Coverage for python/lsst/sphgeom/_yaml.py : 63%

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1# This file is part of sphgeom.
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/>.
22"""Add support for YAML serialization of regions."""
24__all__ = ()
26# YAML representers and constructors are only useful if yaml itself can
27# be imported. If yaml can not be imported then there is no reason to
28# break the entire module import of sphgeom.
29try:
30 import yaml
31except ImportError:
32 yaml = None
34from ._sphgeom import (
35 Box,
36 Circle,
37 ConvexPolygon,
38 Ellipse,
39 HtmPixelization,
40 Mq3cPixelization,
41 Region,
42 Q3cPixelization,
43)
46if yaml: 46 ↛ 60line 46 didn't jump to line 60, because the condition on line 46 was never false
47 try:
48 # CLoader is not always available
49 from yaml import CLoader
50 except ImportError:
51 CLoader = None
53 YamlLoaders = (yaml.Loader, yaml.FullLoader, yaml.SafeLoader, yaml.UnsafeLoader)
54 if CLoader is not None: 54 ↛ 60line 54 didn't jump to line 60, because the condition on line 54 was never false
55 YamlLoaders += (CLoader,)
58# Regions
60def region_representer(dumper, data):
61 """Represent a sphgeom region object in a form suitable for YAML.
63 Stores the region as a mapping with a single ``encoded`` key
64 storing the hex encoded byte string.
65 """
66 encoded = data.encode()
67 return dumper.represent_mapping(f"lsst.sphgeom.{type(data).__name__}",
68 {"encoded": encoded.hex()})
71def region_constructor(loader, node):
72 """Construct a sphgeom region from YAML"""
73 mapping = loader.construct_mapping(node)
74 encoded = bytes.fromhex(mapping["encoded"])
75 # The generic Region base class can instantiate a region of the
76 # correct type.
77 return Region.decode(encoded)
80# Register all the region classes with the same constructor and representer
81if yaml: 81 ↛ 91line 81 didn't jump to line 91, because the condition on line 81 was never false
82 for region_class in (ConvexPolygon, Ellipse, Circle, Box):
83 yaml.add_representer(region_class, region_representer)
85 for loader in YamlLoaders:
86 yaml.add_constructor(f"lsst.sphgeom.{region_class.__name__}", region_constructor, Loader=loader)
89# Pixelization schemes
91def pixel_representer(dumper, data):
92 """Represent a pixelization in YAML
94 Stored as the pixelization level in a mapping with a single key
95 ``level``.
96 """
97 return dumper.represent_mapping(f"lsst.sphgeom.{type(data).__name__}",
98 {"level": data.getLevel()})
101def pixel_constructor(loader, node):
102 """Construct a pixelization object from YAML.
103 """
104 mapping = loader.construct_mapping(node)
106 className = node.tag
107 pixelMap = {"lsst.sphgeom.Q3cPixelization": Q3cPixelization,
108 "lsst.sphgeom.Mq3cPixelization": Mq3cPixelization,
109 "lsst.sphgeom.HtmPixelization": HtmPixelization,
110 }
112 if className not in pixelMap:
113 raise RuntimeError(f"Encountered unexpected class {className} associated with"
114 " sphgeom pixelization YAML constructor")
116 return pixelMap[className](mapping["level"])
119# All the pixelization schemes use the same approach with getLevel
120if yaml: 120 ↛ exitline 120 didn't exit the module, because the condition on line 120 was never false
121 for pixelSchemeCls in (HtmPixelization, Q3cPixelization, Mq3cPixelization):
122 yaml.add_representer(pixelSchemeCls, pixel_representer)
123 for loader in YamlLoaders:
124 yaml.add_constructor(f"lsst.sphgeom.{pixelSchemeCls.__name__}", pixel_constructor, Loader=loader)