backups: Remove incorrectly set buffer size during download

- Don't set bufsize to 1 while streaming backup download. This is only effective
  with text streams with universal_newline flag set. An actual buffer size of 1
  is very inefficient and plain wrong. Leave the python default of
  io.DEFAULT_BUFFER_SIZE.

- Minor simplification to argument passing.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/actions.py

@@ -100,38 +100,35 @@ from plinth.errors import ActionError
 LOGGER = logging.getLogger(__name__)
 
 
-def run(action, options=None, input=None, run_in_background=False,
-        bufsize=None):
+def run(action, options=None, input=None, run_in_background=False):
     """Safely run a specific action as the current user.
 
     See actions._run for more information.
     """
-    return _run(action, options, input, run_in_background, False,
-                bufsize=bufsize)
+    return _run(action, options, input, run_in_background, False)
 
 
 def superuser_run(action, options=None, input=None, run_in_background=False,
-                  bufsize=None, log_error=True):
+                  log_error=True):
     """Safely run a specific action as root.
 
     See actions._run for more information.
     """
     return _run(action, options, input, run_in_background, True,
-                bufsize=bufsize, log_error=log_error)
+                log_error=log_error)
 
 
 def run_as_user(action, options=None, input=None, run_in_background=False,
-                bufsize=None, become_user=None):
+                become_user=None):
     """Run a command as a different user.
 
     If become_user is None, run as current user.
     """
-    return _run(action, options, input, run_in_background, False, become_user,
-                bufsize=bufsize)
+    return _run(action, options, input, run_in_background, False, become_user)
 
 
 def _run(action, options=None, input=None, run_in_background=False,
-         run_as_root=False, become_user=None, log_error=True, bufsize=None):
+         run_as_root=False, become_user=None, log_error=True):
     """Safely run a specific action as a normal user or root.
 
     Actions are pulled from the actions directory.
@@ -196,8 +193,7 @@ def _run(action, options=None, input=None, run_in_background=False,
     if cfg.develop:
         # In development mode pass on local pythonpath to access Plinth
         kwargs['env'] = {'PYTHONPATH': cfg.root}
-    if bufsize is not None:
-        kwargs['bufsize'] = bufsize
+
     proc = subprocess.Popen(cmd, **kwargs)
 
     if not run_in_background:

plinth/modules/backups/repository.py

@@ -139,9 +139,7 @@ class BorgRepository(object):
         archive_path = self.get_archive_path(archive_name)
         args = ['export-tar', '--path', archive_path]
         args = self.append_encryption_passphrase(args, self.credentials)
-        kwargs = {'run_in_background': True,
-                  'bufsize': 1}
-        proc = self._run('backups', args, kwargs=kwargs)
+        proc = self._run('backups', args, run_in_background=True)
         return zipstream.ZipStream(proc.stdout, 'readline')
 
     def get_archive(self, name):
@@ -166,15 +164,13 @@ class BorgRepository(object):
     def get_archive_path(self, archive_name):
         return "::".join([self.repo_path, archive_name])
 
-    def _run(self, cmd, arguments, superuser=True, kwargs=None):
+    def _run(self, cmd, arguments, superuser=True, **kwargs):
         """Run a backups or sshfs action script command."""
-        if kwargs is None:
-            kwargs = {}
         try:
             if superuser:
                 return actions.superuser_run(cmd, arguments, **kwargs)
-            else:
-                return actions.run(cmd, arguments, **kwargs)
+
+            return actions.run(cmd, arguments, **kwargs)
         except ActionError as err:
             self.reraise_known_error(err)
 
@@ -293,7 +289,7 @@ class SshBorgRepository(BorgRepository):
                      self._path]
         arguments, kwargs = self._append_sshfs_arguments(arguments,
                                                          self.credentials)
-        self._run('sshfs', arguments, kwargs=kwargs)
+        self._run('sshfs', arguments, **kwargs)
 
     def umount(self):
         if not self.is_mounted:
@@ -314,14 +310,16 @@ class SshBorgRepository(BorgRepository):
         except Exception as err:
             logger.error(err)
 
-    def _append_sshfs_arguments(self, arguments, credentials, kwargs=None):
+    def _append_sshfs_arguments(self, arguments, credentials):
         """Add credentials to a run command and kwargs"""
-        if kwargs is None:
-            kwargs = {}
+        kwargs = {}
+
         if 'ssh_password' in credentials and credentials['ssh_password']:
             kwargs['input'] = credentials['ssh_password'].encode()
+
         if 'ssh_keyfile' in credentials and credentials['ssh_keyfile']:
             arguments += ['--ssh-keyfile', credentials['ssh_keyfile']]
+
         return (arguments, kwargs)
 
     def run(self, arguments, superuser=True):