git/config.h
Glen Choo 5b3c650777 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 <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-14 15:08:29 -07:00

650 lines
22 KiB
C

#ifndef CONFIG_H
#define CONFIG_H
#include "hashmap.h"
#include "string-list.h"
/**
* The config API gives callers a way to access Git configuration files
* (and files which have the same syntax).
*
* General Usage
* -------------
*
* Config files are parsed linearly, and each variable found is passed to a
* caller-provided callback function. The callback function is responsible
* for any actions to be taken on the config option, and is free to ignore
* some options. It is not uncommon for the configuration to be parsed
* several times during the run of a Git program, with different callbacks
* picking out different variables useful to themselves.
*/
struct object_id;
/* git_config_parse_key() returns these negated: */
#define CONFIG_INVALID_KEY 1
#define CONFIG_NO_SECTION_OR_NAME 2
/* git_config_set_gently(), git_config_set_multivar_gently() return the above or these: */
#define CONFIG_NO_LOCK -1
#define CONFIG_INVALID_FILE 3
#define CONFIG_NO_WRITE 4
#define CONFIG_NOTHING_SET 5
#define CONFIG_INVALID_PATTERN 6
#define CONFIG_GENERIC_ERROR 7
#define CONFIG_REGEX_NONE ((void *)1)
enum config_scope {
CONFIG_SCOPE_UNKNOWN = 0,
CONFIG_SCOPE_SYSTEM,
CONFIG_SCOPE_GLOBAL,
CONFIG_SCOPE_LOCAL,
CONFIG_SCOPE_WORKTREE,
CONFIG_SCOPE_COMMAND,
CONFIG_SCOPE_SUBMODULE,
};
const char *config_scope_name(enum config_scope scope);
struct git_config_source {
unsigned int use_stdin:1;
const char *file;
/* The repository if blob is not NULL; leave blank for the_repository */
struct repository *repo;
const char *blob;
enum config_scope scope;
};
enum config_origin_type {
CONFIG_ORIGIN_BLOB,
CONFIG_ORIGIN_FILE,
CONFIG_ORIGIN_STDIN,
CONFIG_ORIGIN_SUBMODULE_BLOB,
CONFIG_ORIGIN_CMDLINE
};
enum config_event_t {
CONFIG_EVENT_SECTION,
CONFIG_EVENT_ENTRY,
CONFIG_EVENT_WHITESPACE,
CONFIG_EVENT_COMMENT,
CONFIG_EVENT_EOF,
CONFIG_EVENT_ERROR
};
/*
* The parser event function (if not NULL) is called with the event type and
* the begin/end offsets of the parsed elements.
*
* Note: for CONFIG_EVENT_ENTRY (i.e. config variables), the trailing newline
* character is considered part of the element.
*/
typedef int (*config_parser_event_fn_t)(enum config_event_t type,
size_t begin_offset, size_t end_offset,
void *event_fn_data);
struct config_options {
unsigned int respect_includes : 1;
unsigned int ignore_repo : 1;
unsigned int ignore_worktree : 1;
unsigned int ignore_cmdline : 1;
unsigned int system_gently : 1;
/*
* For internal use. Include all includeif.hasremoteurl paths without
* checking if the repo has that remote URL, and when doing so, verify
* that files included in this way do not configure any remote URLs
* themselves.
*/
unsigned int unconditional_remote_url : 1;
const char *commondir;
const char *git_dir;
config_parser_event_fn_t event_fn;
void *event_fn_data;
enum config_error_action {
CONFIG_ERROR_UNSET = 0, /* use source-specific default */
CONFIG_ERROR_DIE, /* die() on error */
CONFIG_ERROR_ERROR, /* error() on error, return -1 */
CONFIG_ERROR_SILENT, /* return -1 */
} error_action;
};
/**
* A config callback function takes three parameters:
*
* - the name of the parsed variable. This is in canonical "flat" form: the
* section, subsection, and variable segments will be separated by dots,
* and the section and variable segments will be all lowercase. E.g.,
* `core.ignorecase`, `diff.SomeType.textconv`.
*
* - the value of the found variable, as a string. If the variable had no
* value specified, the value will be NULL (typically this means it
* should be interpreted as boolean true).
*
* - a void pointer passed in by the caller of the config API; this can
* contain callback-specific data
*
* A config callback should return 0 for success, or -1 if the variable
* could not be parsed properly.
*/
typedef int (*config_fn_t)(const char *, const char *, void *);
int git_default_config(const char *, const char *, void *);
/**
* Read a specific file in git-config format.
* This function takes the same callback and data parameters as `git_config`.
*
* Unlike git_config(), this function does not respect includes.
*/
int git_config_from_file(config_fn_t fn, const char *, void *);
int git_config_from_file_with_options(config_fn_t fn, const char *,
void *,
const struct config_options *);
int git_config_from_mem(config_fn_t fn,
const enum config_origin_type,
const char *name,
const char *buf, size_t len,
void *data, const struct config_options *opts);
int git_config_from_blob_oid(config_fn_t fn, const char *name,
struct repository *repo,
const struct object_id *oid, void *data);
void git_config_push_parameter(const char *text);
void git_config_push_env(const char *spec);
int git_config_from_parameters(config_fn_t fn, void *data);
void read_early_config(config_fn_t cb, void *data);
void read_very_early_config(config_fn_t cb, void *data);
/**
* Most programs will simply want to look up variables in all config files
* that Git knows about, using the normal precedence rules. To do this,
* call `git_config` with a callback function and void data pointer.
*
* `git_config` will read all config sources in order of increasing
* priority. Thus a callback should typically overwrite previously-seen
* entries with new ones (e.g., if both the user-wide `~/.gitconfig` and
* repo-specific `.git/config` contain `color.ui`, the config machinery
* will first feed the user-wide one to the callback, and then the
* repo-specific one; by overwriting, the higher-priority repo-specific
* value is left at the end).
*
* Unlike git_config_from_file(), this function respects includes.
*/
void git_config(config_fn_t fn, void *);
/**
* Lets the caller examine config while adjusting some of the default
* behavior of `git_config`. It should almost never be used by "regular"
* Git code that is looking up configuration variables.
* It is intended for advanced callers like `git-config`, which are
* intentionally tweaking the normal config-lookup process.
* It takes two extra parameters:
*
* - `config_source`
* If this parameter is non-NULL, it specifies the source to parse for
* configuration, rather than looking in the usual files. See `struct
* git_config_source` in `config.h` for details. Regular `git_config` defaults
* to `NULL`.
*
* - `opts`
* Specify options to adjust the behavior of parsing config files. See `struct
* config_options` in `config.h` for details. As an example: regular `git_config`
* sets `opts.respect_includes` to `1` by default.
*/
int config_with_options(config_fn_t fn, void *,
struct git_config_source *config_source,
const struct config_options *opts);
/**
* Value Parsing Helpers
* ---------------------
*
* The following helper functions aid in parsing string values
*/
int git_parse_ssize_t(const char *, ssize_t *);
int git_parse_ulong(const char *, unsigned long *);
/**
* Same as `git_config_bool`, except that it returns -1 on error rather
* than dying.
*/
int git_parse_maybe_bool(const char *);
/**
* Parse the string to an integer, including unit factors. Dies on error;
* otherwise, returns the parsed result.
*/
int git_config_int(const char *, const char *);
int64_t git_config_int64(const char *, const char *);
/**
* Identical to `git_config_int`, but for unsigned longs.
*/
unsigned long git_config_ulong(const char *, const char *);
ssize_t git_config_ssize_t(const char *, const char *);
/**
* Same as `git_config_bool`, except that integers are returned as-is, and
* an `is_bool` flag is unset.
*/
int git_config_bool_or_int(const char *, const char *, int *);
/**
* Parse a string into a boolean value, respecting keywords like "true" and
* "false". Integer values are converted into true/false values (when they
* are non-zero or zero, respectively). Other values cause a die(). If
* parsing is successful, the return value is the result.
*/
int git_config_bool(const char *, const char *);
/**
* Allocates and copies the value string into the `dest` parameter; if no
* string is given, prints an error message and returns -1.
*/
int git_config_string(const char **, const char *, const char *);
/**
* Similar to `git_config_string`, but expands `~` or `~user` into the
* user's home directory when found at the beginning of the path.
*/
int git_config_pathname(const char **, const char *, const char *);
int git_config_expiry_date(timestamp_t *, const char *, const char *);
int git_config_color(char *, const char *, const char *);
int git_config_set_in_file_gently(const char *, const char *, const char *);
/**
* write config values to a specific config file, takes a key/value pair as
* parameter.
*/
void git_config_set_in_file(const char *, const char *, const char *);
int git_config_set_gently(const char *, const char *);
/**
* Write a config value that should apply to the current worktree. If
* extensions.worktreeConfig is enabled, then the write will happen in the
* current worktree's config. Otherwise, write to the common config file.
*/
int repo_config_set_worktree_gently(struct repository *, const char *, const char *);
/**
* write config values to `.git/config`, takes a key/value pair as parameter.
*/
void git_config_set(const char *, const char *);
int git_config_parse_key(const char *, char **, size_t *);
/*
* The following macros specify flag bits that alter the behavior
* of the git_config_set_multivar*() methods.
*/
/*
* When CONFIG_FLAGS_MULTI_REPLACE is specified, all matching key/values
* are removed before a single new pair is written. If the flag is not
* present, then set operations replace only the first match.
*/
#define CONFIG_FLAGS_MULTI_REPLACE (1 << 0)
/*
* When CONFIG_FLAGS_FIXED_VALUE is specified, match key/value pairs
* by string comparison (not regex match) to the provided value_pattern
* parameter.
*/
#define CONFIG_FLAGS_FIXED_VALUE (1 << 1)
int git_config_set_multivar_gently(const char *, const char *, const char *, unsigned);
void git_config_set_multivar(const char *, const char *, const char *, unsigned);
int repo_config_set_multivar_gently(struct repository *, const char *, const char *, const char *, unsigned);
int git_config_set_multivar_in_file_gently(const char *, const char *, const char *, const char *, unsigned);
/**
* takes four parameters:
*
* - the name of the file, as a string, to which key/value pairs will be written.
*
* - the name of key, as a string. This is in canonical "flat" form: the section,
* subsection, and variable segments will be separated by dots, and the section
* and variable segments will be all lowercase.
* E.g., `core.ignorecase`, `diff.SomeType.textconv`.
*
* - the value of the variable, as a string. If value is equal to NULL, it will
* remove the matching key from the config file.
*
* - the value regex, as a string. It will disregard key/value pairs where value
* does not match.
*
* - a flags value with bits corresponding to the CONFIG_FLAG_* macros.
*
* It returns 0 on success.
*/
void git_config_set_multivar_in_file(const char *config_filename,
const char *key,
const char *value,
const char *value_pattern,
unsigned flags);
/**
* rename or remove sections in the config file
* parameters `old_name` and `new_name`
* If NULL is passed through `new_name` parameter,
* the section will be removed from the config file.
*/
int git_config_rename_section(const char *, const char *);
int git_config_rename_section_in_file(const char *, const char *, const char *);
int git_config_copy_section(const char *, const char *);
int git_config_copy_section_in_file(const char *, const char *, const char *);
int git_env_bool(const char *, int);
unsigned long git_env_ulong(const char *, unsigned long);
int git_config_system(void);
int config_error_nonbool(const char *);
#if defined(__GNUC__)
#define config_error_nonbool(s) (config_error_nonbool(s), const_error())
#endif
char *git_system_config(void);
void git_global_config(char **user, char **xdg);
int git_config_parse_parameter(const char *, config_fn_t fn, void *data);
enum config_scope current_config_scope(void);
const char *current_config_origin_type(void);
const char *current_config_name(void);
int current_config_line(void);
/*
* Match and parse a config key of the form:
*
* section.(subsection.)?key
*
* (i.e., what gets handed to a config_fn_t). The caller provides the section;
* we return -1 if it does not match, 0 otherwise. The subsection and key
* out-parameters are filled by the function (and *subsection is NULL if it is
* missing).
*
* If the subsection pointer-to-pointer passed in is NULL, returns 0 only if
* there is no subsection at all.
*/
int parse_config_key(const char *var,
const char *section,
const char **subsection, size_t *subsection_len,
const char **key);
/**
* Custom Configsets
* -----------------
*
* A `config_set` can be used to construct an in-memory cache for
* config-like files that the caller specifies (i.e., files like `.gitmodules`,
* `~/.gitconfig` etc.). For example,
*
* ----------------------------------------
* struct config_set gm_config;
* git_configset_init(&gm_config);
* int b;
* //we add config files to the config_set
* git_configset_add_file(&gm_config, ".gitmodules");
* git_configset_add_file(&gm_config, ".gitmodules_alt");
*
* if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
* //hack hack hack
* }
*
* when we are done with the configset:
* git_configset_clear(&gm_config);
* ----------------------------------------
*
* Configset API provides functions for the above mentioned work flow
*/
struct config_set_element {
struct hashmap_entry ent;
char *key;
struct string_list value_list;
};
struct configset_list_item {
struct config_set_element *e;
int value_index;
};
/*
* the contents of the list are ordered according to their
* position in the config files and order of parsing the files.
* (i.e. key-value pair at the last position of .git/config will
* be at the last item of the list)
*/
struct configset_list {
struct configset_list_item *items;
unsigned int nr, alloc;
};
struct config_set {
struct hashmap config_hash;
int hash_initialized;
struct configset_list list;
};
/**
* Initializes the config_set `cs`.
*/
void git_configset_init(struct config_set *cs);
/**
* Parses the file and adds the variable-value pairs to the `config_set`,
* dies if there is an error in parsing the file. Returns 0 on success, or
* -1 if the file does not exist or is inaccessible. The caller decides
* whether to free the incomplete configset or continue using it when
* the function returns -1.
*/
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
* configuration variable `key` is not found, returns NULL. The caller
* should not free or modify the returned pointer, as it is owned by the cache.
*/
const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key);
/**
* Clears `config_set` structure, removes all saved variable-value pairs.
*/
void git_configset_clear(struct config_set *cs);
/*
* These functions return 1 if not found, and 0 if found, leaving the found
* value in the 'dest' pointer.
*/
/*
* Finds the highest-priority value for the configuration variable `key`
* and config set `cs`, stores the pointer to it in `value` and returns 0.
* When the configuration variable `key` is not found, returns 1 without
* touching `value`. The caller should not free or modify `value`, as it
* is owned by the cache.
*/
int git_configset_get_value(struct config_set *cs, const char *key, const char **dest);
int git_configset_get_string(struct config_set *cs, const char *key, char **dest);
int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest);
int git_configset_get_bool(struct config_set *cs, const char *key, int *dest);
int git_configset_get_bool_or_int(struct config_set *cs, const char *key, int *is_bool, int *dest);
int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest);
int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest);
/* Functions for reading a repository's config */
struct repository;
void repo_config(struct repository *repo, config_fn_t fn, void *data);
int repo_config_get_value(struct repository *repo,
const char *key, const char **value);
const struct string_list *repo_config_get_value_multi(struct repository *repo,
const char *key);
int repo_config_get_string(struct repository *repo,
const char *key, char **dest);
int repo_config_get_string_tmp(struct repository *repo,
const char *key, const char **dest);
int repo_config_get_int(struct repository *repo,
const char *key, int *dest);
int repo_config_get_ulong(struct repository *repo,
const char *key, unsigned long *dest);
int repo_config_get_bool(struct repository *repo,
const char *key, int *dest);
int repo_config_get_bool_or_int(struct repository *repo,
const char *key, int *is_bool, int *dest);
int repo_config_get_maybe_bool(struct repository *repo,
const char *key, int *dest);
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
* -------------------------------
*
* For programs wanting to query for specific variables in a non-callback
* manner, the config API provides two functions `git_config_get_value`
* and `git_config_get_value_multi`. They both read values from an internal
* cache generated previously from reading the config files.
*/
/**
* Finds the highest-priority value for the configuration variable `key`,
* stores the pointer to it in `value` and returns 0. When the
* configuration variable `key` is not found, returns 1 without touching
* `value`. The caller should not free or modify `value`, as it is owned
* by the cache.
*/
int git_config_get_value(const char *key, const char **value);
/**
* Finds and returns the value list, sorted in order of increasing priority
* for the configuration variable `key`. When the configuration variable
* `key` is not found, returns NULL. The caller should not free or modify
* the returned pointer, as it is owned by the cache.
*/
const struct string_list *git_config_get_value_multi(const char *key);
/**
* Resets and invalidates the config cache.
*/
void git_config_clear(void);
/**
* Allocates and copies the retrieved string into the `dest` parameter for
* the configuration variable `key`; if NULL string is given, prints an
* error message and returns -1. When the configuration variable `key` is
* not found, returns 1 without touching `dest`.
*/
int git_config_get_string(const char *key, char **dest);
/**
* Similar to `git_config_get_string`, but does not allocate any new
* memory; on success `dest` will point to memory owned by the config
* machinery, which could be invalidated if it is discarded and reloaded.
*/
int git_config_get_string_tmp(const char *key, const char **dest);
/**
* Finds and parses the value to an integer for the configuration variable
* `key`. Dies on error; otherwise, stores the value of the parsed integer in
* `dest` and returns 0. When the configuration variable `key` is not found,
* returns 1 without touching `dest`.
*/
int git_config_get_int(const char *key, int *dest);
/**
* Similar to `git_config_get_int` but for unsigned longs.
*/
int git_config_get_ulong(const char *key, unsigned long *dest);
/**
* Finds and parses the value into a boolean value, for the configuration
* variable `key` respecting keywords like "true" and "false". Integer
* values are converted into true/false values (when they are non-zero or
* zero, respectively). Other values cause a die(). If parsing is successful,
* stores the value of the parsed result in `dest` and returns 0. When the
* configuration variable `key` is not found, returns 1 without touching
* `dest`.
*/
int git_config_get_bool(const char *key, int *dest);
/**
* Similar to `git_config_get_bool`, except that integers are copied as-is,
* and `is_bool` flag is unset.
*/
int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
/**
* Similar to `git_config_get_bool`, except that it returns -1 on error
* rather than dying.
*/
int git_config_get_maybe_bool(const char *key, int *dest);
/**
* Similar to `git_config_get_string`, but expands `~` or `~user` into
* the user's home directory when found at the beginning of the path.
*/
int git_config_get_pathname(const char *key, const char **dest);
int git_config_get_index_threads(int *dest);
int git_config_get_split_index(void);
int git_config_get_max_percent_split_change(void);
/* This dies if the configured or default date is in the future */
int git_config_get_expiry(const char *key, const char **output);
/* parse either "this many days" integer, or "5.days.ago" approxidate */
int git_config_get_expiry_in_days(const char *key, timestamp_t *, timestamp_t now);
struct key_value_info {
const char *filename;
int linenr;
enum config_origin_type origin_type;
enum config_scope scope;
};
/**
* First prints the error message specified by the caller in `err` and then
* dies printing the line number and the file name of the highest priority
* value for the configuration variable `key`.
*/
NORETURN void git_die_config(const char *key, const char *err, ...) __attribute__((format(printf, 2, 3)));
/**
* Helper function which formats the die error message according to the
* parameters entered. Used by `git_die_config()`. It can be used by callers
* handling `git_config_get_value_multi()` to print the correct error message
* for the desired value.
*/
NORETURN void git_die_config_linenr(const char *key, const char *filename, int linenr);
#define LOOKUP_CONFIG(mapping, var) \
lookup_config(mapping, ARRAY_SIZE(mapping), var)
int lookup_config(const char **mapping, int nr_mapping, const char *var);
#endif /* CONFIG_H */