed (and unlock).
>>
>> I don't think controlling the LOCK file through hg and coordinating via
>> the central repository can work, though.  It's not possible to update just
>> the LOCK file independent of any other file, in either direction; a push
>> or a pull can always bring or send extra stuff, whatever else happens to
>> have been changed.
>
> bfiles (my extension for handling large binary files) has a vaguely
> similar problem: clients need to communicate with the central store
> using the same underlying protocol as hg (SSH, HTTP) without
> reinventing the world.  Since Mercurial does not (yet) have a nice way
> for extensions to extend the wire protocol, we (well, really David
> Douard did all the work) cobbled together an SSH protocol that is very
> similar to Mercurial's own.  Conceptually this duplicates many ideas
> from core hg, and unfortunately there is a bit of duplicate code too.
> But it seems to work.
>
> The latest code is here:
> http://vc.gerg.ca/hg/hg-bfiles/file/tip/bfiles.py.  The code of
> particular interest to you is the classes sshstore and sshstoreserver.
>   In protocol terms, sshstore is the client and sshstoreserver is the
> server.

Thanks.  I may have thought of some other problems, but I'm making at 
least some progress on this set of problems.  At least I'm learning stuff.

>> Are extensions a lot more powerful than hooks?  Can they solve this problem?
>
> "Yes" and "Probably, but it's a fair amount of work".

Isn't it always?  But if it was easy, they wouldn't pay us the big 
bucks, I suppose.

> Good luck!

Thank you.
-- 
David Dyer-Bennet, dd-b at dd-b.net; http://dd-b.net/
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