Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/google/protobuf/text_encoding.py: 59%

1# Protocol Buffers - Google's data interchange format 

2# Copyright 2008 Google Inc. All rights reserved. 

3# https://developers.google.com/protocol-buffers/ 

4# 

5# Redistribution and use in source and binary forms, with or without 

6# modification, are permitted provided that the following conditions are 

7# met: 

8# 

9# * Redistributions of source code must retain the above copyright 

10# notice, this list of conditions and the following disclaimer. 

11# * Redistributions in binary form must reproduce the above 

12# copyright notice, this list of conditions and the following disclaimer 

13# in the documentation and/or other materials provided with the 

14# distribution. 

15# * Neither the name of Google Inc. nor the names of its 

16# contributors may be used to endorse or promote products derived from 

17# this software without specific prior written permission. 

18# 

19# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 

20# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 

21# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 

22# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 

23# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 

24# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 

25# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 

26# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 

27# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 

28# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 

29# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

30 

31"""Encoding related utilities.""" 

32import re 

33 

34_cescape_chr_to_symbol_map = {} 

35_cescape_chr_to_symbol_map[9] = r'\t' # optional escape 

36_cescape_chr_to_symbol_map[10] = r'\n' # optional escape 

37_cescape_chr_to_symbol_map[13] = r'\r' # optional escape 

38_cescape_chr_to_symbol_map[34] = r'\"' # necessary escape 

39_cescape_chr_to_symbol_map[39] = r"\'" # optional escape 

40_cescape_chr_to_symbol_map[92] = r'\\' # necessary escape 

41 

42# Lookup table for unicode 

43_cescape_unicode_to_str = [chr(i) for i in range(0, 256)] 

44for byte, string in _cescape_chr_to_symbol_map.items(): 

45 _cescape_unicode_to_str[byte] = string 

46 

47# Lookup table for non-utf8, with necessary escapes at (o >= 127 or o < 32) 

48_cescape_byte_to_str = ([r'\%03o' % i for i in range(0, 32)] + 

49 [chr(i) for i in range(32, 127)] + 

50 [r'\%03o' % i for i in range(127, 256)]) 

51for byte, string in _cescape_chr_to_symbol_map.items(): 

52 _cescape_byte_to_str[byte] = string 

53del byte, string 

54 

55 

56def CEscape(text, as_utf8) -> str: 

57 """Escape a bytes string for use in an text protocol buffer. 

58 

59 Args: 

60 text: A byte string to be escaped. 

61 as_utf8: Specifies if result may contain non-ASCII characters. 

62 In Python 3 this allows unescaped non-ASCII Unicode characters. 

63 In Python 2 the return value will be valid UTF-8 rather than only ASCII. 

64 Returns: 

65 Escaped string (str). 

66 """ 

67 # Python's text.encode() 'string_escape' or 'unicode_escape' codecs do not 

68 # satisfy our needs; they encodes unprintable characters using two-digit hex 

69 # escapes whereas our C++ unescaping function allows hex escapes to be any 

70 # length. So, "\0011".encode('string_escape') ends up being "\\x011", which 

71 # will be decoded in C++ as a single-character string with char code 0x11. 

72 text_is_unicode = isinstance(text, str) 

73 if as_utf8 and text_is_unicode: 

74 # We're already unicode, no processing beyond control char escapes. 

75 return text.translate(_cescape_chr_to_symbol_map) 

76 ord_ = ord if text_is_unicode else lambda x: x # bytes iterate as ints. 

77 if as_utf8: 

78 return ''.join(_cescape_unicode_to_str[ord_(c)] for c in text) 

79 return ''.join(_cescape_byte_to_str[ord_(c)] for c in text) 

80 

81 

82_CUNESCAPE_HEX = re.compile(r'(\\+)x([0-9a-fA-F])(?![0-9a-fA-F])') 

83 

84 

85def CUnescape(text: str) -> bytes: 

86 """Unescape a text string with C-style escape sequences to UTF-8 bytes. 

87 

88 Args: 

89 text: The data to parse in a str. 

90 Returns: 

91 A byte string. 

92 """ 

93 

94 def ReplaceHex(m): 

95 # Only replace the match if the number of leading back slashes is odd. i.e. 

96 # the slash itself is not escaped. 

97 if len(m.group(1)) & 1: 

98 return m.group(1) + 'x0' + m.group(2) 

99 return m.group(0) 

100 

101 # This is required because the 'string_escape' encoding doesn't 

102 # allow single-digit hex escapes (like '\xf'). 

103 result = _CUNESCAPE_HEX.sub(ReplaceHex, text) 

104 

105 return (result.encode('utf-8') # Make it bytes to allow decode. 

106 .decode('unicode_escape') 

107 # Make it bytes again to return the proper type. 

108 .encode('raw_unicode_escape'))