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/>. 

21 

22"""Add support for YAML serialization of regions.""" 

23 

24__all__ = () 

25 

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 

33 

34from ._sphgeom import ( 

35 Box, 

36 Circle, 

37 ConvexPolygon, 

38 Ellipse, 

39 HtmPixelization, 

40 Mq3cPixelization, 

41 Region, 

42 Q3cPixelization, 

43) 

44 

45from ._healpixPixelization import HealpixPixelization 

46 

47 

48if yaml: 48 ↛ 62line 48 didn't jump to line 62, because the condition on line 48 was never false

49 try: 

50 # CLoader is not always available 

51 from yaml import CLoader 

52 except ImportError: 

53 CLoader = None 

54 

55 YamlLoaders = (yaml.Loader, yaml.FullLoader, yaml.SafeLoader, yaml.UnsafeLoader) 

56 if CLoader is not None: 56 ↛ 62line 56 didn't jump to line 62, because the condition on line 56 was never false

57 YamlLoaders += (CLoader,) 

58 

59 

60# Regions 

61 

62def region_representer(dumper, data): 

63 """Represent a sphgeom region object in a form suitable for YAML. 

64 

65 Stores the region as a mapping with a single ``encoded`` key 

66 storing the hex encoded byte string. 

67 """ 

68 encoded = data.encode() 

69 return dumper.represent_mapping(f"lsst.sphgeom.{type(data).__name__}", 

70 {"encoded": encoded.hex()}) 

71 

72 

73def region_constructor(loader, node): 

74 """Construct a sphgeom region from YAML""" 

75 mapping = loader.construct_mapping(node) 

76 encoded = bytes.fromhex(mapping["encoded"]) 

77 # The generic Region base class can instantiate a region of the 

78 # correct type. 

79 return Region.decode(encoded) 

80 

81 

82# Register all the region classes with the same constructor and representer 

83if yaml: 83 ↛ 93line 83 didn't jump to line 93, because the condition on line 83 was never false

84 for region_class in (ConvexPolygon, Ellipse, Circle, Box): 

85 yaml.add_representer(region_class, region_representer) 

86 

87 for loader in YamlLoaders: 

88 yaml.add_constructor(f"lsst.sphgeom.{region_class.__name__}", region_constructor, Loader=loader) 

89 

90 

91# Pixelization schemes 

92 

93def pixel_representer(dumper, data): 

94 """Represent a pixelization in YAML 

95 

96 Stored as the pixelization level in a mapping with a single key 

97 ``level``. 

98 """ 

99 return dumper.represent_mapping(f"lsst.sphgeom.{type(data).__name__}", 

100 {"level": data.getLevel()}) 

101 

102 

103def pixel_constructor(loader, node): 

104 """Construct a pixelization object from YAML. 

105 """ 

106 mapping = loader.construct_mapping(node) 

107 

108 className = node.tag 

109 pixelMap = {"lsst.sphgeom.Q3cPixelization": Q3cPixelization, 

110 "lsst.sphgeom.Mq3cPixelization": Mq3cPixelization, 

111 "lsst.sphgeom.HtmPixelization": HtmPixelization, 

112 "lsst.sphgeom.HealpixPixelization": HealpixPixelization, 

113 } 

114 

115 if className not in pixelMap: 

116 raise RuntimeError(f"Encountered unexpected class {className} associated with" 

117 " sphgeom pixelization YAML constructor") 

118 

119 return pixelMap[className](mapping["level"]) 

120 

121 

122# All the pixelization schemes use the same approach with getLevel 

123if yaml: 123 ↛ exitline 123 didn't exit the module, because the condition on line 123 was never false

124 for pixelSchemeCls in (HtmPixelization, Q3cPixelization, Mq3cPixelization, HealpixPixelization): 

125 yaml.add_representer(pixelSchemeCls, pixel_representer) 

126 for loader in YamlLoaders: 

127 yaml.add_constructor(f"lsst.sphgeom.{pixelSchemeCls.__name__}", pixel_constructor, Loader=loader)