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Diffstat (limited to 'refs.h')
| -rw-r--r-- | refs.h | 556 |
1 files changed, 556 insertions, 0 deletions
@@ -0,0 +1,556 @@ +#ifndef REFS_H +#define REFS_H + +/* + * Resolve a reference, recursively following symbolic refererences. + * + * Store the referred-to object's name in sha1 and return the name of + * the non-symbolic reference that ultimately pointed at it. The + * return value, if not NULL, is a pointer into either a static buffer + * or the input ref. + * + * 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 sha1 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 sha1 for a symbolic + * reference will always be null_sha1 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 sha1 will be null_sha1 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 special refs, 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 *resolve_ref_unsafe(const char *refname, int resolve_flags, + unsigned char *sha1, int *flags); + +char *resolve_refdup(const char *refname, int resolve_flags, + unsigned char *sha1, int *flags); + +int read_ref_full(const char *refname, int resolve_flags, + unsigned char *sha1, int *flags); +int read_ref(const char *refname, unsigned char *sha1); + +int ref_exists(const char *refname); + +int is_branch(const char *refname); + +extern int refs_init_db(struct strbuf *err); + +/* + * If refname is a non-symbolic reference that refers to a tag object, + * and the tag can be (recursively) dereferenced to a non-tag object, + * store the SHA1 of the referred-to object to sha1 and return 0. If + * any of these conditions are not met, return a non-zero value. + * Symbolic references are considered unpeelable, even if they + * ultimately resolve to a peelable tag. + */ +int peel_ref(const char *refname, unsigned char *sha1); + +/** + * 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 sha1 to the name of the object; + * otherwise, return a non-zero value. + */ +int resolve_gitlink_ref(const char *submodule, const char *refname, + unsigned char *sha1); + +/* + * 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); + +int expand_ref(const char *str, int len, unsigned char *sha1, char **ref); +int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref); +int dwim_log(const char *str, int len, unsigned char *sha1, char **ref); + +/* + * A ref_transaction represents a collection of ref updates + * that should succeed or fail together. + * + * Calling sequence + * ---------------- + * - Allocate and initialize a `struct ref_transaction` by calling + * `ref_transaction_begin()`. + * + * - List intended ref updates by calling functions like + * `ref_transaction_update()` and `ref_transaction_create()`. + * + * - Call `ref_transaction_commit()` to execute the transaction. + * If this succeeds, the ref updates will have taken place and + * the transaction cannot be rolled back. + * + * - Instead of `ref_transaction_commit`, use + * `initial_ref_transaction_commit()` if the ref database is known + * to be empty (e.g. during clone). This is likely to be much + * faster. + * + * - At any time call `ref_transaction_free()` to discard the + * transaction and free associated resources. In particular, + * this rolls back the transaction if it has not been + * successfully committed. + * + * 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_commit` is called. So `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 sha1 + * arguments is only guaranteed to be valid for the duration of a + * single callback invocation. + */ +typedef int each_ref_fn(const char *refname, + 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. + */ +int head_ref(each_ref_fn fn, void *cb_data); +int for_each_ref(each_ref_fn fn, void *cb_data); +int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data); +int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, + unsigned int broken); +int for_each_tag_ref(each_ref_fn fn, void *cb_data); +int for_each_branch_ref(each_ref_fn fn, void *cb_data); +int for_each_remote_ref(each_ref_fn fn, void *cb_data); +int for_each_replace_ref(each_ref_fn fn, void *cb_data); +int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data); +int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, + const char *prefix, void *cb_data); + +int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data); +int for_each_ref_submodule(const char *submodule, + each_ref_fn fn, void *cb_data); +int for_each_ref_in_submodule(const char *submodule, const char *prefix, + each_ref_fn fn, void *cb_data); +int for_each_tag_ref_submodule(const char *submodule, + each_ref_fn fn, void *cb_data); +int for_each_branch_ref_submodule(const char *submodule, + each_ref_fn fn, void *cb_data); +int for_each_remote_ref_submodule(const char *submodule, + each_ref_fn fn, void *cb_data); + +int head_ref_namespaced(each_ref_fn fn, void *cb_data); +int for_each_namespaced_ref(each_ref_fn fn, void *cb_data); + +/* can be used to learn about broken ref and symref */ +int for_each_rawref(each_ref_fn fn, void *cb_data); + +static inline const char *has_glob_specials(const char *pattern) +{ + return strpbrk(pattern, "?*["); +} + +void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname); +void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, + const struct string_list *refnames); + +/* + * Flags for controlling behaviour of pack_refs() + * PACK_REFS_PRUNE: Prune loose refs after packing + * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs + */ +#define PACK_REFS_PRUNE 0x0001 +#define PACK_REFS_ALL 0x0002 + +/* + * Write a packed-refs file for the current repository. + * flags: Combination of the above PACK_REFS_* flags. + */ +int pack_refs(unsigned int flags); + +/* + * Flags controlling ref_transaction_update(), ref_transaction_create(), etc. + * REF_NODEREF: act on the ref directly, instead of dereferencing + * symbolic references. + * + * Other flags are reserved for internal use. + */ +#define REF_NODEREF 0x01 +#define REF_FORCE_CREATE_REFLOG 0x40 + +/* + * Setup reflog before using. Fill in err and return -1 on failure. + */ +int safe_create_reflog(const char *refname, int force_create, struct strbuf *err); + +/** Reads log for the value of ref during at_time. **/ +int read_ref_at(const char *refname, unsigned int flags, + unsigned long at_time, int cnt, + unsigned char *sha1, char **msg, + unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt); + +/** Check if a particular reflog exists */ +int reflog_exists(const char *refname); + +/* + * Delete the specified reference. If old_sha1 is non-NULL, then + * verify that the current value of the reference is old_sha1 before + * deleting it. If old_sha1 is NULL, delete the reference if it + * exists, regardless of its old value. It is an error for old_sha1 to + * be NULL_SHA1. flags is passed through to ref_transaction_delete(). + */ +int delete_ref(const char *refname, const unsigned char *old_sha1, + 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). flags is passed through to + * ref_transaction_delete(). + */ +int delete_refs(struct string_list *refnames, unsigned int flags); + +/** Delete a reflog */ +int delete_reflog(const char *refname); + +/* iterate over reflog entries */ +typedef int each_reflog_ent_fn( + unsigned char *old_sha1, unsigned char *new_sha1, + const char *committer, unsigned long timestamp, + int tz, const char *msg, void *cb_data); + +int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data); +int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data); + +/* + * Calls the specified function for each reflog file until it returns nonzero, + * and returns the value + */ +int for_each_reflog(each_ref_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.txt. + * 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); + +const char *prettify_refname(const char *refname); + +char *shorten_unambiguous_ref(const char *refname, int strict); + +/** rename ref, return 0 on success **/ +int rename_ref(const char *oldref, const char *newref, const char *logmsg); + +int create_symref(const char *refname, const char *target, const char *logmsg); + +/* + * Update HEAD of the specified gitdir. + * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but + * this can update the main working tree's HEAD regardless of where + * $GIT_DIR points to. + * Return 0 if successful, non-zero otherwise. + * */ +int set_worktree_head_symref(const char *gitdir, const char *target); + +enum action_on_err { + UPDATE_REFS_MSG_ON_ERR, + UPDATE_REFS_DIE_ON_ERR, + UPDATE_REFS_QUIET_ON_ERR +}; + +/* + * Begin a reference transaction. The reference transaction must + * be freed by calling ref_transaction_free(). + */ +struct ref_transaction *ref_transaction_begin(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. + * + * flags -- flags affecting the update, passed to + * update_ref_lock(). Can be REF_NODEREF, which means that + * symbolic references should not be followed. + * + * 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. + */ + +/* + * Add a reference update to transaction. new_sha1 is the value that + * the reference should have after the update, or null_sha1 if it + * should be deleted. If new_sha1 is NULL, then the reference is not + * changed at all. old_sha1 is the value that the reference must have + * before the update, or null_sha1 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_sha1, the + * whole transaction fails. If old_sha1 is NULL, then the previous + * value is not checked. + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_update(struct ref_transaction *transaction, + const char *refname, + const unsigned char *new_sha1, + const unsigned char *old_sha1, + unsigned int flags, const char *msg, + struct strbuf *err); + +/* + * Add a reference creation to transaction. new_sha1 is the value that + * the reference should have after the update; it must not be + * null_sha1. 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 unsigned char *new_sha1, + unsigned int flags, const char *msg, + struct strbuf *err); + +/* + * Add a reference deletion to transaction. If old_sha1 is non-NULL, + * then it holds the value that the reference should have had before + * the update (which must not be null_sha1). + * + * See the above comment "Reference transaction updates" for more + * information. + */ +int ref_transaction_delete(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + unsigned int flags, const char *msg, + struct strbuf *err); + +/* + * Verify, within a transaction, that refname has the value old_sha1, + * or, if old_sha1 is null_sha1, then verify that the reference + * doesn't exist. old_sha1 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 unsigned char *old_sha1, + unsigned int flags, + struct strbuf *err); + +/* + * Commit all of the changes that have been queued in transaction, as + * atomically as possible. + * + * Returns 0 for success, or one of the below error codes for errors. + */ +/* Naming conflict (for example, the ref names A and A/B conflict). */ +#define TRANSACTION_NAME_CONFLICT -1 +/* All other errors. */ +#define TRANSACTION_GENERIC_ERROR -2 +int ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err); + +/* + * Like ref_transaction_commit(), but optimized for creating + * references when originally initializing a repository (e.g., by "git + * clone"). It writes the new references directly to packed-refs + * without locking the individual references. + * + * It is a bug to call this function 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_sha1 values must either be absent or NULL_SHA1. + */ +int initial_ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err); + +/* + * Free an existing 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 update_ref(const char *msg, const char *refname, + const unsigned char *new_sha1, const unsigned char *old_sha1, + unsigned int flags, enum action_on_err onerr); +int update_ref_oid(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 *); + +/* + * 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 *); + +enum ref_type { + REF_TYPE_PER_WORKTREE, + REF_TYPE_PSEUDOREF, + REF_TYPE_NORMAL, +}; + +enum ref_type ref_type(const char *refname); + +enum expire_reflog_flags { + EXPIRE_REFLOGS_DRY_RUN = 1 << 0, + EXPIRE_REFLOGS_UPDATE_REF = 1 << 1, + EXPIRE_REFLOGS_VERBOSE = 1 << 2, + EXPIRE_REFLOGS_REWRITE = 1 << 3 +}; + +/* + * The following interface is used for reflog expiration. The caller + * calls 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. + * + * 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 unsigned char *sha1, + void *cb_data); +typedef int reflog_expiry_should_prune_fn(unsigned char *osha1, + unsigned char *nsha1, + const char *email, + unsigned long 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. sha1 is the old + * value of the 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 reflog_expire(const char *refname, const unsigned char *sha1, + 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); + +int ref_storage_backend_exists(const char *name); + +#endif /* REFS_H */ |