rep-cache.db: was SVN repo

[Stephen Montgomery-Smith]

On 08/10/2011 06:04 PM, Julian H. Stacey wrote:
> Hi Stephen&  all
>
>> I created a .0001 delta for svn.  It is about 5G.  When compressed with
>> gzip, it goes down to 1.8G.  When compressed with bzip2, it goes down to
>> 1.4G.  When compressed with xz, it goes down to 1G.  These are some huge
>> differences in my opinion.
>
> Yup ! Too big to ignore.  Just in case,
> did you possibly overlook ensuring comparing like with like ? eg:
>
> man gzip
>       -9, --best        These options change the compression level used, with
>                         the -1 option being the fastest, with less compression,
>                         and the -9 option being the slowest, with optimal com-
>                         pression.  The default compression level is 6.
>     BTW I have : printenv | grep -i gzip	# GZIP=--best
>
> man bzip2:
> 	And --best merely selects the default behaviour.
>
> man xz
> 	      -0 ... -9
>                Select a compression preset level.  The default is -6.
> 		......
> 		

The CTM's are created with "gzip -9."  For bzip2 and xz I simply checked 
default behavior.  But bzip2 is already best by default.

Tests I have done in the past suggest that the difference created by 
adjusting these numbers is not very great.  I think what happens is that 
the compression program splits the file into parts, and then compresses 
each part.  The -n options simply say how big those parts can be.  As 
you can imagine, making these parts super big will bring diminishing 
returns.

>
>> If FreeBSD were to switch to svn, and stop supporting cvs, how many
>> people would be negatively impacted by not having svn on CTM?
>
> I'd miss it. I could live without,
> I could doubtless switch to running csup of ctm then svn,
> 	(but dont much want to punch another hole in firewall,

I get the impression that svn is via ssh.  Do you have ssh blocked in 
your firewall?

> 	figure packet proxying (cos gate disk too small),
> 	&/or fix my ftp proxy (only my http proxy works)
> 	I could fix or reconfig all, but I'd miss it :-),
> ctm via email, fed to local cvs tree has always been just so
> nice&  efficient, allowing lots of offline for max security&/or
> better response for other interactive stuff,&  quick load to laptop
> for travel, whatever.
>
>
>> I tried deleting base/db/repo-cache.db.
>
> I have the book Version Control with Subversion 2nd Ed. but never read it,

I found an online book on svn.  I think it was this book.  I searched 
this book for rep-cache.db, but it came up blank.

> Maybe you might find an SVN expert to discuss with on one of the SVN lists at
> http://lists.freebsd.org/mailman/listinfo
> maybe
> http://lists.freebsd.org/mailman/listinfo/svn-src-svnadmin

I might do that, but probably not in the near future.

>
> Thanks for all the CTM work you do for us !
>
> Cheers,
> Julian