-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);
- }
- }
- 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_entry(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_from_dir(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_entry(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;
-}
-