diff options
Diffstat (limited to 'refs.h')
| -rw-r--r-- | refs.h | 155 |
1 files changed, 155 insertions, 0 deletions
@@ -1194,4 +1194,159 @@ int repo_migrate_ref_storage_format(struct repository *repo, unsigned int flags, struct strbuf *err); +/* + * 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_free(), you must make a copy. When the iteration has + * been exhausted, ref_iterator_advance() releases any resources + * associated with the iteration, frees the ref_iterator object, and + * returns ITER_DONE. If you want to abort the iteration early, call + * ref_iterator_free(), 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 = ITER_DONE; + * 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(); + * ref_iterator_free(iter); + */ +struct ref_iterator; + +/* + * These flags are passed to refs_ref_iterator_begin() (and do_for_each_ref(), + * which feeds it). + */ +enum do_for_each_ref_flags { + /* + * Include broken references in a do_for_each_ref*() iteration, which + * would normally be omitted. This includes both refs that point to + * missing objects (a true repository corruption), ones with illegal + * names (which we prefer not to expose to callers), as well as + * dangling symbolic refs (i.e., those that point to a non-existent + * ref; this is not a corruption, but as they have no valid oid, we + * omit them from normal iteration results). + */ + DO_FOR_EACH_INCLUDE_BROKEN = (1 << 0), + + /* + * 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. + */ + DO_FOR_EACH_PER_WORKTREE_ONLY = (1 << 1), + + /* + * Omit dangling symrefs from output; this only has an effect with + * INCLUDE_BROKEN, since they are otherwise not included at all. + */ + DO_FOR_EACH_OMIT_DANGLING_SYMREFS = (1 << 2), + + /* + * Include root refs i.e. HEAD and pseudorefs along with the regular + * refs. + */ + DO_FOR_EACH_INCLUDE_ROOT_REFS = (1 << 3), +}; + +/* + * 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. + * The output is ordered by refname. + */ +struct ref_iterator *refs_ref_iterator_begin( + struct ref_store *refs, + const char *prefix, const char **exclude_patterns, + int trim, enum do_for_each_ref_flags 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); + +enum ref_iterator_seek_flag { + /* + * When the REF_ITERATOR_SEEK_SET_PREFIX flag is set, the iterator's prefix is + * updated to match the provided string, affecting all subsequent iterations. If + * not, the iterator seeks to the specified reference and clears any previously + * set prefix. + */ + REF_ITERATOR_SEEK_SET_PREFIX = (1 << 0), +}; + +/* + * Seek the iterator to the first reference matching the given seek string. + * The seek string is matched as a literal string, without regard for path + * separators. If seek is NULL or the empty string, seek the iterator to the + * first reference again. + * + * This function is expected to behave as if a new ref iterator has been + * created, but allows reuse of existing iterators for optimization. + * + * Returns 0 on success, a negative error code otherwise. + */ +int ref_iterator_seek(struct ref_iterator *ref_iterator, const char *refname, + unsigned int flags); + +/* + * 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); + +/* Free the reference iterator and any associated resources. */ +void ref_iterator_free(struct ref_iterator *ref_iterator); + +/* + * 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); + #endif /* REFS_H */ |