import json from contextlib import suppress from pathlib import PurePath from typing import Any, Callable, Dict, List, Optional, Tuple from .registry import _import_class, get_filesystem_class from .spec import AbstractFileSystem class FilesystemJSONEncoder(json.JSONEncoder): def default(self, o: Any) -> Any: if isinstance(o, AbstractFileSystem): return o.to_dict() if isinstance(o, PurePath): cls = type(o) return {"cls": f"{cls.__module__}.{cls.__name__}", "str": str(o)} return super().default(o) class FilesystemJSONDecoder(json.JSONDecoder): def __init__( self, *, object_hook: Optional[Callable[[Dict[str, Any]], Any]] = None, parse_float: Optional[Callable[[str], Any]] = None, parse_int: Optional[Callable[[str], Any]] = None, parse_constant: Optional[Callable[[str], Any]] = None, strict: bool = True, object_pairs_hook: Optional[Callable[[List[Tuple[str, Any]]], Any]] = None, ) -> None: self.original_object_hook = object_hook super().__init__( object_hook=self.custom_object_hook, parse_float=parse_float, parse_int=parse_int, parse_constant=parse_constant, strict=strict, object_pairs_hook=object_pairs_hook, ) @classmethod def try_resolve_path_cls(cls, dct: Dict[str, Any]): with suppress(Exception): fqp = dct["cls"] path_cls = _import_class(fqp) if issubclass(path_cls, PurePath): return path_cls return None @classmethod def try_resolve_fs_cls(cls, dct: Dict[str, Any]): with suppress(Exception): if "cls" in dct: try: fs_cls = _import_class(dct["cls"]) if issubclass(fs_cls, AbstractFileSystem): return fs_cls except Exception: if "protocol" in dct: # Fallback if cls cannot be imported return get_filesystem_class(dct["protocol"]) raise return None def custom_object_hook(self, dct: Dict[str, Any]): if "cls" in dct: if (obj_cls := self.try_resolve_fs_cls(dct)) is not None: return AbstractFileSystem.from_dict(dct) if (obj_cls := self.try_resolve_path_cls(dct)) is not None: return obj_cls(dct["str"]) if self.original_object_hook is not None: return self.original_object_hook(dct) return dct