| #ifndef REFS_REFS_INTERNAL_H |
| #define REFS_REFS_INTERNAL_H |
| |
| /* |
| * Data structures and functions for the internal use of the refs |
| * module. Code outside of the refs module should use only the public |
| * functions defined in "refs.h", and should *not* include this file. |
| */ |
| |
| /* |
| * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken |
| * refs (i.e., because the reference is about to be deleted anyway). |
| */ |
| #define REF_DELETING 0x02 |
| |
| /* |
| * Used as a flag in ref_update::flags when a loose ref is being |
| * pruned. This flag must only be used when REF_NODEREF is set. |
| */ |
| #define REF_ISPRUNING 0x04 |
| |
| /* |
| * Used as a flag in ref_update::flags when the reference should be |
| * updated to new_sha1. |
| */ |
| #define REF_HAVE_NEW 0x08 |
| |
| /* |
| * Used as a flag in ref_update::flags when old_sha1 should be |
| * checked. |
| */ |
| #define REF_HAVE_OLD 0x10 |
| |
| /* |
| * Used as a flag in ref_update::flags when the lockfile needs to be |
| * committed. |
| */ |
| #define REF_NEEDS_COMMIT 0x20 |
| |
| /* |
| * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a |
| * value to ref_update::flags |
| */ |
| |
| /* |
| * Used as a flag in ref_update::flags when we want to log a ref |
| * update but not actually perform it. This is used when a symbolic |
| * ref update is split up. |
| */ |
| #define REF_LOG_ONLY 0x80 |
| |
| /* |
| * Internal flag, meaning that the containing ref_update was via an |
| * update to HEAD. |
| */ |
| #define REF_UPDATE_VIA_HEAD 0x100 |
| |
| /* |
| * Used as a flag in ref_update::flags when the loose reference has |
| * been deleted. |
| */ |
| #define REF_DELETED_LOOSE 0x200 |
| |
| /* |
| * Return true iff refname is minimally safe. "Safe" here means that |
| * deleting a loose reference by this name will not do any damage, for |
| * example by causing a file that is not a reference to be deleted. |
| * This function does not check that the reference name is legal; for |
| * that, use check_refname_format(). |
| * |
| * A refname that starts with "refs/" is considered safe iff it |
| * doesn't contain any "." or ".." components or consecutive '/' |
| * characters, end with '/', or (on Windows) contain any '\' |
| * characters. Names that do not start with "refs/" are considered |
| * safe iff they consist entirely of upper case characters and '_' |
| * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR"). |
| */ |
| int refname_is_safe(const char *refname); |
| |
| enum peel_status { |
| /* object was peeled successfully: */ |
| PEEL_PEELED = 0, |
| |
| /* |
| * object cannot be peeled because the named object (or an |
| * object referred to by a tag in the peel chain), does not |
| * exist. |
| */ |
| PEEL_INVALID = -1, |
| |
| /* object cannot be peeled because it is not a tag: */ |
| PEEL_NON_TAG = -2, |
| |
| /* ref_entry contains no peeled value because it is a symref: */ |
| PEEL_IS_SYMREF = -3, |
| |
| /* |
| * ref_entry cannot be peeled because it is broken (i.e., the |
| * symbolic reference cannot even be resolved to an object |
| * name): |
| */ |
| PEEL_BROKEN = -4 |
| }; |
| |
| /* |
| * Peel the named object; i.e., if the object is a tag, resolve the |
| * tag recursively until a non-tag is found. If successful, store the |
| * result to sha1 and return PEEL_PEELED. If the object is not a tag |
| * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively, |
| * and leave sha1 unchanged. |
| */ |
| enum peel_status peel_object(const unsigned char *name, unsigned char *sha1); |
| |
| /* |
| * Copy the reflog message msg to buf, which has been allocated sufficiently |
| * large, while cleaning up the whitespaces. Especially, convert LF to space, |
| * because reflog file is one line per entry. |
| */ |
| int copy_reflog_msg(char *buf, const char *msg); |
| |
| /** |
| * Information needed for a single ref update. Set new_sha1 to the new |
| * value or to null_sha1 to delete the ref. To check the old value |
| * while the ref is locked, set (flags & REF_HAVE_OLD) and set |
| * old_sha1 to the old value, or to null_sha1 to ensure the ref does |
| * not exist before update. |
| */ |
| struct ref_update { |
| |
| /* |
| * If (flags & REF_HAVE_NEW), set the reference to this value: |
| */ |
| unsigned char new_sha1[20]; |
| |
| /* |
| * If (flags & REF_HAVE_OLD), check that the reference |
| * previously had this value: |
| */ |
| unsigned char old_sha1[20]; |
| |
| /* |
| * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, |
| * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY, |
| * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and |
| * REF_DELETED_LOOSE: |
| */ |
| unsigned int flags; |
| |
| void *backend_data; |
| unsigned int type; |
| char *msg; |
| |
| /* |
| * If this ref_update was split off of a symref update via |
| * split_symref_update(), then this member points at that |
| * update. This is used for two purposes: |
| * 1. When reporting errors, we report the refname under which |
| * the update was originally requested. |
| * 2. When we read the old value of this reference, we |
| * propagate it back to its parent update for recording in |
| * the latter's reflog. |
| */ |
| struct ref_update *parent_update; |
| |
| const char refname[FLEX_ARRAY]; |
| }; |
| |
| int refs_read_raw_ref(struct ref_store *ref_store, |
| const char *refname, unsigned char *sha1, |
| struct strbuf *referent, unsigned int *type); |
| |
| /* |
| * Add a ref_update with the specified properties to transaction, and |
| * return a pointer to the new object. This function does not verify |
| * that refname is well-formed. new_sha1 and old_sha1 are only |
| * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits, |
| * respectively, are set in flags. |
| */ |
| struct ref_update *ref_transaction_add_update( |
| struct ref_transaction *transaction, |
| const char *refname, unsigned int flags, |
| const unsigned char *new_sha1, |
| const unsigned char *old_sha1, |
| const char *msg); |
| |
| /* |
| * Transaction states. |
| * OPEN: The transaction is in a valid state and can accept new updates. |
| * An OPEN transaction can be committed. |
| * CLOSED: A closed transaction is no longer active and no other operations |
| * than free can be used on it in this state. |
| * A transaction can either become closed by successfully committing |
| * an active transaction or if there is a failure while building |
| * the transaction thus rendering it failed/inactive. |
| */ |
| enum ref_transaction_state { |
| REF_TRANSACTION_OPEN = 0, |
| REF_TRANSACTION_CLOSED = 1 |
| }; |
| |
| /* |
| * Data structure for holding a reference transaction, which can |
| * consist of checks and updates to multiple references, carried out |
| * as atomically as possible. This structure is opaque to callers. |
| */ |
| struct ref_transaction { |
| struct ref_store *ref_store; |
| struct ref_update **updates; |
| size_t alloc; |
| size_t nr; |
| enum ref_transaction_state state; |
| }; |
| |
| /* |
| * Check for entries in extras that are within the specified |
| * directory, where dirname is a reference directory name including |
| * the trailing slash (e.g., "refs/heads/foo/"). Ignore any |
| * conflicting references that are found in skip. If there is a |
| * conflicting reference, return its name. |
| * |
| * extras and skip must be sorted lists of reference names. Either one |
| * can be NULL, signifying the empty list. |
| */ |
| const char *find_descendant_ref(const char *dirname, |
| const struct string_list *extras, |
| const struct string_list *skip); |
| |
| /* |
| * Check whether an attempt to rename old_refname to new_refname would |
| * cause a D/F conflict with any existing reference (other than |
| * possibly old_refname). If there would be a conflict, emit an error |
| * message and return false; otherwise, return true. |
| * |
| * Note that this function is not safe against all races with other |
| * processes (though rename_ref() catches some races that might get by |
| * this check). |
| */ |
| int refs_rename_ref_available(struct ref_store *refs, |
| const char *old_refname, |
| const char *new_refname); |
| |
| /* We allow "recursive" symbolic refs. Only within reason, though */ |
| #define SYMREF_MAXDEPTH 5 |
| |
| /* Include broken references in a do_for_each_ref*() iteration: */ |
| #define DO_FOR_EACH_INCLUDE_BROKEN 0x01 |
| |
| /* |
| * Reference iterators |
| * |
| * A reference iterator encapsulates the state of an in-progress |
| * iteration over references. Create an instance of `struct |
| * ref_iterator` via one of the functions in this module. |
| * |
| * A freshly-created ref_iterator doesn't yet point at a reference. To |
| * advance the iterator, call ref_iterator_advance(). If successful, |
| * this sets the iterator's refname, oid, and flags fields to describe |
| * the next reference and returns ITER_OK. The data pointed at by |
| * refname and oid belong to the iterator; if you want to retain them |
| * after calling ref_iterator_advance() again or calling |
| * ref_iterator_abort(), you must make a copy. When the iteration has |
| * been exhausted, ref_iterator_advance() releases any resources |
| * assocated with the iteration, frees the ref_iterator object, and |
| * returns ITER_DONE. If you want to abort the iteration early, call |
| * ref_iterator_abort(), which also frees the ref_iterator object and |
| * any associated resources. If there was an internal error advancing |
| * to the next entry, ref_iterator_advance() aborts the iteration, |
| * frees the ref_iterator, and returns ITER_ERROR. |
| * |
| * The reference currently being looked at can be peeled by calling |
| * ref_iterator_peel(). This function is often faster than peel_ref(), |
| * so it should be preferred when iterating over references. |
| * |
| * Putting it all together, a typical iteration looks like this: |
| * |
| * int ok; |
| * struct ref_iterator *iter = ...; |
| * |
| * while ((ok = ref_iterator_advance(iter)) == ITER_OK) { |
| * if (want_to_stop_iteration()) { |
| * ok = ref_iterator_abort(iter); |
| * break; |
| * } |
| * |
| * // Access information about the current reference: |
| * if (!(iter->flags & REF_ISSYMREF)) |
| * printf("%s is %s\n", iter->refname, oid_to_hex(&iter->oid)); |
| * |
| * // If you need to peel the reference: |
| * ref_iterator_peel(iter, &oid); |
| * } |
| * |
| * if (ok != ITER_DONE) |
| * handle_error(); |
| */ |
| struct ref_iterator { |
| struct ref_iterator_vtable *vtable; |
| const char *refname; |
| const struct object_id *oid; |
| unsigned int flags; |
| }; |
| |
| /* |
| * Advance the iterator to the first or next item and return ITER_OK. |
| * If the iteration is exhausted, free the resources associated with |
| * the ref_iterator and return ITER_DONE. On errors, free the iterator |
| * resources and return ITER_ERROR. It is a bug to use ref_iterator or |
| * call this function again after it has returned ITER_DONE or |
| * ITER_ERROR. |
| */ |
| int ref_iterator_advance(struct ref_iterator *ref_iterator); |
| |
| /* |
| * If possible, peel the reference currently being viewed by the |
| * iterator. Return 0 on success. |
| */ |
| int ref_iterator_peel(struct ref_iterator *ref_iterator, |
| struct object_id *peeled); |
| |
| /* |
| * End the iteration before it has been exhausted, freeing the |
| * reference iterator and any associated resources and returning |
| * ITER_DONE. If the abort itself failed, return ITER_ERROR. |
| */ |
| int ref_iterator_abort(struct ref_iterator *ref_iterator); |
| |
| /* |
| * An iterator over nothing (its first ref_iterator_advance() call |
| * returns ITER_DONE). |
| */ |
| struct ref_iterator *empty_ref_iterator_begin(void); |
| |
| /* |
| * Return true iff ref_iterator is an empty_ref_iterator. |
| */ |
| int is_empty_ref_iterator(struct ref_iterator *ref_iterator); |
| |
| /* |
| * Return an iterator that goes over each reference in `refs` for |
| * which the refname begins with prefix. If trim is non-zero, then |
| * trim that many characters off the beginning of each refname. flags |
| * can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in |
| * the iteration. |
| */ |
| struct ref_iterator *refs_ref_iterator_begin( |
| struct ref_store *refs, |
| const char *prefix, int trim, int flags); |
| |
| /* |
| * A callback function used to instruct merge_ref_iterator how to |
| * interleave the entries from iter0 and iter1. The function should |
| * return one of the constants defined in enum iterator_selection. It |
| * must not advance either of the iterators itself. |
| * |
| * The function must be prepared to handle the case that iter0 and/or |
| * iter1 is NULL, which indicates that the corresponding sub-iterator |
| * has been exhausted. Its return value must be consistent with the |
| * current states of the iterators; e.g., it must not return |
| * ITER_SKIP_1 if iter1 has already been exhausted. |
| */ |
| typedef enum iterator_selection ref_iterator_select_fn( |
| struct ref_iterator *iter0, struct ref_iterator *iter1, |
| void *cb_data); |
| |
| /* |
| * Iterate over the entries from iter0 and iter1, with the values |
| * interleaved as directed by the select function. The iterator takes |
| * ownership of iter0 and iter1 and frees them when the iteration is |
| * over. |
| */ |
| struct ref_iterator *merge_ref_iterator_begin( |
| struct ref_iterator *iter0, struct ref_iterator *iter1, |
| ref_iterator_select_fn *select, void *cb_data); |
| |
| /* |
| * An iterator consisting of the union of the entries from front and |
| * back. If there are entries common to the two sub-iterators, use the |
| * one from front. Each iterator must iterate over its entries in |
| * strcmp() order by refname for this to work. |
| * |
| * The new iterator takes ownership of its arguments and frees them |
| * when the iteration is over. As a convenience to callers, if front |
| * or back is an empty_ref_iterator, then abort that one immediately |
| * and return the other iterator directly, without wrapping it. |
| */ |
| struct ref_iterator *overlay_ref_iterator_begin( |
| struct ref_iterator *front, struct ref_iterator *back); |
| |
| /* |
| * Wrap iter0, only letting through the references whose names start |
| * with prefix. If trim is set, set iter->refname to the name of the |
| * reference with that many characters trimmed off the front; |
| * otherwise set it to the full refname. The new iterator takes over |
| * ownership of iter0 and frees it when iteration is over. It makes |
| * its own copy of prefix. |
| * |
| * As an convenience to callers, if prefix is the empty string and |
| * trim is zero, this function returns iter0 directly, without |
| * wrapping it. |
| */ |
| struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0, |
| const char *prefix, |
| int trim); |
| |
| /* Internal implementation of reference iteration: */ |
| |
| /* |
| * Base class constructor for ref_iterators. Initialize the |
| * ref_iterator part of iter, setting its vtable pointer as specified. |
| * This is meant to be called only by the initializers of derived |
| * classes. |
| */ |
| void base_ref_iterator_init(struct ref_iterator *iter, |
| struct ref_iterator_vtable *vtable); |
| |
| /* |
| * Base class destructor for ref_iterators. Destroy the ref_iterator |
| * part of iter and shallow-free the object. This is meant to be |
| * called only by the destructors of derived classes. |
| */ |
| void base_ref_iterator_free(struct ref_iterator *iter); |
| |
| /* Virtual function declarations for ref_iterators: */ |
| |
| typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator); |
| |
| typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator, |
| struct object_id *peeled); |
| |
| /* |
| * Implementations of this function should free any resources specific |
| * to the derived class, then call base_ref_iterator_free() to clean |
| * up and free the ref_iterator object. |
| */ |
| typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator); |
| |
| struct ref_iterator_vtable { |
| ref_iterator_advance_fn *advance; |
| ref_iterator_peel_fn *peel; |
| ref_iterator_abort_fn *abort; |
| }; |
| |
| /* |
| * current_ref_iter is a performance hack: when iterating over |
| * references using the for_each_ref*() functions, current_ref_iter is |
| * set to the reference iterator before calling the callback function. |
| * If the callback function calls peel_ref(), then peel_ref() first |
| * checks whether the reference to be peeled is the one referred to by |
| * the iterator (it usually is) and if so, asks the iterator for the |
| * peeled version of the reference if it is available. This avoids a |
| * refname lookup in a common case. current_ref_iter is set to NULL |
| * when the iteration is over. |
| */ |
| extern struct ref_iterator *current_ref_iter; |
| |
| /* |
| * The common backend for the for_each_*ref* functions. Call fn for |
| * each reference in iter. If the iterator itself ever returns |
| * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop |
| * the iteration and return that value. Otherwise, return 0. In any |
| * case, free the iterator when done. This function is basically an |
| * adapter between the callback style of reference iteration and the |
| * iterator style. |
| */ |
| int do_for_each_ref_iterator(struct ref_iterator *iter, |
| each_ref_fn fn, void *cb_data); |
| |
| /* |
| * Only include per-worktree refs in a do_for_each_ref*() iteration. |
| * Normally this will be used with a files ref_store, since that's |
| * where all reference backends will presumably store their |
| * per-worktree refs. |
| */ |
| #define DO_FOR_EACH_PER_WORKTREE_ONLY 0x02 |
| |
| struct ref_store; |
| |
| /* refs backends */ |
| |
| /* ref_store_init flags */ |
| #define REF_STORE_READ (1 << 0) |
| #define REF_STORE_WRITE (1 << 1) /* can perform update operations */ |
| #define REF_STORE_ODB (1 << 2) /* has access to object database */ |
| #define REF_STORE_MAIN (1 << 3) |
| |
| /* |
| * Initialize the ref_store for the specified gitdir. These functions |
| * should call base_ref_store_init() to initialize the shared part of |
| * the ref_store and to record the ref_store for later lookup. |
| */ |
| typedef struct ref_store *ref_store_init_fn(const char *gitdir, |
| unsigned int flags); |
| |
| typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err); |
| |
| typedef int ref_transaction_commit_fn(struct ref_store *refs, |
| struct ref_transaction *transaction, |
| struct strbuf *err); |
| |
| typedef int pack_refs_fn(struct ref_store *ref_store, unsigned int flags); |
| typedef int peel_ref_fn(struct ref_store *ref_store, |
| const char *refname, unsigned char *sha1); |
| typedef int create_symref_fn(struct ref_store *ref_store, |
| const char *ref_target, |
| const char *refs_heads_master, |
| const char *logmsg); |
| typedef int delete_refs_fn(struct ref_store *ref_store, |
| struct string_list *refnames, unsigned int flags); |
| typedef int rename_ref_fn(struct ref_store *ref_store, |
| const char *oldref, const char *newref, |
| const char *logmsg); |
| |
| /* |
| * Iterate over the references in the specified ref_store that are |
| * within find_containing_dir(prefix). If prefix is NULL or the empty |
| * string, iterate over all references in the submodule. |
| */ |
| typedef struct ref_iterator *ref_iterator_begin_fn( |
| struct ref_store *ref_store, |
| const char *prefix, unsigned int flags); |
| |
| /* reflog functions */ |
| |
| /* |
| * Iterate over the references in the specified ref_store that have a |
| * reflog. The refs are iterated over in arbitrary order. |
| */ |
| typedef struct ref_iterator *reflog_iterator_begin_fn( |
| struct ref_store *ref_store); |
| |
| typedef int for_each_reflog_ent_fn(struct ref_store *ref_store, |
| const char *refname, |
| each_reflog_ent_fn fn, |
| void *cb_data); |
| typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store, |
| const char *refname, |
| each_reflog_ent_fn fn, |
| void *cb_data); |
| typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname); |
| typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname, |
| int force_create, struct strbuf *err); |
| typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname); |
| typedef int reflog_expire_fn(struct ref_store *ref_store, |
| 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); |
| |
| /* |
| * Read a reference from the specified reference store, non-recursively. |
| * Set type to describe the reference, and: |
| * |
| * - If refname is the name of a normal reference, fill in sha1 |
| * (leaving referent unchanged). |
| * |
| * - If refname is the name of a symbolic reference, write the full |
| * name of the reference to which it refers (e.g. |
| * "refs/heads/master") to referent and set the REF_ISSYMREF bit in |
| * type (leaving sha1 unchanged). The caller is responsible for |
| * validating that referent is a valid reference name. |
| * |
| * WARNING: refname might be used as part of a filename, so it is |
| * important from a security standpoint that it be safe in the sense |
| * of refname_is_safe(). Moreover, for symrefs this function sets |
| * referent to whatever the repository says, which might not be a |
| * properly-formatted or even safe reference name. NEITHER INPUT NOR |
| * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION. |
| * |
| * Return 0 on success. If the ref doesn't exist, set errno to ENOENT |
| * and return -1. If the ref exists but is neither a symbolic ref nor |
| * a sha1, it is broken; set REF_ISBROKEN in type, set errno to |
| * EINVAL, and return -1. If there is another error reading the ref, |
| * set errno appropriately and return -1. |
| * |
| * Backend-specific flags might be set in type as well, regardless of |
| * outcome. |
| * |
| * It is OK for refname to point into referent. If so: |
| * |
| * - if the function succeeds with REF_ISSYMREF, referent will be |
| * overwritten and the memory formerly pointed to by it might be |
| * changed or even freed. |
| * |
| * - in all other cases, referent will be untouched, and therefore |
| * refname will still be valid and unchanged. |
| */ |
| typedef int read_raw_ref_fn(struct ref_store *ref_store, |
| const char *refname, unsigned char *sha1, |
| struct strbuf *referent, unsigned int *type); |
| |
| struct ref_storage_be { |
| struct ref_storage_be *next; |
| const char *name; |
| ref_store_init_fn *init; |
| ref_init_db_fn *init_db; |
| ref_transaction_commit_fn *transaction_commit; |
| ref_transaction_commit_fn *initial_transaction_commit; |
| |
| pack_refs_fn *pack_refs; |
| peel_ref_fn *peel_ref; |
| create_symref_fn *create_symref; |
| delete_refs_fn *delete_refs; |
| rename_ref_fn *rename_ref; |
| |
| ref_iterator_begin_fn *iterator_begin; |
| read_raw_ref_fn *read_raw_ref; |
| |
| reflog_iterator_begin_fn *reflog_iterator_begin; |
| for_each_reflog_ent_fn *for_each_reflog_ent; |
| for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse; |
| reflog_exists_fn *reflog_exists; |
| create_reflog_fn *create_reflog; |
| delete_reflog_fn *delete_reflog; |
| reflog_expire_fn *reflog_expire; |
| }; |
| |
| extern struct ref_storage_be refs_be_files; |
| |
| /* |
| * A representation of the reference store for the main repository or |
| * a submodule. The ref_store instances for submodules are kept in a |
| * linked list. |
| */ |
| struct ref_store { |
| /* The backend describing this ref_store's storage scheme: */ |
| const struct ref_storage_be *be; |
| }; |
| |
| /* |
| * Fill in the generic part of refs and add it to our collection of |
| * reference stores. |
| */ |
| void base_ref_store_init(struct ref_store *refs, |
| const struct ref_storage_be *be); |
| |
| #endif /* REFS_REFS_INTERNAL_H */ |