diff options
Diffstat (limited to 'refs.h')
| -rw-r--r-- | refs.h | 317 |
1 files changed, 255 insertions, 62 deletions
@@ -1,28 +1,39 @@ #ifndef REFS_H #define REFS_H -struct ref_lock { - char *ref_name; - char *orig_ref_name; - struct lock_file *lk; - unsigned char old_sha1[20]; - int lock_fd; - 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(): @@ -36,19 +47,27 @@ struct ref_update { /* * Reference cannot be resolved to an object name: dangling symbolic - * reference (directly or indirectly), corrupt reference file, or - * symbolic reference refers to ill-formatted reference name. + * 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 unsigned char *sha1, int flags, void *cb_data); + const struct object_id *oid, int flags, void *cb_data); /* * The following functions invoke the specified callback function for @@ -89,11 +108,12 @@ static inline const char *has_glob_specials(const char *pattern) extern int for_each_rawref(each_ref_fn, void *); extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname); -extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list* refnames); +extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames); /* * 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 +129,7 @@ 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 +154,21 @@ extern void rollback_packed_refs(void); */ int pack_refs(unsigned int flags); -extern int repack_without_refs(const char **refnames, int n); +/* + * Rewrite the packed-refs file, omitting any refs listed in + * 'refnames'. On error, packed-refs will be unchanged, the return + * value is nonzero, and a message about the error is written to the + * 'err' strbuf. + * + * The refs in 'refnames' needn't be sorted. `err` must not be NULL. + */ +extern int repack_without_refs(struct string_list *refnames, + 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, @@ -147,35 +179,32 @@ 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 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 -extern struct ref_lock *lock_any_ref_for_update(const char *refname, - const unsigned char *old_sha1, - int flags, int *type_p); - -/** Close the file descriptor owned by a lock and return the status */ -extern int close_ref(struct ref_lock *lock); - -/** Close and commit the ref locked by the lock */ -extern int commit_ref(struct ref_lock *lock); - -/** Release any lock taken but not written. **/ -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, struct strbuf *logfile); /** Reads log for the value of ref during at_time. **/ -extern int read_ref_at(const char *refname, unsigned long at_time, int cnt, +extern 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 */ +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); @@ -189,7 +218,6 @@ extern int for_each_reflog(each_ref_fn, void *); #define REFNAME_ALLOW_ONELEVEL 1 #define REFNAME_REFSPEC_PATTERN 2 -#define REFNAME_DOT_COMPONENT 4 /* * Return 0 iff refname has the correct format for a refname according @@ -197,10 +225,7 @@ extern int for_each_reflog(each_ref_fn, void *); * 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 "*" wildcard character in place of one of the name - * components. No leading or repeated slashes are accepted. If - * REFNAME_DOT_COMPONENT is set in flags, then allow refname - * components to start with "." (but not a whole component equal to - * "." or ".."). + * components. No leading or repeated slashes are accepted. */ extern int check_refname_format(const char *refname, int flags); @@ -217,19 +242,187 @@ 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 }; -int update_ref(const char *action, const char *refname, - const unsigned char *sha1, const unsigned char *oldval, - int flags, enum action_on_err onerr); +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 occured. + * + * 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); + +/* + * Free an existing transaction and all associated data. + */ +void ref_transaction_free(struct ref_transaction *transaction); /** - * Lock all refs and then perform all modifications. + * 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_refs(const char *action, const struct ref_update **updates, - int n, enum action_on_err onerr); +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); extern int parse_hide_refs_config(const char *var, const char *value, const char *); extern int ref_is_hidden(const char *); +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. + */ +extern 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); + #endif /* REFS_H */ |