git/environment.h, branch v2.48.2

config: make `delta_base_cache_limit` a non-global variable

2024-12-03T23:21:55Z

The `delta_base_cache_limit` variable is a global config variable used by multiple subsystems. Let's make this non-global, by adding this variable independently to the subsystems where it is used. First, add the setting to the `repo_settings` struct, this provides access to the config in places where the repository is available. Use this in `packfile.c`. In `index-pack.c` we add it to the `pack_idx_option` struct and its constructor. While the repository struct is available here, it may not be set because `git index-pack` can be used without a repository. In `gc.c` add it to the `gc_config` struct and also the constructor function. The gc functions currently do not have direct access to a repository struct. These changes are made to remove the usage of `delta_base_cache_limit` as a global variable in `packfile.c`. This brings us one step closer to removing the `USE_THE_REPOSITORY_VARIABLE` definition in `packfile.c` which we complete in the next patch. Signed-off-by: Karthik Nayak Signed-off-by: Junio C Hamano

environment: stop storing "core.notesRef" globally

2024-09-12T17:15:44Z

Stop storing the "core.notesRef" config value globally. Instead, retrieve the value in `default_notes_ref()`. The code is never called in a hot loop anyway, so doing this on every invocation should be perfectly fine. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: stop storing "core.warnAmbiguousRefs" globally

2024-09-12T17:15:44Z

Same as the preceding commits, storing the "core.warnAmbiguousRefs" value globally is misdesigned as this setting may be set per repository. Move the logic into the repo-settings subsystem. The usual pattern here is that users are expected to call `prepare_repo_settings()` before they access the settings themselves. This seems somewhat fragile though, as it is easy to miss and leads to somewhat ugly code patterns at the call sites. Instead, introduce a new function that encapsulates this logic for us. This also allows us to change how exactly the lazy initialization works in the future, e.g. by only partially initializing values as requested by the caller. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: stop storing "core.preferSymlinkRefs" globally

2024-09-12T17:15:43Z

Same as the preceding commit, storing the "core.preferSymlinkRefs" value globally is misdesigned as this setting may be set per repository. There is only a single user of this value anyway, namely the "files" backend. So let's just remove the global variable and read the value of this setting when initializing the backend. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: stop storing "core.logAllRefUpdates" globally

2024-09-12T17:15:43Z

The value of "core.logAllRefUpdates" is being stored in the global variable `log_all_ref_updates`. This design is somewhat aged nowadays, where it is entirely possible to access multiple repositories in the same process which all have different values for this setting. So using a single global variable to track it is plain wrong. Remove the global variable. Instead, we now provide a new function part of the repo-settings subsystem that parses the value for a specific repository. While that may require us to read the value multiple times, we work around this by reading it once when the ref backends are set up and caching the value there. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

refs: stop modifying global `log_all_ref_updates` variable

2024-09-12T17:15:43Z

In refs-related code we modify the global `log_all_ref_updates` variable, which is done because `should_autocreate_reflog()` does not accept passing an `enum log_refs_config` but instead accesses the global variable. Adapt its interface such that the value is provided by the caller, which allows us to compute the proper value locally without having to modify global state. This change requires us to move the enum to "repo-settings.h", or otherwise we get compilation errors due to include cycles. We're about to fully move this setting into the repo-settings subsystem anyway, so this is fine. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: guard state depending on a repository

2024-09-12T17:15:42Z

In "environment.h" we have quite a lot of functions and variables that either explicitly or implicitly depend on `the_repository`. The implicit set of stateful declarations includes for example variables which get populated when parsing a repository's Git configuration. This set of variables is broken by design, as their state often depends on the last repository config that has been parsed. So they may or may not represent the state of `the_repository`. Fixing that is quite a big undertaking, and later patches in this series will demonstrate a solution for a first small set of those variables. So for now, let's guard these with `USE_THE_REPOSITORY_VARIABLE` so that callers are aware of the implicit dependency. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: reorder header to split out `the_repository`-free section

2024-09-12T17:15:42Z

Reorder the "environment.h" header such that declarations which are free from `the_repository` come before those which aren't. The new structure is now: - Defines for environment variable names. - Things which do not rely on a repository. - Things which do, including those that implicitly rely on a parsed repository. This includes for example variables which get populated when reading repository config. This will allow us to guard the last category of declarations with `USE_THE_REPOSITORY_VARIABLE`. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: move `set_git_dir()` and related into setup layer

2024-09-12T17:15:41Z

The functions `set_git_dir()` and friends are used to set up repositories. As such, they are quite clearly part of the setup subsystem, but still live in "environment.c". Move them over, which also helps to get rid of dependencies on `the_repository` in the environment subsystem. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

environment: move object database functions into object layer

2024-09-12T17:15:40Z

The `odb_mkstemp()` and `odb_pack_keep()` functions are quite clearly tied to the object store, but regardless of that they are located in "environment.c". Move them over, which also helps to get rid of dependencies on `the_repository` in the environment subsystem. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano