1 This is a fork of Kristian Høgsberg's razor. The bits live here:
3 http://project.juiblex.co.uk/git?p=razor.git;a=summary
5 Kristian's original README follows:
7 ----------------------------------------------------------------------
8 Just random notes at this point:
10 - Razor is a package management system replacing rpm and yum. Razor
11 implements management of packages installed on the system,
12 dependency solving, and upgrading in a small compact code base with
15 - Key points: one file format for package sets, specified and
16 implemented by razor; no point in splitting dep-solver and package
17 manager, there is too much implementation overlap. By hand coding
18 the on-disk format we have a solid foundation on which to
19 implementing fast dependency solving, error recovery etc. No
20 complex dependencies in package management stack. In other words,
21 package management is *simple*, no need to overdesign it.
23 - Use one simple file format as the core of the system. The razor
24 package set data structure represents a set of packages and is used
25 for the current installed set, the sets available from upstream
26 sources, and the set currently being install during a transaction.
27 Tiered systems such as rpm+yum, deb+apt etc end up duplicating and
28 reimplementing common operations on packages. Other systems
29 typically pull in external database libraries to manage the package
30 meta data and in some cases each layer in the stack uses a
31 different database dependency to represent essentially the same
34 - Using external database libraries may seem a good idea up front,
35 but monotone vs git is a good example of how you need to control
36 the data structure and the on-disk format to really get excellent
37 performance. The razor package set data structure is fairly
38 simple; it's an read-only, mmap()'able on-disk data structure. The
39 package set has a sorted index of the packages in the set, a sorted
40 index of all dependencies and a sorted, compact directory of all
41 files in all the packages. Operations such as merging package
42 sets, satisfying requires from one set against another can all be
43 implemented in linear time. Razor implements the package set
44 representation down to the bytes on the disk and can optimize the
45 representation and access methods to make the necessary operations
48 - The set of installed packages on a system is represented by just
49 one package set file. As we install a set of new packages, we
50 prepare the new package set a temporary file and once the install
51 has succeeded, we copy the package set file to the real filename.
52 If there is a system crash, razor will notice the temporary file on
53 boot and resume the update.
55 - We want to keep the numer of dependencies down in a system critical
56 component such as the package manager. Between rpm and yum we're
57 pulling in berkeley db, sqlite, expat, python.
59 - During update of several packages rpm+yum leaves the system in an
60 inconsistent state for long periods of time. Power failure in this
61 window causes critical system corruption. We want to minimize the