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

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

addon-sdk/source/python-lib/simplejson/encoder.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 JSONEncoder
 """
 import re
 try:
     from simplejson._speedups import encode_basestring_ascii as c_encode_basestring_ascii
 except ImportError:
     pass
 ESCAPE = re.compile(r'[\x00-\x1f\\"\b\f\n\r\t]')
 ESCAPE_ASCII = re.compile(r'([\\"]|[^\ -~])')
 HAS_UTF8 = re.compile(r'[\x80-\xff]')
 ESCAPE_DCT = {
     '\\': '\\\\',
     '"': '\\"',
     '\b': '\\b',
     '\f': '\\f',
     '\n': '\\n',
     '\r': '\\r',
     '\t': '\\t',
 }
 for i in range(0x20):
     ESCAPE_DCT.setdefault(chr(i), '\\u%04x' % (i,))
 # Assume this produces an infinity on all machines (probably not guaranteed)
 INFINITY = float('1e66666')
 FLOAT_REPR = repr
 def floatstr(o, allow_nan=True):
     # Check for specials.  Note that this type of test is processor- and/or
     # platform-specific, so do tests which don't depend on the internals.
     if o != o:
         text = 'NaN'
     elif o == INFINITY:
         text = 'Infinity'
     elif o == -INFINITY:
         text = '-Infinity'
     else:
         return FLOAT_REPR(o)
     if not allow_nan:
         raise ValueError("Out of range float values are not JSON compliant: %r"
             % (o,))
     return text
 def encode_basestring(s):
     """
     Return a JSON representation of a Python string
     """
     def replace(match):
         return ESCAPE_DCT[match.group(0)]
     return '"' + ESCAPE.sub(replace, s) + '"'
 def py_encode_basestring_ascii(s):
     if isinstance(s, str) and HAS_UTF8.search(s) is not None:
         s = s.decode('utf-8')
     def replace(match):
         s = match.group(0)
         try:
             return ESCAPE_DCT[s]
         except KeyError:
             n = ord(s)
             if n < 0x10000:
                 return '\\u%04x' % (n,)
             else:
                 # surrogate pair
                 n -= 0x10000
                 s1 = 0xd800 | ((n >> 10) & 0x3ff)
                 s2 = 0xdc00 | (n & 0x3ff)
                 return '\\u%04x\\u%04x' % (s1, s2)
     return '"' + str(ESCAPE_ASCII.sub(replace, s)) + '"'
 try:
     encode_basestring_ascii = c_encode_basestring_ascii
 except NameError:
     encode_basestring_ascii = py_encode_basestring_ascii
 class JSONEncoder(object):
     """
     Extensible JSON <http://json.org> encoder for Python data structures.
     Supports the following objects and types by default:
     +-------------------+---------------+
     | Python            | JSON          |
     +===================+===============+
     | dict              | object        |
     +-------------------+---------------+
     | list, tuple       | array         |
     +-------------------+---------------+
     | str, unicode      | string        |
     +-------------------+---------------+
     | int, long, float  | number        |
     +-------------------+---------------+
     | True              | true          |
     +-------------------+---------------+
     | False             | false         |
     +-------------------+---------------+
     | None              | null          |
     +-------------------+---------------+
     To extend this to recognize other objects, subclass and implement a
     ``.default()`` method with another method that returns a serializable
     object for ``o`` if possible, otherwise it should call the superclass
     implementation (to raise ``TypeError``).
     """
     __all__ = ['__init__', 'default', 'encode', 'iterencode']
     item_separator = ', '
     key_separator = ': '
     def __init__(self, skipkeys=False, ensure_ascii=True,
             check_circular=True, allow_nan=True, sort_keys=False,
             indent=None, separators=None, encoding='utf-8', default=None):
         """
         Constructor for JSONEncoder, with sensible defaults.
         If skipkeys is False, then it is a TypeError to attempt
         encoding of keys that are not str, int, long, float or None.  If
         skipkeys is True, such items are simply skipped.
         If ensure_ascii is True, the output is guaranteed to be str
         objects with all incoming unicode characters escaped.  If
         ensure_ascii is false, the output will be unicode object.
         If check_circular is True, then lists, dicts, and custom encoded
         objects will be checked for circular references during encoding to
         prevent an infinite recursion (which would cause an OverflowError).
         Otherwise, no such check takes place.
         If allow_nan is True, then NaN, Infinity, and -Infinity will be
         encoded as such.  This behavior is not JSON specification compliant,
         but is consistent with most JavaScript based encoders and decoders.
         Otherwise, it will be a ValueError to encode such floats.
         If sort_keys is True, then the output of dictionaries will be
         sorted by key; this is useful for regression tests to ensure
         that JSON serializations can be compared on a day-to-day basis.
         If indent is a non-negative integer, then JSON array
         elements and object members will be pretty-printed with that
         indent level.  An indent level of 0 will only insert newlines.
         None is the most compact representation.
         If specified, separators should be a (item_separator, key_separator)
         tuple.  The default is (', ', ': ').  To get the most compact JSON
         representation you should specify (',', ':') to eliminate whitespace.
         If specified, default is a function that gets called for objects
         that can't otherwise be serialized.  It should return a JSON encodable
         version of the object or raise a ``TypeError``.
         If encoding is not None, then all input strings will be
         transformed into unicode using that encoding prior to JSON-encoding.
         The default is UTF-8.
         """
         self.skipkeys = skipkeys
         self.ensure_ascii = ensure_ascii
         self.check_circular = check_circular
         self.allow_nan = allow_nan
         self.sort_keys = sort_keys
         self.indent = indent
         self.current_indent_level = 0
         if separators is not None:
             self.item_separator, self.key_separator = separators
         if default is not None:
             self.default = default
         self.encoding = encoding
     def _newline_indent(self):
         return '\n' + (' ' * (self.indent * self.current_indent_level))
     def _iterencode_list(self, lst, markers=None):
         if not lst:
             yield '[]'
             return
         if markers is not None:
             markerid = id(lst)
             if markerid in markers:
                 raise ValueError("Circular reference detected")
             markers[markerid] = lst
         yield '['
         if self.indent is not None:
             self.current_indent_level += 1
             newline_indent = self._newline_indent()
             separator = self.item_separator + newline_indent
             yield newline_indent
         else:
             newline_indent = None
             separator = self.item_separator
         first = True
         for value in lst:
             if first:
                 first = False
             else:
                 yield separator
             for chunk in self._iterencode(value, markers):
                 yield chunk
         if newline_indent is not None:
             self.current_indent_level -= 1
             yield self._newline_indent()
         yield ']'
         if markers is not None:
             del markers[markerid]
     def _iterencode_dict(self, dct, markers=None):
         if not dct:
             yield '{}'
             return
         if markers is not None:
             markerid = id(dct)
             if markerid in markers:
                 raise ValueError("Circular reference detected")
             markers[markerid] = dct
         yield '{'
         key_separator = self.key_separator
         if self.indent is not None:
             self.current_indent_level += 1
             newline_indent = self._newline_indent()
             item_separator = self.item_separator + newline_indent
             yield newline_indent
         else:
             newline_indent = None
             item_separator = self.item_separator
         first = True
         if self.ensure_ascii:
             encoder = encode_basestring_ascii
         else:
             encoder = encode_basestring
         allow_nan = self.allow_nan
         if self.sort_keys:
             keys = dct.keys()
             keys.sort()
             items = [(k, dct[k]) for k in keys]
         else:
             items = dct.iteritems()
         _encoding = self.encoding
         _do_decode = (_encoding is not None
             and not (_encoding == 'utf-8'))
         for key, value in items:
             if isinstance(key, str):
                 if _do_decode:
                     key = key.decode(_encoding)
             elif isinstance(key, basestring):
                 pass
             # JavaScript is weakly typed for these, so it makes sense to
             # also allow them.  Many encoders seem to do something like this.
             elif isinstance(key, float):
                 key = floatstr(key, allow_nan)
             elif isinstance(key, (int, long)):
                 key = str(key)
             elif key is True:
                 key = 'true'
             elif key is False:
                 key = 'false'
             elif key is None:
                 key = 'null'
             elif self.skipkeys:
                 continue
             else:
                 raise TypeError("key %r is not a string" % (key,))
             if first:
                 first = False
             else:
                 yield item_separator
             yield encoder(key)
             yield key_separator
             for chunk in self._iterencode(value, markers):
                 yield chunk
         if newline_indent is not None:
             self.current_indent_level -= 1
             yield self._newline_indent()
         yield '}'
         if markers is not None:
             del markers[markerid]
     def _iterencode(self, o, markers=None):
         if isinstance(o, basestring):
             if self.ensure_ascii:
                 encoder = encode_basestring_ascii
             else:
                 encoder = encode_basestring
             _encoding = self.encoding
             if (_encoding is not None and isinstance(o, str)
                     and not (_encoding == 'utf-8')):
                 o = o.decode(_encoding)
             yield encoder(o)
         elif o is None:
             yield 'null'
         elif o is True:
             yield 'true'
         elif o is False:
             yield 'false'
         elif isinstance(o, (int, long)):
             yield str(o)
         elif isinstance(o, float):
             yield floatstr(o, self.allow_nan)
         elif isinstance(o, (list, tuple)):
             for chunk in self._iterencode_list(o, markers):
                 yield chunk
         elif isinstance(o, dict):
             for chunk in self._iterencode_dict(o, markers):
                 yield chunk
         else:
             if markers is not None:
                 markerid = id(o)
                 if markerid in markers:
                     raise ValueError("Circular reference detected")
                 markers[markerid] = o
             for chunk in self._iterencode_default(o, markers):
                 yield chunk
             if markers is not None:
                 del markers[markerid]
     def _iterencode_default(self, o, markers=None):
         newobj = self.default(o)
         return self._iterencode(newobj, markers)
     def default(self, o):
         """
         Implement this method in a subclass such that it returns
         a serializable object for ``o``, or calls the base implementation
         (to raise a ``TypeError``).
         For example, to support arbitrary iterators, you could
         implement default like this::
             def default(self, o):
                 try:
                     iterable = iter(o)
                 except TypeError:
                     pass
                 else:
                     return list(iterable)
                 return JSONEncoder.default(self, o)
         """
         raise TypeError("%r is not JSON serializable" % (o,))
     def encode(self, o):
         """
         Return a JSON string representation of a Python data structure.
         >>> JSONEncoder().encode({"foo": ["bar", "baz"]})
         '{"foo": ["bar", "baz"]}'
         """
         # This is for extremely simple cases and benchmarks.
         if isinstance(o, basestring):
             if isinstance(o, str):
                 _encoding = self.encoding
                 if (_encoding is not None
                         and not (_encoding == 'utf-8')):
                     o = o.decode(_encoding)
             if self.ensure_ascii:
                 return encode_basestring_ascii(o)
             else:
                 return encode_basestring(o)
         # This doesn't pass the iterator directly to ''.join() because the
         # exceptions aren't as detailed.  The list call should be roughly
         # equivalent to the PySequence_Fast that ''.join() would do.
         chunks = list(self.iterencode(o))
         return ''.join(chunks)
     def iterencode(self, o):
         """
         Encode the given object and yield each string
         representation as available.
         For example::
             for chunk in JSONEncoder().iterencode(bigobject):
                 mysocket.write(chunk)
         """
         if self.check_circular:
             markers = {}
         else:
             markers = None
         return self._iterencode(o, markers)
 __all__ = ['JSONEncoder']

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

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