diff options
Diffstat (limited to 'testing/web-platform/tests/tools/html5lib/html5lib/inputstream.py')
| -rw-r--r-- | testing/web-platform/tests/tools/html5lib/html5lib/inputstream.py | 886 |
1 files changed, 886 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/html5lib/html5lib/inputstream.py b/testing/web-platform/tests/tools/html5lib/html5lib/inputstream.py new file mode 100644 index 000000000..9e03b9313 --- /dev/null +++ b/testing/web-platform/tests/tools/html5lib/html5lib/inputstream.py @@ -0,0 +1,886 @@ +from __future__ import absolute_import, division, unicode_literals +from six import text_type +from six.moves import http_client + +import codecs +import re + +from .constants import EOF, spaceCharacters, asciiLetters, asciiUppercase +from .constants import encodings, ReparseException +from . import utils + +from io import StringIO + +try: + from io import BytesIO +except ImportError: + BytesIO = StringIO + +try: + from io import BufferedIOBase +except ImportError: + class BufferedIOBase(object): + pass + +# Non-unicode versions of constants for use in the pre-parser +spaceCharactersBytes = frozenset([item.encode("ascii") for item in spaceCharacters]) +asciiLettersBytes = frozenset([item.encode("ascii") for item in asciiLetters]) +asciiUppercaseBytes = frozenset([item.encode("ascii") for item in asciiUppercase]) +spacesAngleBrackets = spaceCharactersBytes | frozenset([b">", b"<"]) + +invalid_unicode_re = re.compile("[\u0001-\u0008\u000B\u000E-\u001F\u007F-\u009F\uD800-\uDFFF\uFDD0-\uFDEF\uFFFE\uFFFF\U0001FFFE\U0001FFFF\U0002FFFE\U0002FFFF\U0003FFFE\U0003FFFF\U0004FFFE\U0004FFFF\U0005FFFE\U0005FFFF\U0006FFFE\U0006FFFF\U0007FFFE\U0007FFFF\U0008FFFE\U0008FFFF\U0009FFFE\U0009FFFF\U000AFFFE\U000AFFFF\U000BFFFE\U000BFFFF\U000CFFFE\U000CFFFF\U000DFFFE\U000DFFFF\U000EFFFE\U000EFFFF\U000FFFFE\U000FFFFF\U0010FFFE\U0010FFFF]") + +non_bmp_invalid_codepoints = set([0x1FFFE, 0x1FFFF, 0x2FFFE, 0x2FFFF, 0x3FFFE, + 0x3FFFF, 0x4FFFE, 0x4FFFF, 0x5FFFE, 0x5FFFF, + 0x6FFFE, 0x6FFFF, 0x7FFFE, 0x7FFFF, 0x8FFFE, + 0x8FFFF, 0x9FFFE, 0x9FFFF, 0xAFFFE, 0xAFFFF, + 0xBFFFE, 0xBFFFF, 0xCFFFE, 0xCFFFF, 0xDFFFE, + 0xDFFFF, 0xEFFFE, 0xEFFFF, 0xFFFFE, 0xFFFFF, + 0x10FFFE, 0x10FFFF]) + +ascii_punctuation_re = re.compile("[\u0009-\u000D\u0020-\u002F\u003A-\u0040\u005B-\u0060\u007B-\u007E]") + +# Cache for charsUntil() +charsUntilRegEx = {} + + +class BufferedStream(object): + """Buffering for streams that do not have buffering of their own + + The buffer is implemented as a list of chunks on the assumption that + joining many strings will be slow since it is O(n**2) + """ + + def __init__(self, stream): + self.stream = stream + self.buffer = [] + self.position = [-1, 0] # chunk number, offset + + def tell(self): + pos = 0 + for chunk in self.buffer[:self.position[0]]: + pos += len(chunk) + pos += self.position[1] + return pos + + def seek(self, pos): + assert pos <= self._bufferedBytes() + offset = pos + i = 0 + while len(self.buffer[i]) < offset: + offset -= len(self.buffer[i]) + i += 1 + self.position = [i, offset] + + def read(self, bytes): + if not self.buffer: + return self._readStream(bytes) + elif (self.position[0] == len(self.buffer) and + self.position[1] == len(self.buffer[-1])): + return self._readStream(bytes) + else: + return self._readFromBuffer(bytes) + + def _bufferedBytes(self): + return sum([len(item) for item in self.buffer]) + + def _readStream(self, bytes): + data = self.stream.read(bytes) + self.buffer.append(data) + self.position[0] += 1 + self.position[1] = len(data) + return data + + def _readFromBuffer(self, bytes): + remainingBytes = bytes + rv = [] + bufferIndex = self.position[0] + bufferOffset = self.position[1] + while bufferIndex < len(self.buffer) and remainingBytes != 0: + assert remainingBytes > 0 + bufferedData = self.buffer[bufferIndex] + + if remainingBytes <= len(bufferedData) - bufferOffset: + bytesToRead = remainingBytes + self.position = [bufferIndex, bufferOffset + bytesToRead] + else: + bytesToRead = len(bufferedData) - bufferOffset + self.position = [bufferIndex, len(bufferedData)] + bufferIndex += 1 + rv.append(bufferedData[bufferOffset:bufferOffset + bytesToRead]) + remainingBytes -= bytesToRead + + bufferOffset = 0 + + if remainingBytes: + rv.append(self._readStream(remainingBytes)) + + return b"".join(rv) + + +def HTMLInputStream(source, encoding=None, parseMeta=True, chardet=True): + if isinstance(source, http_client.HTTPResponse): + # Work around Python bug #20007: read(0) closes the connection. + # http://bugs.python.org/issue20007 + isUnicode = False + elif hasattr(source, "read"): + isUnicode = isinstance(source.read(0), text_type) + else: + isUnicode = isinstance(source, text_type) + + if isUnicode: + if encoding is not None: + raise TypeError("Cannot explicitly set an encoding with a unicode string") + + return HTMLUnicodeInputStream(source) + else: + return HTMLBinaryInputStream(source, encoding, parseMeta, chardet) + + +class HTMLUnicodeInputStream(object): + """Provides a unicode stream of characters to the HTMLTokenizer. + + This class takes care of character encoding and removing or replacing + incorrect byte-sequences and also provides column and line tracking. + + """ + + _defaultChunkSize = 10240 + + def __init__(self, source): + """Initialises the HTMLInputStream. + + HTMLInputStream(source, [encoding]) -> Normalized stream from source + for use by html5lib. + + source can be either a file-object, local filename or a string. + + The optional encoding parameter must be a string that indicates + the encoding. If specified, that encoding will be used, + regardless of any BOM or later declaration (such as in a meta + element) + + parseMeta - Look for a <meta> element containing encoding information + + """ + + # Craziness + if len("\U0010FFFF") == 1: + self.reportCharacterErrors = self.characterErrorsUCS4 + self.replaceCharactersRegexp = re.compile("[\uD800-\uDFFF]") + else: + self.reportCharacterErrors = self.characterErrorsUCS2 + self.replaceCharactersRegexp = re.compile("([\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF])") + + # List of where new lines occur + self.newLines = [0] + + self.charEncoding = ("utf-8", "certain") + self.dataStream = self.openStream(source) + + self.reset() + + def reset(self): + self.chunk = "" + self.chunkSize = 0 + self.chunkOffset = 0 + self.errors = [] + + # number of (complete) lines in previous chunks + self.prevNumLines = 0 + # number of columns in the last line of the previous chunk + self.prevNumCols = 0 + + # Deal with CR LF and surrogates split over chunk boundaries + self._bufferedCharacter = None + + def openStream(self, source): + """Produces a file object from source. + + source can be either a file object, local filename or a string. + + """ + # Already a file object + if hasattr(source, 'read'): + stream = source + else: + stream = StringIO(source) + + return stream + + def _position(self, offset): + chunk = self.chunk + nLines = chunk.count('\n', 0, offset) + positionLine = self.prevNumLines + nLines + lastLinePos = chunk.rfind('\n', 0, offset) + if lastLinePos == -1: + positionColumn = self.prevNumCols + offset + else: + positionColumn = offset - (lastLinePos + 1) + return (positionLine, positionColumn) + + def position(self): + """Returns (line, col) of the current position in the stream.""" + line, col = self._position(self.chunkOffset) + return (line + 1, col) + + def char(self): + """ Read one character from the stream or queue if available. Return + EOF when EOF is reached. + """ + # Read a new chunk from the input stream if necessary + if self.chunkOffset >= self.chunkSize: + if not self.readChunk(): + return EOF + + chunkOffset = self.chunkOffset + char = self.chunk[chunkOffset] + self.chunkOffset = chunkOffset + 1 + + return char + + def readChunk(self, chunkSize=None): + if chunkSize is None: + chunkSize = self._defaultChunkSize + + self.prevNumLines, self.prevNumCols = self._position(self.chunkSize) + + self.chunk = "" + self.chunkSize = 0 + self.chunkOffset = 0 + + data = self.dataStream.read(chunkSize) + + # Deal with CR LF and surrogates broken across chunks + if self._bufferedCharacter: + data = self._bufferedCharacter + data + self._bufferedCharacter = None + elif not data: + # We have no more data, bye-bye stream + return False + + if len(data) > 1: + lastv = ord(data[-1]) + if lastv == 0x0D or 0xD800 <= lastv <= 0xDBFF: + self._bufferedCharacter = data[-1] + data = data[:-1] + + self.reportCharacterErrors(data) + + # Replace invalid characters + # Note U+0000 is dealt with in the tokenizer + data = self.replaceCharactersRegexp.sub("\ufffd", data) + + data = data.replace("\r\n", "\n") + data = data.replace("\r", "\n") + + self.chunk = data + self.chunkSize = len(data) + + return True + + def characterErrorsUCS4(self, data): + for i in range(len(invalid_unicode_re.findall(data))): + self.errors.append("invalid-codepoint") + + def characterErrorsUCS2(self, data): + # Someone picked the wrong compile option + # You lose + skip = False + for match in invalid_unicode_re.finditer(data): + if skip: + continue + codepoint = ord(match.group()) + pos = match.start() + # Pretty sure there should be endianness issues here + if utils.isSurrogatePair(data[pos:pos + 2]): + # We have a surrogate pair! + char_val = utils.surrogatePairToCodepoint(data[pos:pos + 2]) + if char_val in non_bmp_invalid_codepoints: + self.errors.append("invalid-codepoint") + skip = True + elif (codepoint >= 0xD800 and codepoint <= 0xDFFF and + pos == len(data) - 1): + self.errors.append("invalid-codepoint") + else: + skip = False + self.errors.append("invalid-codepoint") + + def charsUntil(self, characters, opposite=False): + """ Returns a string of characters from the stream up to but not + including any character in 'characters' or EOF. 'characters' must be + a container that supports the 'in' method and iteration over its + characters. + """ + + # Use a cache of regexps to find the required characters + try: + chars = charsUntilRegEx[(characters, opposite)] + except KeyError: + if __debug__: + for c in characters: + assert(ord(c) < 128) + regex = "".join(["\\x%02x" % ord(c) for c in characters]) + if not opposite: + regex = "^%s" % regex + chars = charsUntilRegEx[(characters, opposite)] = re.compile("[%s]+" % regex) + + rv = [] + + while True: + # Find the longest matching prefix + m = chars.match(self.chunk, self.chunkOffset) + if m is None: + # If nothing matched, and it wasn't because we ran out of chunk, + # then stop + if self.chunkOffset != self.chunkSize: + break + else: + end = m.end() + # If not the whole chunk matched, return everything + # up to the part that didn't match + if end != self.chunkSize: + rv.append(self.chunk[self.chunkOffset:end]) + self.chunkOffset = end + break + # If the whole remainder of the chunk matched, + # use it all and read the next chunk + rv.append(self.chunk[self.chunkOffset:]) + if not self.readChunk(): + # Reached EOF + break + + r = "".join(rv) + return r + + def unget(self, char): + # Only one character is allowed to be ungotten at once - it must + # be consumed again before any further call to unget + if char is not None: + if self.chunkOffset == 0: + # unget is called quite rarely, so it's a good idea to do + # more work here if it saves a bit of work in the frequently + # called char and charsUntil. + # So, just prepend the ungotten character onto the current + # chunk: + self.chunk = char + self.chunk + self.chunkSize += 1 + else: + self.chunkOffset -= 1 + assert self.chunk[self.chunkOffset] == char + + +class HTMLBinaryInputStream(HTMLUnicodeInputStream): + """Provides a unicode stream of characters to the HTMLTokenizer. + + This class takes care of character encoding and removing or replacing + incorrect byte-sequences and also provides column and line tracking. + + """ + + def __init__(self, source, encoding=None, parseMeta=True, chardet=True): + """Initialises the HTMLInputStream. + + HTMLInputStream(source, [encoding]) -> Normalized stream from source + for use by html5lib. + + source can be either a file-object, local filename or a string. + + The optional encoding parameter must be a string that indicates + the encoding. If specified, that encoding will be used, + regardless of any BOM or later declaration (such as in a meta + element) + + parseMeta - Look for a <meta> element containing encoding information + + """ + # Raw Stream - for unicode objects this will encode to utf-8 and set + # self.charEncoding as appropriate + self.rawStream = self.openStream(source) + + HTMLUnicodeInputStream.__init__(self, self.rawStream) + + self.charEncoding = (codecName(encoding), "certain") + + # Encoding Information + # Number of bytes to use when looking for a meta element with + # encoding information + self.numBytesMeta = 512 + # Number of bytes to use when using detecting encoding using chardet + self.numBytesChardet = 100 + # Encoding to use if no other information can be found + self.defaultEncoding = "windows-1252" + + # Detect encoding iff no explicit "transport level" encoding is supplied + if (self.charEncoding[0] is None): + self.charEncoding = self.detectEncoding(parseMeta, chardet) + + # Call superclass + self.reset() + + def reset(self): + self.dataStream = codecs.getreader(self.charEncoding[0])(self.rawStream, + 'replace') + HTMLUnicodeInputStream.reset(self) + + def openStream(self, source): + """Produces a file object from source. + + source can be either a file object, local filename or a string. + + """ + # Already a file object + if hasattr(source, 'read'): + stream = source + else: + stream = BytesIO(source) + + try: + stream.seek(stream.tell()) + except: + stream = BufferedStream(stream) + + return stream + + def detectEncoding(self, parseMeta=True, chardet=True): + # First look for a BOM + # This will also read past the BOM if present + encoding = self.detectBOM() + confidence = "certain" + # If there is no BOM need to look for meta elements with encoding + # information + if encoding is None and parseMeta: + encoding = self.detectEncodingMeta() + confidence = "tentative" + # Guess with chardet, if avaliable + if encoding is None and chardet: + confidence = "tentative" + try: + try: + from charade.universaldetector import UniversalDetector + except ImportError: + from chardet.universaldetector import UniversalDetector + buffers = [] + detector = UniversalDetector() + while not detector.done: + buffer = self.rawStream.read(self.numBytesChardet) + assert isinstance(buffer, bytes) + if not buffer: + break + buffers.append(buffer) + detector.feed(buffer) + detector.close() + encoding = detector.result['encoding'] + self.rawStream.seek(0) + except ImportError: + pass + # If all else fails use the default encoding + if encoding is None: + confidence = "tentative" + encoding = self.defaultEncoding + + # Substitute for equivalent encodings: + encodingSub = {"iso-8859-1": "windows-1252"} + + if encoding.lower() in encodingSub: + encoding = encodingSub[encoding.lower()] + + return encoding, confidence + + def changeEncoding(self, newEncoding): + assert self.charEncoding[1] != "certain" + newEncoding = codecName(newEncoding) + if newEncoding in ("utf-16", "utf-16-be", "utf-16-le"): + newEncoding = "utf-8" + if newEncoding is None: + return + elif newEncoding == self.charEncoding[0]: + self.charEncoding = (self.charEncoding[0], "certain") + else: + self.rawStream.seek(0) + self.reset() + self.charEncoding = (newEncoding, "certain") + raise ReparseException("Encoding changed from %s to %s" % (self.charEncoding[0], newEncoding)) + + def detectBOM(self): + """Attempts to detect at BOM at the start of the stream. If + an encoding can be determined from the BOM return the name of the + encoding otherwise return None""" + bomDict = { + codecs.BOM_UTF8: 'utf-8', + codecs.BOM_UTF16_LE: 'utf-16-le', codecs.BOM_UTF16_BE: 'utf-16-be', + codecs.BOM_UTF32_LE: 'utf-32-le', codecs.BOM_UTF32_BE: 'utf-32-be' + } + + # Go to beginning of file and read in 4 bytes + string = self.rawStream.read(4) + assert isinstance(string, bytes) + + # Try detecting the BOM using bytes from the string + encoding = bomDict.get(string[:3]) # UTF-8 + seek = 3 + if not encoding: + # Need to detect UTF-32 before UTF-16 + encoding = bomDict.get(string) # UTF-32 + seek = 4 + if not encoding: + encoding = bomDict.get(string[:2]) # UTF-16 + seek = 2 + + # Set the read position past the BOM if one was found, otherwise + # set it to the start of the stream + self.rawStream.seek(encoding and seek or 0) + + return encoding + + def detectEncodingMeta(self): + """Report the encoding declared by the meta element + """ + buffer = self.rawStream.read(self.numBytesMeta) + assert isinstance(buffer, bytes) + parser = EncodingParser(buffer) + self.rawStream.seek(0) + encoding = parser.getEncoding() + + if encoding in ("utf-16", "utf-16-be", "utf-16-le"): + encoding = "utf-8" + + return encoding + + +class EncodingBytes(bytes): + """String-like object with an associated position and various extra methods + If the position is ever greater than the string length then an exception is + raised""" + def __new__(self, value): + assert isinstance(value, bytes) + return bytes.__new__(self, value.lower()) + + def __init__(self, value): + self._position = -1 + + def __iter__(self): + return self + + def __next__(self): + p = self._position = self._position + 1 + if p >= len(self): + raise StopIteration + elif p < 0: + raise TypeError + return self[p:p + 1] + + def next(self): + # Py2 compat + return self.__next__() + + def previous(self): + p = self._position + if p >= len(self): + raise StopIteration + elif p < 0: + raise TypeError + self._position = p = p - 1 + return self[p:p + 1] + + def setPosition(self, position): + if self._position >= len(self): + raise StopIteration + self._position = position + + def getPosition(self): + if self._position >= len(self): + raise StopIteration + if self._position >= 0: + return self._position + else: + return None + + position = property(getPosition, setPosition) + + def getCurrentByte(self): + return self[self.position:self.position + 1] + + currentByte = property(getCurrentByte) + + def skip(self, chars=spaceCharactersBytes): + """Skip past a list of characters""" + p = self.position # use property for the error-checking + while p < len(self): + c = self[p:p + 1] + if c not in chars: + self._position = p + return c + p += 1 + self._position = p + return None + + def skipUntil(self, chars): + p = self.position + while p < len(self): + c = self[p:p + 1] + if c in chars: + self._position = p + return c + p += 1 + self._position = p + return None + + def matchBytes(self, bytes): + """Look for a sequence of bytes at the start of a string. If the bytes + are found return True and advance the position to the byte after the + match. Otherwise return False and leave the position alone""" + p = self.position + data = self[p:p + len(bytes)] + rv = data.startswith(bytes) + if rv: + self.position += len(bytes) + return rv + + def jumpTo(self, bytes): + """Look for the next sequence of bytes matching a given sequence. If + a match is found advance the position to the last byte of the match""" + newPosition = self[self.position:].find(bytes) + if newPosition > -1: + # XXX: This is ugly, but I can't see a nicer way to fix this. + if self._position == -1: + self._position = 0 + self._position += (newPosition + len(bytes) - 1) + return True + else: + raise StopIteration + + +class EncodingParser(object): + """Mini parser for detecting character encoding from meta elements""" + + def __init__(self, data): + """string - the data to work on for encoding detection""" + self.data = EncodingBytes(data) + self.encoding = None + + def getEncoding(self): + methodDispatch = ( + (b"<!--", self.handleComment), + (b"<meta", self.handleMeta), + (b"</", self.handlePossibleEndTag), + (b"<!", self.handleOther), + (b"<?", self.handleOther), + (b"<", self.handlePossibleStartTag)) + for byte in self.data: + keepParsing = True + for key, method in methodDispatch: + if self.data.matchBytes(key): + try: + keepParsing = method() + break + except StopIteration: + keepParsing = False + break + if not keepParsing: + break + + return self.encoding + + def handleComment(self): + """Skip over comments""" + return self.data.jumpTo(b"-->") + + def handleMeta(self): + if self.data.currentByte not in spaceCharactersBytes: + # if we have <meta not followed by a space so just keep going + return True + # We have a valid meta element we want to search for attributes + hasPragma = False + pendingEncoding = None + while True: + # Try to find the next attribute after the current position + attr = self.getAttribute() + if attr is None: + return True + else: + if attr[0] == b"http-equiv": + hasPragma = attr[1] == b"content-type" + if hasPragma and pendingEncoding is not None: + self.encoding = pendingEncoding + return False + elif attr[0] == b"charset": + tentativeEncoding = attr[1] + codec = codecName(tentativeEncoding) + if codec is not None: + self.encoding = codec + return False + elif attr[0] == b"content": + contentParser = ContentAttrParser(EncodingBytes(attr[1])) + tentativeEncoding = contentParser.parse() + if tentativeEncoding is not None: + codec = codecName(tentativeEncoding) + if codec is not None: + if hasPragma: + self.encoding = codec + return False + else: + pendingEncoding = codec + + def handlePossibleStartTag(self): + return self.handlePossibleTag(False) + + def handlePossibleEndTag(self): + next(self.data) + return self.handlePossibleTag(True) + + def handlePossibleTag(self, endTag): + data = self.data + if data.currentByte not in asciiLettersBytes: + # If the next byte is not an ascii letter either ignore this + # fragment (possible start tag case) or treat it according to + # handleOther + if endTag: + data.previous() + self.handleOther() + return True + + c = data.skipUntil(spacesAngleBrackets) + if c == b"<": + # return to the first step in the overall "two step" algorithm + # reprocessing the < byte + data.previous() + else: + # Read all attributes + attr = self.getAttribute() + while attr is not None: + attr = self.getAttribute() + return True + + def handleOther(self): + return self.data.jumpTo(b">") + + def getAttribute(self): + """Return a name,value pair for the next attribute in the stream, + if one is found, or None""" + data = self.data + # Step 1 (skip chars) + c = data.skip(spaceCharactersBytes | frozenset([b"/"])) + assert c is None or len(c) == 1 + # Step 2 + if c in (b">", None): + return None + # Step 3 + attrName = [] + attrValue = [] + # Step 4 attribute name + while True: + if c == b"=" and attrName: + break + elif c in spaceCharactersBytes: + # Step 6! + c = data.skip() + break + elif c in (b"/", b">"): + return b"".join(attrName), b"" + elif c in asciiUppercaseBytes: + attrName.append(c.lower()) + elif c is None: + return None + else: + attrName.append(c) + # Step 5 + c = next(data) + # Step 7 + if c != b"=": + data.previous() + return b"".join(attrName), b"" + # Step 8 + next(data) + # Step 9 + c = data.skip() + # Step 10 + if c in (b"'", b'"'): + # 10.1 + quoteChar = c + while True: + # 10.2 + c = next(data) + # 10.3 + if c == quoteChar: + next(data) + return b"".join(attrName), b"".join(attrValue) + # 10.4 + elif c in asciiUppercaseBytes: + attrValue.append(c.lower()) + # 10.5 + else: + attrValue.append(c) + elif c == b">": + return b"".join(attrName), b"" + elif c in asciiUppercaseBytes: + attrValue.append(c.lower()) + elif c is None: + return None + else: + attrValue.append(c) + # Step 11 + while True: + c = next(data) + if c in spacesAngleBrackets: + return b"".join(attrName), b"".join(attrValue) + elif c in asciiUppercaseBytes: + attrValue.append(c.lower()) + elif c is None: + return None + else: + attrValue.append(c) + + +class ContentAttrParser(object): + def __init__(self, data): + assert isinstance(data, bytes) + self.data = data + + def parse(self): + try: + # Check if the attr name is charset + # otherwise return + self.data.jumpTo(b"charset") + self.data.position += 1 + self.data.skip() + if not self.data.currentByte == b"=": + # If there is no = sign keep looking for attrs + return None + self.data.position += 1 + self.data.skip() + # Look for an encoding between matching quote marks + if self.data.currentByte in (b'"', b"'"): + quoteMark = self.data.currentByte + self.data.position += 1 + oldPosition = self.data.position + if self.data.jumpTo(quoteMark): + return self.data[oldPosition:self.data.position] + else: + return None + else: + # Unquoted value + oldPosition = self.data.position + try: + self.data.skipUntil(spaceCharactersBytes) + return self.data[oldPosition:self.data.position] + except StopIteration: + # Return the whole remaining value + return self.data[oldPosition:] + except StopIteration: + return None + + +def codecName(encoding): + """Return the python codec name corresponding to an encoding or None if the + string doesn't correspond to a valid encoding.""" + if isinstance(encoding, bytes): + try: + encoding = encoding.decode("ascii") + except UnicodeDecodeError: + return None + if encoding: + canonicalName = ascii_punctuation_re.sub("", encoding).lower() + return encodings.get(canonicalName, None) + else: + return None |