On Thu, Jun 12, 2025 at 3:03 AM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > Junio C Hamano <gitster@xxxxxxxxx> writes: > > > My gut feeling, if I have to choose between "lazy loading" and > > "popluate in prepare_repo_settings() and then access the member > > directly thereafter" for this variable, I may pick the latter for > > this particular variable. > > I left the reason behind this choice unsaid, but let's spell it out. > > Originally, this was read in git_config(git_default_config) into a > global, and that is probably because almost everybody that touches > the working tree files needs to know about it. So populating it in > prepare_repo_settings() for everybody, even though the calling code > path does not even need it, would be OK---they were paying the cost > to read it when they read the default configuration variables. > > It seems Patrick earlier made a confused comment on the two models > that may need a bit clarifying. > > Here are the rules to follow. > > - "lazy loading" is not wrong. Initialize the member to an > "uninitialized" state, never touch the member in > prepare_repo_settings(), and have its getter check for the > "uninitialized" state to lazily load it, or have its setter do > its thing. prepare_repo_settings() should not even be aware of > the member, if we are going to give the member a getter/setter > pair. > > - "Without getter/setter" is not wrong, either. Load the member in > prepare_repo_settings(), which will turn into a no-op once it is > called to a repo instance. Use the member directly afterwards. > > You cannot mix and match. If the variable is rarely used, you'd > want to catch the initial access and lazily load it, hence you are > required to have a getter/setter pair and lazily populate the member > in your getter. If your variable is very commonly used, load it > once in prepare_repo_settings(), and because you are not going to do > anything special upon the first access, there is no need to have a > getter/setter pair. > > Oh, now I understand it. I will keep this in mind when working on these settings. I will send a new version of this patch soon. Thanks a lot, this helped clarify things.
