2020-05-06 14:08:29 -07:00

91 lines
3.4 KiB
Python

# Copyright (c) 2011-2020 Eric Froemling
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# -----------------------------------------------------------------------------
"""Custom json compressor/decompressor with support for more data times/etc."""
from __future__ import annotations
import datetime
import json
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import Any
# Special attr we included for our extended type information
# (extended-json-type)
TYPE_TAG = '_xjtp'
_pytz_utc: Any
# We don't *require* pytz since it must be installed through pip
# but it is used by firestore client for its utc tzinfos.
# (in which case it should be installed as a dependency anyway)
try:
import pytz
_pytz_utc = pytz.utc
except ModuleNotFoundError:
_pytz_utc = None # pylint: disable=invalid-name
class ExtendedJSONEncoder(json.JSONEncoder):
"""Custom json encoder supporting additional types."""
def default(self, obj: Any) -> Any: # pylint: disable=W0221
if isinstance(obj, datetime.datetime):
# We only support timezone-aware utc times.
if (obj.tzinfo is not datetime.timezone.utc
and (_pytz_utc is None or obj.tzinfo is not _pytz_utc)):
raise ValueError(
'datetime values must have timezone set as timezone.utc')
return {
TYPE_TAG:
'dt',
'v': [
obj.year, obj.month, obj.day, obj.hour, obj.minute,
obj.second, obj.microsecond
],
}
return super().default(obj)
class ExtendedJSONDecoder(json.JSONDecoder):
"""Custom json decoder supporting extended types."""
def __init__(self, *args: Any, **kwargs: Any):
json.JSONDecoder.__init__(self,
object_hook=self.object_hook,
*args,
**kwargs)
def object_hook(self, obj: Any) -> Any: # pylint: disable=E0202
"""Custom hook."""
if TYPE_TAG not in obj:
return obj
objtype = obj[TYPE_TAG]
if objtype == 'dt':
vals = obj.get('v', [])
if len(vals) != 7:
raise ValueError('malformed datetime value')
return datetime.datetime( # type: ignore
*vals, tzinfo=datetime.timezone.utc)
return obj