Don't require a transaction for sync DB updates

Instead, just do the required locking directly in the backend in calls
to alpm_db_update().

Signed-off-by: Dan McGee <dan@archlinux.org>

2 files changed, 24 insertions, 25 deletions

diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index c1703ffe..f51ab97a 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -113,26 +113,22 @@ valid:
  * \a force is true, the update will only be performed if the remote
  * database was modified since the last update.
  *
- * A transaction is necessary for this operation, in order to obtain a
- * database lock. During this transaction the front-end will be informed
- * of the download progress of the database via the download callback.
+ * This operation requires a database lock, and will return an applicable error
+ * if the lock could not be obtained.
  *
  * Example:
  * @code
  * alpm_list_t *syncs = alpm_option_get_syncdbs();
- * if(alpm_trans_init(0, NULL, NULL, NULL) == 0) {
- *     for(i = syncs; i; i = alpm_list_next(i)) {
- *         pmdb_t *db = alpm_list_getdata(i);
- *         result = alpm_db_update(0, db);
- *         alpm_trans_release();
+ * for(i = syncs; i; i = alpm_list_next(i)) {
+ *     pmdb_t *db = alpm_list_getdata(i);
+ *     result = alpm_db_update(0, db);
  *
- *         if(result < 0) {
- *	           printf("Unable to update database: %s\n", alpm_strerrorlast());
- *         } else if(result == 1) {
- *             printf("Database already up to date\n");
- *         } else {
- *             printf("Database updated\n");
- *         }
+ *     if(result < 0) {
+ *	       printf("Unable to update database: %s\n", alpm_strerrorlast());
+ *     } else if(result == 1) {
+ *         printf("Database already up to date\n");
+ *     } else {
+ *         printf("Database updated\n");
  *     }
  * }
  * @endcode
@@ -162,15 +158,21 @@ int SYMEXPORT alpm_db_update(int force, pmdb_t *db)
 	ASSERT(db != handle->db_local, RET_ERR(handle, PM_ERR_WRONG_ARGS, -1));
 	ASSERT(db->servers != NULL, RET_ERR(handle, PM_ERR_SERVER_NONE, -1));
 
-	/* make sure we have a sane umask */
-	oldmask = umask(0022);
-
 	syncpath = get_sync_dir(handle);
 	if(!syncpath) {
 		return -1;
 	}
+
+	/* make sure we have a sane umask */
+	oldmask = umask(0022);
+
 	check_sig = _alpm_db_get_sigverify_level(db);
 
+	/* attempt to grab a lock */
+	if(_alpm_handle_lock(handle)) {
+		RET_ERR(handle, PM_ERR_HANDLE_LOCK, -1);
+	}
+
 	for(i = db->servers; i; i = i->next) {
 		const char *server = i->data;
 		char *fileurl;
@@ -232,6 +234,10 @@ int SYMEXPORT alpm_db_update(int force, pmdb_t *db)
 
 cleanup:
 
+	if(_alpm_handle_unlock(handle)) {
+		_alpm_log(handle, PM_LOG_WARNING, _("could not remove lock file %s\n"),
+				alpm_option_get_lockfile(handle));
+	}
 	free(syncpath);
 	umask(oldmask);
 	return ret;
diff --git a/src/pacman/sync.c b/src/pacman/sync.c
index 6c86bd10..f242c827 100644
--- a/src/pacman/sync.c
+++ b/src/pacman/sync.c
@@ -283,10 +283,6 @@ static int sync_synctree(int level, alpm_list_t *syncs)
 	alpm_list_t *i;
 	int success = 0, ret;
 
-	if(trans_init(0) == -1) {
-		return 0;
-	}
-
 	for(i = syncs; i; i = alpm_list_next(i)) {
 		pmdb_t *db = alpm_list_getdata(i);
 
@@ -302,9 +298,6 @@ static int sync_synctree(int level, alpm_list_t *syncs)
 		}
 	}
 
-	if(trans_release() == -1) {
-		return 0;
-	}
 	/* We should always succeed if at least one DB was upgraded - we may possibly
 	 * fail later with unresolved deps, but that should be rare, and would be
 	 * expected