From: Sean Russell <ser@...>
Date: 2002-07-05T00:35:23+09:00
Subject: Re: [ANN] Archive 0.1 and version.rb

Massimiliano Mirra wrote:

> http://www.allruby.com/rpkg/archive-0.1.tar.gz
> http://www.allruby.com/rpkg/version.rb
> 
> Both modules are also included in the (to be released) development
> version of rpkg.

Very cool, Massimiliano.

Say, I thought I'd take our private conversation public, and a little 
further.

We'd been talking about the difference between Debians package management 
system and Gentoo's Portage.  Since rpkg is a port of Debian's system, I'll 
refer to it instead of .deb.

There's one other thing that I'd like to see in a package management system: 
sparse updates.

In Portage, everything is compiled on the client; binaries are allowed, but 
discouraged.  rpkg will allow you to compile on the client, but the primary 
distribution mode is binary.   One thing that neither of these systems 
support is sparse updates.  A sparse update is like rsync, CVS, or unison.  
You only get the diffs between files.  This would reduce network traffic in 
the vast majority of source-based distributions; it probably wouldn't help 
binary-based distributions too much.  However, practically all Ruby 
packages are distributed as source; either they're Ruby code, or they have 
some native component that is compiled on the client.

Consider a hypothetical system.  I use CVS here because CVS is extremely 
common as a source repository, and CVS clients for practically every OS.

        FRESH INSTALL:
        1) 'cvs checkout' project.
        2) Make a tarball from checkout directory.
        3) Build and install.
        4) Delete build directory

        UPGRADE:
        1) Unpack previous tarball
        2) 'cvs up -z3' the directory
        3) Rebuild tarball
        3) Build and install
        4) Delete build directory

Rather than downloading a binary in which only a couple of files may have 
changed, we sparsely download only the diffs.

An alternative for Ruby that I was considering for a while was using rsync 
to directly upgrade a package, but this would only work for pure Ruby 
projects, and would require that the software source supply an rsync 
server, which is much less common than CVS.

-- 
 |..  "Put your hand on a hot stove for a minute and it seems like an
<|>    hour.  Sit with a pretty girl for an hour and it seems like a
/|\    minute.  THAT's relativity."
/|    -- Albert Einstein
 |