git/refs.h
Cornelius Weig 341fb28621 refs: add option core.logAllRefUpdates = always
When core.logallrefupdates is true, we only create a new reflog for refs
that are under certain well-known hierarchies. The reason is that we
know that some hierarchies (like refs/tags) are not meant to change, and
that unknown hierarchies might not want reflogs at all (e.g., a
hypothetical refs/foo might be meant to change often and drop old
history immediately).

However, sometimes it is useful to override this decision and simply log
for all refs, because the safety and audit trail is more important than
the performance implications of keeping the log around.

This patch introduces a new "always" mode for the core.logallrefupdates
option which will log updates to everything under refs/, regardless
where in the hierarchy it is (we still will not log things like
ORIG_HEAD and FETCH_HEAD, which are known to be transient).

Based-on-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Cornelius Weig <cornelius.weig@tngtech.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-31 10:01:24 -08:00

559 lines
20 KiB
C

#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 should_autocreate_reflog(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 */