[PATCH 06/32] repository: Implement core.compatMap
- From
Eric W. Biederman <ebiederm@xmission.com>
- Date
- Sep 8, 2023, 23:10 UTC
- Message-ID
- <20230908231049.2035003-6-ebiederm@xmission.com>
- In-Reply-To
- <87sf7ol0z3.fsf@email.froward.int.ebiederm.org>
From: "brian m. carlson" <sandals@crustytoothpaste.net>
Add a configuration option to enable updating and reading from compatibility hash maps when git accesses the reposotiry.
Add a helper function repo_enable_compat_map that when passed false disables the compatiblily hash algorithm and when passed true computes the compatibilty hash algorithm and sets "repo->compat_hash_algo".
For now the option is limited to being specified in ".git/config". Perhaps in the future we can allow specifying it in ".gitconfig" as well.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- Documentation/config/core.txt | 6 ++++++ repository.c | 11 +++++++++++ repository.h | 1 + setup.c | 5 +++++ setup.h | 1 + 5 files changed, 24 insertions(+)
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index dfbdaf00b8bc..a9eb2006cc32 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -736,3 +736,9 @@ core.abbrev:: If set to "no", no abbreviation is made and the object names are shown in their full length. The minimum length is 4. + +core.compatMap:: + Enables the use of a compat map to recored the hash in the + other object format. This allows repositories in different + objects formats to interoperate. It allows looking up old oids + in a repository that has been converted from sha1 to sha256. diff --git a/repository.c b/repository.c index a7679ceeaa45..de620d82bfc6 100644 --- a/repository.c +++ b/repository.c @@ -104,6 +104,16 @@ void repo_set_hash_algo(struct repository *repo, int hash_algo) repo->hash_algo = &hash_algos[hash_algo]; } +void repo_enable_compat_map(struct repository *repo, int enable_compat) +{ + const struct git_hash_algo *other_algo = + &hash_algos[(hash_algo_by_ptr(repo->hash_algo) == GIT_HASH_SHA1) ? + GIT_HASH_SHA256 : + GIT_HASH_SHA1]; + + repo->compat_hash_algo = enable_compat ? other_algo : NULL; +} + /* * Attempt to resolve and set the provided 'gitdir' for repository 'repo'. * Return 0 upon success and a non-zero value upon failure. @@ -184,6 +194,7 @@ int repo_init(struct repository *repo, goto error; repo_set_hash_algo(repo, format.hash_algo); + repo_enable_compat_map(repo, format.use_compat_map); repo->repository_format_worktree_config = format.worktree_config; /* take ownership of format.partial_clone */ diff --git a/repository.h b/repository.h index 6c4130f0c36e..03cadf6d9a98 100644 --- a/repository.h +++ b/repository.h @@ -202,6 +202,7 @@ void repo_set_gitdir(struct repository *repo, const char *root, const struct set_gitdir_args *extra_args); void repo_set_worktree(struct repository *repo, const char *path); void repo_set_hash_algo(struct repository *repo, int algo); +void repo_enable_compat_map(struct repository *repo, int enable_compat); void initialize_the_repository(void); RESULT_MUST_BE_USED int repo_init(struct repository *r, const char *gitdir, const char *worktree); diff --git a/setup.c b/setup.c index 18927a847b86..b4d32bd820f1 100644 --- a/setup.c +++ b/setup.c @@ -623,6 +623,8 @@ static int check_repo_format(const char *var, const char *value, return 0; } } + else if (strcmp(var, "core.compatmap") == 0) + data->use_compat_map = git_config_bool(var, value); return read_worktree_config(var, value, ctx, vdata); } @@ -1564,8 +1566,10 @@ const char *setup_git_directory_gently(int *nongit_ok) } if (startup_info->have_repository) { repo_set_hash_algo(the_repository, repo_fmt.hash_algo); + repo_enable_compat_map(the_repository, repo_fmt.use_compat_map); the_repository->repository_format_worktree_config = repo_fmt.worktree_config; + /* take ownership of repo_fmt.partial_clone */ the_repository->repository_format_partial_clone = repo_fmt.partial_clone; @@ -1657,6 +1661,7 @@ void check_repository_format(struct repository_format *fmt) check_repository_format_gently(get_git_dir(), fmt, NULL); startup_info->have_repository = 1; repo_set_hash_algo(the_repository, fmt->hash_algo); + repo_enable_compat_map(the_repository, fmt->use_compat_map); the_repository->repository_format_worktree_config = fmt->worktree_config; the_repository->repository_format_partial_clone = diff --git a/setup.h b/setup.h index 58fd2605dd26..afa05b2b64f3 100644 --- a/setup.h +++ b/setup.h @@ -86,6 +86,7 @@ struct repository_format { int worktree_config; int is_bare; int hash_algo; + int use_compat_map; int sparse_index; char *work_tree; struct string_list unknown_extensions;
-- 2.41.0