README

dpm - Debian package manager
----------------------------

I've got some crazy ideas about a unified apt+dpkg implementation, and
this is the place where early experimentation happens.  I do this
mostly to write some real code again, not really with the hope of
replacing dpkg and apt.

This is not about the Debian package or archive formats, it's just
about the implementation and user interfaces of dpkg and apt.  It's
maybe also a bit about algorithms to compute a package management
operation.

Initially, dpm will be compatible with the dpkg data base in
/var/lib/dpkg (if it ever gets as far as actually installing
packages), but only as a crutch: dpm will notice changes in
/var/lib/dpkg and will keep it up-to-date, but it will not rely on it.

* Steps

- A nice, fast storage for structured data, similar to apt's caches.
  It will not be a cache, but the primary storage.  It will be binary,
  with tools to export/import plain text.  Mutations of existing data
  are not allowed.  Modifications will be journalled, with the
  occasional garbage collection.

  That store will be used to store package info about available and
  installed packages and the file lists of installed packages.

  The data structure in the store should be able to deal with a
  complete archive: multiple distributions and multiple architectures.
  It should be useable not only for managing a Debian installation but
  also for tools that rummage around in a Debian archive in general.
  Thus, it needs to be efficient.

  The store should be extensible so that tools can store their own
  private information efficiently.  But it's not a general purpose
  data base.

  The store will of course store the current situation, but it might
  also store a 'planned future', similar to apt's in-core depcache.

  In libdpm, store.h

- A nice simple library for parsing the file formats commonly
  encountered with Debian packages.

  Particularily files like /var/lib/dpkg/status and .deb archives, of
  course.

  In libdpm, parse.h

- Importing the existing apt and dpkg state into a store.

  See libdpm/db.h