#include "../cache.h"
#include "../refs.h"
#include "refs-internal.h"
+#include "../iterator.h"
+#include "../dir-iterator.h"
#include "../lockfile.h"
#include "../object.h"
#include "../dir.h"
struct ref_lock {
char *ref_name;
- char *orig_ref_name;
struct lock_file *lk;
struct object_id old_oid;
};
}
/*
- * Return true iff the reference described by entry can be resolved to
- * an object in the database. Emit a warning if the referred-to
- * object does not exist.
+ * 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
+ * does not exist, emit a warning and return false.
*/
-static int ref_resolves_to_object(struct ref_entry *entry)
+static int ref_resolves_to_object(const char *refname,
+ const struct object_id *oid,
+ unsigned int flags)
{
- if (entry->flag & REF_ISBROKEN)
+ if (flags & REF_ISBROKEN)
return 0;
- if (!has_sha1_file(entry->u.value.oid.hash)) {
- error("%s does not point to a valid object!", entry->name);
+ if (!has_sha1_file(oid->hash)) {
+ error("%s does not point to a valid object!", refname);
return 0;
}
return 1;
}
/*
- * current_ref is a performance hack: when iterating over references
- * using the for_each_ref*() functions, current_ref is set to the
- * current reference's entry 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 current reference
- * (it usually is) and if so, returns that reference's peeled version
- * if it is available. This avoids a refname lookup in a common case.
- */
-static struct ref_entry *current_ref;
-
-typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
-
-struct ref_entry_cb {
- const char *base;
- int trim;
- int flags;
- each_ref_fn *fn;
- void *cb_data;
-};
-
-/*
- * Handle one reference in a do_for_each_ref*()-style iteration,
- * calling an each_ref_fn for each entry.
+ * 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 do_one_ref(struct ref_entry *entry, void *cb_data)
+static int entry_resolves_to_object(struct ref_entry *entry)
{
- struct ref_entry_cb *data = cb_data;
- struct ref_entry *old_current_ref;
- int retval;
-
- if (!starts_with(entry->name, data->base))
- return 0;
-
- if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
- !ref_resolves_to_object(entry))
- return 0;
-
- /* Store the old value, in case this is a recursive call: */
- old_current_ref = current_ref;
- current_ref = entry;
- retval = data->fn(entry->name + data->trim, &entry->u.value.oid,
- entry->flag, data->cb_data);
- current_ref = old_current_ref;
- return retval;
+ 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
return 0;
}
-/*
- * Call fn for each reference in the union of dir1 and dir2, in order
- * by refname. Recurse into subdirectories. If a value entry appears
- * in both dir1 and dir2, then only process the version that is in
- * dir2. The input dirs must already be sorted, but subdirs will be
- * sorted as needed. fn is called for all references, including
- * broken ones.
- */
-static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
- struct ref_dir *dir2,
- each_ref_entry_fn fn, void *cb_data)
-{
- int retval;
- int i1 = 0, i2 = 0;
-
- assert(dir1->sorted == dir1->nr);
- assert(dir2->sorted == dir2->nr);
- while (1) {
- struct ref_entry *e1, *e2;
- int cmp;
- if (i1 == dir1->nr) {
- return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
- }
- if (i2 == dir2->nr) {
- return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
- }
- e1 = dir1->entries[i1];
- e2 = dir2->entries[i2];
- cmp = strcmp(e1->name, e2->name);
- if (cmp == 0) {
- if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
- /* Both are directories; descend them in parallel. */
- struct ref_dir *subdir1 = get_ref_dir(e1);
- struct ref_dir *subdir2 = get_ref_dir(e2);
- sort_ref_dir(subdir1);
- sort_ref_dir(subdir2);
- retval = do_for_each_entry_in_dirs(
- subdir1, subdir2, fn, cb_data);
- i1++;
- i2++;
- } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
- /* Both are references; ignore the one from dir1. */
- retval = fn(e2, cb_data);
- i1++;
- i2++;
- } else {
- die("conflict between reference and directory: %s",
- e1->name);
- }
- } else {
- struct ref_entry *e;
- if (cmp < 0) {
- e = e1;
- i1++;
- } else {
- e = e2;
- i2++;
- }
- if (e->flag & REF_DIR) {
- struct ref_dir *subdir = get_ref_dir(e);
- sort_ref_dir(subdir);
- retval = do_for_each_entry_in_dir(
- subdir, 0, fn, cb_data);
- } else {
- retval = fn(e, cb_data);
- }
- }
- if (retval)
- return retval;
- }
-}
-
/*
* 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
}
}
+/*
+ * 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;
+ hashcpy(peeled->hash, entry->u.value.peeled.hash);
+ 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;
/*
* Return a pointer to a ref_cache for the specified submodule. For
- * the main repository, use submodule==NULL. The returned structure
- * will be allocated and initialized but not necessarily populated; it
- * should not be freed.
+ * the main repository, use submodule==NULL; such a call cannot fail.
+ * For a submodule, the submodule must exist and be a nonbare
+ * repository, otherwise return NULL.
+ *
+ * The returned structure will be allocated and initialized but not
+ * necessarily populated; it should not be freed.
*/
static struct ref_cache *get_ref_cache(const char *submodule)
{
struct ref_cache *refs = lookup_ref_cache(submodule);
- if (!refs)
- refs = create_ref_cache(submodule);
+
+ if (!refs) {
+ struct strbuf submodule_sb = STRBUF_INIT;
+
+ strbuf_addstr(&submodule_sb, submodule);
+ if (is_nonbare_repository_dir(&submodule_sb))
+ refs = create_ref_cache(submodule);
+ strbuf_release(&submodule_sb);
+ }
+
return refs;
}
return -1;
strbuf_add(&submodule, path, len);
- refs = lookup_ref_cache(submodule.buf);
+ refs = get_ref_cache(submodule.buf);
if (!refs) {
- if (!is_nonbare_repository_dir(&submodule)) {
- strbuf_release(&submodule);
- return -1;
- }
- refs = create_ref_cache(submodule.buf);
+ strbuf_release(&submodule);
+ return -1;
}
strbuf_release(&submodule);
return -1;
}
-/*
- * Read a raw ref from the filesystem or packed refs file.
- *
- * If the ref is a sha1, fill in sha1 and return 0.
- *
- * If the ref is symbolic, fill in *symref with the referrent
- * (e.g. "refs/heads/master") and return 0. The caller is responsible
- * for validating the referrent. Set REF_ISSYMREF in flags.
- *
- * 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 flags, 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 flags as well, regardless of
- * outcome.
- *
- * sb_path is workspace: the caller should allocate and free it.
- *
- * It is OK for refname to point into symref. In this case:
- * - if the function succeeds with REF_ISSYMREF, symref will be
- * overwritten and the memory pointed to by refname might be changed
- * or even freed.
- * - in all other cases, symref will be untouched, and therefore
- * refname will still be valid and unchanged.
- */
int read_raw_ref(const char *refname, unsigned char *sha1,
- struct strbuf *symref, unsigned int *flags)
+ struct strbuf *referent, unsigned int *type)
{
struct strbuf sb_contents = STRBUF_INIT;
struct strbuf sb_path = STRBUF_INIT;
int ret = -1;
int save_errno;
+ *type = 0;
strbuf_reset(&sb_path);
strbuf_git_path(&sb_path, "%s", refname);
path = sb_path.buf;
if (lstat(path, &st) < 0) {
if (errno != ENOENT)
goto out;
- if (resolve_missing_loose_ref(refname, sha1, flags)) {
+ if (resolve_missing_loose_ref(refname, sha1, type)) {
errno = ENOENT;
goto out;
}
}
if (starts_with(sb_contents.buf, "refs/") &&
!check_refname_format(sb_contents.buf, 0)) {
- strbuf_swap(&sb_contents, symref);
- *flags |= REF_ISSYMREF;
+ strbuf_swap(&sb_contents, referent);
+ *type |= REF_ISSYMREF;
ret = 0;
goto out;
}
/* Is it a directory? */
if (S_ISDIR(st.st_mode)) {
- errno = EISDIR;
+ /*
+ * Even though there is a directory where the loose
+ * ref is supposed to be, there could still be a
+ * packed ref:
+ */
+ if (resolve_missing_loose_ref(refname, sha1, type)) {
+ errno = EISDIR;
+ goto out;
+ }
+ ret = 0;
goto out;
}
while (isspace(*buf))
buf++;
- strbuf_reset(symref);
- strbuf_addstr(symref, buf);
- *flags |= REF_ISSYMREF;
+ strbuf_reset(referent);
+ strbuf_addstr(referent, buf);
+ *type |= REF_ISSYMREF;
ret = 0;
goto out;
}
*/
if (get_sha1_hex(buf, sha1) ||
(buf[40] != '\0' && !isspace(buf[40]))) {
- *flags |= REF_ISBROKEN;
+ *type |= REF_ISBROKEN;
errno = EINVAL;
goto out;
}
return ret;
}
+static void unlock_ref(struct ref_lock *lock)
+{
+ /* Do not free lock->lk -- atexit() still looks at them */
+ if (lock->lk)
+ rollback_lock_file(lock->lk);
+ free(lock->ref_name);
+ free(lock);
+}
+
+/*
+ * Lock refname, without following symrefs, and set *lock_p to point
+ * at a newly-allocated lock object. Fill in lock->old_oid, referent,
+ * and type similarly to read_raw_ref().
+ *
+ * The caller must verify that refname is a "safe" reference name (in
+ * the sense of refname_is_safe()) before calling this function.
+ *
+ * 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.
+ *
+ * If mustexist is not set and the reference is not found or is
+ * broken, lock the reference anyway but clear sha1.
+ *
+ * Return 0 on success. On failure, write an error message to err and
+ * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
+ *
+ * Implementation note: This function is basically
+ *
+ * lock reference
+ * read_raw_ref()
+ *
+ * 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
+ * avoided, namely if we were successfully able to read the ref
+ * - Generate informative error messages in the case of failure
+ */
+static int lock_raw_ref(const char *refname, int mustexist,
+ const struct string_list *extras,
+ const struct string_list *skip,
+ struct ref_lock **lock_p,
+ struct strbuf *referent,
+ unsigned int *type,
+ struct strbuf *err)
+{
+ struct ref_lock *lock;
+ struct strbuf ref_file = STRBUF_INIT;
+ int attempts_remaining = 3;
+ int ret = TRANSACTION_GENERIC_ERROR;
+
+ assert(err);
+ *type = 0;
+
+ /* First lock the file so it can't change out from under us. */
+
+ *lock_p = lock = xcalloc(1, sizeof(*lock));
+
+ lock->ref_name = xstrdup(refname);
+ strbuf_git_path(&ref_file, "%s", refname);
+
+retry:
+ switch (safe_create_leading_directories(ref_file.buf)) {
+ case SCLD_OK:
+ break; /* success */
+ case SCLD_EXISTS:
+ /*
+ * Suppose refname is "refs/foo/bar". We just failed
+ * to create the containing directory, "refs/foo",
+ * because there was a non-directory in the way. This
+ * indicates a D/F conflict, probably because of
+ * another reference such as "refs/foo". There is no
+ * reason to expect this error to be transitory.
+ */
+ if (verify_refname_available(refname, extras, skip, err)) {
+ if (mustexist) {
+ /*
+ * To the user the relevant error is
+ * that the "mustexist" reference is
+ * missing:
+ */
+ strbuf_reset(err);
+ strbuf_addf(err, "unable to resolve reference '%s'",
+ refname);
+ } else {
+ /*
+ * The error message set by
+ * verify_refname_available_dir() is OK.
+ */
+ ret = TRANSACTION_NAME_CONFLICT;
+ }
+ } else {
+ /*
+ * The file that is in the way isn't a loose
+ * reference. Report it as a low-level
+ * failure.
+ */
+ strbuf_addf(err, "unable to create lock file %s.lock; "
+ "non-directory in the way",
+ ref_file.buf);
+ }
+ goto error_return;
+ case SCLD_VANISHED:
+ /* Maybe another process was tidying up. Try again. */
+ if (--attempts_remaining > 0)
+ goto retry;
+ /* fall through */
+ default:
+ strbuf_addf(err, "unable to create directory for %s",
+ ref_file.buf);
+ goto error_return;
+ }
+
+ if (!lock->lk)
+ lock->lk = xcalloc(1, sizeof(struct lock_file));
+
+ if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) {
+ if (errno == ENOENT && --attempts_remaining > 0) {
+ /*
+ * Maybe somebody just deleted one of the
+ * directories leading to ref_file. Try
+ * again:
+ */
+ goto retry;
+ } else {
+ unable_to_lock_message(ref_file.buf, errno, err);
+ goto error_return;
+ }
+ }
+
+ /*
+ * Now we hold the lock and can read the reference without
+ * fear that its value will change.
+ */
+
+ if (read_raw_ref(refname, lock->old_oid.hash, referent, type)) {
+ if (errno == ENOENT) {
+ if (mustexist) {
+ /* Garden variety missing reference. */
+ strbuf_addf(err, "unable to resolve reference '%s'",
+ refname);
+ goto error_return;
+ } else {
+ /*
+ * Reference is missing, but that's OK. We
+ * know that there is not a conflict with
+ * another loose reference because
+ * (supposing that we are trying to lock
+ * reference "refs/foo/bar"):
+ *
+ * - We were successfully able to create
+ * the lockfile refs/foo/bar.lock, so we
+ * know there cannot be a loose reference
+ * named "refs/foo".
+ *
+ * - We got ENOENT and not EISDIR, so we
+ * know that there cannot be a loose
+ * reference named "refs/foo/bar/baz".
+ */
+ }
+ } else if (errno == EISDIR) {
+ /*
+ * There is a directory in the way. It might have
+ * contained references that have been deleted. If
+ * we don't require that the reference already
+ * exists, try to remove the directory so that it
+ * doesn't cause trouble when we want to rename the
+ * lockfile into place later.
+ */
+ if (mustexist) {
+ /* Garden variety missing reference. */
+ strbuf_addf(err, "unable to resolve reference '%s'",
+ refname);
+ 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(&ref_cache),
+ err)) {
+ /*
+ * The error message set by
+ * verify_refname_available() is OK.
+ */
+ ret = TRANSACTION_NAME_CONFLICT;
+ goto error_return;
+ } else {
+ /*
+ * We can't delete the directory,
+ * but we also don't know of any
+ * references that it should
+ * contain.
+ */
+ strbuf_addf(err, "there is a non-empty directory '%s' "
+ "blocking reference '%s'",
+ ref_file.buf, refname);
+ goto error_return;
+ }
+ }
+ } else if (errno == EINVAL && (*type & REF_ISBROKEN)) {
+ strbuf_addf(err, "unable to resolve reference '%s': "
+ "reference broken", refname);
+ goto error_return;
+ } else {
+ strbuf_addf(err, "unable to resolve reference '%s': %s",
+ refname, strerror(errno));
+ goto error_return;
+ }
+
+ /*
+ * 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.
+ */
+ if (verify_refname_available_dir(
+ refname, extras, skip,
+ get_packed_refs(&ref_cache),
+ err)) {
+ goto error_return;
+ }
+ }
+
+ ret = 0;
+ goto out;
+
+error_return:
+ unlock_ref(lock);
+ *lock_p = NULL;
+
+out:
+ strbuf_release(&ref_file);
+ 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
int flag;
unsigned char base[20];
- if (current_ref && (current_ref->name == refname
- || !strcmp(current_ref->name, refname))) {
- if (peel_entry(current_ref, 0))
+ if (current_ref_iter && current_ref_iter->refname == refname) {
+ struct object_id peeled;
+
+ if (ref_iterator_peel(current_ref_iter, &peeled))
return -1;
- hashcpy(sha1, current_ref->u.value.peeled.hash);
+ hashcpy(sha1, peeled.hash);
return 0;
}
return peel_object(base, sha1);
}
-/*
- * Call fn for each reference in the specified ref_cache, omitting
- * references not in the containing_dir of base. fn is called for all
- * references, including broken ones. If fn ever returns a non-zero
- * value, stop the iteration and return that value; otherwise, return
- * 0.
- */
-static int do_for_each_entry(struct ref_cache *refs, const char *base,
- each_ref_entry_fn fn, void *cb_data)
-{
+struct files_ref_iterator {
+ struct ref_iterator base;
+
struct packed_ref_cache *packed_ref_cache;
- struct ref_dir *loose_dir;
- struct ref_dir *packed_dir;
- int retval = 0;
+ struct ref_iterator *iter0;
+ unsigned int flags;
+};
- /*
- * We must make sure that all loose refs are read before accessing the
- * packed-refs file; this avoids a race condition in which loose refs
- * are migrated to the packed-refs file by a simultaneous process, but
- * our in-memory view is from before the migration. get_packed_ref_cache()
- * takes care of making sure our view is up to date with what is on
- * disk.
- */
- loose_dir = get_loose_refs(refs);
- if (base && *base) {
- loose_dir = find_containing_dir(loose_dir, base, 0);
- }
- if (loose_dir)
- prime_ref_dir(loose_dir);
+static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
+ int ok;
- packed_ref_cache = get_packed_ref_cache(refs);
- acquire_packed_ref_cache(packed_ref_cache);
- packed_dir = get_packed_ref_dir(packed_ref_cache);
- if (base && *base) {
- packed_dir = find_containing_dir(packed_dir, base, 0);
- }
-
- if (packed_dir && loose_dir) {
- sort_ref_dir(packed_dir);
- sort_ref_dir(loose_dir);
- retval = do_for_each_entry_in_dirs(
- packed_dir, loose_dir, fn, cb_data);
- } else if (packed_dir) {
- sort_ref_dir(packed_dir);
- retval = do_for_each_entry_in_dir(
- packed_dir, 0, fn, cb_data);
- } else if (loose_dir) {
- sort_ref_dir(loose_dir);
- retval = do_for_each_entry_in_dir(
- loose_dir, 0, fn, cb_data);
+ while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
+ !ref_resolves_to_object(iter->iter0->refname,
+ iter->iter0->oid,
+ iter->iter0->flags))
+ continue;
+
+ iter->base.refname = iter->iter0->refname;
+ iter->base.oid = iter->iter0->oid;
+ iter->base.flags = iter->iter0->flags;
+ return ITER_OK;
}
- release_packed_ref_cache(packed_ref_cache);
- return retval;
+ iter->iter0 = NULL;
+ if (ref_iterator_abort(ref_iterator) != ITER_DONE)
+ ok = ITER_ERROR;
+
+ return ok;
}
-/*
- * Call fn for each reference in the specified ref_cache for which the
- * refname begins with base. If trim is non-zero, then trim that many
- * characters off the beginning of each refname before passing the
- * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
- * broken references in the iteration. If fn ever returns a non-zero
- * value, stop the iteration and return that value; otherwise, return
- * 0.
- */
-int do_for_each_ref(const char *submodule, const char *base,
- each_ref_fn fn, int trim, int flags, void *cb_data)
+static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
{
- struct ref_entry_cb data;
- struct ref_cache *refs;
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
+
+ return ref_iterator_peel(iter->iter0, peeled);
+}
+
+static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->iter0)
+ ok = ref_iterator_abort(iter->iter0);
- refs = get_ref_cache(submodule);
- data.base = base;
- data.trim = trim;
- data.flags = flags;
- data.fn = fn;
- data.cb_data = cb_data;
+ release_packed_ref_cache(iter->packed_ref_cache);
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable files_ref_iterator_vtable = {
+ files_ref_iterator_advance,
+ files_ref_iterator_peel,
+ files_ref_iterator_abort
+};
+
+struct ref_iterator *files_ref_iterator_begin(
+ const char *submodule,
+ const char *prefix, unsigned int flags)
+{
+ struct ref_cache *refs = get_ref_cache(submodule);
+ struct ref_dir *loose_dir, *packed_dir;
+ struct ref_iterator *loose_iter, *packed_iter;
+ struct files_ref_iterator *iter;
+ struct ref_iterator *ref_iterator;
+
+ if (!refs)
+ return empty_ref_iterator_begin();
if (ref_paranoia < 0)
ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
if (ref_paranoia)
- data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;
+ flags |= DO_FOR_EACH_INCLUDE_BROKEN;
- return do_for_each_entry(refs, base, do_one_ref, &data);
-}
+ iter = xcalloc(1, sizeof(*iter));
+ ref_iterator = &iter->base;
+ base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
-static void unlock_ref(struct ref_lock *lock)
-{
- /* Do not free lock->lk -- atexit() still looks at them */
- if (lock->lk)
- rollback_lock_file(lock->lk);
- free(lock->ref_name);
- free(lock->orig_ref_name);
- free(lock);
+ /*
+ * We must make sure that all loose refs are read before
+ * accessing the packed-refs file; this avoids a race
+ * 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.
+ */
+
+ 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();
+ }
+
+ 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();
+ }
+
+ iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
+ iter->flags = flags;
+
+ return ref_iterator;
}
/*
lock->old_oid.hash, NULL)) {
if (old_sha1) {
int save_errno = errno;
- strbuf_addf(err, "can't verify ref %s", lock->ref_name);
+ strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
errno = save_errno;
return -1;
} else {
}
}
if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
- strbuf_addf(err, "ref %s is at %s but expected %s",
+ strbuf_addf(err, "ref '%s' is at %s but expected %s",
lock->ref_name,
oid_to_hex(&lock->old_oid),
sha1_to_hex(old_sha1));
const unsigned char *old_sha1,
const struct string_list *extras,
const struct string_list *skip,
- unsigned int flags, int *type_p,
+ unsigned int flags, int *type,
struct strbuf *err)
{
struct strbuf ref_file = STRBUF_INIT;
- struct strbuf orig_ref_file = STRBUF_INIT;
- const char *orig_refname = refname;
struct ref_lock *lock;
int last_errno = 0;
- int type;
- int lflags = 0;
+ int lflags = LOCK_NO_DEREF;
int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
- int resolve_flags = 0;
+ int resolve_flags = RESOLVE_REF_NO_RECURSE;
int attempts_remaining = 3;
+ int resolved;
assert(err);
resolve_flags |= RESOLVE_REF_READING;
if (flags & REF_DELETING)
resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
- if (flags & REF_NODEREF) {
- resolve_flags |= RESOLVE_REF_NO_RECURSE;
- lflags |= LOCK_NO_DEREF;
- }
- refname = resolve_ref_unsafe(refname, resolve_flags,
- lock->old_oid.hash, &type);
- if (!refname && errno == EISDIR) {
+ strbuf_git_path(&ref_file, "%s", refname);
+ resolved = !!resolve_ref_unsafe(refname, resolve_flags,
+ lock->old_oid.hash, type);
+ if (!resolved && errno == EISDIR) {
/*
* we are trying to lock foo but we used to
* have foo/bar which now does not exist;
* it is normal for the empty directory 'foo'
* to remain.
*/
- strbuf_git_path(&orig_ref_file, "%s", orig_refname);
- if (remove_empty_directories(&orig_ref_file)) {
+ if (remove_empty_directories(&ref_file)) {
last_errno = errno;
- if (!verify_refname_available_dir(orig_refname, extras, skip,
+ if (!verify_refname_available_dir(refname, extras, skip,
get_loose_refs(&ref_cache), err))
strbuf_addf(err, "there are still refs under '%s'",
- orig_refname);
+ refname);
goto error_return;
}
- refname = resolve_ref_unsafe(orig_refname, resolve_flags,
- lock->old_oid.hash, &type);
+ resolved = !!resolve_ref_unsafe(refname, resolve_flags,
+ lock->old_oid.hash, type);
}
- if (type_p)
- *type_p = type;
- if (!refname) {
+ if (!resolved) {
last_errno = errno;
if (last_errno != ENOTDIR ||
- !verify_refname_available_dir(orig_refname, extras, skip,
+ !verify_refname_available_dir(refname, extras, skip,
get_loose_refs(&ref_cache), err))
- strbuf_addf(err, "unable to resolve reference %s: %s",
- orig_refname, strerror(last_errno));
+ strbuf_addf(err, "unable to resolve reference '%s': %s",
+ refname, strerror(last_errno));
goto error_return;
}
- if (flags & REF_NODEREF)
- refname = orig_refname;
-
/*
* If the ref did not exist and we are creating it, make sure
* there is no existing packed ref whose name begins with our
lock->lk = xcalloc(1, sizeof(struct lock_file));
lock->ref_name = xstrdup(refname);
- lock->orig_ref_name = xstrdup(orig_refname);
- strbuf_git_path(&ref_file, "%s", refname);
retry:
switch (safe_create_leading_directories_const(ref_file.buf)) {
/* fall through */
default:
last_errno = errno;
- strbuf_addf(err, "unable to create directory for %s",
+ strbuf_addf(err, "unable to create directory for '%s'",
ref_file.buf);
goto error_return;
}
out:
strbuf_release(&ref_file);
- strbuf_release(&orig_ref_file);
errno = last_errno;
return lock;
}
return 0;
/* Do not pack symbolic or broken refs: */
- if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
+ if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))
return 0;
/* Add a packed ref cache entry equivalent to the loose entry. */
transaction = ref_transaction_begin(&err);
if (!transaction ||
ref_transaction_delete(transaction, r->name, r->sha1,
- REF_ISPRUNING, NULL, &err) ||
+ REF_ISPRUNING | REF_NODEREF, NULL, &err) ||
ref_transaction_commit(transaction, &err)) {
ref_transaction_free(transaction);
error("%s", err.buf);
return 0;
}
-int delete_refs(struct string_list *refnames)
+int delete_refs(struct string_list *refnames, unsigned int flags)
{
struct strbuf err = STRBUF_INIT;
int i, result = 0;
for (i = 0; i < refnames->nr; i++) {
const char *refname = refnames->items[i].string;
- if (delete_ref(refname, NULL, 0))
+ if (delete_ref(refname, NULL, flags))
result |= error(_("could not remove reference %s"), refname);
}
}
int verify_refname_available(const char *newname,
- struct string_list *extras,
- struct string_list *skip,
+ const struct string_list *extras,
+ const struct string_list *skip,
struct strbuf *err)
{
struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
const unsigned char *sha1, struct strbuf *err);
static int commit_ref_update(struct ref_lock *lock,
const unsigned char *sha1, const char *logmsg,
- int flags, struct strbuf *err);
+ struct strbuf *err);
int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
{
struct ref_lock *lock;
struct stat loginfo;
int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
- const char *symref = NULL;
struct strbuf err = STRBUF_INIT;
if (log && S_ISLNK(loginfo.st_mode))
return error("reflog for %s is a symlink", oldrefname);
- symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
- orig_sha1, &flag);
+ if (!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
+ orig_sha1, &flag))
+ return error("refname %s not found", oldrefname);
+
if (flag & REF_ISSYMREF)
return error("refname %s is a symbolic ref, renaming it is not supported",
oldrefname);
- if (!symref)
- return error("refname %s not found", oldrefname);
-
if (!rename_ref_available(oldrefname, newrefname))
return 1;
goto rollback;
}
- if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
- delete_ref(newrefname, sha1, REF_NODEREF)) {
+ /*
+ * Since we are doing a shallow lookup, sha1 is not the
+ * correct value to pass to delete_ref as old_sha1. But that
+ * doesn't matter, because an old_sha1 check wouldn't add to
+ * the safety anyway; we want to delete the reference whatever
+ * its current value.
+ */
+ if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
+ sha1, NULL) &&
+ delete_ref(newrefname, NULL, REF_NODEREF)) {
if (errno==EISDIR) {
struct strbuf path = STRBUF_INIT;
int result;
logmoved = log;
- lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);
+ lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,
+ NULL, &err);
if (!lock) {
error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
strbuf_release(&err);
hashcpy(lock->old_oid.hash, orig_sha1);
if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
- commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) {
+ commit_ref_update(lock, orig_sha1, logmsg, &err)) {
error("unable to write current sha1 into %s: %s", newrefname, err.buf);
strbuf_release(&err);
goto rollback;
return 0;
rollback:
- lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);
+ lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,
+ NULL, &err);
if (!lock) {
error("unable to lock %s for rollback: %s", oldrefname, err.buf);
strbuf_release(&err);
flag = log_all_ref_updates;
log_all_ref_updates = 0;
if (write_ref_to_lockfile(lock, orig_sha1, &err) ||
- commit_ref_update(lock, orig_sha1, NULL, 0, &err)) {
+ commit_ref_update(lock, orig_sha1, NULL, &err)) {
error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
strbuf_release(&err);
}
static int commit_ref(struct ref_lock *lock)
{
+ char *path = get_locked_file_path(lock->lk);
+ struct stat st;
+
+ if (!lstat(path, &st) && S_ISDIR(st.st_mode)) {
+ /*
+ * There is a directory at the path we want to rename
+ * the lockfile to. Hopefully it is empty; try to
+ * delete it.
+ */
+ size_t len = strlen(path);
+ struct strbuf sb_path = STRBUF_INIT;
+
+ strbuf_attach(&sb_path, path, len, len);
+
+ /*
+ * If this fails, commit_lock_file() will also fail
+ * and will report the problem.
+ */
+ remove_empty_directories(&sb_path);
+ strbuf_release(&sb_path);
+ } else {
+ free(path);
+ }
+
if (commit_lock_file(lock->lk))
return -1;
return 0;
strbuf_git_path(logfile, "logs/%s", refname);
if (force_create || should_autocreate_reflog(refname)) {
if (safe_create_leading_directories(logfile->buf) < 0) {
- strbuf_addf(err, "unable to create directory for %s: "
+ strbuf_addf(err, "unable to create directory for '%s': "
"%s", logfile->buf, strerror(errno));
return -1;
}
if (errno == EISDIR) {
if (remove_empty_directories(logfile)) {
- strbuf_addf(err, "There are still logs under "
+ strbuf_addf(err, "there are still logs under "
"'%s'", logfile->buf);
return -1;
}
}
if (logfd < 0) {
- strbuf_addf(err, "unable to append to %s: %s",
+ strbuf_addf(err, "unable to append to '%s': %s",
logfile->buf, strerror(errno));
return -1;
}
result = log_ref_write_fd(logfd, old_sha1, new_sha1,
git_committer_info(0), msg);
if (result) {
- strbuf_addf(err, "unable to append to %s: %s", logfile->buf,
+ strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
strerror(errno));
close(logfd);
return -1;
}
if (close(logfd)) {
- strbuf_addf(err, "unable to append to %s: %s", logfile->buf,
+ strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
strerror(errno));
return -1;
}
o = parse_object(sha1);
if (!o) {
strbuf_addf(err,
- "Trying to write ref %s with nonexistent object %s",
+ "trying to write ref '%s' with nonexistent object %s",
lock->ref_name, sha1_to_hex(sha1));
unlock_ref(lock);
return -1;
}
if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
strbuf_addf(err,
- "Trying to write non-commit object %s to branch %s",
+ "trying to write non-commit object %s to branch '%s'",
sha1_to_hex(sha1), lock->ref_name);
unlock_ref(lock);
return -1;
write_in_full(fd, &term, 1) != 1 ||
close_ref(lock) < 0) {
strbuf_addf(err,
- "Couldn't write %s", get_lock_file_path(lock->lk));
+ "couldn't write '%s'", get_lock_file_path(lock->lk));
unlock_ref(lock);
return -1;
}
*/
static int commit_ref_update(struct ref_lock *lock,
const unsigned char *sha1, const char *logmsg,
- int flags, struct strbuf *err)
+ struct strbuf *err)
{
clear_loose_ref_cache(&ref_cache);
- if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 ||
- (strcmp(lock->ref_name, lock->orig_ref_name) &&
- log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) {
+ if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {
char *old_msg = strbuf_detach(err, NULL);
- strbuf_addf(err, "Cannot update the ref '%s': %s",
+ strbuf_addf(err, "cannot update the ref '%s': %s",
lock->ref_name, old_msg);
free(old_msg);
unlock_ref(lock);
return -1;
}
- if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
+
+ if (strcmp(lock->ref_name, "HEAD") != 0) {
/*
* Special hack: If a branch is updated directly and HEAD
* points to it (may happen on the remote side of a push
unsigned char head_sha1[20];
int head_flag;
const char *head_ref;
+
head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
head_sha1, &head_flag);
if (head_ref && (head_flag & REF_ISSYMREF) &&
}
}
}
+
if (commit_ref(lock)) {
- error("Couldn't set %s", lock->ref_name);
+ strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
unlock_ref(lock);
return -1;
}
lock = xcalloc(1, sizeof(struct ref_lock));
lock->lk = &head_lock;
lock->ref_name = xstrdup(head_rel);
- lock->orig_ref_name = xstrdup(head_rel);
ret = create_symref_locked(lock, head_rel, target, NULL);
strbuf_release(&sb);
return ret;
}
-/*
- * Call fn for each reflog in the namespace indicated by name. name
- * must be empty or end with '/'. Name will be used as a scratch
- * space, but its contents will be restored before return.
- */
-static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
-{
- DIR *d = opendir(git_path("logs/%s", name->buf));
- int retval = 0;
- struct dirent *de;
- int oldlen = name->len;
- if (!d)
- return name->len ? errno : 0;
+struct files_reflog_iterator {
+ struct ref_iterator base;
- while ((de = readdir(d)) != NULL) {
- struct stat st;
+ struct dir_iterator *dir_iterator;
+ struct object_id oid;
+};
- if (de->d_name[0] == '.')
+static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct files_reflog_iterator *iter =
+ (struct files_reflog_iterator *)ref_iterator;
+ struct dir_iterator *diter = iter->dir_iterator;
+ int ok;
+
+ while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
+ int flags;
+
+ if (!S_ISREG(diter->st.st_mode))
continue;
- if (ends_with(de->d_name, ".lock"))
+ if (diter->basename[0] == '.')
+ continue;
+ if (ends_with(diter->basename, ".lock"))
continue;
- strbuf_addstr(name, de->d_name);
- if (stat(git_path("logs/%s", name->buf), &st) < 0) {
- ; /* silently ignore */
- } else {
- if (S_ISDIR(st.st_mode)) {
- strbuf_addch(name, '/');
- retval = do_for_each_reflog(name, fn, cb_data);
- } else {
- struct object_id oid;
- if (read_ref_full(name->buf, 0, oid.hash, NULL))
- retval = error("bad ref for %s", name->buf);
- else
- retval = fn(name->buf, &oid, 0, cb_data);
- }
- if (retval)
- break;
+ if (read_ref_full(diter->relative_path, 0,
+ iter->oid.hash, &flags)) {
+ error("bad ref for %s", diter->path.buf);
+ continue;
}
- strbuf_setlen(name, oldlen);
+
+ iter->base.refname = diter->relative_path;
+ iter->base.oid = &iter->oid;
+ iter->base.flags = flags;
+ return ITER_OK;
}
- closedir(d);
- return retval;
+
+ iter->dir_iterator = NULL;
+ if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
+ ok = ITER_ERROR;
+ return ok;
+}
+
+static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ die("BUG: ref_iterator_peel() called for reflog_iterator");
+}
+
+static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct files_reflog_iterator *iter =
+ (struct files_reflog_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->dir_iterator)
+ ok = dir_iterator_abort(iter->dir_iterator);
+
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable files_reflog_iterator_vtable = {
+ files_reflog_iterator_advance,
+ files_reflog_iterator_peel,
+ files_reflog_iterator_abort
+};
+
+struct ref_iterator *files_reflog_iterator_begin(void)
+{
+ struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
+ struct ref_iterator *ref_iterator = &iter->base;
+
+ base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
+ iter->dir_iterator = dir_iterator_begin(git_path("logs"));
+ return ref_iterator;
}
int for_each_reflog(each_ref_fn fn, void *cb_data)
{
- int retval;
- struct strbuf name;
- strbuf_init(&name, PATH_MAX);
- retval = do_for_each_reflog(&name, fn, cb_data);
- strbuf_release(&name);
- return retval;
+ return do_for_each_ref_iterator(files_reflog_iterator_begin(),
+ fn, cb_data);
}
static int ref_update_reject_duplicates(struct string_list *refnames,
for (i = 1; i < n; i++)
if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
strbuf_addf(err,
- "Multiple updates for ref '%s' not allowed.",
+ "multiple updates for ref '%s' not allowed.",
refnames->items[i].string);
return 1;
}
return 0;
}
+/*
+ * If update is a direct update of head_ref (the reference pointed to
+ * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
+ */
+static int split_head_update(struct ref_update *update,
+ struct ref_transaction *transaction,
+ const char *head_ref,
+ struct string_list *affected_refnames,
+ struct strbuf *err)
+{
+ struct string_list_item *item;
+ struct ref_update *new_update;
+
+ if ((update->flags & REF_LOG_ONLY) ||
+ (update->flags & REF_ISPRUNING) ||
+ (update->flags & REF_UPDATE_VIA_HEAD))
+ return 0;
+
+ if (strcmp(update->refname, head_ref))
+ return 0;
+
+ /*
+ * First make sure that HEAD is not already in the
+ * transaction. This insertion is O(N) in the transaction
+ * size, but it happens at most once per transaction.
+ */
+ item = string_list_insert(affected_refnames, "HEAD");
+ if (item->util) {
+ /* An entry already existed */
+ strbuf_addf(err,
+ "multiple updates for 'HEAD' (including one "
+ "via its referent '%s') are not allowed",
+ update->refname);
+ return TRANSACTION_NAME_CONFLICT;
+ }
+
+ new_update = ref_transaction_add_update(
+ transaction, "HEAD",
+ update->flags | REF_LOG_ONLY | REF_NODEREF,
+ update->new_sha1, update->old_sha1,
+ update->msg);
+
+ item->util = new_update;
+
+ return 0;
+}
+
+/*
+ * update is for a symref that points at referent and doesn't have
+ * REF_NODEREF set. Split it into two updates:
+ * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
+ * - A new, separate update for the referent reference
+ * Note that the new update will itself be subject to splitting when
+ * the iteration gets to it.
+ */
+static int split_symref_update(struct ref_update *update,
+ const char *referent,
+ struct ref_transaction *transaction,
+ struct string_list *affected_refnames,
+ struct strbuf *err)
+{
+ struct string_list_item *item;
+ struct ref_update *new_update;
+ unsigned int new_flags;
+
+ /*
+ * First make sure that referent is not already in the
+ * transaction. This insertion is O(N) in the transaction
+ * size, but it happens at most once per symref in a
+ * transaction.
+ */
+ item = string_list_insert(affected_refnames, referent);
+ if (item->util) {
+ /* An entry already existed */
+ strbuf_addf(err,
+ "multiple updates for '%s' (including one "
+ "via symref '%s') are not allowed",
+ referent, update->refname);
+ return TRANSACTION_NAME_CONFLICT;
+ }
+
+ new_flags = update->flags;
+ if (!strcmp(update->refname, "HEAD")) {
+ /*
+ * Record that the new update came via HEAD, so that
+ * when we process it, split_head_update() doesn't try
+ * to add another reflog update for HEAD. Note that
+ * this bit will be propagated if the new_update
+ * itself needs to be split.
+ */
+ new_flags |= REF_UPDATE_VIA_HEAD;
+ }
+
+ new_update = ref_transaction_add_update(
+ transaction, referent, new_flags,
+ update->new_sha1, update->old_sha1,
+ update->msg);
+
+ new_update->parent_update = update;
+
+ /*
+ * Change the symbolic ref update to log only. Also, it
+ * doesn't need to check its old SHA-1 value, as that will be
+ * done when new_update is processed.
+ */
+ update->flags |= REF_LOG_ONLY | REF_NODEREF;
+ update->flags &= ~REF_HAVE_OLD;
+
+ item->util = new_update;
+
+ return 0;
+}
+
+/*
+ * Return the refname under which update was originally requested.
+ */
+static const char *original_update_refname(struct ref_update *update)
+{
+ while (update->parent_update)
+ update = update->parent_update;
+
+ return update->refname;
+}
+
+/*
+ * Check whether the REF_HAVE_OLD and old_oid values stored in update
+ * are consistent with oid, which is the reference's current value. If
+ * everything is OK, return 0; otherwise, write an error message to
+ * err and return -1.
+ */
+static int check_old_oid(struct ref_update *update, struct object_id *oid,
+ struct strbuf *err)
+{
+ if (!(update->flags & REF_HAVE_OLD) ||
+ !hashcmp(oid->hash, update->old_sha1))
+ return 0;
+
+ if (is_null_sha1(update->old_sha1))
+ strbuf_addf(err, "cannot lock ref '%s': "
+ "reference already exists",
+ original_update_refname(update));
+ else if (is_null_oid(oid))
+ strbuf_addf(err, "cannot lock ref '%s': "
+ "reference is missing but expected %s",
+ original_update_refname(update),
+ sha1_to_hex(update->old_sha1));
+ else
+ strbuf_addf(err, "cannot lock ref '%s': "
+ "is at %s but expected %s",
+ original_update_refname(update),
+ oid_to_hex(oid),
+ sha1_to_hex(update->old_sha1));
+
+ return -1;
+}
+
+/*
+ * Prepare for carrying out update:
+ * - Lock the reference referred to by update.
+ * - Read the reference under lock.
+ * - Check that its old SHA-1 value (if specified) is correct, and in
+ * any case record it in update->lock->old_oid for later use when
+ * writing the reflog.
+ * - If it is a symref update without REF_NODEREF, split it up into a
+ * REF_LOG_ONLY update of the symref and add a separate update for
+ * the referent to transaction.
+ * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
+ * update of HEAD.
+ */
+static int lock_ref_for_update(struct ref_update *update,
+ struct ref_transaction *transaction,
+ const char *head_ref,
+ struct string_list *affected_refnames,
+ struct strbuf *err)
+{
+ struct strbuf referent = STRBUF_INIT;
+ int mustexist = (update->flags & REF_HAVE_OLD) &&
+ !is_null_sha1(update->old_sha1);
+ int ret;
+ struct ref_lock *lock;
+
+ if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
+ update->flags |= REF_DELETING;
+
+ if (head_ref) {
+ ret = split_head_update(update, transaction, head_ref,
+ affected_refnames, err);
+ if (ret)
+ return ret;
+ }
+
+ ret = lock_raw_ref(update->refname, mustexist,
+ affected_refnames, NULL,
+ &update->lock, &referent,
+ &update->type, err);
+
+ if (ret) {
+ char *reason;
+
+ reason = strbuf_detach(err, NULL);
+ strbuf_addf(err, "cannot lock ref '%s': %s",
+ original_update_refname(update), reason);
+ free(reason);
+ return ret;
+ }
+
+ lock = update->lock;
+
+ if (update->type & REF_ISSYMREF) {
+ if (update->flags & REF_NODEREF) {
+ /*
+ * We won't be reading the referent as part of
+ * the transaction, so we have to read it here
+ * to record and possibly check old_sha1:
+ */
+ if (read_ref_full(referent.buf, 0,
+ lock->old_oid.hash, NULL)) {
+ if (update->flags & REF_HAVE_OLD) {
+ strbuf_addf(err, "cannot lock ref '%s': "
+ "error reading reference",
+ original_update_refname(update));
+ return -1;
+ }
+ } else if (check_old_oid(update, &lock->old_oid, err)) {
+ return TRANSACTION_GENERIC_ERROR;
+ }
+ } else {
+ /*
+ * Create a new update for the reference this
+ * symref is pointing at. Also, we will record
+ * and verify old_sha1 for this update as part
+ * of processing the split-off update, so we
+ * don't have to do it here.
+ */
+ ret = split_symref_update(update, referent.buf, transaction,
+ affected_refnames, err);
+ if (ret)
+ return ret;
+ }
+ } else {
+ struct ref_update *parent_update;
+
+ if (check_old_oid(update, &lock->old_oid, err))
+ return TRANSACTION_GENERIC_ERROR;
+
+ /*
+ * If this update is happening indirectly because of a
+ * symref update, record the old SHA-1 in the parent
+ * update:
+ */
+ for (parent_update = update->parent_update;
+ parent_update;
+ parent_update = parent_update->parent_update) {
+ oidcpy(&parent_update->lock->old_oid, &lock->old_oid);
+ }
+ }
+
+ if ((update->flags & REF_HAVE_NEW) &&
+ !(update->flags & REF_DELETING) &&
+ !(update->flags & REF_LOG_ONLY)) {
+ if (!(update->type & REF_ISSYMREF) &&
+ !hashcmp(lock->old_oid.hash, update->new_sha1)) {
+ /*
+ * The reference already has the desired
+ * value, so we don't need to write it.
+ */
+ } else if (write_ref_to_lockfile(lock, update->new_sha1,
+ err)) {
+ char *write_err = strbuf_detach(err, NULL);
+
+ /*
+ * The lock was freed upon failure of
+ * write_ref_to_lockfile():
+ */
+ update->lock = NULL;
+ strbuf_addf(err,
+ "cannot update ref '%s': %s",
+ update->refname, write_err);
+ free(write_err);
+ return TRANSACTION_GENERIC_ERROR;
+ } else {
+ update->flags |= REF_NEEDS_COMMIT;
+ }
+ }
+ if (!(update->flags & REF_NEEDS_COMMIT)) {
+ /*
+ * We didn't call write_ref_to_lockfile(), so
+ * the lockfile is still open. Close it to
+ * free up the file descriptor:
+ */
+ if (close_ref(lock)) {
+ strbuf_addf(err, "couldn't close '%s.lock'",
+ update->refname);
+ return TRANSACTION_GENERIC_ERROR;
+ }
+ }
+ return 0;
+}
+
int ref_transaction_commit(struct ref_transaction *transaction,
struct strbuf *err)
{
int ret = 0, i;
- int n = transaction->nr;
- struct ref_update **updates = transaction->updates;
struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
struct string_list_item *ref_to_delete;
struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
+ char *head_ref = NULL;
+ int head_type;
+ struct object_id head_oid;
assert(err);
if (transaction->state != REF_TRANSACTION_OPEN)
die("BUG: commit called for transaction that is not open");
- if (!n) {
+ if (!transaction->nr) {
transaction->state = REF_TRANSACTION_CLOSED;
return 0;
}
- /* Fail if a refname appears more than once in the transaction: */
- for (i = 0; i < n; i++)
- string_list_append(&affected_refnames, updates[i]->refname);
+ /*
+ * Fail if a refname appears more than once in the
+ * transaction. (If we end up splitting up any updates using
+ * split_symref_update() or split_head_update(), those
+ * functions will check that the new updates don't have the
+ * same refname as any existing ones.)
+ */
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
+ struct string_list_item *item =
+ string_list_append(&affected_refnames, update->refname);
+
+ /*
+ * We store a pointer to update in item->util, but at
+ * the moment we never use the value of this field
+ * except to check whether it is non-NULL.
+ */
+ item->util = update;
+ }
string_list_sort(&affected_refnames);
if (ref_update_reject_duplicates(&affected_refnames, err)) {
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
}
+ /*
+ * Special hack: If a branch is updated directly and HEAD
+ * points to it (may happen on the remote side of a push
+ * for example) then logically the HEAD reflog should be
+ * updated too.
+ *
+ * A generic solution would require reverse symref lookups,
+ * but finding all symrefs pointing to a given branch would be
+ * rather costly for this rare event (the direct update of a
+ * branch) to be worth it. So let's cheat and check with HEAD
+ * only, which should cover 99% of all usage scenarios (even
+ * 100% of the default ones).
+ *
+ * So if HEAD is a symbolic reference, then record the name of
+ * the reference that it points to. If we see an update of
+ * head_ref within the transaction, then split_head_update()
+ * arranges for the reflog of HEAD to be updated, too.
+ */
+ head_ref = resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,
+ head_oid.hash, &head_type);
+
+ if (head_ref && !(head_type & REF_ISSYMREF)) {
+ free(head_ref);
+ head_ref = NULL;
+ }
+
/*
* Acquire all locks, verify old values if provided, check
* that new values are valid, and write new values to the
* lockfiles, ready to be activated. Only keep one lockfile
* open at a time to avoid running out of file descriptors.
*/
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
- if ((update->flags & REF_HAVE_NEW) &&
- is_null_sha1(update->new_sha1))
- update->flags |= REF_DELETING;
- update->lock = lock_ref_sha1_basic(
- update->refname,
- ((update->flags & REF_HAVE_OLD) ?
- update->old_sha1 : NULL),
- &affected_refnames, NULL,
- update->flags,
- &update->type,
- err);
- if (!update->lock) {
- char *reason;
-
- ret = (errno == ENOTDIR)
- ? TRANSACTION_NAME_CONFLICT
- : TRANSACTION_GENERIC_ERROR;
- reason = strbuf_detach(err, NULL);
- strbuf_addf(err, "cannot lock ref '%s': %s",
- update->refname, reason);
- free(reason);
+ ret = lock_ref_for_update(update, transaction, head_ref,
+ &affected_refnames, err);
+ if (ret)
goto cleanup;
- }
- if ((update->flags & REF_HAVE_NEW) &&
- !(update->flags & REF_DELETING)) {
- int overwriting_symref = ((update->type & REF_ISSYMREF) &&
- (update->flags & REF_NODEREF));
-
- if (!overwriting_symref &&
- !hashcmp(update->lock->old_oid.hash, update->new_sha1)) {
- /*
- * The reference already has the desired
- * value, so we don't need to write it.
- */
- } else if (write_ref_to_lockfile(update->lock,
- update->new_sha1,
- err)) {
- char *write_err = strbuf_detach(err, NULL);
+ }
- /*
- * The lock was freed upon failure of
- * write_ref_to_lockfile():
- */
+ /* Perform updates first so live commits remain referenced */
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
+ struct ref_lock *lock = update->lock;
+
+ if (update->flags & REF_NEEDS_COMMIT ||
+ update->flags & REF_LOG_ONLY) {
+ if (log_ref_write(lock->ref_name, lock->old_oid.hash,
+ update->new_sha1,
+ update->msg, update->flags, err)) {
+ char *old_msg = strbuf_detach(err, NULL);
+
+ strbuf_addf(err, "cannot update the ref '%s': %s",
+ lock->ref_name, old_msg);
+ free(old_msg);
+ unlock_ref(lock);
update->lock = NULL;
- strbuf_addf(err,
- "cannot update the ref '%s': %s",
- update->refname, write_err);
- free(write_err);
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
- } else {
- update->flags |= REF_NEEDS_COMMIT;
- }
- }
- if (!(update->flags & REF_NEEDS_COMMIT)) {
- /*
- * We didn't have to write anything to the lockfile.
- * Close it to free up the file descriptor:
- */
- if (close_ref(update->lock)) {
- strbuf_addf(err, "Couldn't close %s.lock",
- update->refname);
- goto cleanup;
}
}
- }
-
- /* Perform updates first so live commits remain referenced */
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
-
if (update->flags & REF_NEEDS_COMMIT) {
- if (commit_ref_update(update->lock,
- update->new_sha1, update->msg,
- update->flags, err)) {
- /* freed by commit_ref_update(): */
+ clear_loose_ref_cache(&ref_cache);
+ if (commit_ref(lock)) {
+ strbuf_addf(err, "couldn't set '%s'", lock->ref_name);
+ unlock_ref(lock);
update->lock = NULL;
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
- } else {
- /* freed by commit_ref_update(): */
- update->lock = NULL;
}
}
}
-
/* Perform deletes now that updates are safely completed */
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
- if (update->flags & REF_DELETING) {
+ if (update->flags & REF_DELETING &&
+ !(update->flags & REF_LOG_ONLY)) {
if (delete_ref_loose(update->lock, update->type, err)) {
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
cleanup:
transaction->state = REF_TRANSACTION_CLOSED;
- for (i = 0; i < n; i++)
- if (updates[i]->lock)
- unlock_ref(updates[i]->lock);
+ for (i = 0; i < transaction->nr; i++)
+ if (transaction->updates[i]->lock)
+ unlock_ref(transaction->updates[i]->lock);
string_list_clear(&refs_to_delete, 0);
+ free(head_ref);
string_list_clear(&affected_refnames, 0);
+
return ret;
}
struct strbuf *err)
{
int ret = 0, i;
- int n = transaction->nr;
- struct ref_update **updates = transaction->updates;
struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
assert(err);
die("BUG: commit called for transaction that is not open");
/* Fail if a refname appears more than once in the transaction: */
- for (i = 0; i < n; i++)
- string_list_append(&affected_refnames, updates[i]->refname);
+ for (i = 0; i < transaction->nr; i++)
+ string_list_append(&affected_refnames,
+ transaction->updates[i]->refname);
string_list_sort(&affected_refnames);
if (ref_update_reject_duplicates(&affected_refnames, err)) {
ret = TRANSACTION_GENERIC_ERROR;
if (for_each_rawref(ref_present, &affected_refnames))
die("BUG: initial ref transaction called with existing refs");
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
if ((update->flags & REF_HAVE_OLD) &&
!is_null_sha1(update->old_sha1))
goto cleanup;
}
- for (i = 0; i < n; i++) {
- struct ref_update *update = updates[i];
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
if ((update->flags & REF_HAVE_NEW) &&
!is_null_sha1(update->new_sha1))