connect: split git:// setup into a separate function
[gitweb.git] / refs.c
diff --git a/refs.c b/refs.c
index df75f8e0d695fc235c1a2497069a9b916a4a04e8..83f0e687857dfaee3b91ce4d47b16f2f16945ce2 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -3,6 +3,7 @@
  */
 
 #include "cache.h"
+#include "config.h"
 #include "hashmap.h"
 #include "lockfile.h"
 #include "iterator.h"
@@ -11,6 +12,7 @@
 #include "object.h"
 #include "tag.h"
 #include "submodule.h"
+#include "worktree.h"
 
 /*
  * List of all available backends
@@ -172,6 +174,24 @@ int refname_is_safe(const char *refname)
        return 1;
 }
 
+/*
+ * 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.
+ */
+int ref_resolves_to_object(const char *refname,
+                          const struct object_id *oid,
+                          unsigned int flags)
+{
+       if (flags & REF_ISBROKEN)
+               return 0;
+       if (!has_sha1_file(oid->hash)) {
+               error("%s does not point to a valid object!", refname);
+               return 0;
+       }
+       return 1;
+}
+
 char *refs_resolve_refdup(struct ref_store *refs,
                          const char *refname, int resolve_flags,
                          unsigned char *sha1, int *flags)
@@ -228,7 +248,7 @@ static int filter_refs(const char *refname, const struct object_id *oid,
 {
        struct ref_filter *filter = (struct ref_filter *)data;
 
-       if (wildmatch(filter->pattern, refname, 0, NULL))
+       if (wildmatch(filter->pattern, refname, 0))
                return 0;
        return filter->fn(refname, oid, flags, filter->cb_data);
 }
@@ -316,12 +336,6 @@ int for_each_tag_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_tag_ref(get_submodule_ref_store(submodule),
-                                    fn, cb_data);
-}
-
 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
        return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
@@ -332,12 +346,6 @@ int for_each_branch_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_branch_ref(get_submodule_ref_store(submodule),
-                                       fn, cb_data);
-}
-
 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
        return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
@@ -348,12 +356,6 @@ int for_each_remote_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
-                                       fn, cb_data);
-}
-
 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 {
        struct strbuf buf = STRBUF_INIT;
@@ -559,6 +561,21 @@ enum ref_type ref_type(const char *refname)
        return REF_TYPE_NORMAL;
 }
 
+long get_files_ref_lock_timeout_ms(void)
+{
+       static int configured = 0;
+
+       /* The default timeout is 100 ms: */
+       static int timeout_ms = 100;
+
+       if (!configured) {
+               git_config_get_int("core.filesreflocktimeout", &timeout_ms);
+               configured = 1;
+       }
+
+       return timeout_ms;
+}
+
 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
                           const unsigned char *old_sha1, struct strbuf *err)
 {
@@ -571,11 +588,13 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
        strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
 
        filename = git_path("%s", pseudoref);
-       fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
+       fd = hold_lock_file_for_update_timeout(&lock, filename,
+                                              LOCK_DIE_ON_ERROR,
+                                              get_files_ref_lock_timeout_ms());
        if (fd < 0) {
                strbuf_addf(err, "could not open '%s' for writing: %s",
                            filename, strerror(errno));
-               return -1;
+               goto done;
        }
 
        if (old_sha1) {
@@ -590,7 +609,7 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
                }
        }
 
-       if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
+       if (write_in_full(fd, buf.buf, buf.len) < 0) {
                strbuf_addf(err, "could not write to '%s'", filename);
                rollback_lock_file(&lock);
                goto done;
@@ -614,8 +633,9 @@ static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1
                int fd;
                unsigned char actual_old_sha1[20];
 
-               fd = hold_lock_file_for_update(&lock, filename,
-                                              LOCK_DIE_ON_ERROR);
+               fd = hold_lock_file_for_update_timeout(
+                               &lock, filename, LOCK_DIE_ON_ERROR,
+                               get_files_ref_lock_timeout_ms());
                if (fd < 0)
                        die_errno(_("Could not open '%s' for writing"), filename);
                if (read_ref(pseudoref, actual_old_sha1))
@@ -713,7 +733,7 @@ int is_branch(const char *refname)
 
 struct read_ref_at_cb {
        const char *refname;
-       unsigned long at_time;
+       timestamp_t at_time;
        int cnt;
        int reccnt;
        unsigned char *sha1;
@@ -722,15 +742,15 @@ struct read_ref_at_cb {
        unsigned char osha1[20];
        unsigned char nsha1[20];
        int tz;
-       unsigned long date;
+       timestamp_t date;
        char **msg;
-       unsigned long *cutoff_time;
+       timestamp_t *cutoff_time;
        int *cutoff_tz;
        int *cutoff_cnt;
 };
 
 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
-               const char *email, unsigned long timestamp, int tz,
+               const char *email, timestamp_t timestamp, int tz,
                const char *message, void *cb_data)
 {
        struct read_ref_at_cb *cb = cb_data;
@@ -777,7 +797,7 @@ static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 }
 
 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
-                                 const char *email, unsigned long timestamp,
+                                 const char *email, timestamp_t timestamp,
                                  int tz, const char *message, void *cb_data)
 {
        struct read_ref_at_cb *cb = cb_data;
@@ -797,9 +817,9 @@ static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid
        return 1;
 }
 
-int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
+int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
                unsigned char *sha1, char **msg,
-               unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
+               timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 {
        struct read_ref_at_cb cb;
 
@@ -816,7 +836,7 @@ int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time,
        for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 
        if (!cb.reccnt) {
-               if (flags & GET_SHA1_QUIETLY)
+               if (flags & GET_OID_QUIETLY)
                        exit(128);
                else
                        die("Log for %s is empty.", refname);
@@ -847,11 +867,24 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 
 void ref_transaction_free(struct ref_transaction *transaction)
 {
-       int i;
+       size_t i;
 
        if (!transaction)
                return;
 
+       switch (transaction->state) {
+       case REF_TRANSACTION_OPEN:
+       case REF_TRANSACTION_CLOSED:
+               /* OK */
+               break;
+       case REF_TRANSACTION_PREPARED:
+               die("BUG: free called on a prepared reference transaction");
+               break;
+       default:
+               die("BUG: unexpected reference transaction state");
+               break;
+       }
+
        for (i = 0; i < transaction->nr; i++) {
                free(transaction->updates[i]->msg);
                free(transaction->updates[i]);
@@ -882,9 +915,9 @@ struct ref_update *ref_transaction_add_update(
        update->flags = flags;
 
        if (flags & REF_HAVE_NEW)
-               hashcpy(update->new_sha1, new_sha1);
+               hashcpy(update->new_oid.hash, new_sha1);
        if (flags & REF_HAVE_OLD)
-               hashcpy(update->old_sha1, old_sha1);
+               hashcpy(update->old_oid.hash, old_sha1);
        update->msg = xstrdup_or_null(msg);
        return update;
 }
@@ -906,6 +939,8 @@ int ref_transaction_update(struct ref_transaction *transaction,
                return -1;
        }
 
+       flags &= REF_TRANSACTION_UPDATE_ALLOWED_FLAGS;
+
        flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
 
        ref_transaction_add_update(transaction, refname, flags,
@@ -1145,7 +1180,7 @@ int ref_is_hidden(const char *refname, const char *refname_full)
                const char *match = hide_refs->items[i].string;
                const char *subject;
                int neg = 0;
-               int len;
+               const char *p;
 
                if (*match == '!') {
                        neg = 1;
@@ -1160,10 +1195,9 @@ int ref_is_hidden(const char *refname, const char *refname_full)
                }
 
                /* refname can be NULL when namespaces are used. */
-               if (!subject || !starts_with(subject, match))
-                       continue;
-               len = strlen(match);
-               if (!subject[len] || subject[len] == '/')
+               if (subject &&
+                   skip_prefix(subject, match, &p) &&
+                   (!*p || *p == '/'))
                        return !neg;
        }
        return 0;
@@ -1216,19 +1250,13 @@ int refs_rename_ref_available(struct ref_store *refs,
        return ok;
 }
 
-int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
+int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
        struct object_id oid;
        int flag;
 
-       if (submodule) {
-               if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
-                       return fn("HEAD", &oid, 0, cb_data);
-
-               return 0;
-       }
-
-       if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
+       if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
+                               oid.hash, &flag))
                return fn("HEAD", &oid, flag, cb_data);
 
        return 0;
@@ -1236,7 +1264,7 @@ int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 
 int head_ref(each_ref_fn fn, void *cb_data)
 {
-       return head_ref_submodule(NULL, fn, cb_data);
+       return refs_head_ref(get_main_ref_store(), fn, cb_data);
 }
 
 struct ref_iterator *refs_ref_iterator_begin(
@@ -1245,8 +1273,19 @@ struct ref_iterator *refs_ref_iterator_begin(
 {
        struct ref_iterator *iter;
 
+       if (ref_paranoia < 0)
+               ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
+       if (ref_paranoia)
+               flags |= DO_FOR_EACH_INCLUDE_BROKEN;
+
        iter = refs->be->iterator_begin(refs, prefix, flags);
-       iter = prefix_ref_iterator_begin(iter, prefix, trim);
+
+       /*
+        * `iterator_begin()` already takes care of prefix, but we
+        * might need to do some trimming:
+        */
+       if (trim)
+               iter = prefix_ref_iterator_begin(iter, "", trim);
 
        return iter;
 }
@@ -1283,11 +1322,6 @@ int for_each_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_ref(get_submodule_ref_store(submodule), fn, cb_data);
-}
-
 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
                         each_ref_fn fn, void *cb_data)
 {
@@ -1309,11 +1343,15 @@ int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsig
                               prefix, fn, 0, flag, cb_data);
 }
 
-int for_each_ref_in_submodule(const char *submodule, const char *prefix,
-                             each_ref_fn fn, void *cb_data)
+int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
+                            each_ref_fn fn, void *cb_data,
+                            unsigned int broken)
 {
-       return refs_for_each_ref_in(get_submodule_ref_store(submodule),
-                                   prefix, fn, cb_data);
+       unsigned int flag = 0;
+
+       if (broken)
+               flag = DO_FOR_EACH_INCLUDE_BROKEN;
+       return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
 }
 
 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
@@ -1321,7 +1359,7 @@ int for_each_replace_ref(each_ref_fn fn, void *cb_data)
        return do_for_each_ref(get_main_ref_store(),
                               git_replace_ref_base, fn,
                               strlen(git_replace_ref_base),
-                              0, cb_data);
+                              DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
 }
 
 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
@@ -1448,25 +1486,10 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 int resolve_gitlink_ref(const char *submodule, const char *refname,
                        unsigned char *sha1)
 {
-       size_t len = strlen(submodule);
        struct ref_store *refs;
        int flags;
 
-       while (len && submodule[len - 1] == '/')
-               len--;
-
-       if (!len)
-               return -1;
-
-       if (submodule[len]) {
-               /* We need to strip off one or more trailing slashes */
-               char *stripped = xmemdupz(submodule, len);
-
-               refs = get_submodule_ref_store(stripped);
-               free(stripped);
-       } else {
-               refs = get_submodule_ref_store(submodule);
-       }
+       refs = get_submodule_ref_store(submodule);
 
        if (!refs)
                return -1;
@@ -1477,32 +1500,33 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
        return 0;
 }
 
-struct submodule_hash_entry
+struct ref_store_hash_entry
 {
        struct hashmap_entry ent; /* must be the first member! */
 
        struct ref_store *refs;
 
-       /* NUL-terminated name of submodule: */
-       char submodule[FLEX_ARRAY];
+       /* NUL-terminated identifier of the ref store: */
+       char name[FLEX_ARRAY];
 };
 
-static int submodule_hash_cmp(const void *entry, const void *entry_or_key,
+static int ref_store_hash_cmp(const void *unused_cmp_data,
+                             const void *entry, const void *entry_or_key,
                              const void *keydata)
 {
-       const struct submodule_hash_entry *e1 = entry, *e2 = entry_or_key;
-       const char *submodule = keydata ? keydata : e2->submodule;
+       const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
+       const char *name = keydata ? keydata : e2->name;
 
-       return strcmp(e1->submodule, submodule);
+       return strcmp(e1->name, name);
 }
 
-static struct submodule_hash_entry *alloc_submodule_hash_entry(
-               const char *submodule, struct ref_store *refs)
+static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
+               const char *name, struct ref_store *refs)
 {
-       struct submodule_hash_entry *entry;
+       struct ref_store_hash_entry *entry;
 
-       FLEX_ALLOC_STR(entry, submodule, submodule);
-       hashmap_entry_init(entry, strhash(submodule));
+       FLEX_ALLOC_STR(entry, name, name);
+       hashmap_entry_init(entry, strhash(name));
        entry->refs = refs;
        return entry;
 }
@@ -1513,20 +1537,23 @@ static struct ref_store *main_ref_store;
 /* A hashmap of ref_stores, stored by submodule name: */
 static struct hashmap submodule_ref_stores;
 
+/* A hashmap of ref_stores, stored by worktree id: */
+static struct hashmap worktree_ref_stores;
+
 /*
- * Return the ref_store instance for the specified submodule. If that
- * ref_store hasn't been initialized yet, return NULL.
+ * Look up a ref store by name. If that ref_store hasn't been
+ * registered yet, return NULL.
  */
-static struct ref_store *lookup_submodule_ref_store(const char *submodule)
+static struct ref_store *lookup_ref_store_map(struct hashmap *map,
+                                             const char *name)
 {
-       struct submodule_hash_entry *entry;
+       struct ref_store_hash_entry *entry;
 
-       if (!submodule_ref_stores.tablesize)
+       if (!map->tablesize)
                /* It's initialized on demand in register_ref_store(). */
                return NULL;
 
-       entry = hashmap_get_from_hash(&submodule_ref_stores,
-                                     strhash(submodule), submodule);
+       entry = hashmap_get_from_hash(map, strhash(name), name);
        return entry ? entry->refs : NULL;
 }
 
@@ -1553,67 +1580,93 @@ struct ref_store *get_main_ref_store(void)
        if (main_ref_store)
                return main_ref_store;
 
-       main_ref_store = ref_store_init(get_git_dir(),
-                                       (REF_STORE_READ |
-                                        REF_STORE_WRITE |
-                                        REF_STORE_ODB |
-                                        REF_STORE_MAIN));
+       main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
        return main_ref_store;
 }
 
 /*
- * Register the specified ref_store to be the one that should be used
- * for submodule. It is a fatal error to call this function twice for
- * the same submodule.
+ * Associate a ref store with a name. It is a fatal error to call this
+ * function twice for the same name.
  */
-static void register_submodule_ref_store(struct ref_store *refs,
-                                        const char *submodule)
+static void register_ref_store_map(struct hashmap *map,
+                                  const char *type,
+                                  struct ref_store *refs,
+                                  const char *name)
 {
-       if (!submodule_ref_stores.tablesize)
-               hashmap_init(&submodule_ref_stores, submodule_hash_cmp, 0);
+       if (!map->tablesize)
+               hashmap_init(map, ref_store_hash_cmp, NULL, 0);
 
-       if (hashmap_put(&submodule_ref_stores,
-                       alloc_submodule_hash_entry(submodule, refs)))
-               die("BUG: ref_store for submodule '%s' initialized twice",
-                   submodule);
+       if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
+               die("BUG: %s ref_store '%s' initialized twice", type, name);
 }
 
 struct ref_store *get_submodule_ref_store(const char *submodule)
 {
        struct strbuf submodule_sb = STRBUF_INIT;
        struct ref_store *refs;
-       int ret;
+       char *to_free = NULL;
+       size_t len;
 
-       if (!submodule || !*submodule) {
-               /*
-                * FIXME: This case is ideally not allowed. But that
-                * can't happen until we clean up all the callers.
-                */
-               return get_main_ref_store();
-       }
+       if (!submodule)
+               return NULL;
 
-       refs = lookup_submodule_ref_store(submodule);
+       len = strlen(submodule);
+       while (len && is_dir_sep(submodule[len - 1]))
+               len--;
+       if (!len)
+               return NULL;
+
+       if (submodule[len])
+               /* We need to strip off one or more trailing slashes */
+               submodule = to_free = xmemdupz(submodule, len);
+
+       refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
        if (refs)
-               return refs;
+               goto done;
 
        strbuf_addstr(&submodule_sb, submodule);
-       ret = is_nonbare_repository_dir(&submodule_sb);
-       strbuf_release(&submodule_sb);
-       if (!ret)
-               return NULL;
+       if (!is_nonbare_repository_dir(&submodule_sb))
+               goto done;
 
-       ret = submodule_to_gitdir(&submodule_sb, submodule);
-       if (ret) {
-               strbuf_release(&submodule_sb);
-               return NULL;
-       }
+       if (submodule_to_gitdir(&submodule_sb, submodule))
+               goto done;
 
        /* assume that add_submodule_odb() has been called */
        refs = ref_store_init(submodule_sb.buf,
                              REF_STORE_READ | REF_STORE_ODB);
-       register_submodule_ref_store(refs, submodule);
+       register_ref_store_map(&submodule_ref_stores, "submodule",
+                              refs, submodule);
 
+done:
        strbuf_release(&submodule_sb);
+       free(to_free);
+
+       return refs;
+}
+
+struct ref_store *get_worktree_ref_store(const struct worktree *wt)
+{
+       struct ref_store *refs;
+       const char *id;
+
+       if (wt->is_current)
+               return get_main_ref_store();
+
+       id = wt->id ? wt->id : "/";
+       refs = lookup_ref_store_map(&worktree_ref_stores, id);
+       if (refs)
+               return refs;
+
+       if (wt->id)
+               refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
+                                     REF_STORE_ALL_CAPS);
+       else
+               refs = ref_store_init(get_git_common_dir(),
+                                     REF_STORE_ALL_CAPS);
+
+       if (refs)
+               register_ref_store_map(&worktree_ref_stores, "worktree",
+                                      refs, id);
        return refs;
 }
 
@@ -1657,18 +1710,108 @@ int create_symref(const char *ref_target, const char *refs_heads_master,
                                  refs_heads_master, logmsg);
 }
 
-int ref_transaction_commit(struct ref_transaction *transaction,
-                          struct strbuf *err)
+int ref_update_reject_duplicates(struct string_list *refnames,
+                                struct strbuf *err)
+{
+       size_t i, n = refnames->nr;
+
+       assert(err);
+
+       for (i = 1; i < n; i++) {
+               int cmp = strcmp(refnames->items[i - 1].string,
+                                refnames->items[i].string);
+
+               if (!cmp) {
+                       strbuf_addf(err,
+                                   "multiple updates for ref '%s' not allowed.",
+                                   refnames->items[i].string);
+                       return 1;
+               } else if (cmp > 0) {
+                       die("BUG: ref_update_reject_duplicates() received unsorted list");
+               }
+       }
+       return 0;
+}
+
+int ref_transaction_prepare(struct ref_transaction *transaction,
+                           struct strbuf *err)
 {
        struct ref_store *refs = transaction->ref_store;
 
+       switch (transaction->state) {
+       case REF_TRANSACTION_OPEN:
+               /* Good. */
+               break;
+       case REF_TRANSACTION_PREPARED:
+               die("BUG: prepare called twice on reference transaction");
+               break;
+       case REF_TRANSACTION_CLOSED:
+               die("BUG: prepare called on a closed reference transaction");
+               break;
+       default:
+               die("BUG: unexpected reference transaction state");
+               break;
+       }
+
        if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
                strbuf_addstr(err,
                              _("ref updates forbidden inside quarantine environment"));
                return -1;
        }
 
-       return refs->be->transaction_commit(refs, transaction, err);
+       return refs->be->transaction_prepare(refs, transaction, err);
+}
+
+int ref_transaction_abort(struct ref_transaction *transaction,
+                         struct strbuf *err)
+{
+       struct ref_store *refs = transaction->ref_store;
+       int ret = 0;
+
+       switch (transaction->state) {
+       case REF_TRANSACTION_OPEN:
+               /* No need to abort explicitly. */
+               break;
+       case REF_TRANSACTION_PREPARED:
+               ret = refs->be->transaction_abort(refs, transaction, err);
+               break;
+       case REF_TRANSACTION_CLOSED:
+               die("BUG: abort called on a closed reference transaction");
+               break;
+       default:
+               die("BUG: unexpected reference transaction state");
+               break;
+       }
+
+       ref_transaction_free(transaction);
+       return ret;
+}
+
+int ref_transaction_commit(struct ref_transaction *transaction,
+                          struct strbuf *err)
+{
+       struct ref_store *refs = transaction->ref_store;
+       int ret;
+
+       switch (transaction->state) {
+       case REF_TRANSACTION_OPEN:
+               /* Need to prepare first. */
+               ret = ref_transaction_prepare(transaction, err);
+               if (ret)
+                       return ret;
+               break;
+       case REF_TRANSACTION_PREPARED:
+               /* Fall through to finish. */
+               break;
+       case REF_TRANSACTION_CLOSED:
+               die("BUG: commit called on a closed reference transaction");
+               break;
+       default:
+               die("BUG: unexpected reference transaction state");
+               break;
+       }
+
+       return refs->be->transaction_finish(refs, transaction, err);
 }
 
 int refs_verify_refname_available(struct ref_store *refs,
@@ -1870,15 +2013,16 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction,
        return refs->be->initial_transaction_commit(refs, transaction, err);
 }
 
-int refs_delete_refs(struct ref_store *refs, struct string_list *refnames,
-                    unsigned int flags)
+int refs_delete_refs(struct ref_store *refs, const char *msg,
+                    struct string_list *refnames, unsigned int flags)
 {
-       return refs->be->delete_refs(refs, refnames, flags);
+       return refs->be->delete_refs(refs, msg, refnames, flags);
 }
 
-int delete_refs(struct string_list *refnames, unsigned int flags)
+int delete_refs(const char *msg, struct string_list *refnames,
+               unsigned int flags)
 {
-       return refs_delete_refs(get_main_ref_store(), refnames, flags);
+       return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
 }
 
 int refs_rename_ref(struct ref_store *refs, const char *oldref,