From 5b3c650777547f2274540a036da641651fb866b0 Mon Sep 17 00:00:00 2001 From: Glen Choo Date: Thu, 14 Jul 2022 21:27:59 +0000 Subject: config: learn `git_protected_config()` `uploadpack.packObjectsHook` is the only 'protected configuration only' variable today, but we've noted that `safe.directory` and the upcoming `safe.bareRepository` should also be 'protected configuration only'. So, for consistency, we'd like to have a single implementation for protected configuration. The primary constraints are: 1. Reading from protected configuration should be fast. Nearly all "git" commands inside a bare repository will read both `safe.directory` and `safe.bareRepository`, so we cannot afford to be slow. 2. Protected configuration must be readable when the gitdir is not known. `safe.directory` and `safe.bareRepository` both affect repository discovery and the gitdir is not known at that point [1]. The chosen implementation in this commit is to read protected configuration and cache the values in a global configset. This is similar to the caching behavior we get with the_repository->config. Introduce git_protected_config(), which reads protected configuration and caches them in the global configset protected_config. Then, refactor `uploadpack.packObjectsHook` to use git_protected_config(). The protected configuration functions are named similarly to their non-protected counterparts, e.g. git_protected_config_check_init() vs git_config_check_init(). In light of constraint 1, this implementation can still be improved. git_protected_config() iterates through every variable in protected_config, which is wasteful, but it makes the conversion simple because it matches existing patterns. We will likely implement constant time lookup functions for protected configuration in a future series (such functions already exist for non-protected configuration, i.e. repo_config_get_*()). An alternative that avoids introducing another configset is to continue to read all config using git_config(), but only accept values that have the correct config scope [2]. This technically fulfills constraint 2, because git_config() simply ignores the local and worktree config when the gitdir is not known. However, this would read incomplete config into the_repository->config, which would need to be reset when the gitdir is known and git_config() needs to read the local and worktree config. Resetting the_repository->config might be reasonable while we only have these 'protected configuration only' variables, but it's not clear whether this extends well to future variables. [1] In this case, we do have a candidate gitdir though, so with a little refactoring, it might be possible to provide a gitdir. [2] This is how `uploadpack.packObjectsHook` was implemented prior to this commit. Signed-off-by: Glen Choo Signed-off-by: Junio C Hamano --- config.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'config.h') diff --git a/config.h b/config.h index 7654f61c63..ca994d7714 100644 --- a/config.h +++ b/config.h @@ -446,6 +446,15 @@ void git_configset_init(struct config_set *cs); */ int git_configset_add_file(struct config_set *cs, const char *filename); +/** + * Parses command line options and environment variables, and adds the + * variable-value pairs to the `config_set`. Returns 0 on success, or -1 + * if there is an error in parsing. The caller decides whether to free + * the incomplete configset or continue using it when the function + * returns -1. + */ +int git_configset_add_parameters(struct config_set *cs); + /** * Finds and returns the value list, sorted in order of increasing priority * for the configuration variable `key` and config set `cs`. When the @@ -505,6 +514,13 @@ int repo_config_get_maybe_bool(struct repository *repo, int repo_config_get_pathname(struct repository *repo, const char *key, const char **dest); +/* + * Functions for reading protected config. By definition, protected + * config ignores repository config, so these do not take a `struct + * repository` parameter. + */ +void git_protected_config(config_fn_t fn, void *data); + /** * Querying For Specific Variables * ------------------------------- -- cgit v1.2.3