Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/fontTools/misc/filenames.py: 16%

1""" 

2This module implements the algorithm for converting between a "user name" - 

3something that a user can choose arbitrarily inside a font editor - and a file 

4name suitable for use in a wide range of operating systems and filesystems. 

5 

6The `UFO 3 specification <http://unifiedfontobject.org/versions/ufo3/conventions/>`_ 

7provides an example of an algorithm for such conversion, which avoids illegal 

8characters, reserved file names, ambiguity between upper- and lower-case 

9characters, and clashes with existing files. 

10 

11This code was originally copied from 

12`ufoLib <https://github.com/unified-font-object/ufoLib/blob/8747da7/Lib/ufoLib/filenames.py>`_ 

13by Tal Leming and is copyright (c) 2005-2016, The RoboFab Developers: 

14 

15- Erik van Blokland 

16- Tal Leming 

17- Just van Rossum 

18""" 

19 

20 

21illegalCharacters = r"\" * + / : < > ? [ \ ] | \0".split(" ") 

22illegalCharacters += [chr(i) for i in range(1, 32)] 

23illegalCharacters += [chr(0x7F)] 

24reservedFileNames = "CON PRN AUX CLOCK$ NUL A:-Z: COM1".lower().split(" ") 

25reservedFileNames += "LPT1 LPT2 LPT3 COM2 COM3 COM4".lower().split(" ") 

26maxFileNameLength = 255 

27 

28 

29class NameTranslationError(Exception): 

30 pass 

31 

32 

33def userNameToFileName(userName, existing=[], prefix="", suffix=""): 

34 """Converts from a user name to a file name. 

35 

36 Takes care to avoid illegal characters, reserved file names, ambiguity between 

37 upper- and lower-case characters, and clashes with existing files. 

38 

39 Args: 

40 userName (str): The input file name. 

41 existing: A case-insensitive list of all existing file names. 

42 prefix: Prefix to be prepended to the file name. 

43 suffix: Suffix to be appended to the file name. 

44 

45 Returns: 

46 A suitable filename. 

47 

48 Raises: 

49 NameTranslationError: If no suitable name could be generated. 

50 

51 Examples:: 

52 

53 >>> userNameToFileName("a") == "a" 

54 True 

55 >>> userNameToFileName("A") == "A_" 

56 True 

57 >>> userNameToFileName("AE") == "A_E_" 

58 True 

59 >>> userNameToFileName("Ae") == "A_e" 

60 True 

61 >>> userNameToFileName("ae") == "ae" 

62 True 

63 >>> userNameToFileName("aE") == "aE_" 

64 True 

65 >>> userNameToFileName("a.alt") == "a.alt" 

66 True 

67 >>> userNameToFileName("A.alt") == "A_.alt" 

68 True 

69 >>> userNameToFileName("A.Alt") == "A_.A_lt" 

70 True 

71 >>> userNameToFileName("A.aLt") == "A_.aL_t" 

72 True 

73 >>> userNameToFileName(u"A.alT") == "A_.alT_" 

74 True 

75 >>> userNameToFileName("T_H") == "T__H_" 

76 True 

77 >>> userNameToFileName("T_h") == "T__h" 

78 True 

79 >>> userNameToFileName("t_h") == "t_h" 

80 True 

81 >>> userNameToFileName("F_F_I") == "F__F__I_" 

82 True 

83 >>> userNameToFileName("f_f_i") == "f_f_i" 

84 True 

85 >>> userNameToFileName("Aacute_V.swash") == "A_acute_V_.swash" 

86 True 

87 >>> userNameToFileName(".notdef") == "_notdef" 

88 True 

89 >>> userNameToFileName("con") == "_con" 

90 True 

91 >>> userNameToFileName("CON") == "C_O_N_" 

92 True 

93 >>> userNameToFileName("con.alt") == "_con.alt" 

94 True 

95 >>> userNameToFileName("alt.con") == "alt._con" 

96 True 

97 """ 

98 # the incoming name must be a str 

99 if not isinstance(userName, str): 

100 raise ValueError("The value for userName must be a string.") 

101 # establish the prefix and suffix lengths 

102 prefixLength = len(prefix) 

103 suffixLength = len(suffix) 

104 # replace an initial period with an _ 

105 # if no prefix is to be added 

106 if not prefix and userName[0] == ".": 

107 userName = "_" + userName[1:] 

108 # filter the user name 

109 filteredUserName = [] 

110 for character in userName: 

111 # replace illegal characters with _ 

112 if character in illegalCharacters: 

113 character = "_" 

114 # add _ to all non-lower characters 

115 elif character != character.lower(): 

116 character += "_" 

117 filteredUserName.append(character) 

118 userName = "".join(filteredUserName) 

119 # clip to 255 

120 sliceLength = maxFileNameLength - prefixLength - suffixLength 

121 userName = userName[:sliceLength] 

122 # test for illegal files names 

123 parts = [] 

124 for part in userName.split("."): 

125 if part.lower() in reservedFileNames: 

126 part = "_" + part 

127 parts.append(part) 

128 userName = ".".join(parts) 

129 # test for clash 

130 fullName = prefix + userName + suffix 

131 if fullName.lower() in existing: 

132 fullName = handleClash1(userName, existing, prefix, suffix) 

133 # finished 

134 return fullName 

135 

136 

137def handleClash1(userName, existing=[], prefix="", suffix=""): 

138 """ 

139 existing should be a case-insensitive list 

140 of all existing file names. 

141 

142 >>> prefix = ("0" * 5) + "." 

143 >>> suffix = "." + ("0" * 10) 

144 >>> existing = ["a" * 5] 

145 

146 >>> e = list(existing) 

147 >>> handleClash1(userName="A" * 5, existing=e, 

148 ... prefix=prefix, suffix=suffix) == ( 

149 ... '00000.AAAAA000000000000001.0000000000') 

150 True 

151 

152 >>> e = list(existing) 

153 >>> e.append(prefix + "aaaaa" + "1".zfill(15) + suffix) 

154 >>> handleClash1(userName="A" * 5, existing=e, 

155 ... prefix=prefix, suffix=suffix) == ( 

156 ... '00000.AAAAA000000000000002.0000000000') 

157 True 

158 

159 >>> e = list(existing) 

160 >>> e.append(prefix + "AAAAA" + "2".zfill(15) + suffix) 

161 >>> handleClash1(userName="A" * 5, existing=e, 

162 ... prefix=prefix, suffix=suffix) == ( 

163 ... '00000.AAAAA000000000000001.0000000000') 

164 True 

165 """ 

166 # if the prefix length + user name length + suffix length + 15 is at 

167 # or past the maximum length, silce 15 characters off of the user name 

168 prefixLength = len(prefix) 

169 suffixLength = len(suffix) 

170 if prefixLength + len(userName) + suffixLength + 15 > maxFileNameLength: 

171 l = prefixLength + len(userName) + suffixLength + 15 

172 sliceLength = maxFileNameLength - l 

173 userName = userName[:sliceLength] 

174 finalName = None 

175 # try to add numbers to create a unique name 

176 counter = 1 

177 while finalName is None: 

178 name = userName + str(counter).zfill(15) 

179 fullName = prefix + name + suffix 

180 if fullName.lower() not in existing: 

181 finalName = fullName 

182 break 

183 else: 

184 counter += 1 

185 if counter >= 999999999999999: 

186 break 

187 # if there is a clash, go to the next fallback 

188 if finalName is None: 

189 finalName = handleClash2(existing, prefix, suffix) 

190 # finished 

191 return finalName 

192 

193 

194def handleClash2(existing=[], prefix="", suffix=""): 

195 """ 

196 existing should be a case-insensitive list 

197 of all existing file names. 

198 

199 >>> prefix = ("0" * 5) + "." 

200 >>> suffix = "." + ("0" * 10) 

201 >>> existing = [prefix + str(i) + suffix for i in range(100)] 

202 

203 >>> e = list(existing) 

204 >>> handleClash2(existing=e, prefix=prefix, suffix=suffix) == ( 

205 ... '00000.100.0000000000') 

206 True 

207 

208 >>> e = list(existing) 

209 >>> e.remove(prefix + "1" + suffix) 

210 >>> handleClash2(existing=e, prefix=prefix, suffix=suffix) == ( 

211 ... '00000.1.0000000000') 

212 True 

213 

214 >>> e = list(existing) 

215 >>> e.remove(prefix + "2" + suffix) 

216 >>> handleClash2(existing=e, prefix=prefix, suffix=suffix) == ( 

217 ... '00000.2.0000000000') 

218 True 

219 """ 

220 # calculate the longest possible string 

221 maxLength = maxFileNameLength - len(prefix) - len(suffix) 

222 maxValue = int("9" * maxLength) 

223 # try to find a number 

224 finalName = None 

225 counter = 1 

226 while finalName is None: 

227 fullName = prefix + str(counter) + suffix 

228 if fullName.lower() not in existing: 

229 finalName = fullName 

230 break 

231 else: 

232 counter += 1 

233 if counter >= maxValue: 

234 break 

235 # raise an error if nothing has been found 

236 if finalName is None: 

237 raise NameTranslationError("No unique name could be found.") 

238 # finished 

239 return finalName 

240 

241 

242if __name__ == "__main__": 

243 import doctest 

244 import sys 

245 

246 sys.exit(doctest.testmod().failed)