import collections import zipfile import pathlib from . import abc def remove_duplicates(items): return iter(collections.OrderedDict.fromkeys(items)) class FileReader(abc.TraversableResources): def __init__(self, loader): self.path = pathlib.Path(loader.path).parent def resource_path(self, resource): """ Return the file system path to prevent `resources.path()` from creating a temporary copy. """ return str(self.path.joinpath(resource)) def files(self): return self.path class ZipReader(abc.TraversableResources): def __init__(self, loader, module): _, _, name = module.rpartition('.') self.prefix = loader.prefix.replace('\\', '/') + name + '/' self.archive = loader.archive def open_resource(self, resource): try: return super().open_resource(resource) except KeyError as exc: raise FileNotFoundError(exc.args[0]) def is_resource(self, path): # workaround for `zipfile.Path.is_file` returning true # for non-existent paths. target = self.files().joinpath(path) return target.is_file() and target.exists() def files(self): return zipfile.Path(self.archive, self.prefix) class MultiplexedPath(abc.Traversable): """ Given a series of Traversable objects, implement a merged version of the interface across all objects. Useful for namespace packages which may be multihomed at a single name. """ def __init__(self, *paths): self._paths = list(map(pathlib.Path, remove_duplicates(paths))) if not self._paths: message = 'MultiplexedPath must contain at least one path' raise FileNotFoundError(message) if not all(path.is_dir() for path in self._paths): raise NotADirectoryError('MultiplexedPath only supports directories') def iterdir(self): visited = [] for path in self._paths: for file in path.iterdir(): if file.name in visited: continue visited.append(file.name) yield file def read_bytes(self): raise FileNotFoundError(f'{self} is not a file') def read_text(self, *args, **kwargs): raise FileNotFoundError(f'{self} is not a file') def is_dir(self): return True def is_file(self): return False def joinpath(self, child): # first try to find child in current paths for file in self.iterdir(): if file.name == child: return file # if it does not exist, construct it with the first path return self._paths[0] / child __truediv__ = joinpath def open(self, *args, **kwargs): raise FileNotFoundError(f'{self} is not a file') @property def name(self): return self._paths[0].name def __repr__(self): paths = ', '.join(f"'{path}'" for path in self._paths) return f'MultiplexedPath({paths})' class NamespaceReader(abc.TraversableResources): def __init__(self, namespace_path): if 'NamespacePath' not in str(namespace_path): raise ValueError('Invalid path') self.path = MultiplexedPath(*list(namespace_path)) def resource_path(self, resource): """ Return the file system path to prevent `resources.path()` from creating a temporary copy. """ return str(self.path.joinpath(resource)) def files(self): return self.path