Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/PIL/BufrStubImagePlugin.py: 73%

1# 

2# The Python Imaging Library 

3# $Id$ 

4# 

5# BUFR stub adapter 

6# 

7# Copyright (c) 1996-2003 by Fredrik Lundh 

8# 

9# See the README file for information on usage and redistribution. 

10# 

11from __future__ import annotations 

12 

13import os 

14from typing import IO 

15 

16from . import Image, ImageFile 

17 

18_handler = None 

19 

20 

21def register_handler(handler: ImageFile.StubHandler | None) -> None: 

22 """ 

23 Install application-specific BUFR image handler. 

24 

25 :param handler: Handler object. 

26 """ 

27 global _handler 

28 _handler = handler 

29 

30 

31# -------------------------------------------------------------------- 

32# Image adapter 

33 

34 

35def _accept(prefix: bytes) -> bool: 

36 return prefix.startswith((b"BUFR", b"ZCZC")) 

37 

38 

39class BufrStubImageFile(ImageFile.StubImageFile): 

40 format = "BUFR" 

41 format_description = "BUFR" 

42 

43 def _open(self) -> None: 

44 if not _accept(self.fp.read(4)): 

45 msg = "Not a BUFR file" 

46 raise SyntaxError(msg) 

47 

48 self.fp.seek(-4, os.SEEK_CUR) 

49 

50 # make something up 

51 self._mode = "F" 

52 self._size = 1, 1 

53 

54 loader = self._load() 

55 if loader: 

56 loader.open(self) 

57 

58 def _load(self) -> ImageFile.StubHandler | None: 

59 return _handler 

60 

61 

62def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: 

63 if _handler is None or not hasattr(_handler, "save"): 

64 msg = "BUFR save handler not installed" 

65 raise OSError(msg) 

66 _handler.save(im, fp, filename) 

67 

68 

69# -------------------------------------------------------------------- 

70# Registry 

71 

72Image.register_open(BufrStubImageFile.format, BufrStubImageFile, _accept) 

73Image.register_save(BufrStubImageFile.format, _save) 

74 

75Image.register_extension(BufrStubImageFile.format, ".bufr")