LSST Applications 27.0.0,g0265f82a02+469cd937ee,g02d81e74bb+21ad69e7e1,g1470d8bcf6+cbe83ee85a,g2079a07aa2+e67c6346a6,g212a7c68fe+04a9158687,g2305ad1205+94392ce272,g295015adf3+81dd352a9d,g2bbee38e9b+469cd937ee,g337abbeb29+469cd937ee,g3939d97d7f+72a9f7b576,g487adcacf7+71499e7cba,g50ff169b8f+5929b3527e,g52b1c1532d+a6fc98d2e7,g591dd9f2cf+df404f777f,g5a732f18d5+be83d3ecdb,g64a986408d+21ad69e7e1,g858d7b2824+21ad69e7e1,g8a8a8dda67+a6fc98d2e7,g99cad8db69+f62e5b0af5,g9ddcbc5298+d4bad12328,ga1e77700b3+9c366c4306,ga8c6da7877+71e4819109,gb0e22166c9+25ba2f69a1,gb6a65358fc+469cd937ee,gbb8dafda3b+69d3c0e320,gc07e1c2157+a98bf949bb,gc120e1dc64+615ec43309,gc28159a63d+469cd937ee,gcf0d15dbbd+72a9f7b576,gdaeeff99f8+a38ce5ea23,ge6526c86ff+3a7c1ac5f1,ge79ae78c31+469cd937ee,gee10cc3b42+a6fc98d2e7,gf1cff7945b+21ad69e7e1,gfbcc870c63+9a11dc8c8f
LSST Data Management Base Package
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apdbConfigFreezer.py
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1# This file is part of dax_apdb.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
21
22from __future__ import annotations
23
24__all__ = ["ApdbConfigFreezer"]
25
26import json
27from collections.abc import Iterable
28from typing import Generic, TypeVar
29
30from .apdb import ApdbConfig
31
32_Config = TypeVar("_Config", bound=ApdbConfig)
33
34
35class ApdbConfigFreezer(Generic[_Config]):
36 """Class that handles freezing of the configuration parameters, this is
37 an implementation detail for use in Apdb subclasses.
38
39 Parameters
40 ----------
41 field_names : `~collections.abc.Iterable` [`str`]
42 Names of configuration fields to be frozen.
43 """
44
45 def __init__(self, field_names: Iterable[str]):
46 self._field_names = list(field_names)
47
48 def to_json(self, config: ApdbConfig) -> str:
49 """Convert part of the configuration object to JSON string.
50
51 Parameters
52 ----------
53 config : `ApdbConfig`
54 Configuration object.
55
56 Returns
57 -------
58 json_str : `str`
59 JSON representation of the frozen part of the config.
60 """
61 config_dict = config.toDict()
62 json_dict = {name: config_dict[name] for name in self._field_names}
63 return json.dumps(json_dict)
64
65 def update(self, config: _Config, json_str: str) -> _Config:
66 """Update configuration field values from a JSON string.
67
68 Parameters
69 ----------
70 config : `ApdbConfig`
71 Configuration object.
72 json_str : str
73 String containing JSON representation of configuration.
74
75 Returns
76 -------
77 updated : `ApdbConfig`
78 Copy of the ``config`` with some fields updated from JSON object.
79
80 Raises
81 ------
82 TypeError
83 Raised if JSON string does not represent JSON object.
84 ValueError
85 Raised if JSON object contains key which is not present in
86 ``field_names``.
87 """
88 data = json.loads(json_str)
89 if not isinstance(data, dict):
90 raise TypeError(f"JSON string must be convertible to object: {json_str!r}")
91
92 new_config = type(config)(**config.toDict())
93 for key, value in data.items():
94 if key not in self._field_names:
95 raise ValueError(f"JSON object contains unknown key: {key}")
96 setattr(new_config, key, value)
97
98 return new_config
_Config update(self, _Config config, str json_str)