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git/refs.h
Michael Haggerty d1dd721f11 refs.h: remove duplication in function docstrings
Add more information to the comment introducing the four reference
transaction update functions, so that each function's docstring
doesn't have to repeat it. Add a pointer from the individual
functions' docstrings to the introductory comment.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:25:18 -08:00

428 lines
15 KiB
C

#ifndef REFS_H
#define REFS_H
/*
* 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():
*/
/* 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 unsigned char *sha1, 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.
*/
extern int head_ref(each_ref_fn, void *);
extern int for_each_ref(each_ref_fn, void *);
extern int for_each_ref_in(const char *, each_ref_fn, void *);
extern int for_each_tag_ref(each_ref_fn, void *);
extern int for_each_branch_ref(each_ref_fn, void *);
extern int for_each_remote_ref(each_ref_fn, void *);
extern int for_each_replace_ref(each_ref_fn, void *);
extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
each_ref_fn fn, void *cb_data);
extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
static inline const char *has_glob_specials(const char *pattern)
{
return strpbrk(pattern, "?*[");
}
/* can be used to learn about broken ref and symref */
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);
/*
* 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);
/*
* Add a reference to the in-memory packed reference cache. This may
* only be called while the packed-refs file is locked (see
* lock_packed_refs()). To actually write the packed-refs file, call
* commit_packed_refs().
*/
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);
/*
* Rollback the lockfile for the packed-refs file, and discard the
* in-memory packed reference cache. (The packed-refs file will be
* read anew if it is needed again after this function is called.)
*/
extern void rollback_packed_refs(void);
/*
* 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);
/*
* 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,
* 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.
*/
extern int peel_ref(const char *refname, unsigned char *sha1);
/*
* 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
/*
* 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 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);
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
*/
extern int for_each_reflog(each_ref_fn, void *);
#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 "*" wildcard character in place of one of the name
* components. No leading or repeated slashes are accepted.
*/
extern int check_refname_format(const char *refname, int flags);
extern const char *prettify_refname(const char *refname);
extern char *shorten_unambiguous_ref(const char *refname, int strict);
/** rename ref, return 0 on success **/
extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
/**
* Resolve refname in the nested "gitlink" repository that is located
* at path. If the resolution is successful, return 0 and set sha1 to
* the name of the object; otherwise, return a non-zero value.
*/
extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
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, 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);
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 */