Taste the Rainbow:0.7.0

This page is a guided tour of the source code of the rainbow-0.7.0 release.

Source Code Overview

Please start in my rainbow-0.7.0 tree.

 ./rainbow
  |--- README : Standard boilerplate about where work gets done; somewhat dated in this release.
  |--- conf : installation-time configuration files
  |     \--- session-olpc.conf : applies some unusual dbus rules to allow many uids
  |                              to use the same session bus and enables OLPC-specific 
  |                              dbus access checks. When /etc/olpc-security exists, 
  |                              session-olpc.conf is loaded by /usr/bin/sugar 
  | 
  |--- docs : explanations & notes
  |     \--- DESIGN : A discussion of how the predecessor to the current architecture arose.
  |     \--- NOTES : various problems I have encountered and thoughts on how to solve them.
  |     *--- rainbow.txt : a sketch & justification of the current design
  |
  |--- rainbow : source code
        |--- permissions : a stub based on the secure installation work that marcopg and 
        |                  neuralis did together a few weeks ago
        |--- util : functions wrapping frequently used idioms or useful syscalls
        |--- stages : logic implementing activity launching
        |--- targets : control flow describing how to call activity-launching code
        \--- service.py : dbus service entry-point
    
 ./rainbow.spec.in : spec-file template for building RPMS
 ./Makefile.package : package-specific variables for use in ../Makefile.fedora
 ../Makefile.fedora : rules for making local snapshot builds and 
                      internal releases, prior to pushing to Fedora

Activity Launching

The key functions for launching activities are

• stages/sugar.py:begin(),
• stages/sugar.py:prepare(), and
• stages/activation.py:launch().

These functions are called in the order listed from

• targets/sugar.py:launch() and
• targets/sugar.py:_exile()

which are, in turn, called from

• service.py:Rainbow.CreateActivity()

These six functions (and the relatively simple helpers they call) exhaust the functionality provided by rainbow-0.7.0.