923 lines
32 KiB
Python
923 lines
32 KiB
Python
from __future__ import absolute_import, division, unicode_literals
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from six import text_type, binary_type
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from six.moves import http_client, urllib
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import codecs
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import re
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import webencodings
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from .constants import EOF, spaceCharacters, asciiLetters, asciiUppercase
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from .constants import _ReparseException
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from . import _utils
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from io import StringIO
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try:
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from io import BytesIO
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except ImportError:
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BytesIO = StringIO
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# Non-unicode versions of constants for use in the pre-parser
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spaceCharactersBytes = frozenset([item.encode("ascii") for item in spaceCharacters])
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asciiLettersBytes = frozenset([item.encode("ascii") for item in asciiLetters])
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asciiUppercaseBytes = frozenset([item.encode("ascii") for item in asciiUppercase])
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spacesAngleBrackets = spaceCharactersBytes | frozenset([b">", b"<"])
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invalid_unicode_no_surrogate = "[\u0001-\u0008\u000B\u000E-\u001F\u007F-\u009F\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]" # noqa
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if _utils.supports_lone_surrogates:
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# Use one extra step of indirection and create surrogates with
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# eval. Not using this indirection would introduce an illegal
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# unicode literal on platforms not supporting such lone
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# surrogates.
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assert invalid_unicode_no_surrogate[-1] == "]" and invalid_unicode_no_surrogate.count("]") == 1
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invalid_unicode_re = re.compile(invalid_unicode_no_surrogate[:-1] +
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eval('"\\uD800-\\uDFFF"') + # pylint:disable=eval-used
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"]")
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else:
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invalid_unicode_re = re.compile(invalid_unicode_no_surrogate)
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non_bmp_invalid_codepoints = set([0x1FFFE, 0x1FFFF, 0x2FFFE, 0x2FFFF, 0x3FFFE,
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0x3FFFF, 0x4FFFE, 0x4FFFF, 0x5FFFE, 0x5FFFF,
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0x6FFFE, 0x6FFFF, 0x7FFFE, 0x7FFFF, 0x8FFFE,
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0x8FFFF, 0x9FFFE, 0x9FFFF, 0xAFFFE, 0xAFFFF,
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0xBFFFE, 0xBFFFF, 0xCFFFE, 0xCFFFF, 0xDFFFE,
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0xDFFFF, 0xEFFFE, 0xEFFFF, 0xFFFFE, 0xFFFFF,
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0x10FFFE, 0x10FFFF])
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ascii_punctuation_re = re.compile("[\u0009-\u000D\u0020-\u002F\u003A-\u0040\u005C\u005B-\u0060\u007B-\u007E]")
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# Cache for charsUntil()
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charsUntilRegEx = {}
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class BufferedStream(object):
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"""Buffering for streams that do not have buffering of their own
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The buffer is implemented as a list of chunks on the assumption that
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joining many strings will be slow since it is O(n**2)
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"""
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def __init__(self, stream):
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self.stream = stream
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self.buffer = []
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self.position = [-1, 0] # chunk number, offset
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def tell(self):
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pos = 0
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for chunk in self.buffer[:self.position[0]]:
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pos += len(chunk)
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pos += self.position[1]
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return pos
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def seek(self, pos):
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assert pos <= self._bufferedBytes()
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offset = pos
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i = 0
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while len(self.buffer[i]) < offset:
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offset -= len(self.buffer[i])
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i += 1
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self.position = [i, offset]
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def read(self, bytes):
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if not self.buffer:
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return self._readStream(bytes)
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elif (self.position[0] == len(self.buffer) and
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self.position[1] == len(self.buffer[-1])):
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return self._readStream(bytes)
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else:
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return self._readFromBuffer(bytes)
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def _bufferedBytes(self):
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return sum([len(item) for item in self.buffer])
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def _readStream(self, bytes):
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data = self.stream.read(bytes)
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self.buffer.append(data)
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self.position[0] += 1
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self.position[1] = len(data)
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return data
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def _readFromBuffer(self, bytes):
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remainingBytes = bytes
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rv = []
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bufferIndex = self.position[0]
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bufferOffset = self.position[1]
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while bufferIndex < len(self.buffer) and remainingBytes != 0:
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assert remainingBytes > 0
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bufferedData = self.buffer[bufferIndex]
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if remainingBytes <= len(bufferedData) - bufferOffset:
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bytesToRead = remainingBytes
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self.position = [bufferIndex, bufferOffset + bytesToRead]
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else:
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bytesToRead = len(bufferedData) - bufferOffset
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self.position = [bufferIndex, len(bufferedData)]
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bufferIndex += 1
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rv.append(bufferedData[bufferOffset:bufferOffset + bytesToRead])
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remainingBytes -= bytesToRead
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bufferOffset = 0
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if remainingBytes:
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rv.append(self._readStream(remainingBytes))
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return b"".join(rv)
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def HTMLInputStream(source, **kwargs):
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# Work around Python bug #20007: read(0) closes the connection.
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# http://bugs.python.org/issue20007
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if (isinstance(source, http_client.HTTPResponse) or
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# Also check for addinfourl wrapping HTTPResponse
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(isinstance(source, urllib.response.addbase) and
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isinstance(source.fp, http_client.HTTPResponse))):
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isUnicode = False
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elif hasattr(source, "read"):
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isUnicode = isinstance(source.read(0), text_type)
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else:
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isUnicode = isinstance(source, text_type)
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if isUnicode:
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encodings = [x for x in kwargs if x.endswith("_encoding")]
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if encodings:
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raise TypeError("Cannot set an encoding with a unicode input, set %r" % encodings)
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return HTMLUnicodeInputStream(source, **kwargs)
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else:
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return HTMLBinaryInputStream(source, **kwargs)
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class HTMLUnicodeInputStream(object):
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"""Provides a unicode stream of characters to the HTMLTokenizer.
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This class takes care of character encoding and removing or replacing
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incorrect byte-sequences and also provides column and line tracking.
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"""
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_defaultChunkSize = 10240
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def __init__(self, source):
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"""Initialises the HTMLInputStream.
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HTMLInputStream(source, [encoding]) -> Normalized stream from source
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for use by html5lib.
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source can be either a file-object, local filename or a string.
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The optional encoding parameter must be a string that indicates
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the encoding. If specified, that encoding will be used,
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regardless of any BOM or later declaration (such as in a meta
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element)
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"""
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if not _utils.supports_lone_surrogates:
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# Such platforms will have already checked for such
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# surrogate errors, so no need to do this checking.
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self.reportCharacterErrors = None
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elif len("\U0010FFFF") == 1:
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self.reportCharacterErrors = self.characterErrorsUCS4
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else:
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self.reportCharacterErrors = self.characterErrorsUCS2
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# List of where new lines occur
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self.newLines = [0]
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self.charEncoding = (lookupEncoding("utf-8"), "certain")
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self.dataStream = self.openStream(source)
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self.reset()
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def reset(self):
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self.chunk = ""
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self.chunkSize = 0
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self.chunkOffset = 0
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self.errors = []
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# number of (complete) lines in previous chunks
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self.prevNumLines = 0
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# number of columns in the last line of the previous chunk
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self.prevNumCols = 0
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# Deal with CR LF and surrogates split over chunk boundaries
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self._bufferedCharacter = None
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def openStream(self, source):
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"""Produces a file object from source.
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source can be either a file object, local filename or a string.
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"""
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# Already a file object
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if hasattr(source, 'read'):
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stream = source
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else:
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stream = StringIO(source)
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return stream
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def _position(self, offset):
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chunk = self.chunk
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nLines = chunk.count('\n', 0, offset)
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positionLine = self.prevNumLines + nLines
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lastLinePos = chunk.rfind('\n', 0, offset)
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if lastLinePos == -1:
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positionColumn = self.prevNumCols + offset
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else:
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positionColumn = offset - (lastLinePos + 1)
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return (positionLine, positionColumn)
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def position(self):
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"""Returns (line, col) of the current position in the stream."""
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line, col = self._position(self.chunkOffset)
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return (line + 1, col)
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def char(self):
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""" Read one character from the stream or queue if available. Return
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EOF when EOF is reached.
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"""
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# Read a new chunk from the input stream if necessary
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if self.chunkOffset >= self.chunkSize:
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if not self.readChunk():
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return EOF
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chunkOffset = self.chunkOffset
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char = self.chunk[chunkOffset]
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self.chunkOffset = chunkOffset + 1
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return char
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def readChunk(self, chunkSize=None):
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if chunkSize is None:
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chunkSize = self._defaultChunkSize
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self.prevNumLines, self.prevNumCols = self._position(self.chunkSize)
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self.chunk = ""
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self.chunkSize = 0
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self.chunkOffset = 0
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data = self.dataStream.read(chunkSize)
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# Deal with CR LF and surrogates broken across chunks
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if self._bufferedCharacter:
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data = self._bufferedCharacter + data
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self._bufferedCharacter = None
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elif not data:
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# We have no more data, bye-bye stream
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return False
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if len(data) > 1:
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lastv = ord(data[-1])
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if lastv == 0x0D or 0xD800 <= lastv <= 0xDBFF:
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self._bufferedCharacter = data[-1]
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data = data[:-1]
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if self.reportCharacterErrors:
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self.reportCharacterErrors(data)
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# Replace invalid characters
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data = data.replace("\r\n", "\n")
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data = data.replace("\r", "\n")
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self.chunk = data
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self.chunkSize = len(data)
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return True
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def characterErrorsUCS4(self, data):
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for _ in range(len(invalid_unicode_re.findall(data))):
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self.errors.append("invalid-codepoint")
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def characterErrorsUCS2(self, data):
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# Someone picked the wrong compile option
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# You lose
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skip = False
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for match in invalid_unicode_re.finditer(data):
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if skip:
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continue
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codepoint = ord(match.group())
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pos = match.start()
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# Pretty sure there should be endianness issues here
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if _utils.isSurrogatePair(data[pos:pos + 2]):
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# We have a surrogate pair!
|
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char_val = _utils.surrogatePairToCodepoint(data[pos:pos + 2])
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if char_val in non_bmp_invalid_codepoints:
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self.errors.append("invalid-codepoint")
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skip = True
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elif (codepoint >= 0xD800 and codepoint <= 0xDFFF and
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pos == len(data) - 1):
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self.errors.append("invalid-codepoint")
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else:
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skip = False
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self.errors.append("invalid-codepoint")
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def charsUntil(self, characters, opposite=False):
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""" Returns a string of characters from the stream up to but not
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including any character in 'characters' or EOF. 'characters' must be
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a container that supports the 'in' method and iteration over its
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characters.
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"""
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# Use a cache of regexps to find the required characters
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try:
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chars = charsUntilRegEx[(characters, opposite)]
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except KeyError:
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if __debug__:
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for c in characters:
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assert(ord(c) < 128)
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regex = "".join(["\\x%02x" % ord(c) for c in characters])
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if not opposite:
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regex = "^%s" % regex
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chars = charsUntilRegEx[(characters, opposite)] = re.compile("[%s]+" % regex)
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rv = []
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while True:
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# Find the longest matching prefix
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m = chars.match(self.chunk, self.chunkOffset)
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if m is None:
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# If nothing matched, and it wasn't because we ran out of chunk,
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# then stop
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if self.chunkOffset != self.chunkSize:
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break
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else:
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end = m.end()
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# If not the whole chunk matched, return everything
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# up to the part that didn't match
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if end != self.chunkSize:
|
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rv.append(self.chunk[self.chunkOffset:end])
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self.chunkOffset = end
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break
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# If the whole remainder of the chunk matched,
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# use it all and read the next chunk
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rv.append(self.chunk[self.chunkOffset:])
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if not self.readChunk():
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# Reached EOF
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break
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r = "".join(rv)
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return r
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def unget(self, char):
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# Only one character is allowed to be ungotten at once - it must
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# be consumed again before any further call to unget
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if char is not None:
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if self.chunkOffset == 0:
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# unget is called quite rarely, so it's a good idea to do
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# more work here if it saves a bit of work in the frequently
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# called char and charsUntil.
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# So, just prepend the ungotten character onto the current
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# chunk:
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self.chunk = char + self.chunk
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self.chunkSize += 1
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else:
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self.chunkOffset -= 1
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assert self.chunk[self.chunkOffset] == char
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class HTMLBinaryInputStream(HTMLUnicodeInputStream):
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"""Provides a unicode stream of characters to the HTMLTokenizer.
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This class takes care of character encoding and removing or replacing
|
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incorrect byte-sequences and also provides column and line tracking.
|
|
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"""
|
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def __init__(self, source, override_encoding=None, transport_encoding=None,
|
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same_origin_parent_encoding=None, likely_encoding=None,
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default_encoding="windows-1252", useChardet=True):
|
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"""Initialises the HTMLInputStream.
|
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HTMLInputStream(source, [encoding]) -> Normalized stream from source
|
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for use by html5lib.
|
|
|
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source can be either a file-object, local filename or a string.
|
|
|
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The optional encoding parameter must be a string that indicates
|
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the encoding. If specified, that encoding will be used,
|
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regardless of any BOM or later declaration (such as in a meta
|
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element)
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|
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"""
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# Raw Stream - for unicode objects this will encode to utf-8 and set
|
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# self.charEncoding as appropriate
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self.rawStream = self.openStream(source)
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|
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HTMLUnicodeInputStream.__init__(self, self.rawStream)
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|
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# Encoding Information
|
|
# Number of bytes to use when looking for a meta element with
|
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# encoding information
|
|
self.numBytesMeta = 1024
|
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# Number of bytes to use when using detecting encoding using chardet
|
|
self.numBytesChardet = 100
|
|
# Things from args
|
|
self.override_encoding = override_encoding
|
|
self.transport_encoding = transport_encoding
|
|
self.same_origin_parent_encoding = same_origin_parent_encoding
|
|
self.likely_encoding = likely_encoding
|
|
self.default_encoding = default_encoding
|
|
|
|
# Determine encoding
|
|
self.charEncoding = self.determineEncoding(useChardet)
|
|
assert self.charEncoding[0] is not None
|
|
|
|
# Call superclass
|
|
self.reset()
|
|
|
|
def reset(self):
|
|
self.dataStream = self.charEncoding[0].codec_info.streamreader(self.rawStream, 'replace')
|
|
HTMLUnicodeInputStream.reset(self)
|
|
|
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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: # pylint:disable=bare-except
|
|
stream = BufferedStream(stream)
|
|
|
|
return stream
|
|
|
|
def determineEncoding(self, chardet=True):
|
|
# BOMs take precedence over everything
|
|
# This will also read past the BOM if present
|
|
charEncoding = self.detectBOM(), "certain"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# If we've been overriden, we've been overriden
|
|
charEncoding = lookupEncoding(self.override_encoding), "certain"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# Now check the transport layer
|
|
charEncoding = lookupEncoding(self.transport_encoding), "certain"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# Look for meta elements with encoding information
|
|
charEncoding = self.detectEncodingMeta(), "tentative"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# Parent document encoding
|
|
charEncoding = lookupEncoding(self.same_origin_parent_encoding), "tentative"
|
|
if charEncoding[0] is not None and not charEncoding[0].name.startswith("utf-16"):
|
|
return charEncoding
|
|
|
|
# "likely" encoding
|
|
charEncoding = lookupEncoding(self.likely_encoding), "tentative"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# Guess with chardet, if available
|
|
if chardet:
|
|
try:
|
|
from chardet.universaldetector import UniversalDetector
|
|
except ImportError:
|
|
pass
|
|
else:
|
|
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 = lookupEncoding(detector.result['encoding'])
|
|
self.rawStream.seek(0)
|
|
if encoding is not None:
|
|
return encoding, "tentative"
|
|
|
|
# Try the default encoding
|
|
charEncoding = lookupEncoding(self.default_encoding), "tentative"
|
|
if charEncoding[0] is not None:
|
|
return charEncoding
|
|
|
|
# Fallback to html5lib's default if even that hasn't worked
|
|
return lookupEncoding("windows-1252"), "tentative"
|
|
|
|
def changeEncoding(self, newEncoding):
|
|
assert self.charEncoding[1] != "certain"
|
|
newEncoding = lookupEncoding(newEncoding)
|
|
if newEncoding is None:
|
|
return
|
|
if newEncoding.name in ("utf-16be", "utf-16le"):
|
|
newEncoding = lookupEncoding("utf-8")
|
|
assert newEncoding is not None
|
|
elif newEncoding == self.charEncoding[0]:
|
|
self.charEncoding = (self.charEncoding[0], "certain")
|
|
else:
|
|
self.rawStream.seek(0)
|
|
self.charEncoding = (newEncoding, "certain")
|
|
self.reset()
|
|
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-16le', codecs.BOM_UTF16_BE: 'utf-16be',
|
|
codecs.BOM_UTF32_LE: 'utf-32le', codecs.BOM_UTF32_BE: 'utf-32be'
|
|
}
|
|
|
|
# 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
|
|
if encoding:
|
|
self.rawStream.seek(seek)
|
|
return lookupEncoding(encoding)
|
|
else:
|
|
self.rawStream.seek(0)
|
|
return None
|
|
|
|
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 is not None and encoding.name in ("utf-16be", "utf-16le"):
|
|
encoding = lookupEncoding("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):
|
|
# pylint:disable=unused-argument
|
|
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 _ 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 = lookupEncoding(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 = lookupEncoding(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 lookupEncoding(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, binary_type):
|
|
try:
|
|
encoding = encoding.decode("ascii")
|
|
except UnicodeDecodeError:
|
|
return None
|
|
|
|
if encoding is not None:
|
|
try:
|
|
return webencodings.lookup(encoding)
|
|
except AttributeError:
|
|
return None
|
|
else:
|
|
return None
|