File size: 3,870 Bytes
985c397 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 | # SPDX-License-Identifier: LGPL-2.1-or-later
# ***************************************************************************
# * Copyright (c) 2025 Samuel Abels <knipknap@gmail.com> *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * This program is distributed in the hope that it will be useful, *
# * but WITHOUT ANY WARRANTY; without even the implied warranty of *
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
# * GNU Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library General Public *
# * License along with this program; if not, write to the Free Software *
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
# * USA *
# * *
# ***************************************************************************
import abc
from abc import ABC
from typing import Mapping, List, Optional, Tuple, Type
from .uri import AssetUri
from .asset import Asset
class AssetSerializer(ABC):
for_class: Type[Asset]
extensions: Tuple[str, ...] = tuple()
mime_type: str
can_import: bool = True
can_export: bool = True
@classmethod
@abc.abstractmethod
def get_label(cls) -> str:
pass
@classmethod
@abc.abstractmethod
def extract_dependencies(cls, data: bytes) -> List[AssetUri]:
"""Extracts URIs of dependencies from serialized data."""
pass
@classmethod
@abc.abstractmethod
def serialize(cls, asset: Asset) -> bytes:
"""Serializes an asset object into bytes."""
pass
@classmethod
@abc.abstractmethod
def deserialize(
cls,
data: bytes,
id: str,
dependencies: Optional[Mapping[AssetUri, Asset]],
) -> "Asset":
"""
Creates an asset object from serialized data and resolved dependencies.
If dependencies is None, it indicates a shallow load where dependencies
were not resolved.
"""
pass
@classmethod
@abc.abstractmethod
def deep_deserialize(cls, data: bytes) -> Asset:
"""
Like deserialize(), but builds dependencies itself if they are
sufficiently defined in the data.
This method is used for export/import, where some dependencies
may be embedded in the data, while others may not.
"""
pass
class DummyAssetSerializer(AssetSerializer):
"""
A serializer that does nothing. Can be used by simple assets that don't
need a non-native serialization. These type of assets can implement
extract_dependencies(), to_bytes() and from_bytes() methods that ignore
the given serializer.
"""
@classmethod
def extract_dependencies(cls, data: bytes) -> List[AssetUri]:
return []
@classmethod
def serialize(cls, asset: Asset) -> bytes:
return b""
@classmethod
def deserialize(
cls,
data: bytes,
id: str,
dependencies: Optional[Mapping[AssetUri, Asset]],
) -> Asset:
raise RuntimeError("DummySerializer.deserialize() was called")
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