The Tor Browser: addon-sdk/source/python-lib/simplejson/decoder.py@ac0c01689b40 (annotated)

addon-sdk/source/python-lib/simplejson/decoder.py@ac0c01689b40 (annotated)

addon-sdk/source/python-lib/simplejson/decoder.py

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 """
 Implementation of JSONDecoder
 """
 import re
 import sys
 from simplejson.scanner import Scanner, pattern
 try:
     from simplejson._speedups import scanstring as c_scanstring
 except ImportError:
     pass
 FLAGS = re.VERBOSE | re.MULTILINE | re.DOTALL
 def _floatconstants():
     import struct
     import sys
     _BYTES = '7FF80000000000007FF0000000000000'.decode('hex')
     if sys.byteorder != 'big':
         _BYTES = _BYTES[:8][::-1] + _BYTES[8:][::-1]
     nan, inf = struct.unpack('dd', _BYTES)
     return nan, inf, -inf
 NaN, PosInf, NegInf = _floatconstants()
 def linecol(doc, pos):
     lineno = doc.count('\n', 0, pos) + 1
     if lineno == 1:
         colno = pos
     else:
         colno = pos - doc.rindex('\n', 0, pos)
     return lineno, colno
 def errmsg(msg, doc, pos, end=None):
     lineno, colno = linecol(doc, pos)
     if end is None:
         return '%s: line %d column %d (char %d)' % (msg, lineno, colno, pos)
     endlineno, endcolno = linecol(doc, end)
     return '%s: line %d column %d - line %d column %d (char %d - %d)' % (
         msg, lineno, colno, endlineno, endcolno, pos, end)
 _CONSTANTS = {
     '-Infinity': NegInf,
     'Infinity': PosInf,
     'NaN': NaN,
     'true': True,
     'false': False,
     'null': None,
 }
 def JSONConstant(match, context, c=_CONSTANTS):
     s = match.group(0)
     fn = getattr(context, 'parse_constant', None)
     if fn is None:
         rval = c[s]
     else:
         rval = fn(s)
     return rval, None
 pattern('(-?Infinity|NaN|true|false|null)')(JSONConstant)
 def JSONNumber(match, context):
     match = JSONNumber.regex.match(match.string, *match.span())
     integer, frac, exp = match.groups()
     if frac or exp:
         fn = getattr(context, 'parse_float', None) or float
         res = fn(integer + (frac or '') + (exp or ''))
     else:
         fn = getattr(context, 'parse_int', None) or int
         res = fn(integer)
     return res, None
 pattern(r'(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?')(JSONNumber)
 STRINGCHUNK = re.compile(r'(.*?)(["\\\x00-\x1f])', FLAGS)
 BACKSLASH = {
     '"': u'"', '\\': u'\\', '/': u'/',
     'b': u'\b', 'f': u'\f', 'n': u'\n', 'r': u'\r', 't': u'\t',
 }
 DEFAULT_ENCODING = "utf-8"
 def py_scanstring(s, end, encoding=None, strict=True, _b=BACKSLASH, _m=STRINGCHUNK.match):
     if encoding is None:
         encoding = DEFAULT_ENCODING
     chunks = []
     _append = chunks.append
     begin = end - 1
     while 1:
         chunk = _m(s, end)
         if chunk is None:
             raise ValueError(
                 errmsg("Unterminated string starting at", s, begin))
         end = chunk.end()
         content, terminator = chunk.groups()
         if content:
             if not isinstance(content, unicode):
                 content = unicode(content, encoding)
             _append(content)
         if terminator == '"':
             break
         elif terminator != '\\':
             if strict:
                 raise ValueError(errmsg("Invalid control character %r at", s, end))
             else:
                 _append(terminator)
                 continue
         try:
             esc = s[end]
         except IndexError:
             raise ValueError(
                 errmsg("Unterminated string starting at", s, begin))
         if esc != 'u':
             try:
                 m = _b[esc]
             except KeyError:
                 raise ValueError(
                     errmsg("Invalid \\escape: %r" % (esc,), s, end))
             end += 1
         else:
             esc = s[end + 1:end + 5]
             next_end = end + 5
             msg = "Invalid \\uXXXX escape"
             try:
                 if len(esc) != 4:
                     raise ValueError
                 uni = int(esc, 16)
                 if 0xd800 <= uni <= 0xdbff and sys.maxunicode > 65535:
                     msg = "Invalid \\uXXXX\\uXXXX surrogate pair"
                     if not s[end + 5:end + 7] == '\\u':
                         raise ValueError
                     esc2 = s[end + 7:end + 11]
                     if len(esc2) != 4:
                         raise ValueError
                     uni2 = int(esc2, 16)
                     uni = 0x10000 + (((uni - 0xd800) << 10) | (uni2 - 0xdc00))
                     next_end += 6
                 m = unichr(uni)
             except ValueError:
                 raise ValueError(errmsg(msg, s, end))
             end = next_end
         _append(m)
     return u''.join(chunks), end
 # Use speedup
 try:
     scanstring = c_scanstring
 except NameError:
     scanstring = py_scanstring
 def JSONString(match, context):
     encoding = getattr(context, 'encoding', None)
     strict = getattr(context, 'strict', True)
     return scanstring(match.string, match.end(), encoding, strict)
 pattern(r'"')(JSONString)
 WHITESPACE = re.compile(r'\s*', FLAGS)
 def JSONObject(match, context, _w=WHITESPACE.match):
     pairs = {}
     s = match.string
     end = _w(s, match.end()).end()
     nextchar = s[end:end + 1]
     # Trivial empty object
     if nextchar == '}':
         return pairs, end + 1
     if nextchar != '"':
         raise ValueError(errmsg("Expecting property name", s, end))
     end += 1
     encoding = getattr(context, 'encoding', None)
     strict = getattr(context, 'strict', True)
     iterscan = JSONScanner.iterscan
     while True:
         key, end = scanstring(s, end, encoding, strict)
         end = _w(s, end).end()
         if s[end:end + 1] != ':':
             raise ValueError(errmsg("Expecting : delimiter", s, end))
         end = _w(s, end + 1).end()
         try:
             value, end = iterscan(s, idx=end, context=context).next()
         except StopIteration:
             raise ValueError(errmsg("Expecting object", s, end))
         pairs[key] = value
         end = _w(s, end).end()
         nextchar = s[end:end + 1]
         end += 1
         if nextchar == '}':
             break
         if nextchar != ',':
             raise ValueError(errmsg("Expecting , delimiter", s, end - 1))
         end = _w(s, end).end()
         nextchar = s[end:end + 1]
         end += 1
         if nextchar != '"':
             raise ValueError(errmsg("Expecting property name", s, end - 1))
     object_hook = getattr(context, 'object_hook', None)
     if object_hook is not None:
         pairs = object_hook(pairs)
     return pairs, end
 pattern(r'{')(JSONObject)
 def JSONArray(match, context, _w=WHITESPACE.match):
     values = []
     s = match.string
     end = _w(s, match.end()).end()
     # Look-ahead for trivial empty array
     nextchar = s[end:end + 1]
     if nextchar == ']':
         return values, end + 1
     iterscan = JSONScanner.iterscan
     while True:
         try:
             value, end = iterscan(s, idx=end, context=context).next()
         except StopIteration:
             raise ValueError(errmsg("Expecting object", s, end))
         values.append(value)
         end = _w(s, end).end()
         nextchar = s[end:end + 1]
         end += 1
         if nextchar == ']':
             break
         if nextchar != ',':
             raise ValueError(errmsg("Expecting , delimiter", s, end))
         end = _w(s, end).end()
     return values, end
 pattern(r'\[')(JSONArray)
 ANYTHING = [
     JSONObject,
     JSONArray,
     JSONString,
     JSONConstant,
     JSONNumber,
 ]
 JSONScanner = Scanner(ANYTHING)
 class JSONDecoder(object):
     """
     Simple JSON <http://json.org> decoder
     Performs the following translations in decoding by default:
     +---------------+-------------------+
     | JSON          | Python            |
     +===============+===================+
     | object        | dict              |
     +---------------+-------------------+
     | array         | list              |
     +---------------+-------------------+
     | string        | unicode           |
     +---------------+-------------------+
     | number (int)  | int, long         |
     +---------------+-------------------+
     | number (real) | float             |
     +---------------+-------------------+
     | true          | True              |
     +---------------+-------------------+
     | false         | False             |
     +---------------+-------------------+
     | null          | None              |
     +---------------+-------------------+
     It also understands ``NaN``, ``Infinity``, and ``-Infinity`` as
     their corresponding ``float`` values, which is outside the JSON spec.
     """
     _scanner = Scanner(ANYTHING)
     __all__ = ['__init__', 'decode', 'raw_decode']
     def __init__(self, encoding=None, object_hook=None, parse_float=None,
             parse_int=None, parse_constant=None, strict=True):
         """
         ``encoding`` determines the encoding used to interpret any ``str``
         objects decoded by this instance (utf-8 by default).  It has no
         effect when decoding ``unicode`` objects.
         Note that currently only encodings that are a superset of ASCII work,
         strings of other encodings should be passed in as ``unicode``.
         ``object_hook``, if specified, will be called with the result
         of every JSON object decoded and its return value will be used in
         place of the given ``dict``.  This can be used to provide custom
         deserializations (e.g. to support JSON-RPC class hinting).
         ``parse_float``, if specified, will be called with the string
         of every JSON float to be decoded. By default this is equivalent to
         float(num_str). This can be used to use another datatype or parser
         for JSON floats (e.g. decimal.Decimal).
         ``parse_int``, if specified, will be called with the string
         of every JSON int to be decoded. By default this is equivalent to
         int(num_str). This can be used to use another datatype or parser
         for JSON integers (e.g. float).
         ``parse_constant``, if specified, will be called with one of the
         following strings: -Infinity, Infinity, NaN, null, true, false.
         This can be used to raise an exception if invalid JSON numbers
         are encountered.
         """
         self.encoding = encoding
         self.object_hook = object_hook
         self.parse_float = parse_float
         self.parse_int = parse_int
         self.parse_constant = parse_constant
         self.strict = strict
     def decode(self, s, _w=WHITESPACE.match):
         """
         Return the Python representation of ``s`` (a ``str`` or ``unicode``
         instance containing a JSON document)
         """
         obj, end = self.raw_decode(s, idx=_w(s, 0).end())
         end = _w(s, end).end()
         if end != len(s):
             raise ValueError(errmsg("Extra data", s, end, len(s)))
         return obj
     def raw_decode(self, s, **kw):
         """
         Decode a JSON document from ``s`` (a ``str`` or ``unicode`` beginning
         with a JSON document) and return a 2-tuple of the Python
         representation and the index in ``s`` where the document ended.
         This can be used to decode a JSON document from a string that may
         have extraneous data at the end.
         """
         kw.setdefault('context', self)
         try:
             obj, end = self._scanner.iterscan(s, **kw).next()
         except StopIteration:
             raise ValueError("No JSON object could be decoded")
         return obj, end
 __all__ = ['JSONDecoder']

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addon-sdk/source/python-lib/simplejson/decoder.py@ac0c01689b40 (annotated)

addon-sdk/source/python-lib/simplejson/decoder.py