RPM and shared library support

[Dario Alcocer]

Chuck Wilson has suggested[1] that RPM dynamically link to the Berkeley
DB database shared library; I imagine this would go for zlib, too.

Well, perusing the RPM mailing list archive, it turns out that it's a
little more involved. According to Jeff Johnson, RPM purposely uses
modified versions of zlib, db4, beecrypt and libelf, which is why the
libraries are embedded in the RPM tarball distribution[2].

In particular:

  * zlib uses 16MB uncompress buffer for RPM speed-up.
  * zlib includes the 'rsync ready' patch.
  * db4 compiled with --with-uniquename=_rpmd.
  * beecrypt has "a home-rolled, Knuth based, gcd mod invert function to
    work around a bug in DSA signature verification."
  * RPM uses libelf gelf_XXX() API which has been widely deployed.

Bottom line, folding in subordinate shared library support to the
upstream RPM 4.x release might take a while. So, the question
becomes: can we move on to shared RPM development libraries
(/usr/lib/librpmdb*.dll) without support for subordinate shared library
support?


Footnotes:

[1] - http://cygwin.com/ml/cygwin/2003-03/msg00526.html
[2] - I think the following URL is only available to rpm-list
subscribers:
https://listman.redhat.com/mailman/private/rpm-list/2002-July/015764.html

-- 
Dario Alcocer -- Sr. Software Developer, Helix Digital Inc.
alcocer@helixdigital.com -- http://www.helixdigital.com