diff options
Diffstat (limited to 'refs.h')
| -rw-r--r-- | refs.h | 168 |
1 files changed, 140 insertions, 28 deletions
@@ -10,19 +10,39 @@ struct ref_lock { int force_write; }; -/** - * Information needed for a single ref update. Set new_sha1 to the - * new value or to zero to delete the ref. To check the old value - * while locking the ref, set have_old to 1 and set old_sha1 to the - * value or to zero to ensure the ref does not exist before update. - */ -struct ref_update { - const char *ref_name; - unsigned char new_sha1[20]; - unsigned char old_sha1[20]; - int flags; /* REF_NODEREF? */ - int have_old; /* 1 if old_sha1 is valid, 0 otherwise */ -}; +/* + * 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. + * + * - 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. + */ +struct ref_transaction; /* * Bit values set in the flags argument passed to each_ref_fn(): @@ -94,6 +114,7 @@ extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct st /* * Lock the packed-refs file for writing. Flags is passed to * hold_lock_file_for_update(). Return 0 on success. + * Errno is set to something meaningful on error. */ extern int lock_packed_refs(int flags); @@ -109,6 +130,7 @@ extern void add_packed_ref(const char *refname, const unsigned char *sha1); * Write the current version of the packed refs cache from memory to * disk. The packed-refs file must already be locked for writing (see * lock_packed_refs()). Return zero on success. + * Sets errno to something meaningful on error. */ extern int commit_packed_refs(void); @@ -133,10 +155,13 @@ extern void rollback_packed_refs(void); */ int pack_refs(unsigned int flags); -extern int repack_without_refs(const char **refnames, int n); +extern int repack_without_refs(const char **refnames, int n, + struct strbuf *err); extern int ref_exists(const char *); +extern int is_branch(const char *refname); + /* * 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, @@ -147,11 +172,18 @@ extern int ref_exists(const char *); */ extern int peel_ref(const char *refname, unsigned char *sha1); -/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/ -extern struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1); - -/** Locks any ref (for 'HEAD' type refs). */ +/* + * Flags controlling lock_any_ref_for_update(), ref_transaction_update(), + * ref_transaction_create(), etc. + * REF_NODEREF: act on the ref directly, instead of dereferencing + * symbolic references. + * + * Flags >= 0x100 are reserved for internal use. + */ #define REF_NODEREF 0x01 +/* + * This function sets errno to something meaningful on failure. + */ extern struct ref_lock *lock_any_ref_for_update(const char *refname, const unsigned char *old_sha1, int flags, int *type_p); @@ -168,14 +200,22 @@ extern void unlock_ref(struct ref_lock *lock); /** Writes sha1 into the ref specified by the lock. **/ extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg); -/** Setup reflog before using. **/ -int log_ref_setup(const char *ref_name, char *logfile, int bufsize); +/* + * Setup reflog before using. Set errno to something meaningful on failure. + */ +int log_ref_setup(const char *refname, char *logfile, int bufsize); /** Reads log for the value of ref during at_time. **/ extern int read_ref_at(const char *refname, 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 */ +extern int reflog_exists(const char *refname); + +/** Delete a reflog */ +extern int delete_reflog(const char *refname); + /* iterate over reflog entries */ typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *); int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data); @@ -217,18 +257,90 @@ extern int rename_ref(const char *oldref, const char *newref, const char *logmsg */ extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1); -/** lock a ref and then write its file */ -enum action_on_err { MSG_ON_ERR, DIE_ON_ERR, QUIET_ON_ERR }; +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); + +/* + * The following functions add a reference check or update to a + * ref_transaction. In all of them, refname is the name of the + * reference to be affected. The functions make internal copies of + * refname, so the caller retains ownership of the parameter. flags + * can be REF_NODEREF; it is passed to update_ref_lock(). + */ + +/* + * Add a reference update to transaction. new_sha1 is the value that + * the reference should have after the update, or zeros if it should + * be deleted. If have_old is true, then old_sha1 holds the value + * that the reference should have had before the update, or zeros if + * it must not have existed beforehand. + * Function returns 0 on success and non-zero on failure. A failure to update + * means that the transaction as a whole has failed and will need to be + * rolled back. + */ +int ref_transaction_update(struct ref_transaction *transaction, + const char *refname, + const unsigned char *new_sha1, + const unsigned char *old_sha1, + int flags, int have_old, + 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 the + * null SHA-1. It is verified that the reference does not exist + * already. + * Function returns 0 on success and non-zero on failure. A failure to create + * means that the transaction as a whole has failed and will need to be + * rolled back. + */ +int ref_transaction_create(struct ref_transaction *transaction, + const char *refname, + const unsigned char *new_sha1, + int flags, + struct strbuf *err); + +/* + * Add a reference deletion to transaction. If have_old is true, then + * old_sha1 holds the value that the reference should have had before + * the update (which must not be the null SHA-1). + * Function returns 0 on success and non-zero on failure. A failure to delete + * means that the transaction as a whole has failed and will need to be + * rolled back. + */ +int ref_transaction_delete(struct ref_transaction *transaction, + const char *refname, + const unsigned char *old_sha1, + int flags, int have_old, + struct strbuf *err); + +/* + * Commit all of the changes that have been queued in transaction, as + * atomically as possible. Return a nonzero value if there is a + * problem. + */ +int ref_transaction_commit(struct ref_transaction *transaction, + const char *msg, struct strbuf *err); + +/* + * Free an existing transaction and all associated data. + */ +void ref_transaction_free(struct ref_transaction *transaction); + +/** Lock a ref and then write its file */ int update_ref(const char *action, const char *refname, const unsigned char *sha1, const unsigned char *oldval, int flags, enum action_on_err onerr); -/** - * Lock all refs and then perform all modifications. - */ -int update_refs(const char *action, const struct ref_update **updates, - int n, enum action_on_err onerr); - extern int parse_hide_refs_config(const char *var, const char *value, const char *); extern int ref_is_hidden(const char *); |