diff --git a/swh/core/api/serializers.py b/swh/core/api/serializers.py index f9aca96..1dcfe88 100644 --- a/swh/core/api/serializers.py +++ b/swh/core/api/serializers.py @@ -1,198 +1,182 @@ # Copyright (C) 2015-2018 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 import json import types from uuid import UUID import arrow import dateutil.parser import msgpack from typing import Any, Dict, Union, Tuple from requests import Response +ENCODERS = [ + (arrow.Arrow, 'arrow', arrow.Arrow.isoformat), + (datetime.datetime, 'datetime', datetime.datetime.isoformat), + (datetime.timedelta, 'timedelta', lambda o: { + 'days': o.days, + 'seconds': o.seconds, + 'microseconds': o.microseconds, + }), + (UUID, 'uuid', str), + + # Only for JSON: + (bytes, 'bytes', lambda o: base64.b85encode(o).decode('ascii')), +] + +DECODERS = { + 'arrow': arrow.get, + 'datetime': dateutil.parser.parse, + 'timedelta': lambda d: datetime.timedelta(**d), + 'uuid': UUID, + + # Only for JSON: + 'bytes': base64.b85decode, +} + + def encode_data_client(data: Any) -> bytes: try: return msgpack_dumps(data) except OverflowError as e: raise ValueError('Limits were reached. Please, check your input.\n' + str(e)) def decode_response(response: Response) -> Any: content_type = response.headers['content-type'] if content_type.startswith('application/x-msgpack'): r = msgpack_loads(response.content) elif content_type.startswith('application/json'): r = json.loads(response.text, cls=SWHJSONDecoder) 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 default(self, o: Any ) -> Union[Dict[str, Union[Dict[str, int], str]], list]: - if isinstance(o, bytes): - return { - 'swhtype': 'bytes', - 'd': base64.b85encode(o).decode('ascii'), - } - elif isinstance(o, datetime.datetime): - return { - 'swhtype': 'datetime', - 'd': o.isoformat(), - } - elif isinstance(o, UUID): - return { - 'swhtype': 'uuid', - 'd': str(o), - } - elif isinstance(o, datetime.timedelta): - return { - 'swhtype': 'timedelta', - 'd': { - 'days': o.days, - 'seconds': o.seconds, - 'microseconds': o.microseconds, - }, - } - elif isinstance(o, arrow.Arrow): - return { - 'swhtype': 'arrow', - 'd': o.isoformat(), - } + for (type_, type_name, encoder) in 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 decode_data(self, o: Any) -> Any: if isinstance(o, dict): if set(o.keys()) == {'d', 'swhtype'}: - datatype = o['swhtype'] - if datatype == 'bytes': + if o['swhtype'] == 'bytes': return base64.b85decode(o['d']) - elif datatype == 'datetime': - return dateutil.parser.parse(o['d']) - elif datatype == 'uuid': - return UUID(o['d']) - elif datatype == 'timedelta': - return datetime.timedelta(**o['d']) - elif datatype == 'arrow': - return arrow.get(o['d']) + decoder = 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 msgpack_dumps(data: Any) -> bytes: """Write data as a msgpack stream""" def encode_types(obj): - if isinstance(obj, datetime.datetime): - return {b'__datetime__': True, b's': obj.isoformat()} if isinstance(obj, types.GeneratorType): return list(obj) - if isinstance(obj, UUID): - return {b'__uuid__': True, b's': str(obj)} - if isinstance(obj, datetime.timedelta): - return { - b'__timedelta__': True, - b's': { - 'days': obj.days, - 'seconds': obj.seconds, - 'microseconds': obj.microseconds, - }, - } - if isinstance(obj, arrow.Arrow): - return {b'__arrow__': True, b's': obj.isoformat()} + + 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) -> Any: """Read data as a msgpack stream""" def decode_types(obj): - if b'__datetime__' in obj and obj[b'__datetime__']: - return dateutil.parser.parse(obj[b's']) - if b'__uuid__' in obj and obj[b'__uuid__']: - return UUID(obj[b's']) - if b'__timedelta__' in obj and obj[b'__timedelta__']: - return datetime.timedelta(**obj[b's']) - if b'__arrow__' in obj and obj[b'__arrow__']: - return arrow.get(obj[b's']) + if set(obj.keys()) == {b'd', b'swhtype'}: + decoder = DECODERS.get(obj[b'swhtype']) + if decoder: + return decoder(obj[b'd']) return obj try: return msgpack.unpackb(data, raw=False, object_hook=decode_types) except TypeError: # msgpack < 0.5.2 return msgpack.unpackb(data, encoding='utf-8', object_hook=decode_types)