git/setup.h
Patrick Steinhardt d7497a42b0 setup: introduce "extensions.refStorage" extension
Introduce a new "extensions.refStorage" extension that allows us to
specify the ref storage format used by a repository. For now, the only
supported format is the "files" format, but this list will likely soon
be extended to also support the upcoming "reftable" format.

There have been discussions on the Git mailing list in the past around
how exactly this extension should look like. One alternative [1] that
was discussed was whether it would make sense to model the extension in
such a way that backends are arbitrarily stackable. This would allow for
a combined value of e.g. "loose,packed-refs" or "loose,reftable", which
indicates that new refs would be written via "loose" files backend and
compressed into "packed-refs" or "reftable" backends, respectively.

It is arguable though whether this flexibility and the complexity that
it brings with it is really required for now. It is not foreseeable that
there will be a proliferation of backends in the near-term future, and
the current set of existing formats and formats which are on the horizon
can easily be configured with the much simpler proposal where we have a
single value, only.

Furthermore, if we ever see that we indeed want to gain the ability to
arbitrarily stack the ref formats, then we can adapt the current
extension rather easily. Given that Git clients will refuse any unknown
value for the "extensions.refStorage" extension they would also know to
ignore a stacked "loose,packed-refs" in the future.

So let's stick with the easy proposal for the time being and wire up the
extension.

[1]: <pull.1408.git.1667846164.gitgitgadget@gmail.com>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-02 09:24:48 -08:00

215 lines
7.1 KiB
C

#ifndef SETUP_H
#define SETUP_H
#include "string-list.h"
int is_inside_git_dir(void);
int is_inside_work_tree(void);
int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
int get_common_dir(struct strbuf *sb, const char *gitdir);
/*
* Return true if the given path is a git directory; note that this _just_
* looks at the directory itself. If you want to know whether "foo/.git"
* is a repository, you must feed that path, not just "foo".
*/
int is_git_directory(const char *path);
/*
* Return 1 if the given path is the root of a git repository or
* submodule, else 0. Will not return 1 for bare repositories with the
* exception of creating a bare repository in "foo/.git" and calling
* is_git_repository("foo").
*
* If we run into read errors, we err on the side of saying "yes, it is",
* as we usually consider sub-repos precious, and would prefer to err on the
* side of not disrupting or deleting them.
*/
int is_nonbare_repository_dir(struct strbuf *path);
#define READ_GITFILE_ERR_STAT_FAILED 1
#define READ_GITFILE_ERR_NOT_A_FILE 2
#define READ_GITFILE_ERR_OPEN_FAILED 3
#define READ_GITFILE_ERR_READ_FAILED 4
#define READ_GITFILE_ERR_INVALID_FORMAT 5
#define READ_GITFILE_ERR_NO_PATH 6
#define READ_GITFILE_ERR_NOT_A_REPO 7
#define READ_GITFILE_ERR_TOO_LARGE 8
void read_gitfile_error_die(int error_code, const char *path, const char *dir);
const char *read_gitfile_gently(const char *path, int *return_error_code);
#define read_gitfile(path) read_gitfile_gently((path), NULL)
const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
#define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)
void setup_work_tree(void);
/*
* discover_git_directory_reason() is similar to discover_git_directory(),
* except it returns an enum value instead. It is important to note that
* a zero-valued return here is actually GIT_DIR_NONE, which is different
* from discover_git_directory.
*/
enum discovery_result {
GIT_DIR_EXPLICIT = 1,
GIT_DIR_DISCOVERED = 2,
GIT_DIR_BARE = 3,
/* these are errors */
GIT_DIR_HIT_CEILING = -1,
GIT_DIR_HIT_MOUNT_POINT = -2,
GIT_DIR_INVALID_GITFILE = -3,
GIT_DIR_INVALID_OWNERSHIP = -4,
GIT_DIR_DISALLOWED_BARE = -5,
GIT_DIR_INVALID_FORMAT = -6,
GIT_DIR_CWD_FAILURE = -7,
};
enum discovery_result discover_git_directory_reason(struct strbuf *commondir,
struct strbuf *gitdir);
/*
* Find the commondir and gitdir of the repository that contains the current
* working directory, without changing the working directory or other global
* state. The result is appended to commondir and gitdir. If the discovered
* gitdir does not correspond to a worktree, then 'commondir' and 'gitdir' will
* both have the same result appended to the buffer. The return value is
* either 0 upon success and -1 if no repository was found.
*/
static inline int discover_git_directory(struct strbuf *commondir,
struct strbuf *gitdir)
{
if (discover_git_directory_reason(commondir, gitdir) <= 0)
return -1;
return 0;
}
const char *setup_git_directory_gently(int *);
const char *setup_git_directory(void);
char *prefix_path(const char *prefix, int len, const char *path);
char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
int check_filename(const char *prefix, const char *name);
void verify_filename(const char *prefix,
const char *name,
int diagnose_misspelt_rev);
void verify_non_filename(const char *prefix, const char *name);
int path_inside_repo(const char *prefix, const char *path);
void sanitize_stdfds(void);
int daemonize(void);
/*
* GIT_REPO_VERSION is the version we write by default. The
* _READ variant is the highest number we know how to
* handle.
*/
#define GIT_REPO_VERSION 0
#define GIT_REPO_VERSION_READ 1
/*
* You _have_ to initialize a `struct repository_format` using
* `= REPOSITORY_FORMAT_INIT` before calling `read_repository_format()`.
*/
struct repository_format {
int version;
int precious_objects;
char *partial_clone; /* value of extensions.partialclone */
int worktree_config;
int is_bare;
int hash_algo;
unsigned int ref_storage_format;
int sparse_index;
char *work_tree;
struct string_list unknown_extensions;
struct string_list v1_only_extensions;
};
/*
* Always use this to initialize a `struct repository_format`
* to a well-defined, default state before calling
* `read_repository()`.
*/
#define REPOSITORY_FORMAT_INIT \
{ \
.version = -1, \
.is_bare = -1, \
.hash_algo = GIT_HASH_SHA1, \
.ref_storage_format = REF_STORAGE_FORMAT_FILES, \
.unknown_extensions = STRING_LIST_INIT_DUP, \
.v1_only_extensions = STRING_LIST_INIT_DUP, \
}
/*
* Read the repository format characteristics from the config file "path" into
* "format" struct. Returns the numeric version. On error, or if no version is
* found in the configuration, -1 is returned, format->version is set to -1,
* and all other fields in the struct are set to the default configuration
* (REPOSITORY_FORMAT_INIT). Always initialize the struct using
* REPOSITORY_FORMAT_INIT before calling this function.
*/
int read_repository_format(struct repository_format *format, const char *path);
/*
* Free the memory held onto by `format`, but not the struct itself.
* (No need to use this after `read_repository_format()` fails.)
*/
void clear_repository_format(struct repository_format *format);
/*
* Verify that the repository described by repository_format is something we
* can read. If it is, return 0. Otherwise, return -1, and "err" will describe
* any errors encountered.
*/
int verify_repository_format(const struct repository_format *format,
struct strbuf *err);
/*
* Check the repository format version in the path found in get_git_dir(),
* and die if it is a version we don't understand. Generally one would
* set_git_dir() before calling this, and use it only for "are we in a valid
* repo?".
*
* If successful and fmt is not NULL, fill fmt with data.
*/
void check_repository_format(struct repository_format *fmt);
#define INIT_DB_QUIET (1 << 0)
#define INIT_DB_EXIST_OK (1 << 1)
#define INIT_DB_SKIP_REFDB (1 << 2)
int init_db(const char *git_dir, const char *real_git_dir,
const char *template_dir, int hash_algo,
unsigned int ref_storage_format,
const char *initial_branch, int init_shared_repository,
unsigned int flags);
void initialize_repository_version(int hash_algo,
unsigned int ref_storage_format,
int reinit);
void create_reference_database(unsigned int ref_storage_format,
const char *initial_branch, int quiet);
/*
* NOTE NOTE NOTE!!
*
* PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
* not be changed. Old repositories have core.sharedrepository written in
* numeric format, and therefore these values are preserved for compatibility
* reasons.
*/
enum sharedrepo {
PERM_UMASK = 0,
OLD_PERM_GROUP = 1,
OLD_PERM_EVERYBODY = 2,
PERM_GROUP = 0660,
PERM_EVERYBODY = 0664
};
int git_config_perm(const char *var, const char *value);
struct startup_info {
int have_repository;
const char *prefix;
const char *original_cwd;
};
extern struct startup_info *startup_info;
extern const char *tmp_original_cwd;
#endif /* SETUP_H */