Coverage for python / lsst / daf / butler / formatters / packages.py: 0%

1# This file is part of daf_butler. 

2# 

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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 software is dual licensed under the GNU General Public License and also 

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13# (but note that there is still no warranty even if you opt for BSD instead): 

14# 

15# This program is free software: you can redistribute it and/or modify 

16# it under the terms of the GNU General Public License as published by 

17# the Free Software Foundation, either version 3 of the License, or 

18# (at your option) any later version. 

19# 

20# This program is distributed in the hope that it will be useful, 

21# but WITHOUT ANY WARRANTY; without even the implied warranty of 

22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

23# GNU General Public License for more details. 

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26# along with this program. If not, see <http://www.gnu.org/licenses/>. 

27 

28__all__ = ("PackagesFormatter",) 

29 

30from typing import Any 

31 

32from lsst.daf.butler import FormatterV2 

33from lsst.resources import ResourcePath 

34from lsst.utils.packages import Packages 

35 

36 

37class PackagesFormatter(FormatterV2): 

38 """Interface for reading and writing `~lsst.utils.packages.Packages`. 

39 

40 This formatter supports write parameters: 

41 

42 * ``format``: The file format to use to write the package data. Allowed 

43 options are ``yaml``, ``json``, and ``pickle``. 

44 """ 

45 

46 supported_write_parameters = frozenset({"format"}) 

47 supported_extensions = frozenset({".yaml", ".pickle", ".pkl", ".json"}) 

48 can_read_from_uri = True 

49 

50 def get_write_extension(self) -> str: 

51 # Default to YAML but allow configuration via write parameter 

52 format = self.write_parameters.get("format", "yaml") 

53 ext = "." + format 

54 if ext not in self.supported_extensions: 

55 raise RuntimeError(f"Requested file format '{format}' is not supported for Packages") 

56 return ext 

57 

58 def read_from_uri(self, uri: ResourcePath, component: str | None = None, expected_size: int = -1) -> Any: 

59 # Read the full file using the class associated with the 

60 # storage class it was originally written with. 

61 # Read the bytes directly from resource. These are not going to be 

62 # large. 

63 pytype = self.file_descriptor.storageClass.pytype 

64 assert issubclass(pytype, Packages) # for mypy 

65 format = uri.getExtension().lstrip(".") # .yaml -> yaml 

66 return pytype.fromBytes(uri.read(), format) 

67 

68 def to_bytes(self, in_memory_dataset: Any) -> bytes: 

69 """Write the in memory dataset to a bytestring. 

70 

71 Parameters 

72 ---------- 

73 in_memory_dataset : `object` 

74 Object to serialize. 

75 

76 Returns 

77 ------- 

78 serializedDataset : `bytes` 

79 YAML string encoded to bytes. 

80 

81 Raises 

82 ------ 

83 Exception 

84 The object could not be serialized. 

85 """ 

86 format = self.get_write_extension().lstrip(".") 

87 return in_memory_dataset.toBytes(format)