[darcs-users] Hashed-storage & darcs 2.3 (Was; Re: 2.3 release schedule)

[Zooko Wilcox-O'Hearn]

I have a request:  speed up the operations which users have to wait  
on when they browse a darcs repository through trac, and deploy it as  
soon as possible!

For example, the front page of http://darcs.net has a link to this page:

http://allmydata.org/trac/darcs-2/browser

If you load that page, trac issues the darcs commands like these:

2009-05-27 09:15:14,095 Trac[command] DEBUG: cd /home/source/darcs/ 
darcs-2/trunk-hashedformat; TZ=UTC darcs --version
2009-05-27 09:15:14,244 Trac[command] DEBUG: cd /home/source/darcs/ 
darcs-2/trunk-hashedformat; TZ=UTC darcs query contents --quiet -- 
match "hash 20090513075931- 
c31ef-94cc8b3d6a88ae270963d60d6d5426bd0bda7245.gz" "GNUmakefile"
2009-05-27 09:15:14,638 Trac[command] DEBUG: cd /home/source/darcs/ 
darcs-2/trunk-hashedformat; TZ=UTC darcs query contents --quiet -- 
match "hash 20090513075931- 
c31ef-94cc8b3d6a88ae270963d60d6d5426bd0bda7245.gz" "configure.ac"

If there are enough files which have been changed since the last time  
trac queried darcs and cached the result, then this can take many  
seconds.  While it is processing, other users of the same trac will  
get a "database is locked" error if they try to view the same  
repository.  On some repositories that I use, it takes more than 30  
seconds and trac times-out (believing that the database or revision  
control tool must have locked up) and gives an error message.

Also if you view the contents of a file like this:

http://allmydata.org/trac/darcs-2/browser/src/darcs.tex

Or the history of a file or directory, like this:

http://allmydata.org/trac/darcs-2/log/src/darcs.tex

Then trac will issue a 'darcs query contents --match "hash ..."'  
command.

So, it would be great for me if 'darcs query contents --match  
"hash ..."' were as fast as possible, and if this speed-up were  
released in a stable and completely bug-free new version of darcs as  
soon as possible.  ;-)

Thanks!

Regards,

Zooko