Reformat code using Black

As discussed over the mailing list, reformat code using Black. This is a
one-off change to reformat all our codebase. Moving forward, we
shouldn't expect such blanket reformats. Rather, we expect each change
to already comply with the Black formatting style.

3 files changed, 112 insertions, 81 deletions

diff --git a/src/buildstream/storage/_casbaseddirectory.py b/src/buildstream/storage/_casbaseddirectory.py
index 3786f25b6..df28dc591 100644
--- a/src/buildstream/storage/_casbaseddirectory.py
+++ b/src/buildstream/storage/_casbaseddirectory.py
@@ -38,10 +38,20 @@ from ._filebaseddirectory import FileBasedDirectory
 from ..utils import FileListResult, BST_ARBITRARY_TIMESTAMP
 
 
-class IndexEntry():
+class IndexEntry:
     """ Directory entry used in CasBasedDirectory.index """
-    def __init__(self, name, entrytype, *, digest=None, target=None, is_executable=False,
-                 buildstream_object=None, modified=False):
+
+    def __init__(
+        self,
+        name,
+        entrytype,
+        *,
+        digest=None,
+        target=None,
+        is_executable=False,
+        buildstream_object=None,
+        modified=False
+    ):
         self.name = name
         self.type = entrytype
         self.digest = digest
@@ -52,8 +62,9 @@ class IndexEntry():
 
     def get_directory(self, parent):
         if not self.buildstream_object:
-            self.buildstream_object = CasBasedDirectory(parent.cas_cache, digest=self.digest,
-                                                        parent=parent, filename=self.name)
+            self.buildstream_object = CasBasedDirectory(
+                parent.cas_cache, digest=self.digest, parent=parent, filename=self.name
+            )
             self.digest = None
 
         return self.buildstream_object
@@ -69,6 +80,7 @@ class IndexEntry():
 # which is meant to be unimplemented.
 # pylint: disable=super-init-not-called
 
+
 class CasBasedDirectory(Directory):
     """
     CAS-based directories can have two names; one is a 'common name' which has no effect
@@ -100,21 +112,19 @@ class CasBasedDirectory(Directory):
     def _populate_index(self, digest):
         try:
             pb2_directory = remote_execution_pb2.Directory()
-            with open(self.cas_cache.objpath(digest), 'rb') as f:
+            with open(self.cas_cache.objpath(digest), "rb") as f:
                 pb2_directory.ParseFromString(f.read())
         except FileNotFoundError as e:
             raise VirtualDirectoryError("Directory not found in local cache: {}".format(e)) from e
 
         for entry in pb2_directory.directories:
-            self.index[entry.name] = IndexEntry(entry.name, _FileType.DIRECTORY,
-                                                digest=entry.digest)
+            self.index[entry.name] = IndexEntry(entry.name, _FileType.DIRECTORY, digest=entry.digest)
         for entry in pb2_directory.files:
-            self.index[entry.name] = IndexEntry(entry.name, _FileType.REGULAR_FILE,
-                                                digest=entry.digest,
-                                                is_executable=entry.is_executable)
+            self.index[entry.name] = IndexEntry(
+                entry.name, _FileType.REGULAR_FILE, digest=entry.digest, is_executable=entry.is_executable
+            )
         for entry in pb2_directory.symlinks:
-            self.index[entry.name] = IndexEntry(entry.name, _FileType.SYMLINK,
-                                                target=entry.target)
+            self.index[entry.name] = IndexEntry(entry.name, _FileType.SYMLINK, target=entry.target)
 
     def _find_self_in_parent(self):
         assert self.parent is not None
@@ -136,8 +146,7 @@ class CasBasedDirectory(Directory):
         return newdir
 
     def _add_file(self, basename, filename, modified=False, can_link=False):
-        entry = IndexEntry(filename, _FileType.REGULAR_FILE,
-                           modified=modified or filename in self.index)
+        entry = IndexEntry(filename, _FileType.REGULAR_FILE, modified=modified or filename in self.index)
         path = os.path.join(basename, filename)
         entry.digest = self.cas_cache.add_object(path=path, link_directly=can_link)
         entry.is_executable = os.access(path, os.X_OK)
@@ -206,14 +215,13 @@ class CasBasedDirectory(Directory):
                         current_dir = current_dir.descend(*newpaths, follow_symlinks=True)
                 else:
                     error = "Cannot descend into {}, which is a '{}' in the directory {}"
-                    raise VirtualDirectoryError(error.format(path,
-                                                             current_dir.index[path].type,
-                                                             current_dir),
-                                                reason="not-a-directory")
+                    raise VirtualDirectoryError(
+                        error.format(path, current_dir.index[path].type, current_dir), reason="not-a-directory"
+                    )
             else:
-                if path == '.':
+                if path == ".":
                     continue
-                elif path == '..':
+                elif path == "..":
                     if current_dir.parent is not None:
                         current_dir = current_dir.parent
                     # In POSIX /.. == / so just stay at the root dir
@@ -222,8 +230,7 @@ class CasBasedDirectory(Directory):
                     current_dir = current_dir._add_directory(path)
                 else:
                     error = "'{}' not found in {}"
-                    raise VirtualDirectoryError(error.format(path, str(current_dir)),
-                                                reason="directory-not-found")
+                    raise VirtualDirectoryError(error.format(path, str(current_dir)), reason="directory-not-found")
 
         return current_dir
 
@@ -299,12 +306,13 @@ class CasBasedDirectory(Directory):
                         dest_subdir = self.descend(name, create=create_subdir)
                     except VirtualDirectoryError:
                         filetype = self.index[name].type
-                        raise VirtualDirectoryError('Destination is a {}, not a directory: /{}'
-                                                    .format(filetype, relative_pathname))
+                        raise VirtualDirectoryError(
+                            "Destination is a {}, not a directory: /{}".format(filetype, relative_pathname)
+                        )
 
-                    dest_subdir._partial_import_cas_into_cas(src_subdir, filter_callback,
-                                                             path_prefix=relative_pathname,
-                                                             origin=origin, result=result)
+                    dest_subdir._partial_import_cas_into_cas(
+                        src_subdir, filter_callback, path_prefix=relative_pathname, origin=origin, result=result
+                    )
 
             if filter_callback and not filter_callback(relative_pathname):
                 if is_dir and create_subdir and dest_subdir.is_empty():
@@ -317,20 +325,22 @@ class CasBasedDirectory(Directory):
             if not is_dir:
                 if self._check_replacement(name, relative_pathname, result):
                     if entry.type == _FileType.REGULAR_FILE:
-                        self.index[name] = IndexEntry(name, _FileType.REGULAR_FILE,
-                                                      digest=entry.digest,
-                                                      is_executable=entry.is_executable,
-                                                      modified=True)
+                        self.index[name] = IndexEntry(
+                            name,
+                            _FileType.REGULAR_FILE,
+                            digest=entry.digest,
+                            is_executable=entry.is_executable,
+                            modified=True,
+                        )
                         self.__invalidate_digest()
                     else:
                         assert entry.type == _FileType.SYMLINK
                         self._add_new_link_direct(name=name, target=entry.target)
                     result.files_written.append(relative_pathname)
 
-    def import_files(self, external_pathspec, *,
-                     filter_callback=None,
-                     report_written=True, update_mtime=False,
-                     can_link=False):
+    def import_files(
+        self, external_pathspec, *, filter_callback=None, report_written=True, update_mtime=False, can_link=False
+    ):
         """ See superclass Directory for arguments """
 
         result = FileListResult()
@@ -358,13 +368,12 @@ class CasBasedDirectory(Directory):
 
     def import_single_file(self, external_pathspec):
         result = FileListResult()
-        if self._check_replacement(os.path.basename(external_pathspec),
-                                   os.path.dirname(external_pathspec),
-                                   result):
-            self._add_file(os.path.dirname(external_pathspec),
-                           os.path.basename(external_pathspec),
-                           modified=os.path.basename(external_pathspec)
-                           in result.overwritten)
+        if self._check_replacement(os.path.basename(external_pathspec), os.path.dirname(external_pathspec), result):
+            self._add_file(
+                os.path.dirname(external_pathspec),
+                os.path.basename(external_pathspec),
+                modified=os.path.basename(external_pathspec) in result.overwritten,
+            )
             result.files_written.append(external_pathspec)
         return result
 
@@ -516,10 +525,8 @@ class CasBasedDirectory(Directory):
 
         """
 
-        file_list = list(filter(lambda i: i[1].type != _FileType.DIRECTORY,
-                                self.index.items()))
-        directory_list = filter(lambda i: i[1].type == _FileType.DIRECTORY,
-                                self.index.items())
+        file_list = list(filter(lambda i: i[1].type != _FileType.DIRECTORY, self.index.items()))
+        directory_list = filter(lambda i: i[1].type == _FileType.DIRECTORY, self.index.items())
 
         if prefix != "":
             yield prefix
@@ -553,10 +560,7 @@ class CasBasedDirectory(Directory):
           """
         for leaf in sorted(self.index.keys()):
             entry = self.index[leaf]
-            info = {
-                "name": os.path.join(prefix, leaf),
-                "type": entry.type
-            }
+            info = {"name": os.path.join(prefix, leaf), "type": entry.type}
             if entry.type == _FileType.REGULAR_FILE:
                 info["executable"] = entry.is_executable
                 info["size"] = self.get_size()
@@ -599,8 +603,9 @@ class CasBasedDirectory(Directory):
     def _get_underlying_directory(self):
         """ There is no underlying directory for a CAS-backed directory, so
         throw an exception. """
-        raise VirtualDirectoryError("_get_underlying_directory was called on a CAS-backed directory," +
-                                    " which has no underlying directory.")
+        raise VirtualDirectoryError(
+            "_get_underlying_directory was called on a CAS-backed directory," + " which has no underlying directory."
+        )
 
     # _get_digest():
     #
diff --git a/src/buildstream/storage/_filebaseddirectory.py b/src/buildstream/storage/_filebaseddirectory.py
index 07c23c192..222b47979 100644
--- a/src/buildstream/storage/_filebaseddirectory.py
+++ b/src/buildstream/storage/_filebaseddirectory.py
@@ -65,23 +65,22 @@ class FileBasedDirectory(Directory):
             try:
                 st = os.lstat(new_path)
                 if not stat.S_ISDIR(st.st_mode):
-                    raise VirtualDirectoryError("Cannot descend into '{}': '{}' is not a directory"
-                                                .format(path, new_path))
+                    raise VirtualDirectoryError(
+                        "Cannot descend into '{}': '{}' is not a directory".format(path, new_path)
+                    )
             except FileNotFoundError:
                 if create:
                     os.mkdir(new_path)
                 else:
-                    raise VirtualDirectoryError("Cannot descend into '{}': '{}' does not exist"
-                                                .format(path, new_path))
+                    raise VirtualDirectoryError("Cannot descend into '{}': '{}' does not exist".format(path, new_path))
 
             current_dir = FileBasedDirectory(new_path)
 
         return current_dir
 
-    def import_files(self, external_pathspec, *,
-                     filter_callback=None,
-                     report_written=True, update_mtime=False,
-                     can_link=False):
+    def import_files(
+        self, external_pathspec, *, filter_callback=None, report_written=True, update_mtime=False, can_link=False
+    ):
         """ See superclass Directory for arguments """
 
         from ._casbaseddirectory import CasBasedDirectory  # pylint: disable=cyclic-import
@@ -101,13 +100,21 @@ class FileBasedDirectory(Directory):
                 source_directory = external_pathspec
 
             if can_link and not update_mtime:
-                import_result = link_files(source_directory, self.external_directory,
-                                           filter_callback=filter_callback,
-                                           ignore_missing=False, report_written=report_written)
+                import_result = link_files(
+                    source_directory,
+                    self.external_directory,
+                    filter_callback=filter_callback,
+                    ignore_missing=False,
+                    report_written=report_written,
+                )
             else:
-                import_result = copy_files(source_directory, self.external_directory,
-                                           filter_callback=filter_callback,
-                                           ignore_missing=False, report_written=report_written)
+                import_result = copy_files(
+                    source_directory,
+                    self.external_directory,
+                    filter_callback=filter_callback,
+                    ignore_missing=False,
+                    report_written=report_written,
+                )
 
         if update_mtime:
             cur_time = time.time()
@@ -190,8 +197,11 @@ class FileBasedDirectory(Directory):
 
         Return value: List(str) - list of modified paths
         """
-        return [f for f in list_relative_paths(self.external_directory)
-                if _get_link_mtime(os.path.join(self.external_directory, f)) != BST_ARBITRARY_TIMESTAMP]
+        return [
+            f
+            for f in list_relative_paths(self.external_directory)
+            if _get_link_mtime(os.path.join(self.external_directory, f)) != BST_ARBITRARY_TIMESTAMP
+        ]
 
     def list_relative_paths(self):
         """Provide a list of all relative paths.
@@ -251,11 +261,13 @@ class FileBasedDirectory(Directory):
                     dest_subdir = self.descend(name, create=create_subdir)
                 except VirtualDirectoryError:
                     filetype = self._get_filetype(name)
-                    raise VirtualDirectoryError('Destination is a {}, not a directory: /{}'
-                                                .format(filetype, relative_pathname))
+                    raise VirtualDirectoryError(
+                        "Destination is a {}, not a directory: /{}".format(filetype, relative_pathname)
+                    )
 
-                dest_subdir._import_files_from_cas(src_subdir, actionfunc, filter_callback,
-                                                   path_prefix=relative_pathname, result=result)
+                dest_subdir._import_files_from_cas(
+                    src_subdir, actionfunc, filter_callback, path_prefix=relative_pathname, result=result
+                )
 
             if filter_callback and not filter_callback(relative_pathname):
                 if is_dir and create_subdir and dest_subdir.is_empty():
@@ -279,8 +291,16 @@ class FileBasedDirectory(Directory):
                     src_path = source_directory.cas_cache.objpath(entry.digest)
                     actionfunc(src_path, dest_path, result=result)
                     if entry.is_executable:
-                        os.chmod(dest_path, stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR |
-                                 stat.S_IRGRP | stat.S_IXGRP | stat.S_IROTH | stat.S_IXOTH)
+                        os.chmod(
+                            dest_path,
+                            stat.S_IRUSR
+                            | stat.S_IWUSR
+                            | stat.S_IXUSR
+                            | stat.S_IRGRP
+                            | stat.S_IXGRP
+                            | stat.S_IROTH
+                            | stat.S_IXOTH,
+                        )
                 else:
                     assert entry.type == _FileType.SYMLINK
                     os.symlink(entry.target, dest_path)
diff --git a/src/buildstream/storage/directory.py b/src/buildstream/storage/directory.py
index 29cbb53f2..89d20c433 100644
--- a/src/buildstream/storage/directory.py
+++ b/src/buildstream/storage/directory.py
@@ -46,11 +46,12 @@ class VirtualDirectoryError(BstError):
     or either of the :class:`.ElementError` or :class:`.SourceError`
     exceptions should be raised from this error.
     """
+
     def __init__(self, message, reason=None):
         super().__init__(message, domain=ErrorDomain.VIRTUAL_FS, reason=reason)
 
 
-class Directory():
+class Directory:
     def __init__(self, external_directory=None):
         raise NotImplementedError()
 
@@ -74,10 +75,15 @@ class Directory():
         raise NotImplementedError()
 
     # Import and export of files and links
-    def import_files(self, external_pathspec: Union['Directory', str], *,
-                     filter_callback: Optional[Callable[[str], bool]] = None,
-                     report_written: bool = True, update_mtime: bool = False,
-                     can_link: bool = False) -> FileListResult:
+    def import_files(
+        self,
+        external_pathspec: Union["Directory", str],
+        *,
+        filter_callback: Optional[Callable[[str], bool]] = None,
+        report_written: bool = True,
+        update_mtime: bool = False,
+        can_link: bool = False
+    ) -> FileListResult:
         """Imports some or all files from external_path into this directory.
 
         Args:
@@ -214,4 +220,4 @@ class _FileType(FastEnum):
 
     def __str__(self):
         # https://github.com/PyCQA/pylint/issues/2062
-        return self.name.lower().replace('_', ' ')  # pylint: disable=no-member
+        return self.name.lower().replace("_", " ")  # pylint: disable=no-member