• Heiko Voigt's avatar
    submodule: implement a config API for lookup of .gitmodules values · 959b5455
    Heiko Voigt authored
    In a superproject some commands need to interact with submodules. They
    need to query values from the .gitmodules file either from the worktree
    of from certain revisions. At the moment this is quite hard since a
    caller would need to read the .gitmodules file from the history and then
    parse the values. We want to provide an API for this so we have one
    place to get values from .gitmodules from any revision (including the
    The API is realized as a cache which allows us to lazily read
    .gitmodules configurations by commit into a runtime cache which can then
    be used to easily lookup values from it. Currently only the values for
    path or name are stored but it can be extended for any value needed.
    It is expected that .gitmodules files do not change often between
    commits. Thats why we lookup the .gitmodules sha1 from a commit and then
    either lookup an already parsed configuration or parse and cache an
    unknown one for each sha1. The cache is lazily build on demand for each
    requested commit.
    This cache can be used for all purposes which need knowledge about
    submodule configurations. Example use cases are:
     * Recursive submodule checkout needs to lookup a submodule name from
       its path when a submodule first appears. This needs be done before
       this configuration exists in the worktree.
     * The implementation of submodule support for 'git archive' needs to
       lookup the submodule name to generate the archive when given a
       revision that is not checked out.
     * 'git fetch' when given the --recurse-submodules=on-demand option (or
       configuration) needs to lookup submodule names by path from the
       database rather than reading from the worktree. For new submodule it
       needs to lookup the name from its path to allow cloning new
       submodules into the .git folder so they can be checked out without
       any network interaction when the user does a checkout of that
    Signed-off-by: Heiko Voigt's avatarHeiko Voigt <hvoigt@hvoigt.net>
    Signed-off-by: Stefan Beller's avatarStefan Beller <sbeller@google.com>
    Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
submodule-config.h 688 Bytes