git-annex config: Only allow configs be set that are ones git-annex
actually supports reading from repo-global config, to avoid confused users
trying to set other configs with this.
It's important that it be clear that it overrides a config, such that
reloading the git config won't change it, and in particular, setConfig
won't change it.
Most of the calls to changeGitConfig were actually after setConfig,
which was redundant and unncessary. So removed those.
The only remaining one, besides --debug, is in the handling of
repository-global config values. That one's ok, because the
way mergeGitConfig is implemented, it does not override any value that
is set in git config. If a value with a repo-global setting was passed
to setConfig, it would set it in the git config, reload the git config,
re-apply mergeGitConfig, and use the newly set value, which is the right
thing.
annex.largefiles can be configured by git-annex config, to more easily set
a default that will also be used by clones, without needing to shoehorn the
expression into the gitattributes file. The git config and gitattributes
override that.
Whenever something is added to git-annex config, we have to consider what
happens if a user puts a purposfully bad value in there. Or, if a new
git-annex adds some new value that an old git-annex can't parse.
In this case, a global annex.largefiles that can't be parsed currently
makes an error be thrown. That might not be ideal, but the gitattribute
behaves the same, and is almost equally repo-global.
Performance notes:
git-annex add and addurl construct a matcher once
and uses it for every file, so the added time penalty for reading the global
config log is minor. If the gitattributes annex.largefiles were deprecated,
git-annex add would get around 2% faster (excluding hashing), because
looking that up for each file is not fast. So this new way of setting
it is progress toward speeding up add.
git-annex smudge does need to load the log every time. As well as checking
the git attribute. Not ideal. Setting annex.gitaddtoannex=false avoids
both overheads.
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.
Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.
(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
... to control the default behavior in all clones of a repository.
This includes a new Configurable data type, so the GitConfig type indicates
which values can be configured this way.
The implementation should be quite efficient; the config log is only read
once, and only when a Configurable value has not already been set by
git-config.
Indeed, it would be nice in the future to extend this, so that git-config
is itself only read on demand. Some commands may not need to look at the
git configuration at all.
This commit was sponsored by Trenton Cronholm on Patreon.
