diff options
Diffstat (limited to 'refs/files-backend.c')
| -rw-r--r-- | refs/files-backend.c | 1229 |
1 files changed, 154 insertions, 1075 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c index c9d900f..83ea080 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -1,6 +1,7 @@ #include "../cache.h" #include "../refs.h" #include "refs-internal.h" +#include "ref-cache.h" #include "../iterator.h" #include "../dir-iterator.h" #include "../lockfile.h" @@ -13,511 +14,6 @@ struct ref_lock { struct object_id old_oid; }; -struct ref_entry; - -/* - * Information used (along with the information in ref_entry) to - * describe a single cached reference. This data structure only - * occurs embedded in a union in struct ref_entry, and only when - * (ref_entry->flag & REF_DIR) is zero. - */ -struct ref_value { - /* - * The name of the object to which this reference resolves - * (which may be a tag object). If REF_ISBROKEN, this is - * null. If REF_ISSYMREF, then this is the name of the object - * referred to by the last reference in the symlink chain. - */ - struct object_id oid; - - /* - * If REF_KNOWS_PEELED, then this field holds the peeled value - * of this reference, or null if the reference is known not to - * be peelable. See the documentation for peel_ref() for an - * exact definition of "peelable". - */ - struct object_id peeled; -}; - -struct files_ref_store; - -/* - * Information used (along with the information in ref_entry) to - * describe a level in the hierarchy of references. This data - * structure only occurs embedded in a union in struct ref_entry, and - * only when (ref_entry.flag & REF_DIR) is set. In that case, - * (ref_entry.flag & REF_INCOMPLETE) determines whether the references - * in the directory have already been read: - * - * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose - * or packed references, already read. - * - * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose - * references that hasn't been read yet (nor has any of its - * subdirectories). - * - * Entries within a directory are stored within a growable array of - * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < - * sorted are sorted by their component name in strcmp() order and the - * remaining entries are unsorted. - * - * Loose references are read lazily, one directory at a time. When a - * directory of loose references is read, then all of the references - * in that directory are stored, and REF_INCOMPLETE stubs are created - * for any subdirectories, but the subdirectories themselves are not - * read. The reading is triggered by get_ref_dir(). - */ -struct ref_dir { - int nr, alloc; - - /* - * Entries with index 0 <= i < sorted are sorted by name. New - * entries are appended to the list unsorted, and are sorted - * only when required; thus we avoid the need to sort the list - * after the addition of every reference. - */ - int sorted; - - /* A pointer to the files_ref_store that contains this ref_dir. */ - struct files_ref_store *ref_store; - - struct ref_entry **entries; -}; - -/* - * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, - * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are - * public values; see refs.h. - */ - -/* - * The field ref_entry->u.value.peeled of this value entry contains - * the correct peeled value for the reference, which might be - * null_sha1 if the reference is not a tag or if it is broken. - */ -#define REF_KNOWS_PEELED 0x10 - -/* ref_entry represents a directory of references */ -#define REF_DIR 0x20 - -/* - * Entry has not yet been read from disk (used only for REF_DIR - * entries representing loose references) - */ -#define REF_INCOMPLETE 0x40 - -/* - * A ref_entry represents either a reference or a "subdirectory" of - * references. - * - * Each directory in the reference namespace is represented by a - * ref_entry with (flags & REF_DIR) set and containing a subdir member - * that holds the entries in that directory that have been read so - * far. If (flags & REF_INCOMPLETE) is set, then the directory and - * its subdirectories haven't been read yet. REF_INCOMPLETE is only - * used for loose reference directories. - * - * References are represented by a ref_entry with (flags & REF_DIR) - * unset and a value member that describes the reference's value. The - * flag member is at the ref_entry level, but it is also needed to - * interpret the contents of the value field (in other words, a - * ref_value object is not very much use without the enclosing - * ref_entry). - * - * Reference names cannot end with slash and directories' names are - * always stored with a trailing slash (except for the top-level - * directory, which is always denoted by ""). This has two nice - * consequences: (1) when the entries in each subdir are sorted - * lexicographically by name (as they usually are), the references in - * a whole tree can be generated in lexicographic order by traversing - * the tree in left-to-right, depth-first order; (2) the names of - * references and subdirectories cannot conflict, and therefore the - * presence of an empty subdirectory does not block the creation of a - * similarly-named reference. (The fact that reference names with the - * same leading components can conflict *with each other* is a - * separate issue that is regulated by verify_refname_available().) - * - * Please note that the name field contains the fully-qualified - * reference (or subdirectory) name. Space could be saved by only - * storing the relative names. But that would require the full names - * to be generated on the fly when iterating in do_for_each_ref(), and - * would break callback functions, who have always been able to assume - * that the name strings that they are passed will not be freed during - * the iteration. - */ -struct ref_entry { - unsigned char flag; /* ISSYMREF? ISPACKED? */ - union { - struct ref_value value; /* if not (flags&REF_DIR) */ - struct ref_dir subdir; /* if (flags&REF_DIR) */ - } u; - /* - * The full name of the reference (e.g., "refs/heads/master") - * or the full name of the directory with a trailing slash - * (e.g., "refs/heads/"): - */ - char name[FLEX_ARRAY]; -}; - -static void read_loose_refs(const char *dirname, struct ref_dir *dir); -static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); -static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, - const char *dirname, size_t len, - int incomplete); -static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); -static int files_log_ref_write(struct files_ref_store *refs, - const char *refname, const unsigned char *old_sha1, - const unsigned char *new_sha1, const char *msg, - int flags, struct strbuf *err); - -static struct ref_dir *get_ref_dir(struct ref_entry *entry) -{ - struct ref_dir *dir; - assert(entry->flag & REF_DIR); - dir = &entry->u.subdir; - if (entry->flag & REF_INCOMPLETE) { - read_loose_refs(entry->name, dir); - - /* - * Manually add refs/bisect, which, being - * per-worktree, might not appear in the directory - * listing for refs/ in the main repo. - */ - if (!strcmp(entry->name, "refs/")) { - int pos = search_ref_dir(dir, "refs/bisect/", 12); - if (pos < 0) { - struct ref_entry *child_entry; - child_entry = create_dir_entry(dir->ref_store, - "refs/bisect/", - 12, 1); - add_entry_to_dir(dir, child_entry); - read_loose_refs("refs/bisect", - &child_entry->u.subdir); - } - } - entry->flag &= ~REF_INCOMPLETE; - } - return dir; -} - -static struct ref_entry *create_ref_entry(const char *refname, - const unsigned char *sha1, int flag, - int check_name) -{ - struct ref_entry *ref; - - if (check_name && - check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) - die("Reference has invalid format: '%s'", refname); - FLEX_ALLOC_STR(ref, name, refname); - hashcpy(ref->u.value.oid.hash, sha1); - oidclr(&ref->u.value.peeled); - ref->flag = flag; - return ref; -} - -static void clear_ref_dir(struct ref_dir *dir); - -static void free_ref_entry(struct ref_entry *entry) -{ - if (entry->flag & REF_DIR) { - /* - * Do not use get_ref_dir() here, as that might - * trigger the reading of loose refs. - */ - clear_ref_dir(&entry->u.subdir); - } - free(entry); -} - -/* - * Add a ref_entry to the end of dir (unsorted). Entry is always - * stored directly in dir; no recursion into subdirectories is - * done. - */ -static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) -{ - ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); - dir->entries[dir->nr++] = entry; - /* optimize for the case that entries are added in order */ - if (dir->nr == 1 || - (dir->nr == dir->sorted + 1 && - strcmp(dir->entries[dir->nr - 2]->name, - dir->entries[dir->nr - 1]->name) < 0)) - dir->sorted = dir->nr; -} - -/* - * Clear and free all entries in dir, recursively. - */ -static void clear_ref_dir(struct ref_dir *dir) -{ - int i; - for (i = 0; i < dir->nr; i++) - free_ref_entry(dir->entries[i]); - free(dir->entries); - dir->sorted = dir->nr = dir->alloc = 0; - dir->entries = NULL; -} - -/* - * Create a struct ref_entry object for the specified dirname. - * dirname is the name of the directory with a trailing slash (e.g., - * "refs/heads/") or "" for the top-level directory. - */ -static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, - const char *dirname, size_t len, - int incomplete) -{ - struct ref_entry *direntry; - FLEX_ALLOC_MEM(direntry, name, dirname, len); - direntry->u.subdir.ref_store = ref_store; - direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); - return direntry; -} - -static int ref_entry_cmp(const void *a, const void *b) -{ - struct ref_entry *one = *(struct ref_entry **)a; - struct ref_entry *two = *(struct ref_entry **)b; - return strcmp(one->name, two->name); -} - -static void sort_ref_dir(struct ref_dir *dir); - -struct string_slice { - size_t len; - const char *str; -}; - -static int ref_entry_cmp_sslice(const void *key_, const void *ent_) -{ - const struct string_slice *key = key_; - const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; - int cmp = strncmp(key->str, ent->name, key->len); - if (cmp) - return cmp; - return '\0' - (unsigned char)ent->name[key->len]; -} - -/* - * Return the index of the entry with the given refname from the - * ref_dir (non-recursively), sorting dir if necessary. Return -1 if - * no such entry is found. dir must already be complete. - */ -static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) -{ - struct ref_entry **r; - struct string_slice key; - - if (refname == NULL || !dir->nr) - return -1; - - sort_ref_dir(dir); - key.len = len; - key.str = refname; - r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), - ref_entry_cmp_sslice); - - if (r == NULL) - return -1; - - return r - dir->entries; -} - -/* - * Search for a directory entry directly within dir (without - * recursing). Sort dir if necessary. subdirname must be a directory - * name (i.e., end in '/'). If mkdir is set, then create the - * directory if it is missing; otherwise, return NULL if the desired - * directory cannot be found. dir must already be complete. - */ -static struct ref_dir *search_for_subdir(struct ref_dir *dir, - const char *subdirname, size_t len, - int mkdir) -{ - int entry_index = search_ref_dir(dir, subdirname, len); - struct ref_entry *entry; - if (entry_index == -1) { - if (!mkdir) - return NULL; - /* - * Since dir is complete, the absence of a subdir - * means that the subdir really doesn't exist; - * therefore, create an empty record for it but mark - * the record complete. - */ - entry = create_dir_entry(dir->ref_store, subdirname, len, 0); - add_entry_to_dir(dir, entry); - } else { - entry = dir->entries[entry_index]; - } - return get_ref_dir(entry); -} - -/* - * If refname is a reference name, find the ref_dir within the dir - * tree that should hold refname. If refname is a directory name - * (i.e., ends in '/'), then return that ref_dir itself. dir must - * represent the top-level directory and must already be complete. - * Sort ref_dirs and recurse into subdirectories as necessary. If - * mkdir is set, then create any missing directories; otherwise, - * return NULL if the desired directory cannot be found. - */ -static struct ref_dir *find_containing_dir(struct ref_dir *dir, - const char *refname, int mkdir) -{ - const char *slash; - for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { - size_t dirnamelen = slash - refname + 1; - struct ref_dir *subdir; - subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); - if (!subdir) { - dir = NULL; - break; - } - dir = subdir; - } - - return dir; -} - -/* - * Find the value entry with the given name in dir, sorting ref_dirs - * and recursing into subdirectories as necessary. If the name is not - * found or it corresponds to a directory entry, return NULL. - */ -static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) -{ - int entry_index; - struct ref_entry *entry; - dir = find_containing_dir(dir, refname, 0); - if (!dir) - return NULL; - entry_index = search_ref_dir(dir, refname, strlen(refname)); - if (entry_index == -1) - return NULL; - entry = dir->entries[entry_index]; - return (entry->flag & REF_DIR) ? NULL : entry; -} - -/* - * Remove the entry with the given name from dir, recursing into - * subdirectories as necessary. If refname is the name of a directory - * (i.e., ends with '/'), then remove the directory and its contents. - * If the removal was successful, return the number of entries - * remaining in the directory entry that contained the deleted entry. - * If the name was not found, return -1. Please note that this - * function only deletes the entry from the cache; it does not delete - * it from the filesystem or ensure that other cache entries (which - * might be symbolic references to the removed entry) are updated. - * Nor does it remove any containing dir entries that might be made - * empty by the removal. dir must represent the top-level directory - * and must already be complete. - */ -static int remove_entry(struct ref_dir *dir, const char *refname) -{ - int refname_len = strlen(refname); - int entry_index; - struct ref_entry *entry; - int is_dir = refname[refname_len - 1] == '/'; - if (is_dir) { - /* - * refname represents a reference directory. Remove - * the trailing slash; otherwise we will get the - * directory *representing* refname rather than the - * one *containing* it. - */ - char *dirname = xmemdupz(refname, refname_len - 1); - dir = find_containing_dir(dir, dirname, 0); - free(dirname); - } else { - dir = find_containing_dir(dir, refname, 0); - } - if (!dir) - return -1; - entry_index = search_ref_dir(dir, refname, refname_len); - if (entry_index == -1) - return -1; - entry = dir->entries[entry_index]; - - memmove(&dir->entries[entry_index], - &dir->entries[entry_index + 1], - (dir->nr - entry_index - 1) * sizeof(*dir->entries) - ); - dir->nr--; - if (dir->sorted > entry_index) - dir->sorted--; - free_ref_entry(entry); - return dir->nr; -} - -/* - * Add a ref_entry to the ref_dir (unsorted), recursing into - * subdirectories as necessary. dir must represent the top-level - * directory. Return 0 on success. - */ -static int add_ref(struct ref_dir *dir, struct ref_entry *ref) -{ - dir = find_containing_dir(dir, ref->name, 1); - if (!dir) - return -1; - add_entry_to_dir(dir, ref); - return 0; -} - -/* - * Emit a warning and return true iff ref1 and ref2 have the same name - * and the same sha1. Die if they have the same name but different - * sha1s. - */ -static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) -{ - if (strcmp(ref1->name, ref2->name)) - return 0; - - /* Duplicate name; make sure that they don't conflict: */ - - if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) - /* This is impossible by construction */ - die("Reference directory conflict: %s", ref1->name); - - if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) - die("Duplicated ref, and SHA1s don't match: %s", ref1->name); - - warning("Duplicated ref: %s", ref1->name); - return 1; -} - -/* - * Sort the entries in dir non-recursively (if they are not already - * sorted) and remove any duplicate entries. - */ -static void sort_ref_dir(struct ref_dir *dir) -{ - int i, j; - struct ref_entry *last = NULL; - - /* - * This check also prevents passing a zero-length array to qsort(), - * which is a problem on some platforms. - */ - if (dir->sorted == dir->nr) - return; - - QSORT(dir->entries, dir->nr, ref_entry_cmp); - - /* Remove any duplicates: */ - for (i = 0, j = 0; j < dir->nr; j++) { - struct ref_entry *entry = dir->entries[j]; - if (last && is_dup_ref(last, entry)) - free_ref_entry(entry); - else - last = dir->entries[i++] = entry; - } - dir->sorted = dir->nr = i; -} - /* * Return true if refname, which has the specified oid and flags, can * be resolved to an object in the database. If the referred-to object @@ -536,358 +32,8 @@ static int ref_resolves_to_object(const char *refname, return 1; } -/* - * Return true if the reference described by entry can be resolved to - * an object in the database; otherwise, emit a warning and return - * false. - */ -static int entry_resolves_to_object(struct ref_entry *entry) -{ - return ref_resolves_to_object(entry->name, - &entry->u.value.oid, entry->flag); -} - -typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); - -/* - * Call fn for each reference in dir that has index in the range - * offset <= index < dir->nr. Recurse into subdirectories that are in - * that index range, sorting them before iterating. This function - * does not sort dir itself; it should be sorted beforehand. fn is - * called for all references, including broken ones. - */ -static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, - each_ref_entry_fn fn, void *cb_data) -{ - int i; - assert(dir->sorted == dir->nr); - for (i = offset; i < dir->nr; i++) { - struct ref_entry *entry = dir->entries[i]; - int retval; - if (entry->flag & REF_DIR) { - struct ref_dir *subdir = get_ref_dir(entry); - sort_ref_dir(subdir); - retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); - } else { - retval = fn(entry, cb_data); - } - if (retval) - return retval; - } - return 0; -} - -/* - * Load all of the refs from the dir into our in-memory cache. The hard work - * of loading loose refs is done by get_ref_dir(), so we just need to recurse - * through all of the sub-directories. We do not even need to care about - * sorting, as traversal order does not matter to us. - */ -static void prime_ref_dir(struct ref_dir *dir) -{ - int i; - for (i = 0; i < dir->nr; i++) { - struct ref_entry *entry = dir->entries[i]; - if (entry->flag & REF_DIR) - prime_ref_dir(get_ref_dir(entry)); - } -} - -/* - * A level in the reference hierarchy that is currently being iterated - * through. - */ -struct cache_ref_iterator_level { - /* - * The ref_dir being iterated over at this level. The ref_dir - * is sorted before being stored here. - */ - struct ref_dir *dir; - - /* - * The index of the current entry within dir (which might - * itself be a directory). If index == -1, then the iteration - * hasn't yet begun. If index == dir->nr, then the iteration - * through this level is over. - */ - int index; -}; - -/* - * Represent an iteration through a ref_dir in the memory cache. The - * iteration recurses through subdirectories. - */ -struct cache_ref_iterator { - struct ref_iterator base; - - /* - * The number of levels currently on the stack. This is always - * at least 1, because when it becomes zero the iteration is - * ended and this struct is freed. - */ - size_t levels_nr; - - /* The number of levels that have been allocated on the stack */ - size_t levels_alloc; - - /* - * A stack of levels. levels[0] is the uppermost level that is - * being iterated over in this iteration. (This is not - * necessary the top level in the references hierarchy. If we - * are iterating through a subtree, then levels[0] will hold - * the ref_dir for that subtree, and subsequent levels will go - * on from there.) - */ - struct cache_ref_iterator_level *levels; -}; - -static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator) -{ - struct cache_ref_iterator *iter = - (struct cache_ref_iterator *)ref_iterator; - - while (1) { - struct cache_ref_iterator_level *level = - &iter->levels[iter->levels_nr - 1]; - struct ref_dir *dir = level->dir; - struct ref_entry *entry; - - if (level->index == -1) - sort_ref_dir(dir); - - if (++level->index == level->dir->nr) { - /* This level is exhausted; pop up a level */ - if (--iter->levels_nr == 0) - return ref_iterator_abort(ref_iterator); - - continue; - } - - entry = dir->entries[level->index]; - - if (entry->flag & REF_DIR) { - /* push down a level */ - ALLOC_GROW(iter->levels, iter->levels_nr + 1, - iter->levels_alloc); - - level = &iter->levels[iter->levels_nr++]; - level->dir = get_ref_dir(entry); - level->index = -1; - } else { - iter->base.refname = entry->name; - iter->base.oid = &entry->u.value.oid; - iter->base.flags = entry->flag; - return ITER_OK; - } - } -} - -static enum peel_status peel_entry(struct ref_entry *entry, int repeel); - -static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator, - struct object_id *peeled) -{ - struct cache_ref_iterator *iter = - (struct cache_ref_iterator *)ref_iterator; - struct cache_ref_iterator_level *level; - struct ref_entry *entry; - - level = &iter->levels[iter->levels_nr - 1]; - - if (level->index == -1) - die("BUG: peel called before advance for cache iterator"); - - entry = level->dir->entries[level->index]; - - if (peel_entry(entry, 0)) - return -1; - oidcpy(peeled, &entry->u.value.peeled); - return 0; -} - -static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator) -{ - struct cache_ref_iterator *iter = - (struct cache_ref_iterator *)ref_iterator; - - free(iter->levels); - base_ref_iterator_free(ref_iterator); - return ITER_DONE; -} - -static struct ref_iterator_vtable cache_ref_iterator_vtable = { - cache_ref_iterator_advance, - cache_ref_iterator_peel, - cache_ref_iterator_abort -}; - -static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) -{ - struct cache_ref_iterator *iter; - struct ref_iterator *ref_iterator; - struct cache_ref_iterator_level *level; - - iter = xcalloc(1, sizeof(*iter)); - ref_iterator = &iter->base; - base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); - ALLOC_GROW(iter->levels, 10, iter->levels_alloc); - - iter->levels_nr = 1; - level = &iter->levels[0]; - level->index = -1; - level->dir = dir; - - return ref_iterator; -} - -struct nonmatching_ref_data { - const struct string_list *skip; - const char *conflicting_refname; -}; - -static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) -{ - struct nonmatching_ref_data *data = vdata; - - if (data->skip && string_list_has_string(data->skip, entry->name)) - return 0; - - data->conflicting_refname = entry->name; - return 1; -} - -/* - * Return 0 if a reference named refname could be created without - * conflicting with the name of an existing reference in dir. - * See verify_refname_available for more information. - */ -static int verify_refname_available_dir(const char *refname, - const struct string_list *extras, - const struct string_list *skip, - struct ref_dir *dir, - struct strbuf *err) -{ - const char *slash; - const char *extra_refname; - int pos; - struct strbuf dirname = STRBUF_INIT; - int ret = -1; - - /* - * For the sake of comments in this function, suppose that - * refname is "refs/foo/bar". - */ - - assert(err); - - strbuf_grow(&dirname, strlen(refname) + 1); - for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { - /* Expand dirname to the new prefix, not including the trailing slash: */ - strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); - - /* - * We are still at a leading dir of the refname (e.g., - * "refs/foo"; if there is a reference with that name, - * it is a conflict, *unless* it is in skip. - */ - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - if (pos >= 0 && - (!skip || !string_list_has_string(skip, dirname.buf))) { - /* - * We found a reference whose name is - * a proper prefix of refname; e.g., - * "refs/foo", and is not in skip. - */ - strbuf_addf(err, "'%s' exists; cannot create '%s'", - dirname.buf, refname); - goto cleanup; - } - } - - if (extras && string_list_has_string(extras, dirname.buf) && - (!skip || !string_list_has_string(skip, dirname.buf))) { - strbuf_addf(err, "cannot process '%s' and '%s' at the same time", - refname, dirname.buf); - goto cleanup; - } - - /* - * Otherwise, we can try to continue our search with - * the next component. So try to look up the - * directory, e.g., "refs/foo/". If we come up empty, - * we know there is nothing under this whole prefix, - * but even in that case we still have to continue the - * search for conflicts with extras. - */ - strbuf_addch(&dirname, '/'); - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - if (pos < 0) { - /* - * There was no directory "refs/foo/", - * so there is nothing under this - * whole prefix. So there is no need - * to continue looking for conflicting - * references. But we need to continue - * looking for conflicting extras. - */ - dir = NULL; - } else { - dir = get_ref_dir(dir->entries[pos]); - } - } - } - - /* - * We are at the leaf of our refname (e.g., "refs/foo/bar"). - * There is no point in searching for a reference with that - * name, because a refname isn't considered to conflict with - * itself. But we still need to check for references whose - * names are in the "refs/foo/bar/" namespace, because they - * *do* conflict. - */ - strbuf_addstr(&dirname, refname + dirname.len); - strbuf_addch(&dirname, '/'); - - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - - if (pos >= 0) { - /* - * We found a directory named "$refname/" - * (e.g., "refs/foo/bar/"). It is a problem - * iff it contains any ref that is not in - * "skip". - */ - struct nonmatching_ref_data data; - - data.skip = skip; - data.conflicting_refname = NULL; - dir = get_ref_dir(dir->entries[pos]); - sort_ref_dir(dir); - if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { - strbuf_addf(err, "'%s' exists; cannot create '%s'", - data.conflicting_refname, refname); - goto cleanup; - } - } - } - - extra_refname = find_descendant_ref(dirname.buf, extras, skip); - if (extra_refname) - strbuf_addf(err, "cannot process '%s' and '%s' at the same time", - refname, extra_refname); - else - ret = 0; - -cleanup: - strbuf_release(&dirname); - return ret; -} - struct packed_ref_cache { - struct ref_entry *root; + struct ref_cache *cache; /* * Count of references to the data structure in this instance, @@ -922,7 +68,7 @@ struct files_ref_store { char *gitcommondir; char *packed_refs_path; - struct ref_entry *loose; + struct ref_cache *loose; struct packed_ref_cache *packed; }; @@ -944,7 +90,7 @@ static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) { if (!--packed_refs->referrers) { - free_ref_entry(packed_refs->root); + free_ref_cache(packed_refs->cache); stat_validity_clear(&packed_refs->validity); free(packed_refs); return 1; @@ -968,7 +114,7 @@ static void clear_packed_ref_cache(struct files_ref_store *refs) static void clear_loose_ref_cache(struct files_ref_store *refs) { if (refs->loose) { - free_ref_entry(refs->loose); + free_ref_cache(refs->loose); refs->loose = NULL; } } @@ -1141,7 +287,7 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir) if (peeled == PEELED_FULLY || (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) last->flag |= REF_KNOWS_PEELED; - add_ref(dir, last); + add_ref_entry(dir, last); continue; } if (last && @@ -1229,11 +375,12 @@ static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *ref refs->packed = xcalloc(1, sizeof(*refs->packed)); acquire_packed_ref_cache(refs->packed); - refs->packed->root = create_dir_entry(refs, "", 0, 0); + refs->packed->cache = create_ref_cache(&refs->base, NULL); + refs->packed->cache->root->flag &= ~REF_INCOMPLETE; f = fopen(packed_refs_file, "r"); if (f) { stat_validity_update(&refs->packed->validity, fileno(f)); - read_packed_refs(f, get_ref_dir(refs->packed->root)); + read_packed_refs(f, get_ref_dir(refs->packed->cache->root)); fclose(f); } } @@ -1242,7 +389,7 @@ static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *ref static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) { - return get_ref_dir(packed_ref_cache->root); + return get_ref_dir(packed_ref_cache->cache->root); } static struct ref_dir *get_packed_refs(struct files_ref_store *refs) @@ -1263,8 +410,8 @@ static void add_packed_ref(struct files_ref_store *refs, if (!packed_ref_cache->lock) die("internal error: packed refs not locked"); - add_ref(get_packed_ref_dir(packed_ref_cache), - create_ref_entry(refname, sha1, REF_ISPACKED, 1)); + add_ref_entry(get_packed_ref_dir(packed_ref_cache), + create_ref_entry(refname, sha1, REF_ISPACKED, 1)); } /* @@ -1272,9 +419,11 @@ static void add_packed_ref(struct files_ref_store *refs, * (without recursing). dirname must end with '/'. dir must be the * directory entry corresponding to dirname. */ -static void read_loose_refs(const char *dirname, struct ref_dir *dir) +static void loose_fill_ref_dir(struct ref_store *ref_store, + struct ref_dir *dir, const char *dirname) { - struct files_ref_store *refs = dir->ref_store; + struct files_ref_store *refs = + files_downcast(ref_store, REF_STORE_READ, "fill_ref_dir"); DIR *d; struct dirent *de; int dirnamelen = strlen(dirname); @@ -1310,7 +459,7 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) } else if (S_ISDIR(st.st_mode)) { strbuf_addch(&refname, '/'); add_entry_to_dir(dir, - create_dir_entry(refs, refname.buf, + create_dir_entry(dir->cache, refname.buf, refname.len, 1)); } else { if (!refs_resolve_ref_unsafe(&refs->base, @@ -1347,9 +496,24 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) strbuf_release(&refname); strbuf_release(&path); closedir(d); + + /* + * Manually add refs/bisect, which, being per-worktree, might + * not appear in the directory listing for refs/ in the main + * repo. + */ + if (!strcmp(dirname, "refs/")) { + int pos = search_ref_dir(dir, "refs/bisect/", 12); + + if (pos < 0) { + struct ref_entry *child_entry = create_dir_entry( + dir->cache, "refs/bisect/", 12, 1); + add_entry_to_dir(dir, child_entry); + } + } } -static struct ref_dir *get_loose_refs(struct files_ref_store *refs) +static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) { if (!refs->loose) { /* @@ -1357,14 +521,19 @@ static struct ref_dir *get_loose_refs(struct files_ref_store *refs) * are about to read the only subdirectory that can * hold references: */ - refs->loose = create_dir_entry(refs, "", 0, 0); + refs->loose = create_ref_cache(&refs->base, loose_fill_ref_dir); + + /* We're going to fill the top level ourselves: */ + refs->loose->root->flag &= ~REF_INCOMPLETE; + /* - * Create an incomplete entry for "refs/": + * Add an incomplete entry for "refs/" (to be filled + * lazily): */ - add_entry_to_dir(get_ref_dir(refs->loose), - create_dir_entry(refs, "refs/", 5, 1)); + add_entry_to_dir(get_ref_dir(refs->loose->root), + create_dir_entry(refs->loose, "refs/", 5, 1)); } - return get_ref_dir(refs->loose); + return refs->loose; } /* @@ -1374,7 +543,7 @@ static struct ref_dir *get_loose_refs(struct files_ref_store *refs) static struct ref_entry *get_packed_ref(struct files_ref_store *refs, const char *refname) { - return find_ref(get_packed_refs(refs), refname); + return find_ref_entry(get_packed_refs(refs), refname); } /* @@ -1564,7 +733,7 @@ static void unlock_ref(struct ref_lock *lock) * * If the reference doesn't already exist, verify that refname doesn't * have a D/F conflict with any existing references. extras and skip - * are passed to verify_refname_available_dir() for this check. + * are passed to refs_verify_refname_available() for this check. * * If mustexist is not set and the reference is not found or is * broken, lock the reference anyway but clear sha1. @@ -1579,7 +748,7 @@ static void unlock_ref(struct ref_lock *lock) * * but it includes a lot more code to * - Deal with possible races with other processes - * - Avoid calling verify_refname_available_dir() when it can be + * - Avoid calling refs_verify_refname_available() when it can be * avoided, namely if we were successfully able to read the ref * - Generate informative error messages in the case of failure */ @@ -1636,7 +805,8 @@ retry: } else { /* * The error message set by - * verify_refname_available_dir() is OK. + * refs_verify_refname_available() is + * OK. */ ret = TRANSACTION_NAME_CONFLICT; } @@ -1726,10 +896,9 @@ retry: goto error_return; } else if (remove_dir_recursively(&ref_file, REMOVE_DIR_EMPTY_ONLY)) { - if (verify_refname_available_dir( - refname, extras, skip, - get_loose_refs(refs), - err)) { + if (refs_verify_refname_available( + &refs->base, refname, + extras, skip, err)) { /* * The error message set by * verify_refname_available() is OK. @@ -1761,16 +930,13 @@ retry: /* * If the ref did not exist and we are creating it, - * make sure there is no existing packed ref whose - * name begins with our refname, nor a packed ref - * whose name is a proper prefix of our refname. + * make sure there is no existing ref that conflicts + * with refname: */ - if (verify_refname_available_dir( - refname, extras, skip, - get_packed_refs(refs), - err)) { + if (refs_verify_refname_available( + &refs->base, refname, + extras, skip, err)) goto error_return; - } } ret = 0; @@ -1785,41 +951,6 @@ out: return ret; } -/* - * Peel the entry (if possible) and return its new peel_status. If - * repeel is true, re-peel the entry even if there is an old peeled - * value that is already stored in it. - * - * It is OK to call this function with a packed reference entry that - * might be stale and might even refer to an object that has since - * been garbage-collected. In such a case, if the entry has - * REF_KNOWS_PEELED then leave the status unchanged and return - * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID. - */ -static enum peel_status peel_entry(struct ref_entry *entry, int repeel) -{ - enum peel_status status; - - if (entry->flag & REF_KNOWS_PEELED) { - if (repeel) { - entry->flag &= ~REF_KNOWS_PEELED; - oidclr(&entry->u.value.peeled); - } else { - return is_null_oid(&entry->u.value.peeled) ? - PEEL_NON_TAG : PEEL_PEELED; - } - } - if (entry->flag & REF_ISBROKEN) - return PEEL_BROKEN; - if (entry->flag & REF_ISSYMREF) - return PEEL_IS_SYMREF; - - status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash); - if (status == PEEL_PEELED || status == PEEL_NON_TAG) - entry->flag |= REF_KNOWS_PEELED; - return status; -} - static int files_peel_ref(struct ref_store *ref_store, const char *refname, unsigned char *sha1) { @@ -1935,7 +1066,6 @@ static struct ref_iterator *files_ref_iterator_begin( const char *prefix, unsigned int flags) { struct files_ref_store *refs; - struct ref_dir *loose_dir, *packed_dir; struct ref_iterator *loose_iter, *packed_iter; struct files_ref_iterator *iter; struct ref_iterator *ref_iterator; @@ -1959,41 +1089,24 @@ static struct ref_iterator *files_ref_iterator_begin( * condition if loose refs are migrated to the packed-refs * file by a simultaneous process, but our in-memory view is * from before the migration. We ensure this as follows: - * First, we call prime_ref_dir(), which pre-reads the loose - * references for the subtree into the cache. (If they've - * already been read, that's OK; we only need to guarantee - * that they're read before the packed refs, not *how much* - * before.) After that, we call get_packed_ref_cache(), which - * internally checks whether the packed-ref cache is up to - * date with what is on disk, and re-reads it if not. + * First, we call start the loose refs iteration with its + * `prime_ref` argument set to true. This causes the loose + * references in the subtree to be pre-read into the cache. + * (If they've already been read, that's OK; we only need to + * guarantee that they're read before the packed refs, not + * *how much* before.) After that, we call + * get_packed_ref_cache(), which internally checks whether the + * packed-ref cache is up to date with what is on disk, and + * re-reads it if not. */ - loose_dir = get_loose_refs(refs); - - if (prefix && *prefix) - loose_dir = find_containing_dir(loose_dir, prefix, 0); - - if (loose_dir) { - prime_ref_dir(loose_dir); - loose_iter = cache_ref_iterator_begin(loose_dir); - } else { - /* There's nothing to iterate over. */ - loose_iter = empty_ref_iterator_begin(); - } + loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), + prefix, 1); iter->packed_ref_cache = get_packed_ref_cache(refs); acquire_packed_ref_cache(iter->packed_ref_cache); - packed_dir = get_packed_ref_dir(iter->packed_ref_cache); - - if (prefix && *prefix) - packed_dir = find_containing_dir(packed_dir, prefix, 0); - - if (packed_dir) { - packed_iter = cache_ref_iterator_begin(packed_dir); - } else { - /* There's nothing to iterate over. */ - packed_iter = empty_ref_iterator_begin(); - } + packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache, + prefix, 0); iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter); iter->flags = flags; @@ -2096,9 +1209,9 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, */ if (remove_empty_directories(&ref_file)) { last_errno = errno; - if (!verify_refname_available_dir( - refname, extras, skip, - get_loose_refs(refs), err)) + if (!refs_verify_refname_available( + &refs->base, + refname, extras, skip, err)) strbuf_addf(err, "there are still refs under '%s'", refname); goto error_return; @@ -2110,9 +1223,8 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, if (!resolved) { last_errno = errno; if (last_errno != ENOTDIR || - !verify_refname_available_dir( - refname, extras, skip, - get_loose_refs(refs), err)) + !refs_verify_refname_available(&refs->base, refname, + extras, skip, err)) strbuf_addf(err, "unable to resolve reference '%s': %s", refname, strerror(last_errno)); @@ -2126,9 +1238,8 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, * our refname. */ if (is_null_oid(&lock->old_oid) && - verify_refname_available_dir(refname, extras, skip, - get_packed_refs(refs), - err)) { + refs_verify_refname_available(&refs->base, refname, + extras, skip, err)) { last_errno = ENOTDIR; goto error_return; } @@ -2163,8 +1274,9 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, * Write an entry to the packed-refs file for the specified refname. * If peeled is non-NULL, write it as the entry's peeled value. */ -static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, - unsigned char *peeled) +static void write_packed_entry(FILE *fh, const char *refname, + const unsigned char *sha1, + const unsigned char *peeled) { fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); if (peeled) @@ -2172,22 +1284,6 @@ static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, } /* - * An each_ref_entry_fn that writes the entry to a packed-refs file. - */ -static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) -{ - enum peel_status peel_status = peel_entry(entry, 0); - - if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) - error("internal error: %s is not a valid packed reference!", - entry->name); - write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash, - peel_status == PEEL_PEELED ? - entry->u.value.peeled.hash : NULL); - return 0; -} - -/* * Lock the packed-refs file for writing. Flags is passed to * hold_lock_file_for_update(). Return 0 on success. On errors, set * errno appropriately and return a nonzero value. @@ -2232,9 +1328,10 @@ static int commit_packed_refs(struct files_ref_store *refs) { struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs); - int error = 0; + int ok, error = 0; int save_errno = 0; FILE *out; + struct ref_iterator *iter; files_assert_main_repository(refs, "commit_packed_refs"); @@ -2246,8 +1343,18 @@ static int commit_packed_refs(struct files_ref_store *refs) die_errno("unable to fdopen packed-refs descriptor"); fprintf_or_die(out, "%s", PACKED_REFS_HEADER); - do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), - 0, write_packed_entry_fn, out); + + iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0); + while ((ok = ref_iterator_advance(iter)) == ITER_OK) { + struct object_id peeled; + int peel_error = ref_iterator_peel(iter, &peeled); + + write_packed_entry(out, iter->refname, iter->oid->hash, + peel_error ? NULL : peeled.hash); + } + + if (ok != ITER_DONE) + die("error while iterating over references"); if (commit_lock_file(packed_ref_cache->lock)) { save_errno = errno; @@ -2285,65 +1392,6 @@ struct ref_to_prune { char name[FLEX_ARRAY]; }; -struct pack_refs_cb_data { - unsigned int flags; - struct ref_dir *packed_refs; - struct ref_to_prune *ref_to_prune; -}; - -/* - * An each_ref_entry_fn that is run over loose references only. If - * the loose reference can be packed, add an entry in the packed ref - * cache. If the reference should be pruned, also add it to - * ref_to_prune in the pack_refs_cb_data. - */ -static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) -{ - struct pack_refs_cb_data *cb = cb_data; - enum peel_status peel_status; - struct ref_entry *packed_entry; - int is_tag_ref = starts_with(entry->name, "refs/tags/"); - - /* Do not pack per-worktree refs: */ - if (ref_type(entry->name) != REF_TYPE_NORMAL) - return 0; - - /* ALWAYS pack tags */ - if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) - return 0; - - /* Do not pack symbolic or broken refs: */ - if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry)) - return 0; - - /* Add a packed ref cache entry equivalent to the loose entry. */ - peel_status = peel_entry(entry, 1); - if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) - die("internal error peeling reference %s (%s)", - entry->name, oid_to_hex(&entry->u.value.oid)); - packed_entry = find_ref(cb->packed_refs, entry->name); - if (packed_entry) { - /* Overwrite existing packed entry with info from loose entry */ - packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED; - oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid); - } else { - packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash, - REF_ISPACKED | REF_KNOWS_PEELED, 0); - add_ref(cb->packed_refs, packed_entry); - } - oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled); - - /* Schedule the loose reference for pruning if requested. */ - if ((cb->flags & PACK_REFS_PRUNE)) { - struct ref_to_prune *n; - FLEX_ALLOC_STR(n, name, entry->name); - hashcpy(n->sha1, entry->u.value.oid.hash); - n->next = cb->ref_to_prune; - cb->ref_to_prune = n; - } - return 0; -} - enum { REMOVE_EMPTY_PARENTS_REF = 0x01, REMOVE_EMPTY_PARENTS_REFLOG = 0x02 @@ -2433,21 +1481,73 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags) struct files_ref_store *refs = files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, "pack_refs"); - struct pack_refs_cb_data cbdata; - - memset(&cbdata, 0, sizeof(cbdata)); - cbdata.flags = flags; + struct ref_iterator *iter; + struct ref_dir *packed_refs; + int ok; + struct ref_to_prune *refs_to_prune = NULL; lock_packed_refs(refs, LOCK_DIE_ON_ERROR); - cbdata.packed_refs = get_packed_refs(refs); + packed_refs = get_packed_refs(refs); + + iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0); + while ((ok = ref_iterator_advance(iter)) == ITER_OK) { + /* + * If the loose reference can be packed, add an entry + * in the packed ref cache. If the reference should be + * pruned, also add it to refs_to_prune. + */ + struct ref_entry *packed_entry; + int is_tag_ref = starts_with(iter->refname, "refs/tags/"); - do_for_each_entry_in_dir(get_loose_refs(refs), 0, - pack_if_possible_fn, &cbdata); + /* Do not pack per-worktree refs: */ + if (ref_type(iter->refname) != REF_TYPE_NORMAL) + continue; + + /* ALWAYS pack tags */ + if (!(flags & PACK_REFS_ALL) && !is_tag_ref) + continue; + + /* Do not pack symbolic or broken refs: */ + if (iter->flags & REF_ISSYMREF) + continue; + + if (!ref_resolves_to_object(iter->refname, iter->oid, iter->flags)) + continue; + + /* + * Create an entry in the packed-refs cache equivalent + * to the one from the loose ref cache, except that + * we don't copy the peeled status, because we want it + * to be re-peeled. + */ + packed_entry = find_ref_entry(packed_refs, iter->refname); + if (packed_entry) { + /* Overwrite existing packed entry with info from loose entry */ + packed_entry->flag = REF_ISPACKED; + oidcpy(&packed_entry->u.value.oid, iter->oid); + } else { + packed_entry = create_ref_entry(iter->refname, iter->oid->hash, + REF_ISPACKED, 0); + add_ref_entry(packed_refs, packed_entry); + } + oidclr(&packed_entry->u.value.peeled); + + /* Schedule the loose reference for pruning if requested. */ + if ((flags & PACK_REFS_PRUNE)) { + struct ref_to_prune *n; + FLEX_ALLOC_STR(n, name, iter->refname); + hashcpy(n->sha1, iter->oid->hash); + n->next = refs_to_prune; + refs_to_prune = n; + } + } + if (ok != ITER_DONE) + die("error while iterating over references"); if (commit_packed_refs(refs)) die_errno("unable to overwrite old ref-pack file"); - prune_refs(refs, cbdata.ref_to_prune); + prune_refs(refs, refs_to_prune); return 0; } @@ -2488,7 +1588,7 @@ static int repack_without_refs(struct files_ref_store *refs, /* Remove refnames from the cache */ for_each_string_list_item(refname, refnames) - if (remove_entry(packed, refname->string) != -1) + if (remove_entry_from_dir(packed, refname->string) != -1) removed = 1; if (!removed) { /* @@ -2608,26 +1708,6 @@ static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname) return ret; } -static int files_verify_refname_available(struct ref_store *ref_store, - const char *newname, - const struct string_list *extras, - const struct string_list *skip, - struct strbuf *err) -{ - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, "verify_refname_available"); - struct ref_dir *packed_refs = get_packed_refs(refs); - struct ref_dir *loose_refs = get_loose_refs(refs); - - if (verify_refname_available_dir(newname, extras, skip, - packed_refs, err) || - verify_refname_available_dir(newname, extras, skip, - loose_refs, err)) - return -1; - - return 0; -} - static int write_ref_to_lockfile(struct ref_lock *lock, const unsigned char *sha1, struct strbuf *err); static int commit_ref_update(struct files_ref_store *refs, @@ -4294,7 +3374,6 @@ struct ref_storage_be refs_be_files = { files_ref_iterator_begin, files_read_raw_ref, - files_verify_refname_available, files_reflog_iterator_begin, files_for_each_reflog_ent, |