def __init__(self, folder):
self._root = None
self._folder = Folder.elf(folder)
if not self._folder.exists():
raise NotRootException(f'Folder does not exists: {self._folder}')
self._file = File.join(self._folder, self._file_name(self._folder))
if not self._file.exists():
raise NotRootException(f'Description file does '
f'not exist: {self._file}')
self.read()
if self.key() != self._folder.name():
raise NotRootException(f'Key/folder mismatch. '
f'key={self._root.key}, '
f'folder={self._folder}, '
f'file={self._file}')
def elf(cls, folder, **kwargs):
"""
Converts an existing folder to root, tolerating missing file but not
invalid key. If a folder already is a valid root, it will be returned
as root. The folder name must be a valid :class:`.Key`
:raise RootError: If file already exists, but does not have the right
key, or if it has an invalid format
:param folder: Folder to convert to root
:type folder: Folder
:param kwargs: Attributes to add to root file
:return: New or existing root
:rtype: Root
"""
if cls.is_root(folder):
return cls(folder)
folder = Folder.elf(folder)
file = File.join(folder, cls._file_name(folder))
if file.exists():
try:
dic = file.read()
if isinstance(dic['_root'], Atom):
key = dic['_root'].key
if key == folder.name():
raise RootError(f'This seems to be a valid root, but '
f'is_root said otherwise. Contact '
f'the rather incompetent developer of '
f'this module.')
else:
raise RootError(f'Root file already exists, but has '
f'the wrong key. '
f'Expected: key={folder.name()}, '
f'Found: key={key}')
else:
raise RootError(f'Root file already exists, but has '
f'invalid format. Should be atom, but '
f'contents is instead: {dic}')
except FileError as fe:
raise RootError(f'Root file exists, does not seem to be a '
f'valid JSON file. '
f'Original error from read: {fe}')
else:
folder.touch()
file.write(cls._dic(folder, **kwargs))
return cls(folder)
def leaf(self, atom):
"""
Get the leaf defined by the given atom
:param atom: Atom defining the leaf contents
:type atom: Atom
:return: Leaf defined by the atom
:rtype: Leaf
"""
atom = Atom.elf(atom)
folder = self._branch(atom)
file_name = File.make_file_name(str(atom),
self.extension,
is_compressed=self.compress_all,
is_encrypted=self.encrypt_all)
file = File.join(folder, file_name)
return Leaf(file)
def _get_file(cls, folder):
return File.join(folder, cls._file_name(folder))