Python code coverage for Lib/encodings/utf_8_sig.py

#	count	content
1	n/a	""" Python 'utf-8-sig' Codec
2	n/a	This work similar to UTF-8 with the following changes:
3	n/a
4	n/a	* On encoding/writing a UTF-8 encoded BOM will be prepended/written as the
5	n/a	first three bytes.
6	n/a
7	n/a	* On decoding/reading if the first three bytes are a UTF-8 encoded BOM, these
8	n/a	bytes will be skipped.
9	n/a	"""
10	n/a	import codecs
11	n/a
12	n/a	### Codec APIs
13	n/a
14	n/a	def encode(input, errors='strict'):
15	n/a	return (codecs.BOM_UTF8 + codecs.utf_8_encode(input, errors)[0],
16	n/a	len(input))
17	n/a
18	n/a	def decode(input, errors='strict'):
19	n/a	prefix = 0
20	n/a	if input[:3] == codecs.BOM_UTF8:
21	n/a	input = input[3:]
22	n/a	prefix = 3
23	n/a	(output, consumed) = codecs.utf_8_decode(input, errors, True)
24	n/a	return (output, consumed+prefix)
25	n/a
26	n/a	class IncrementalEncoder(codecs.IncrementalEncoder):
27	n/a	def __init__(self, errors='strict'):
28	n/a	codecs.IncrementalEncoder.__init__(self, errors)
29	n/a	self.first = 1
30	n/a
31	n/a	def encode(self, input, final=False):
32	n/a	if self.first:
33	n/a	self.first = 0
34	n/a	return codecs.BOM_UTF8 + \
35	n/a	codecs.utf_8_encode(input, self.errors)[0]
36	n/a	else:
37	n/a	return codecs.utf_8_encode(input, self.errors)[0]
38	n/a
39	n/a	def reset(self):
40	n/a	codecs.IncrementalEncoder.reset(self)
41	n/a	self.first = 1
42	n/a
43	n/a	def getstate(self):
44	n/a	return self.first
45	n/a
46	n/a	def setstate(self, state):
47	n/a	self.first = state
48	n/a
49	n/a	class IncrementalDecoder(codecs.BufferedIncrementalDecoder):
50	n/a	def __init__(self, errors='strict'):
51	n/a	codecs.BufferedIncrementalDecoder.__init__(self, errors)
52	n/a	self.first = 1
53	n/a
54	n/a	def _buffer_decode(self, input, errors, final):
55	n/a	if self.first:
56	n/a	if len(input) < 3:
57	n/a	if codecs.BOM_UTF8.startswith(input):
58	n/a	# not enough data to decide if this really is a BOM
59	n/a	# => try again on the next call
60	n/a	return ("", 0)
61	n/a	else:
62	n/a	self.first = 0
63	n/a	else:
64	n/a	self.first = 0
65	n/a	if input[:3] == codecs.BOM_UTF8:
66	n/a	(output, consumed) = \
67	n/a	codecs.utf_8_decode(input[3:], errors, final)
68	n/a	return (output, consumed+3)
69	n/a	return codecs.utf_8_decode(input, errors, final)
70	n/a
71	n/a	def reset(self):
72	n/a	codecs.BufferedIncrementalDecoder.reset(self)
73	n/a	self.first = 1
74	n/a
75	n/a	def getstate(self):
76	n/a	state = codecs.BufferedIncrementalDecoder.getstate(self)
77	n/a	# state[1] must be 0 here, as it isn't passed along to the caller
78	n/a	return (state[0], self.first)
79	n/a
80	n/a	def setstate(self, state):
81	n/a	# state[1] will be ignored by BufferedIncrementalDecoder.setstate()
82	n/a	codecs.BufferedIncrementalDecoder.setstate(self, state)
83	n/a	self.first = state[1]
84	n/a
85	n/a	class StreamWriter(codecs.StreamWriter):
86	n/a	def reset(self):
87	n/a	codecs.StreamWriter.reset(self)
88	n/a	try:
89	n/a	del self.encode
90	n/a	except AttributeError:
91	n/a	pass
92	n/a
93	n/a	def encode(self, input, errors='strict'):
94	n/a	self.encode = codecs.utf_8_encode
95	n/a	return encode(input, errors)
96	n/a
97	n/a	class StreamReader(codecs.StreamReader):
98	n/a	def reset(self):
99	n/a	codecs.StreamReader.reset(self)
100	n/a	try:
101	n/a	del self.decode
102	n/a	except AttributeError:
103	n/a	pass
104	n/a
105	n/a	def decode(self, input, errors='strict'):
106	n/a	if len(input) < 3:
107	n/a	if codecs.BOM_UTF8.startswith(input):
108	n/a	# not enough data to decide if this is a BOM
109	n/a	# => try again on the next call
110	n/a	return ("", 0)
111	n/a	elif input[:3] == codecs.BOM_UTF8:
112	n/a	self.decode = codecs.utf_8_decode
113	n/a	(output, consumed) = codecs.utf_8_decode(input[3:],errors)
114	n/a	return (output, consumed+3)
115	n/a	# (else) no BOM present
116	n/a	self.decode = codecs.utf_8_decode
117	n/a	return codecs.utf_8_decode(input, errors)
118	n/a
119	n/a	### encodings module API
120	n/a
121	n/a	def getregentry():
122	n/a	return codecs.CodecInfo(
123	n/a	name='utf-8-sig',
124	n/a	encode=encode,
125	n/a	decode=decode,
126	n/a	incrementalencoder=IncrementalEncoder,
127	n/a	incrementaldecoder=IncrementalDecoder,
128	n/a	streamreader=StreamReader,
129	n/a	streamwriter=StreamWriter,
130	n/a	)