[RFC/PATCH 0/2] Submodules: refactoring the `module_list` function

Hi,

so eventually we want to have the whole Android project inside a git repository, which includes > 500 submodules for the different sub systems. To make that feasable we want to improve git-submodule for a huge set of submodules such as parallelizing `git submodule update`. As a first step I was toying around the `module_list` function as that is one key component for all the submodule operations. Also that part of the code is where the operations are split up to the different submodules, so that would be the natural place where we'd approach introducing threads later on.

This is an early RFC as it breaks the test suite. I do not remember ever interacting with pathspecs or cache entries before, so I'd appreciate some guiding comments. (Am I holding it wrong? Also the git code base seems large, it's easy to find new playgrounds :)

Thanks, Stefan

Stefan Beller (2):
  submodule: implement `module_list` as a builtin helper
  Testing the new code

 Makefile                    |  1 +
 builtin.h                   |  1 +
 builtin/submodule--helper.c | 99 +++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            | 25 +++++++++++-
 git.c                       |  1 +
 5 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 builtin/submodule--helper.c