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Diffstat (limited to 'refs.h')
| -rw-r--r-- | refs.h | 1352 |
1 files changed, 1352 insertions, 0 deletions
diff --git a/refs.h b/refs.h new file mode 100644 index 0000000000..eedbb599c5 --- /dev/null +++ b/refs.h @@ -0,0 +1,1352 @@ +#ifndef REFS_H +#define REFS_H + +#include "commit.h" +#include "repository.h" +#include "repo-settings.h" + +struct fsck_options; +struct object_id; +struct ref_store; +struct strbuf; +struct string_list; +struct string_list_item; +struct worktree; + +enum ref_storage_format ref_storage_format_by_name(const char *name); +const char *ref_storage_format_to_name(enum ref_storage_format ref_storage_format); + +enum ref_transaction_error { + /* Default error code */ + REF_TRANSACTION_ERROR_GENERIC = -1, + /* Ref name conflict like A vs A/B */ + REF_TRANSACTION_ERROR_NAME_CONFLICT = -2, + /* Ref to be created already exists */ + REF_TRANSACTION_ERROR_CREATE_EXISTS = -3, + /* ref expected but doesn't exist */ + REF_TRANSACTION_ERROR_NONEXISTENT_REF = -4, + /* Provided old_oid or old_target of reference doesn't match actual */ + REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE = -5, + /* Provided new_oid or new_target is invalid */ + REF_TRANSACTION_ERROR_INVALID_NEW_VALUE = -6, + /* Expected ref to be symref, but is a regular ref */ + REF_TRANSACTION_ERROR_EXPECTED_SYMREF = -7, +}; + +/* + * Resolve a reference, recursively following symbolic references. + * + * Return the name of the non-symbolic reference that ultimately pointed + * at the resolved object name. The return value, if not NULL, is a + * pointer into either a static buffer or the input ref. + * + * If oid is non-NULL, store the referred-to object's name in it. + * + * If the reference cannot be resolved to an object, the behavior + * depends on the RESOLVE_REF_READING flag: + * + * - If RESOLVE_REF_READING is set, return NULL. + * + * - If RESOLVE_REF_READING is not set, clear oid and return the name of + * the last reference name in the chain, which will either be a non-symbolic + * reference or an undefined reference. If this is a prelude to + * "writing" to the ref, the return value is the name of the ref + * that will actually be created or changed. + * + * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one + * level of symbolic reference. The value stored in oid for a symbolic + * reference will always be null_oid in this case, and the return + * value is the reference that the symref refers to directly. + * + * If flags is non-NULL, set the value that it points to the + * combination of REF_ISPACKED (if the reference was found among the + * packed references), REF_ISSYMREF (if the initial reference was a + * symbolic reference), REF_BAD_NAME (if the reference name is ill + * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN + * (if the ref is malformed or has a bad name). See refs.h for more detail + * on each flag. + * + * If ref is not a properly-formatted, normalized reference, return + * NULL. If more than MAXDEPTH recursive symbolic lookups are needed, + * give up and return NULL. + * + * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their + * name is invalid according to git-check-ref-format(1). If the name + * is bad then the value stored in oid will be null_oid and the two + * flags REF_ISBROKEN and REF_BAD_NAME will be set. + * + * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/ + * directory and do not consist of all caps and underscores cannot be + * resolved. The function returns NULL for such ref names. + * Caps and underscores refers to the pseudorefs, such as HEAD, + * FETCH_HEAD and friends, that all live outside of the refs/ directory. + */ +#define RESOLVE_REF_READING 0x01 +#define RESOLVE_REF_NO_RECURSE 0x02 +#define RESOLVE_REF_ALLOW_BAD_NAME 0x04 + +const char *refs_resolve_ref_unsafe(struct ref_store *refs, + const char *refname, + int resolve_flags, + struct object_id *oid, + int *flags); + +char *refs_resolve_refdup(struct ref_store *refs, + const char *refname, int resolve_flags, + struct object_id *oid, int *flags); + +int refs_read_ref_full(struct ref_store *refs, const char *refname, + int resolve_flags, struct object_id *oid, int *flags); + +int refs_read_ref(struct ref_store *refs, const char *refname, struct object_id *oid); + +#define NOT_A_SYMREF -2 + +/* + * Read the symbolic ref named "refname" and write its immediate referent into + * the provided buffer. Referent is left empty if "refname" is not a symbolic + * ref. It does not resolve the symbolic reference recursively in case the + * target is also a symbolic ref. + * + * Returns 0 on success, -2 if the "refname" is not a symbolic ref, + * -1 otherwise. + */ +int refs_read_symbolic_ref(struct ref_store *ref_store, const char *refname, + struct strbuf *referent); + +/* + * Return 0 if a reference named refname could be created without + * conflicting with the name of an existing reference. Otherwise, + * return a negative value and write an explanation to err. If extras + * is non-NULL, it is a list of additional refnames with which refname + * is not allowed to conflict. If skip is non-NULL, ignore potential + * conflicts with refs in skip (e.g., because they are scheduled for + * deletion in the same operation). Behavior is undefined if the same + * name is listed in both extras and skip. + * + * Two reference names conflict if one of them exactly matches the + * leading components of the other; e.g., "foo/bar" conflicts with + * both "foo" and with "foo/bar/baz" but not with "foo/bar" or + * "foo/barbados". + * + * If `initial_transaction` is truish, then all collision checks with + * preexisting refs are skipped. + * + * extras and skip must be sorted. + */ +enum ref_transaction_error refs_verify_refname_available(struct ref_store *refs, + const char *refname, + const struct string_list *extras, + const struct string_list *skip, + unsigned int initial_transaction, + struct strbuf *err); + +int refs_ref_exists(struct ref_store *refs, const char *refname); + +int should_autocreate_reflog(enum log_refs_config log_all_ref_updates, + const char *refname); + +int is_branch(const char *refname); + +#define REF_STORE_CREATE_ON_DISK_IS_WORKTREE (1 << 0) + +int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *err); + +/* + * Release all memory and resources associated with the ref store. + */ +void ref_store_release(struct ref_store *ref_store); + +/* + * Remove the ref store from disk. This deletes all associated data. + */ +int ref_store_remove_on_disk(struct ref_store *refs, struct strbuf *err); + +/* + * Return the peeled value of the oid currently being iterated via + * for_each_ref(), etc. This is equivalent to calling: + * + * peel_object(r, oid, &peeled); + * + * with the "oid" value given to the each_ref_fn callback, except + * that some ref storage may be able to answer the query without + * actually loading the object in memory. + */ +int peel_iterated_oid(struct repository *r, + const struct object_id *base, struct object_id *peeled); + +/** + * Resolve refname in the nested "gitlink" repository in the specified + * submodule (which must be non-NULL). If the resolution is + * successful, return 0 and set oid to the name of the object; + * otherwise, return a non-zero value. + */ +int repo_resolve_gitlink_ref(struct repository *r, + const char *submodule, const char *refname, + struct object_id *oid); + +/* + * Return true iff abbrev_name is a possible abbreviation for + * full_name according to the rules defined by ref_rev_parse_rules in + * refs.c. + */ +int refname_match(const char *abbrev_name, const char *full_name); + +/* + * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add + * the results to 'prefixes' + */ +struct strvec; +void expand_ref_prefix(struct strvec *prefixes, const char *prefix); + +int expand_ref(struct repository *r, const char *str, int len, struct object_id *oid, char **ref); +int repo_dwim_ref(struct repository *r, const char *str, int len, + struct object_id *oid, char **ref, int nonfatal_dangling_mark); +int repo_dwim_log(struct repository *r, const char *str, int len, struct object_id *oid, char **ref); + +/* + * Retrieves the default branch name for newly-initialized repositories. + * + * The return value is an allocated string. + */ +char *repo_default_branch_name(struct repository *r, int quiet); + +/* + * Copy "name" to "sb", expanding any special @-marks as handled by + * repo_interpret_branch_name(). The result is a non-qualified branch name + * (so "foo" or "origin/master" instead of "refs/heads/foo" or + * "refs/remotes/origin/master"). + * + * Note that the resulting name may not be a syntactically valid refname. + * + * If "allowed" is non-zero, restrict the set of allowed expansions. See + * repo_interpret_branch_name() for details. + */ +void copy_branchname(struct strbuf *sb, const char *name, + unsigned allowed); + +/* + * Like copy_branchname() above, but confirm that the result is + * syntactically valid to be used as a local branch name in refs/heads/. + * + * The return value is "0" if the result is valid, and "-1" otherwise. + */ +int check_branch_ref(struct strbuf *sb, const char *name); + +/* + * Similar for a tag name in refs/tags/. + * + * The return value is "0" if the result is valid, and "-1" otherwise. + */ +int check_tag_ref(struct strbuf *sb, const char *name); + +/* + * A ref_transaction represents a collection of reference updates that + * should succeed or fail together. + * + * Calling sequence + * ---------------- + * + * - Allocate and initialize a `struct ref_transaction` by calling + * `ref_transaction_begin()`. + * + * - Specify the intended ref updates by calling one or more of the + * following functions: + * - `ref_transaction_update()` + * - `ref_transaction_create()` + * - `ref_transaction_delete()` + * - `ref_transaction_verify()` + * + * - Then either: + * + * - Optionally call `ref_transaction_prepare()` to prepare the + * transaction. This locks all references, checks preconditions, + * etc. but doesn't finalize anything. If this step fails, the + * transaction has been closed and can only be freed. If this step + * succeeds, then `ref_transaction_commit()` is almost certain to + * succeed. However, you can still call `ref_transaction_abort()` + * if you decide not to commit the transaction after all. + * + * - Call `ref_transaction_commit()` to execute the transaction, + * make the changes permanent, and release all locks. If you + * haven't already called `ref_transaction_prepare()`, then + * `ref_transaction_commit()` calls it for you. + * + * Or + * + * - Call `ref_transaction_begin()` with REF_TRANSACTION_FLAG_INITIAL if the + * ref database is known to be empty and have no other writers (e.g. during + * clone). This is likely to be much faster than without the flag. + * + * - Then finally, call `ref_transaction_free()` to free the + * `ref_transaction` data structure. + * + * At any time before calling `ref_transaction_commit()`, you can call + * `ref_transaction_abort()` to abort the transaction, rollback any + * locks, and free any associated resources (including the + * `ref_transaction` data structure). + * + * Putting it all together, a complete reference update looks like + * + * struct ref_transaction *transaction; + * struct strbuf err = STRBUF_INIT; + * int ret = 0; + * + * transaction = ref_store_transaction_begin(refs, 0, &err); + * if (!transaction || + * ref_transaction_update(...) || + * ref_transaction_create(...) || + * ...etc... || + * ref_transaction_commit(transaction, &err)) { + * error("%s", err.buf); + * ret = -1; + * } + * ref_transaction_free(transaction); + * strbuf_release(&err); + * return ret; + * + * Error handling + * -------------- + * + * On error, transaction functions append a message about what + * went wrong to the 'err' argument. The message mentions what + * ref was being updated (if any) when the error occurred so it + * can be passed to 'die' or 'error' as-is. + * + * The message is appended to err without first clearing err. + * err will not be '\n' terminated. + * + * Caveats + * ------- + * + * Note that no locks are taken, and no refs are read, until + * `ref_transaction_prepare()` or `ref_transaction_commit()` is + * called. So, for example, `ref_transaction_verify()` won't report a + * verification failure until the commit is attempted. + */ +struct ref_transaction; + +/* + * Bit values set in the flags argument passed to each_ref_fn() and + * stored in ref_iterator::flags. Other bits are for internal use + * only: + */ + +/* Reference is a symbolic reference. */ +#define REF_ISSYMREF 0x01 + +/* Reference is a packed reference. */ +#define REF_ISPACKED 0x02 + +/* + * Reference cannot be resolved to an object name: dangling symbolic + * reference (directly or indirectly), corrupt reference file, + * reference exists but name is bad, or symbolic reference refers to + * ill-formatted reference name. + */ +#define REF_ISBROKEN 0x04 + +/* + * Reference name is not well formed. + * + * See git-check-ref-format(1) for the definition of well formed ref names. + */ +#define REF_BAD_NAME 0x08 + +/* + * The signature for the callback function for the for_each_*() + * functions below. The memory pointed to by the refname and oid + * arguments is only guaranteed to be valid for the duration of a + * single callback invocation. + */ +typedef int each_ref_fn(const char *refname, const char *referent, + const struct object_id *oid, int flags, void *cb_data); + +/* + * The following functions invoke the specified callback function for + * each reference indicated. If the function ever returns a nonzero + * value, stop the iteration and return that value. Please note that + * it is not safe to modify references while an iteration is in + * progress, unless the same callback function invocation that + * modifies the reference also returns a nonzero value to immediately + * stop the iteration. Returned references are sorted. + */ +int refs_head_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); +int refs_for_each_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); +int refs_for_each_ref_in(struct ref_store *refs, const char *prefix, + each_ref_fn fn, void *cb_data); +int refs_for_each_tag_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); +int refs_for_each_branch_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); +int refs_for_each_remote_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); +int refs_for_each_replace_ref(struct ref_store *refs, + each_ref_fn fn, void *cb_data); + +/* + * references matching any pattern in "exclude_patterns" are omitted from the + * result set on a best-effort basis. + */ +int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data); + +/** + * iterate all refs in "patterns" by partitioning patterns into disjoint sets + * and iterating the longest-common prefix of each set. + * + * references matching any pattern in "exclude_patterns" are omitted from the + * result set on a best-effort basis. + * + * callers should be prepared to ignore references that they did not ask for. + */ +int refs_for_each_fullref_in_prefixes(struct ref_store *refs, + const char *namespace, + const char **patterns, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data); + +/* iterates all refs that match the specified glob pattern. */ +int refs_for_each_glob_ref(struct ref_store *refs, each_ref_fn fn, + const char *pattern, void *cb_data); + +int refs_for_each_glob_ref_in(struct ref_store *refs, each_ref_fn fn, + const char *pattern, const char *prefix, void *cb_data); + +int refs_head_ref_namespaced(struct ref_store *refs, each_ref_fn fn, void *cb_data); + +/* + * references matching any pattern in "exclude_patterns" are omitted from the + * result set on a best-effort basis. + */ +int refs_for_each_namespaced_ref(struct ref_store *refs, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data); + +/* can be used to learn about broken ref and symref */ +int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data); + +/* + * Iterates over all refs including root refs, i.e. pseudorefs and HEAD. + */ +int refs_for_each_include_root_refs(struct ref_store *refs, each_ref_fn fn, + void *cb_data); + +/* + * Normalizes partial refs to their fully qualified form. + * Will prepend <prefix> to the <pattern> if it doesn't start with 'refs/'. + * <prefix> will default to 'refs/' if NULL. + * + * item.string will be set to the result. + * item.util will be set to NULL if <pattern> contains glob characters, or + * non-NULL if it doesn't. + */ +void normalize_glob_ref(struct string_list_item *item, const char *prefix, + const char *pattern); + +static inline const char *has_glob_specials(const char *pattern) +{ + return strpbrk(pattern, "?*["); +} + +void refs_warn_dangling_symrefs(struct ref_store *refs, FILE *fp, + const char *indent, int dry_run, + const struct string_list *refnames); + +/* + * Flags for controlling behaviour of pack_refs() + * PACK_REFS_PRUNE: Prune loose refs after packing + * PACK_REFS_AUTO: Pack refs on a best effort basis. The heuristics and end + * result are decided by the ref backend. Backends may ignore + * this flag and fall back to a normal repack. + */ +#define PACK_REFS_PRUNE (1 << 0) +#define PACK_REFS_AUTO (1 << 1) + +struct pack_refs_opts { + unsigned int flags; + struct ref_exclusions *exclusions; + struct string_list *includes; +}; + +/* + * Write a packed-refs file for the current repository. + * flags: Combination of the above PACK_REFS_* flags. + */ +int refs_pack_refs(struct ref_store *refs, struct pack_refs_opts *opts); + +/* + * Setup reflog before using. Fill in err and return -1 on failure. + */ +int refs_create_reflog(struct ref_store *refs, const char *refname, + struct strbuf *err); + +/** + * Reads log for the value of ref during at_time (in which case "cnt" should be + * negative) or the reflog "cnt" entries from the top (in which case "at_time" + * should be 0). + * + * If we found the reflog entry in question, returns 0 (and details of the + * entry can be found in the out-parameters). + * + * If we ran out of reflog entries, the out-parameters are filled with the + * details of the oldest entry we did find, and the function returns 1. Note + * that there is one important special case here! If the reflog was empty + * and the caller asked for the 0-th cnt, we will return "1" but leave the + * "oid" field untouched. + **/ +int read_ref_at(struct ref_store *refs, + const char *refname, unsigned int flags, + timestamp_t at_time, int cnt, + struct object_id *oid, char **msg, + timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt); + +/** Check if a particular reflog exists */ +int refs_reflog_exists(struct ref_store *refs, const char *refname); + +/* + * Delete the specified reference. If old_oid is non-NULL, then + * verify that the current value of the reference is old_oid before + * deleting it. If old_oid is NULL, delete the reference if it + * exists, regardless of its old value. It is an error for old_oid to + * be null_oid. msg and flags are passed through to + * ref_transaction_delete(). + */ +int refs_delete_ref(struct ref_store *refs, const char *msg, + const char *refname, + const struct object_id *old_oid, + unsigned int flags); + +/* + * Delete the specified references. If there are any problems, emit + * errors but attempt to keep going (i.e., the deletes are not done in + * an all-or-nothing transaction). msg and flags are passed through to + * ref_transaction_delete(). + */ +int refs_delete_refs(struct ref_store *refs, const char *msg, + struct string_list *refnames, unsigned int flags); + +/** Delete a reflog */ +int refs_delete_reflog(struct ref_store *refs, const char *refname); + +/* + * Callback to process a reflog entry found by the iteration functions (see + * below). + * + * The committer parameter is a single string, in the form + * "$GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>" (without double quotes). + * + * The timestamp parameter gives the time when entry was created as the number + * of seconds since the UNIX epoch. + * + * The tz parameter gives the timezone offset for the user who created + * the reflog entry, and its value gives a positive or negative offset + * from UTC. Its absolute value is formed by multiplying the hour + * part by 100 and adding the minute part. For example, 1 hour ahead + * of UTC, CET == "+0100", is represented as positive one hundred (not + * positive sixty). + * + * The msg parameter is a single complete line; a reflog message given + * to refs_delete_ref, refs_update_ref, etc. is returned to the + * callback normalized---each run of whitespaces are squashed into a + * single whitespace, trailing whitespace, if exists, is trimmed, and + * then a single LF is added at the end. + * + * The cb_data is a caller-supplied pointer given to the iterator + * functions. + */ +typedef int each_reflog_ent_fn( + struct object_id *old_oid, struct object_id *new_oid, + const char *committer, timestamp_t timestamp, + int tz, const char *msg, void *cb_data); + +/* Iterate over reflog entries in the log for `refname`. */ + +/* oldest entry first */ +int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname, + each_reflog_ent_fn fn, void *cb_data); + +/* youngest entry first */ +int refs_for_each_reflog_ent_reverse(struct ref_store *refs, + const char *refname, + each_reflog_ent_fn fn, + void *cb_data); + +/* + * The signature for the callback function for the refs_for_each_reflog() + * functions below. The memory pointed to by the refname argument is only + * guaranteed to be valid for the duration of a single callback invocation. + */ +typedef int each_reflog_fn(const char *refname, void *cb_data); + +/* + * Calls the specified function for each reflog file until it returns nonzero, + * and returns the value. Reflog file order is unspecified. + */ +int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data); + +#define REFNAME_ALLOW_ONELEVEL 1 +#define REFNAME_REFSPEC_PATTERN 2 + +/* + * Return 0 iff refname has the correct format for a refname according + * to the rules described in Documentation/git-check-ref-format.adoc. + * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level + * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then + * allow a single "*" wildcard character in the refspec. No leading or + * repeated slashes are accepted. + */ +int check_refname_format(const char *refname, int flags); + +/* + * Check the reference database for consistency. Return 0 if refs and + * reflogs are consistent, and non-zero otherwise. The errors will be + * written to stderr. + */ +int refs_fsck(struct ref_store *refs, struct fsck_options *o, + struct worktree *wt); + +/* + * Apply the rules from check_refname_format, but mutate the result until it + * is acceptable, and place the result in "out". + */ +void sanitize_refname_component(const char *refname, struct strbuf *out); + +const char *prettify_refname(const char *refname); + +char *refs_shorten_unambiguous_ref(struct ref_store *refs, + const char *refname, int strict); + +/** rename ref, return 0 on success **/ +int refs_rename_ref(struct ref_store *refs, const char *oldref, + const char *newref, const char *logmsg); + +/** copy ref, return 0 on success **/ +int refs_copy_existing_ref(struct ref_store *refs, const char *oldref, + const char *newref, const char *logmsg); + +int refs_update_symref(struct ref_store *refs, const char *refname, + const char *target, const char *logmsg); + +int refs_update_symref_extended(struct ref_store *refs, const char *refname, + const char *target, const char *logmsg, + struct strbuf *referent, int create_only); + +enum action_on_err { + UPDATE_REFS_MSG_ON_ERR, + UPDATE_REFS_DIE_ON_ERR, + UPDATE_REFS_QUIET_ON_ERR +}; + +enum ref_transaction_flag { + /* + * The ref transaction is part of the initial creation of the ref store + * and can thus assume that the ref store is completely empty. This + * allows the backend to perform the transaction more efficiently by + * skipping certain checks. + * + * It is a bug to set this flag when there might be other processes + * accessing the repository or if there are existing references that + * might conflict with the ones being created. All old_oid values must + * either be absent or null_oid. + */ + REF_TRANSACTION_FLAG_INITIAL = (1 << 0), + + /* + * The transaction mechanism by default fails all updates if any conflict + * is detected. This flag allows transactions to partially apply updates + * while rejecting updates which do not match the expected state. + */ + REF_TRANSACTION_ALLOW_FAILURE = (1 << 1), +}; + +/* + * Begin a reference transaction. The reference transaction must + * be freed by calling ref_transaction_free(). + */ +struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs, + unsigned int flags, + struct strbuf *err); + +/* + * Reference transaction updates + * + * The following four functions add a reference check or update to a + * ref_transaction. They have some common similar parameters: + * + * transaction -- a pointer to an open ref_transaction, obtained + * from ref_transaction_begin(). + * + * refname -- the name of the reference to be affected. + * + * new_oid -- the object ID that should be set to be the new value + * of the reference. Some functions allow this parameter to be + * NULL, meaning that the reference is not changed, or + * null_oid, meaning that the reference should be deleted. A + * copy of this value is made in the transaction. + * + * old_oid -- the object ID that the reference must have before + * the update. Some functions allow this parameter to be NULL, + * meaning that the old value of the reference is not checked, + * or null_oid, meaning that the reference must not exist + * before the update. A copy of this value is made in the + * transaction. + * + * new_target -- the target reference that the reference will be + * updated to point to. If the reference is a regular reference, + * it will be converted to a symbolic reference. Cannot be set + * together with `new_oid`. A copy of this value is made in the + * transaction. + * + * old_target -- the reference that the reference must be pointing to. + * Canont be set together with `old_oid`. A copy of this value is + * made in the transaction. + * + * flags -- flags affecting the update, passed to + * update_ref_lock(). Possible flags: REF_NO_DEREF, + * REF_FORCE_CREATE_REFLOG. See those constants for more + * information. + * + * msg -- a message describing the change (for the reflog). + * + * err -- a strbuf for receiving a description of any error that + * might have occurred. + * + * The functions make internal copies of refname and msg, so the + * caller retains ownership of these parameters. + * + * The functions return 0 on success and non-zero on failure. A + * failure means that the transaction as a whole has failed and needs + * to be rolled back. + */ + +/* + * The following flags can be passed to ref_transaction_update() etc. + * Internally, they are stored in `ref_update::flags`, along with some + * internal flags. + */ + +/* + * Act on the ref directly; i.e., without dereferencing symbolic refs. + * If this flag is not specified, then symbolic references are + * dereferenced and the update is applied to the referent. + */ +#define REF_NO_DEREF (1 << 0) + +/* + * Force the creation of a reflog for this reference, even if it + * didn't previously have a reflog. + */ +#define REF_FORCE_CREATE_REFLOG (1 << 1) + +/* + * Blindly write an object_id. This is useful for testing data corruption + * scenarios. + */ +#define REF_SKIP_OID_VERIFICATION (1 << 10) + +/* + * Skip verifying refname. This is useful for testing data corruption scenarios. + */ +#define REF_SKIP_REFNAME_VERIFICATION (1 << 11) + +/* + * Skip creation of a reflog entry, even if it would have otherwise been + * created. + */ +#define REF_SKIP_CREATE_REFLOG (1 << 12) + +/* + * Bitmask of all of the flags that are allowed to be passed in to + * ref_transaction_update() and friends: + */ +#define REF_TRANSACTION_UPDATE_ALLOWED_FLAGS \ + (REF_NO_DEREF | REF_FORCE_CREATE_REFLOG | REF_SKIP_OID_VERIFICATION | \ + REF_SKIP_REFNAME_VERIFICATION | REF_SKIP_CREATE_REFLOG) + +/* + * Add a reference update to transaction. `new_oid` is the value that + * the reference should have after the update, or `null_oid` if it + * should be deleted. If `new_oid` is NULL, then the reference is not + * changed at all. `old_oid` is the value that the reference must have + * before the update, or `null_oid` if it must not have existed + * beforehand. The old value is checked after the lock is taken to + * prevent races. If the old value doesn't agree with old_oid, the + * whole transaction fails. If old_oid is NULL, then the previous + * value is not checked. If `old_target` is not NULL, treat the reference + * as a symbolic ref and validate that its target before the update is + * `old_target`. If the `new_target` is not NULL, then the reference + * will be updated to a symbolic ref which targets `new_target`. + * Together, these allow us to update between regular refs and symrefs. + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_update(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const struct object_id *old_oid, + const char *new_target, + const char *old_target, + unsigned int flags, const char *msg, + struct strbuf *err); + +/* + * Add a reference creation to transaction. new_oid is the value that + * the reference should have after the update; it must not be + * null_oid. It is verified that the reference does not exist + * already. + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_create(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const char *new_target, + unsigned int flags, const char *msg, + struct strbuf *err); + +/* + * Add a reference deletion to transaction. If old_oid is non-NULL, + * then it holds the value that the reference should have had before + * the update (which must not be null_oid). + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_delete(struct ref_transaction *transaction, + const char *refname, + const struct object_id *old_oid, + const char *old_target, + unsigned int flags, + const char *msg, + struct strbuf *err); + +/* + * Verify, within a transaction, that refname has the value old_oid, + * or, if old_oid is null_oid, then verify that the reference + * doesn't exist. old_oid must be non-NULL. + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_verify(struct ref_transaction *transaction, + const char *refname, + const struct object_id *old_oid, + const char *old_target, + unsigned int flags, + struct strbuf *err); + +/* + * Perform the preparatory stages of committing `transaction`. Acquire + * any needed locks, check preconditions, etc.; basically, do as much + * as possible to ensure that the transaction will be able to go + * through, stopping just short of making any irrevocable or + * user-visible changes. The updates that this function prepares can + * be finished up by calling `ref_transaction_commit()` or rolled back + * by calling `ref_transaction_abort()`. + * + * On success, return 0 and leave the transaction in "prepared" state. + * On failure, abort the transaction, write an error message to `err`, + * and return one of the `TRANSACTION_*` constants. + * + * Callers who don't need such fine-grained control over committing + * reference transactions should just call `ref_transaction_commit()`. + */ +int ref_transaction_prepare(struct ref_transaction *transaction, + struct strbuf *err); + +/* + * Commit all of the changes that have been queued in transaction, as + * atomically as possible. On success, return 0 and leave the + * transaction in "closed" state. On failure, roll back the + * transaction, write an error message to `err`, and return one of the + * `TRANSACTION_*` constants + */ +int ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err); + +/* + * Abort `transaction`, which has been begun and possibly prepared, + * but not yet committed. + */ +int ref_transaction_abort(struct ref_transaction *transaction, + struct strbuf *err); + +/* + * Execute the given callback function for each of the reference updates which + * have been queued in the given transaction. `old_oid` and `new_oid` may be + * `NULL` pointers depending on whether the update has these object IDs set or + * not. + */ +typedef void ref_transaction_for_each_queued_update_fn(const char *refname, + const struct object_id *old_oid, + const struct object_id *new_oid, + void *cb_data); +void ref_transaction_for_each_queued_update(struct ref_transaction *transaction, + ref_transaction_for_each_queued_update_fn cb, + void *cb_data); + +/* + * Execute the given callback function for each of the reference updates which + * have been rejected in the given transaction. + */ +typedef void ref_transaction_for_each_rejected_update_fn(const char *refname, + const struct object_id *old_oid, + const struct object_id *new_oid, + const char *old_target, + const char *new_target, + enum ref_transaction_error err, + void *cb_data); +void ref_transaction_for_each_rejected_update(struct ref_transaction *transaction, + ref_transaction_for_each_rejected_update_fn cb, + void *cb_data); + +/* + * Translate errors to human readable error messages. + */ +const char *ref_transaction_error_msg(enum ref_transaction_error err); + +/* + * Free `*transaction` and all associated data. + */ +void ref_transaction_free(struct ref_transaction *transaction); + +/** + * Lock, update, and unlock a single reference. This function + * basically does a transaction containing a single call to + * ref_transaction_update(). The parameters to this function have the + * same meaning as the corresponding parameters to + * ref_transaction_update(). Handle errors as requested by the `onerr` + * argument. + */ +int refs_update_ref(struct ref_store *refs, const char *msg, const char *refname, + const struct object_id *new_oid, const struct object_id *old_oid, + unsigned int flags, enum action_on_err onerr); + +int parse_hide_refs_config(const char *var, const char *value, const char *, + struct strvec *); + +/* + * Check whether a ref is hidden. If no namespace is set, both the first and + * the second parameter point to the full ref name. If a namespace is set and + * the ref is inside that namespace, the first parameter is a pointer to the + * name of the ref with the namespace prefix removed. If a namespace is set and + * the ref is outside that namespace, the first parameter is NULL. The second + * parameter always points to the full ref name. + */ +int ref_is_hidden(const char *, const char *, const struct strvec *); + +/* + * Returns an array of patterns to use as excluded_patterns, if none of the + * hidden references use the token '!' or '^'. + */ +const char **hidden_refs_to_excludes(const struct strvec *hide_refs); + +/* + * Prefix all exclude patterns with the namespace, if any. This is required + * because exclude patterns apply to the stripped reference name, not the full + * reference name with the namespace. + */ +const char **get_namespaced_exclude_patterns(const char **exclude_patterns, + const char *namespace, + struct strvec *out); + +/* Is this a per-worktree ref living in the refs/ namespace? */ +int is_per_worktree_ref(const char *refname); + +/* Describes how a refname relates to worktrees */ +enum ref_worktree_type { + REF_WORKTREE_CURRENT, /* implicitly per worktree, eg. HEAD or + refs/bisect/SOMETHING */ + REF_WORKTREE_MAIN, /* explicitly in main worktree, eg. + main-worktree/HEAD */ + REF_WORKTREE_OTHER, /* explicitly in named worktree, eg. + worktrees/bla/HEAD */ + REF_WORKTREE_SHARED, /* the default, eg. refs/heads/main */ +}; + +/* + * Parse a `maybe_worktree_ref` as a ref that possibly refers to a worktree ref + * (ie. either REFNAME, main-worktree/REFNAME or worktree/WORKTREE/REFNAME). It + * returns what kind of ref was found, and in case of REF_WORKTREE_OTHER, the + * worktree name is returned in `worktree_name` (pointing into + * `maybe_worktree_ref`) and `worktree_name_length`. The bare refname (the + * refname stripped of prefixes) is returned in `bare_refname`. The + * `worktree_name`, `worktree_name_length` and `bare_refname` arguments may be + * NULL. + */ +enum ref_worktree_type parse_worktree_ref(const char *maybe_worktree_ref, + const char **worktree_name, + int *worktree_name_length, + const char **bare_refname); + +enum expire_reflog_flags { + EXPIRE_REFLOGS_DRY_RUN = 1 << 0, + EXPIRE_REFLOGS_UPDATE_REF = 1 << 1, + EXPIRE_REFLOGS_REWRITE = 1 << 2, +}; + +/* + * The following interface is used for reflog expiration. The caller + * calls refs_reflog_expire(), supplying it with three callback functions, + * of the following types. The callback functions define the + * expiration policy that is desired. + * + * reflog_expiry_prepare_fn -- Called once after the reference is + * locked. Called with the OID of the locked reference. + * + * reflog_expiry_should_prune_fn -- Called once for each entry in the + * existing reflog. It should return true iff that entry should be + * pruned. + * + * reflog_expiry_cleanup_fn -- Called once before the reference is + * unlocked again. + */ +typedef void reflog_expiry_prepare_fn(const char *refname, + const struct object_id *oid, + void *cb_data); +typedef int reflog_expiry_should_prune_fn(struct object_id *ooid, + struct object_id *noid, + const char *email, + timestamp_t timestamp, int tz, + const char *message, void *cb_data); +typedef void reflog_expiry_cleanup_fn(void *cb_data); + +/* + * Expire reflog entries for the specified reference. + * flags is a combination of the constants in + * enum expire_reflog_flags. The three function pointers are described + * above. On success, return zero. + */ +int refs_reflog_expire(struct ref_store *refs, + const char *refname, + unsigned int flags, + reflog_expiry_prepare_fn prepare_fn, + reflog_expiry_should_prune_fn should_prune_fn, + reflog_expiry_cleanup_fn cleanup_fn, + void *policy_cb_data); + +struct ref_store *get_main_ref_store(struct repository *r); + +/** + * Submodules + * ---------- + * + * If you want to iterate the refs of a submodule you first need to add the + * submodules object database. You can do this by a code-snippet like + * this: + * + * const char *path = "path/to/submodule" + * if (add_submodule_odb(path)) + * die("Error submodule '%s' not populated.", path); + * + * `add_submodule_odb()` will return zero on success. If you + * do not do this you will get an error for each ref that it does not point + * to a valid object. + * + * Note: As a side-effect of this you cannot safely assume that all + * objects you lookup are available in superproject. All submodule objects + * will be available the same way as the superprojects objects. + * + * Example: + * -------- + * + * ---- + * static int handle_remote_ref(const char *refname, + * const unsigned char *sha1, int flags, void *cb_data) + * { + * struct strbuf *output = cb_data; + * strbuf_addf(output, "%s\n", refname); + * return 0; + * } + * + */ + +/* + * Return the ref_store instance for the specified submodule. For the + * main repository, use submodule==NULL; such a call cannot fail. For + * a submodule, the submodule must exist and be a nonbare repository, + * otherwise return NULL. If the requested reference store has not yet + * been initialized, initialize it first. + * + * For backwards compatibility, submodule=="" is treated the same as + * submodule==NULL. + */ +struct ref_store *repo_get_submodule_ref_store(struct repository *repo, + const char *submodule); +struct ref_store *get_worktree_ref_store(const struct worktree *wt); + +/* + * Some of the names specified by refs have special meaning to Git. + * Organize these namespaces in a common 'ref_namespace' array for + * reference from multiple places in the codebase. + */ + +struct ref_namespace_info { + const char *ref; + enum decoration_type decoration; + + /* + * If 'exact' is true, then we must match the 'ref' exactly. + * Otherwise, use a prefix match. + * + * 'ref_updated' is for internal use. It represents whether the + * 'ref' value was replaced from its original literal version. + */ + unsigned exact:1, + ref_updated:1; +}; + +enum ref_namespace { + NAMESPACE_HEAD, + NAMESPACE_BRANCHES, + NAMESPACE_TAGS, + NAMESPACE_REMOTE_REFS, + NAMESPACE_STASH, + NAMESPACE_REPLACE, + NAMESPACE_NOTES, + NAMESPACE_PREFETCH, + NAMESPACE_REWRITTEN, + + /* Must be last */ + NAMESPACE__COUNT +}; + +/* See refs.c for the contents of this array. */ +extern struct ref_namespace_info ref_namespace[NAMESPACE__COUNT]; + +/* + * Some ref namespaces can be modified by config values or environment + * variables. Modify a namespace as specified by its ref_namespace key. + */ +void update_ref_namespace(enum ref_namespace namespace, char *ref); + +/* + * Check whether the provided name names a root reference. This function only + * performs a syntactic check. + * + * A root ref is a reference that lives in the root of the reference hierarchy. + * These references must conform to special syntax: + * + * - Their name must be all-uppercase or underscores ("_"). + * + * - Their name must end with "_HEAD". As a special rule, "HEAD" is a root + * ref, as well. + * + * - Their name may not contain a slash. + * + * There is a special set of irregular root refs that exist due to historic + * reasons, only. This list shall not be expanded in the future: + * + * - AUTO_MERGE + * + * - BISECT_EXPECTED_REV + * + * - NOTES_MERGE_PARTIAL + * + * - NOTES_MERGE_REF + * + * - MERGE_AUTOSTASH + */ +int is_root_ref(const char *refname); + +/* + * Pseudorefs are refs that have different semantics compared to + * "normal" refs. These refs can thus not be stored in the ref backend, + * but must always be accessed via the filesystem. The following refs + * are pseudorefs: + * + * - FETCH_HEAD may contain multiple object IDs, and each one of them + * carries additional metadata like where it came from. + * + * - MERGE_HEAD may contain multiple object IDs when merging multiple + * heads. + * + * Reading, writing or deleting references must consistently go either + * through the filesystem (pseudorefs) or through the reference + * backend (normal ones). + */ +int is_pseudo_ref(const char *refname); + +/* + * The following flags can be passed to `repo_migrate_ref_storage_format()`: + * + * - REPO_MIGRATE_REF_STORAGE_FORMAT_DRYRUN: perform a dry-run migration + * without touching the main repository. The result will be written into a + * temporary ref storage directory. + * + * - REPO_MIGRATE_REF_STORAGE_FORMAT_SKIP_REFLOG: skip migration of reflogs. + */ +#define REPO_MIGRATE_REF_STORAGE_FORMAT_DRYRUN (1 << 0) +#define REPO_MIGRATE_REF_STORAGE_FORMAT_SKIP_REFLOG (1 << 1) + +/* + * Migrate the ref storage format used by the repository to the + * specified one. + */ +int repo_migrate_ref_storage_format(struct repository *repo, + enum ref_storage_format format, + unsigned int flags, + struct strbuf *err); + +/* + * Reference iterators + * + * A reference iterator encapsulates the state of an in-progress + * iteration over references. Create an instance of `struct + * ref_iterator` via one of the functions in this module. + * + * A freshly-created ref_iterator doesn't yet point at a reference. To + * advance the iterator, call ref_iterator_advance(). If successful, + * this sets the iterator's refname, oid, and flags fields to describe + * the next reference and returns ITER_OK. The data pointed at by + * refname and oid belong to the iterator; if you want to retain them + * after calling ref_iterator_advance() again or calling + * ref_iterator_free(), you must make a copy. When the iteration has + * been exhausted, ref_iterator_advance() releases any resources + * associated with the iteration, frees the ref_iterator object, and + * returns ITER_DONE. If you want to abort the iteration early, call + * ref_iterator_free(), which also frees the ref_iterator object and + * any associated resources. If there was an internal error advancing + * to the next entry, ref_iterator_advance() aborts the iteration, + * frees the ref_iterator, and returns ITER_ERROR. + * + * The reference currently being looked at can be peeled by calling + * ref_iterator_peel(). This function is often faster than peel_ref(), + * so it should be preferred when iterating over references. + * + * Putting it all together, a typical iteration looks like this: + * + * int ok; + * struct ref_iterator *iter = ...; + * + * while ((ok = ref_iterator_advance(iter)) == ITER_OK) { + * if (want_to_stop_iteration()) { + * ok = ITER_DONE; + * break; + * } + * + * // Access information about the current reference: + * if (!(iter->flags & REF_ISSYMREF)) + * printf("%s is %s\n", iter->refname, oid_to_hex(iter->oid)); + * + * // If you need to peel the reference: + * ref_iterator_peel(iter, &oid); + * } + * + * if (ok != ITER_DONE) + * handle_error(); + * ref_iterator_free(iter); + */ +struct ref_iterator; + +/* + * These flags are passed to refs_ref_iterator_begin() (and do_for_each_ref(), + * which feeds it). + */ +enum do_for_each_ref_flags { + /* + * Include broken references in a do_for_each_ref*() iteration, which + * would normally be omitted. This includes both refs that point to + * missing objects (a true repository corruption), ones with illegal + * names (which we prefer not to expose to callers), as well as + * dangling symbolic refs (i.e., those that point to a non-existent + * ref; this is not a corruption, but as they have no valid oid, we + * omit them from normal iteration results). + */ + DO_FOR_EACH_INCLUDE_BROKEN = (1 << 0), + + /* + * Only include per-worktree refs in a do_for_each_ref*() iteration. + * Normally this will be used with a files ref_store, since that's + * where all reference backends will presumably store their + * per-worktree refs. + */ + DO_FOR_EACH_PER_WORKTREE_ONLY = (1 << 1), + + /* + * Omit dangling symrefs from output; this only has an effect with + * INCLUDE_BROKEN, since they are otherwise not included at all. + */ + DO_FOR_EACH_OMIT_DANGLING_SYMREFS = (1 << 2), + + /* + * Include root refs i.e. HEAD and pseudorefs along with the regular + * refs. + */ + DO_FOR_EACH_INCLUDE_ROOT_REFS = (1 << 3), +}; + +/* + * Return an iterator that goes over each reference in `refs` for + * which the refname begins with prefix. If trim is non-zero, then + * trim that many characters off the beginning of each refname. + * The output is ordered by refname. + */ +struct ref_iterator *refs_ref_iterator_begin( + struct ref_store *refs, + const char *prefix, const char **exclude_patterns, + int trim, enum do_for_each_ref_flags flags); + +/* + * Advance the iterator to the first or next item and return ITER_OK. + * If the iteration is exhausted, free the resources associated with + * the ref_iterator and return ITER_DONE. On errors, free the iterator + * resources and return ITER_ERROR. It is a bug to use ref_iterator or + * call this function again after it has returned ITER_DONE or + * ITER_ERROR. + */ +int ref_iterator_advance(struct ref_iterator *ref_iterator); + +enum ref_iterator_seek_flag { + /* + * When the REF_ITERATOR_SEEK_SET_PREFIX flag is set, the iterator's prefix is + * updated to match the provided string, affecting all subsequent iterations. If + * not, the iterator seeks to the specified reference and clears any previously + * set prefix. + */ + REF_ITERATOR_SEEK_SET_PREFIX = (1 << 0), +}; + +/* + * Seek the iterator to the first reference matching the given seek string. + * The seek string is matched as a literal string, without regard for path + * separators. If seek is NULL or the empty string, seek the iterator to the + * first reference again. + * + * This function is expected to behave as if a new ref iterator has been + * created, but allows reuse of existing iterators for optimization. + * + * Returns 0 on success, a negative error code otherwise. + */ +int ref_iterator_seek(struct ref_iterator *ref_iterator, const char *refname, + unsigned int flags); + +/* + * If possible, peel the reference currently being viewed by the + * iterator. Return 0 on success. + */ +int ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled); + +/* Free the reference iterator and any associated resources. */ +void ref_iterator_free(struct ref_iterator *ref_iterator); + +/* + * The common backend for the for_each_*ref* functions. Call fn for + * each reference in iter. If the iterator itself ever returns + * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop + * the iteration and return that value. Otherwise, return 0. In any + * case, free the iterator when done. This function is basically an + * adapter between the callback style of reference iteration and the + * iterator style. + */ +int do_for_each_ref_iterator(struct ref_iterator *iter, + each_ref_fn fn, void *cb_data); + +#endif /* REFS_H */ |