diff --git a/swh/core/api/serializers.py b/swh/core/api/serializers.py index fdca760..34511d0 100644 --- a/swh/core/api/serializers.py +++ b/swh/core/api/serializers.py @@ -1,301 +1,311 @@ # Copyright (C) 2015-2020 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import base64 import datetime from enum import Enum import json import traceback import types from typing import Any, Callable, Dict, List, Optional, Tuple, Type, Union from uuid import UUID import iso8601 import msgpack from requests import Response from swh.core.api.classes import PagedResult def encode_datetime(dt: datetime.datetime) -> str: """Wrapper of datetime.datetime.isoformat() that forbids naive datetimes.""" if dt.tzinfo is None: raise ValueError(f"{dt} is a naive datetime.") return dt.isoformat() def _encode_paged_result(obj: PagedResult) -> Dict[str, Any]: """Serialize PagedResult to a Dict.""" return { "results": obj.results, "next_page_token": obj.next_page_token, } def _decode_paged_result(obj: Dict[str, Any]) -> PagedResult: """Deserialize Dict into PagedResult""" return PagedResult(results=obj["results"], next_page_token=obj["next_page_token"],) def exception_to_dict(exception: Exception) -> Dict[str, Any]: tb = traceback.format_exception(None, exception, exception.__traceback__) exc_type = type(exception) return { "type": exc_type.__name__, "module": exc_type.__module__, "args": exception.args, "message": str(exception), "traceback": tb, } def dict_to_exception(exc_dict: Dict[str, Any]) -> Exception: temp = __import__(exc_dict["module"], fromlist=[exc_dict["type"]]) return getattr(temp, exc_dict["type"])(*exc_dict["args"]) def encode_timedelta(td: datetime.timedelta) -> Dict[str, int]: return { "days": td.days, "seconds": td.seconds, "microseconds": td.microseconds, } ENCODERS: List[Tuple[type, str, Callable]] = [ (datetime.datetime, "datetime", encode_datetime), (UUID, "uuid", str), (datetime.timedelta, "timedelta", encode_timedelta), (PagedResult, "paged_result", _encode_paged_result), - # Only for JSON: - (bytes, "bytes", lambda o: base64.b85encode(o).decode("ascii")), (Exception, "exception", exception_to_dict), ] +JSON_ENCODERS: List[Tuple[type, str, Callable]] = [ + (bytes, "bytes", lambda o: base64.b85encode(o).decode("ascii")), +] + DECODERS: Dict[str, Callable] = { "datetime": lambda d: iso8601.parse_date(d, default_timezone=None), "timedelta": lambda d: datetime.timedelta(**d), "uuid": UUID, "paged_result": _decode_paged_result, - # Only for JSON: - "bytes": base64.b85decode, "exception": dict_to_exception, } +JSON_DECODERS: Dict[str, Callable] = { + "bytes": base64.b85decode, +} + def get_encoders( - extra_encoders: Optional[List[Tuple[Type, str, Callable]]] + extra_encoders: Optional[List[Tuple[Type, str, Callable]]], with_json: bool = False ) -> List[Tuple[Type, str, Callable]]: - if extra_encoders is not None: - return [*ENCODERS, *extra_encoders] - else: - return ENCODERS - - -def get_decoders(extra_decoders: Optional[Dict[str, Callable]]) -> Dict[str, Callable]: + encoders = ENCODERS + if with_json: + encoders = [*encoders, *JSON_ENCODERS] + if extra_encoders: + encoders = [*encoders, *extra_encoders] + return encoders + + +def get_decoders( + extra_decoders: Optional[Dict[str, Callable]], with_json: bool = False +) -> Dict[str, Callable]: + decoders = DECODERS + if with_json: + decoders = {**decoders, **JSON_DECODERS} if extra_decoders is not None: - return {**DECODERS, **extra_decoders} - else: - return DECODERS + decoders = {**decoders, **extra_decoders} + return decoders class MsgpackExtTypeCodes(Enum): LONG_INT = 1 LONG_NEG_INT = 2 def encode_data_client(data: Any, extra_encoders=None) -> bytes: try: return msgpack_dumps(data, extra_encoders=extra_encoders) except OverflowError as e: raise ValueError("Limits were reached. Please, check your input.\n" + str(e)) def decode_response(response: Response, extra_decoders=None) -> Any: content_type = response.headers["content-type"] if content_type.startswith("application/x-msgpack"): r = msgpack_loads(response.content, extra_decoders=extra_decoders) elif content_type.startswith("application/json"): r = json_loads(response.text, extra_decoders=extra_decoders) elif content_type.startswith("text/"): r = response.text else: raise ValueError("Wrong content type `%s` for API response" % content_type) return r class SWHJSONEncoder(json.JSONEncoder): """JSON encoder for data structures generated by Software Heritage. This JSON encoder extends the default Python JSON encoder and adds awareness for the following specific types: - bytes (get encoded as a Base85 string); - datetime.datetime (get encoded as an ISO8601 string). Non-standard types get encoded as a a dictionary with two keys: - swhtype with value 'bytes' or 'datetime'; - d containing the encoded value. SWHJSONEncoder also encodes arbitrary iterables as a list (allowing serialization of generators). Caveats: Limitations in the JSONEncoder extension mechanism prevent us from "escaping" dictionaries that only contain the swhtype and d keys, and therefore arbitrary data structures can't be round-tripped through SWHJSONEncoder and SWHJSONDecoder. """ def __init__(self, extra_encoders=None, **kwargs): super().__init__(**kwargs) - self.encoders = get_encoders(extra_encoders) + self.encoders = get_encoders(extra_encoders, with_json=True) def default(self, o: Any) -> Union[Dict[str, Union[Dict[str, int], str]], list]: for (type_, type_name, encoder) in self.encoders: if isinstance(o, type_): return { "swhtype": type_name, "d": encoder(o), } try: return super().default(o) except TypeError as e: try: iterable = iter(o) except TypeError: raise e from None else: return list(iterable) class SWHJSONDecoder(json.JSONDecoder): """JSON decoder for data structures encoded with SWHJSONEncoder. This JSON decoder extends the default Python JSON decoder, allowing the decoding of: - bytes (encoded as a Base85 string); - datetime.datetime (encoded as an ISO8601 string). Non-standard types must be encoded as a a dictionary with exactly two keys: - swhtype with value 'bytes' or 'datetime'; - d containing the encoded value. To limit the impact our encoding, if the swhtype key doesn't contain a known value, the dictionary is decoded as-is. """ def __init__(self, extra_decoders=None, **kwargs): super().__init__(**kwargs) - self.decoders = get_decoders(extra_decoders) + self.decoders = get_decoders(extra_decoders, with_json=True) def decode_data(self, o: Any) -> Any: if isinstance(o, dict): if set(o.keys()) == {"d", "swhtype"}: if o["swhtype"] == "bytes": return base64.b85decode(o["d"]) decoder = self.decoders.get(o["swhtype"]) if decoder: return decoder(self.decode_data(o["d"])) return {key: self.decode_data(value) for key, value in o.items()} if isinstance(o, list): return [self.decode_data(value) for value in o] else: return o def raw_decode(self, s: str, idx: int = 0) -> Tuple[Any, int]: data, index = super().raw_decode(s, idx) return self.decode_data(data), index def json_dumps(data: Any, extra_encoders=None) -> str: return json.dumps(data, cls=SWHJSONEncoder, extra_encoders=extra_encoders) def json_loads(data: str, extra_decoders=None) -> Any: return json.loads(data, cls=SWHJSONDecoder, extra_decoders=extra_decoders) def msgpack_dumps(data: Any, extra_encoders=None) -> bytes: """Write data as a msgpack stream""" encoders = get_encoders(extra_encoders) def encode_types(obj): if isinstance(obj, int): # integer overflowed while packing. Handle it as an extended type if obj > 0: code = MsgpackExtTypeCodes.LONG_INT.value else: code = MsgpackExtTypeCodes.LONG_NEG_INT.value obj = -obj length, rem = divmod(obj.bit_length(), 8) if rem: length += 1 return msgpack.ExtType(code, int.to_bytes(obj, length, "big")) if isinstance(obj, types.GeneratorType): return list(obj) for (type_, type_name, encoder) in encoders: if isinstance(obj, type_): return { b"swhtype": type_name, b"d": encoder(obj), } return obj return msgpack.packb(data, use_bin_type=True, default=encode_types) def msgpack_loads(data: bytes, extra_decoders=None) -> Any: """Read data as a msgpack stream. .. Caution:: This function is used by swh.journal to decode the contents of the journal. This function **must** be kept backwards-compatible. """ decoders = get_decoders(extra_decoders) def ext_hook(code, data): if code == MsgpackExtTypeCodes.LONG_INT.value: return int.from_bytes(data, "big") elif code == MsgpackExtTypeCodes.LONG_NEG_INT.value: return -int.from_bytes(data, "big") raise ValueError("Unknown msgpack extended code %s" % code) def decode_types(obj): # Support for current encodings if set(obj.keys()) == {b"d", b"swhtype"}: decoder = decoders.get(obj[b"swhtype"]) if decoder: return decoder(obj[b"d"]) # Fallthrough return obj try: try: return msgpack.unpackb( data, raw=False, object_hook=decode_types, ext_hook=ext_hook, strict_map_key=False, ) except TypeError: # msgpack < 0.6.0 return msgpack.unpackb( data, raw=False, object_hook=decode_types, ext_hook=ext_hook ) except TypeError: # msgpack < 0.5.2 return msgpack.unpackb( data, encoding="utf-8", object_hook=decode_types, ext_hook=ext_hook )