text: # Protocol Buffers - Google's data interchange format
  # Copyright 2008 Google Inc.  All rights reserved.
  # https://developers.google.com/protocol-buffers/
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions are
  # met:
  #
  #     * Redistributions of source code must retain the above copyright
  # notice, this list of conditions and the following disclaimer.
  #     * Redistributions in binary form must reproduce the above
  # copyright notice, this list of conditions and the following disclaimer
  # in the documentation and/or other materials provided with the
  # distribution.
  #     * Neither the name of Google Inc. nor the names of its
  # contributors may be used to endorse or promote products derived from
  # this software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  """Contains routines for printing protocol messages in JSON format.
  
  Simple usage example:
  
    # Create a proto object and serialize it to a json format string.
    message = my_proto_pb2.MyMessage(foo='bar')
    json_string = json_format.MessageToJson(message)
  
    # Parse a json format string to proto object.
    message = json_format.Parse(json_string, my_proto_pb2.MyMessage())
  """
  
  __author__ = 'jieluo@google.com (Jie Luo)'
  
  # pylint: disable=g-statement-before-imports,g-import-not-at-top
  try:
    from collections import OrderedDict
  except ImportError:
    from ordereddict import OrderedDict  # PY26
  # pylint: enable=g-statement-before-imports,g-import-not-at-top
  
  import base64
  import json
  import math
  
  from operator import methodcaller
  
  import re
  import sys
  
  import six
  
  from google.protobuf import descriptor
  from google.protobuf import symbol_database
  
  
  _TIMESTAMPFOMAT = '%Y-%m-%dT%H:%M:%S'
  _INT_TYPES = frozenset([descriptor.FieldDescriptor.CPPTYPE_INT32,
                          descriptor.FieldDescriptor.CPPTYPE_UINT32,
                          descriptor.FieldDescriptor.CPPTYPE_INT64,
                          descriptor.FieldDescriptor.CPPTYPE_UINT64])
  _INT64_TYPES = frozenset([descriptor.FieldDescriptor.CPPTYPE_INT64,
                            descriptor.FieldDescriptor.CPPTYPE_UINT64])
  _FLOAT_TYPES = frozenset([descriptor.FieldDescriptor.CPPTYPE_FLOAT,
                            descriptor.FieldDescriptor.CPPTYPE_DOUBLE])
  _INFINITY = 'Infinity'
  _NEG_INFINITY = '-Infinity'
  _NAN = 'NaN'
  
  _UNPAIRED_SURROGATE_PATTERN = re.compile(six.u(
      r'[\ud800-\udbff](?![\udc00-\udfff])|(?<![\ud800-\udbff])[\udc00-\udfff]'
  ))
  
  _VALID_EXTENSION_NAME = re.compile(r'\[[a-zA-Z0-9\._]*\]$')
  
  
  class Error(Exception):
    """Top-level module error for json_format."""
  
  
  class SerializeToJsonError(Error):
    """Thrown if serialization to JSON fails."""
  
  
  class ParseError(Error):
    """Thrown in case of parsing error."""
  
  
  def MessageToJson(message,
                    including_default_value_fields=False,
                    preserving_proto_field_name=False,
                    indent=2,
                    sort_keys=False,
                    use_integers_for_enums=False):
    """Converts protobuf message to JSON format.
  
    Args:
      message: The protocol buffers message instance to serialize.
      including_default_value_fields: If True, singular primitive fields,
          repeated fields, and map fields will always be serialized.  If
          False, only serialize non-empty fields.  Singular message fields
          and oneof fields are not affected by this option.
      preserving_proto_field_name: If True, use the original proto field
          names as defined in the .proto file. If False, convert the field
          names to lowerCamelCase.
      indent: The JSON object will be pretty-printed with this indent level.
          An indent level of 0 or negative will only insert newlines.
      sort_keys: If True, then the output will be sorted by field names.
      use_integers_for_enums: If true, print integers instead of enum names.
  
    Returns:
      A string containing the JSON formatted protocol buffer message.
    """
    printer = _Printer(including_default_value_fields,
                       preserving_proto_field_name,
                       use_integers_for_enums)
    return printer.ToJsonString(message, indent, sort_keys)
  
  
  def MessageToDict(message,
                    including_default_value_fields=False,
                    preserving_proto_field_name=False,
                    use_integers_for_enums=False):
    """Converts protobuf message to a dictionary.
  
    When the dictionary is encoded to JSON, it conforms to proto3 JSON spec.
  
    Args:
      message: The protocol buffers message instance to serialize.
      including_default_value_fields: If True, singular primitive fields,
          repeated fields, and map fields will always be serialized.  If
          False, only serialize non-empty fields.  Singular message fields
          and oneof fields are not affected by this option.
      preserving_proto_field_name: If True, use the original proto field
          names as defined in the .proto file. If False, convert the field
          names to lowerCamelCase.
      use_integers_for_enums: If true, print integers instead of enum names.
  
    Returns:
      A dict representation of the protocol buffer message.
    """
    printer = _Printer(including_default_value_fields,
                       preserving_proto_field_name,
                       use_integers_for_enums)
    # pylint: disable=protected-access
    return printer._MessageToJsonObject(message)
  
  
  def _IsMapEntry(field):
    return (field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
            field.message_type.has_options and
            field.message_type.GetOptions().map_entry)
  
  
  class _Printer(object):
    """JSON format printer for protocol message."""
  
    def __init__(self,
                 including_default_value_fields=False,
                 preserving_proto_field_name=False,
                 use_integers_for_enums=False):
      self.including_default_value_fields = including_default_value_fields
      self.preserving_proto_field_name = preserving_proto_field_name
      self.use_integers_for_enums = use_integers_for_enums
  
    def ToJsonString(self, message, indent, sort_keys):
      js = self._MessageToJsonObject(message)
      return json.dumps(js, indent=indent, sort_keys=sort_keys)
  
    def _MessageToJsonObject(self, message):
      """Converts message to an object according to Proto3 JSON Specification."""
      message_descriptor = message.DESCRIPTOR
      full_name = message_descriptor.full_name
      if _IsWrapperMessage(message_descriptor):
        return self._WrapperMessageToJsonObject(message)
      if full_name in _WKTJSONMETHODS:
        return methodcaller(_WKTJSONMETHODS[full_name][0], message)(self)
      js = {}
      return self._RegularMessageToJsonObject(message, js)
  
    def _RegularMessageToJsonObject(self, message, js):
      """Converts normal message according to Proto3 JSON Specification."""
      fields = message.ListFields()
  
      try:
        for field, value in fields:
          if self.preserving_proto_field_name:
            name = field.name
          else:
            name = field.json_name
          if _IsMapEntry(field):
            # Convert a map field.
            v_field = field.message_type.fields_by_name['value']
            js_map = {}
            for key in value:
              if isinstance(key, bool):
                if key:
                  recorded_key = 'true'
                else:
                  recorded_key = 'false'
              else:
                recorded_key = key
              js_map[recorded_key] = self._FieldToJsonObject(
                  v_field, value[key])
            js[name] = js_map
          elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
            # Convert a repeated field.
            js[name] = [self._FieldToJsonObject(field, k)
                        for k in value]
          elif field.is_extension:
            f = field
            if (f.containing_type.GetOptions().message_set_wire_format and
                f.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
                f.label == descriptor.FieldDescriptor.LABEL_OPTIONAL):
              f = f.message_type
            name = '[%s.%s]' % (f.full_name, name)
            js[name] = self._FieldToJsonObject(field, value)
          else:
            js[name] = self._FieldToJsonObject(field, value)
  
        # Serialize default value if including_default_value_fields is True.
        if self.including_default_value_fields:
          message_descriptor = message.DESCRIPTOR
          for field in message_descriptor.fields:
            # Singular message fields and oneof fields will not be affected.
            if ((field.label != descriptor.FieldDescriptor.LABEL_REPEATED and
                 field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE) or
                field.containing_oneof):
              continue
            if self.preserving_proto_field_name:
              name = field.name
            else:
              name = field.json_name
            if name in js:
              # Skip the field which has been serailized already.
              continue
            if _IsMapEntry(field):
              js[name] = {}
            elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
              js[name] = []
            else:
              js[name] = self._FieldToJsonObject(field, field.default_value)
  
      except ValueError as e:
        raise SerializeToJsonError(
            'Failed to serialize {0} field: {1}.'.format(field.name, e))
  
      return js
  
    def _FieldToJsonObject(self, field, value):
      """Converts field value according to Proto3 JSON Specification."""
      if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
        return self._MessageToJsonObject(value)
      elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
        if self.use_integers_for_enums:
          return value
        enum_value = field.enum_type.values_by_number.get(value, None)
        if enum_value is not None:
          return enum_value.name
        else:
          if field.file.syntax == 'proto3':
            return value
          raise SerializeToJsonError('Enum field contains an integer value '
                                     'which can not mapped to an enum value.')
      elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_STRING:
        if field.type == descriptor.FieldDescriptor.TYPE_BYTES:
          # Use base64 Data encoding for bytes
          return base64.b64encode(value).decode('utf-8')
        else:
          return value
      elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_BOOL:
        return bool(value)
      elif field.cpp_type in _INT64_TYPES:
        return str(value)
      elif field.cpp_type in _FLOAT_TYPES:
        if math.isinf(value):
          if value < 0.0:
            return _NEG_INFINITY
          else:
            return _INFINITY
        if math.isnan(value):
          return _NAN
      return value
  
    def _AnyMessageToJsonObject(self, message):
      """Converts Any message according to Proto3 JSON Specification."""
      if not message.ListFields():
        return {}
      # Must print @type first, use OrderedDict instead of {}
      js = OrderedDict()
      type_url = message.type_url
      js['@type'] = type_url
      sub_message = _CreateMessageFromTypeUrl(type_url)
      sub_message.ParseFromString(message.value)
      message_descriptor = sub_message.DESCRIPTOR
      full_name = message_descriptor.full_name
      if _IsWrapperMessage(message_descriptor):
        js['value'] = self._WrapperMessageToJsonObject(sub_message)
        return js
      if full_name in _WKTJSONMETHODS:
        js['value'] = methodcaller(_WKTJSONMETHODS[full_name][0],
                                   sub_message)(self)
        return js
      return self._RegularMessageToJsonObject(sub_message, js)
  
    def _GenericMessageToJsonObject(self, message):
      """Converts message according to Proto3 JSON Specification."""
      # Duration, Timestamp and FieldMask have ToJsonString method to do the
      # convert. Users can also call the method directly.
      return message.ToJsonString()
  
    def _ValueMessageToJsonObject(self, message):
      """Converts Value message according to Proto3 JSON Specification."""
      which = message.WhichOneof('kind')
      # If the Value message is not set treat as null_value when serialize
      # to JSON. The parse back result will be different from original message.
      if which is None or which == 'null_value':
        return None
      if which == 'list_value':
        return self._ListValueMessageToJsonObject(message.list_value)
      if which == 'struct_value':
        value = message.struct_value
      else:
        value = getattr(message, which)
      oneof_descriptor = message.DESCRIPTOR.fields_by_name[which]
      return self._FieldToJsonObject(oneof_descriptor, value)
  
    def _ListValueMessageToJsonObject(self, message):
      """Converts ListValue message according to Proto3 JSON Specification."""
      return [self._ValueMessageToJsonObject(value)
              for value in message.values]
  
    def _StructMessageToJsonObject(self, message):
      """Converts Struct message according to Proto3 JSON Specification."""
      fields = message.fields
      ret = {}
      for key in fields:
        ret[key] = self._ValueMessageToJsonObject(fields[key])
      return ret
  
    def _WrapperMessageToJsonObject(self, message):
      return self._FieldToJsonObject(
          message.DESCRIPTOR.fields_by_name['value'], message.value)
  
  
  def _IsWrapperMessage(message_descriptor):
    return message_descriptor.file.name == 'google/protobuf/wrappers.proto'
  
  
  def _DuplicateChecker(js):
    result = {}
    for name, value in js:
      if name in result:
        raise ParseError('Failed to load JSON: duplicate key {0}.'.format(name))
      result[name] = value
    return result
  
  
  def _CreateMessageFromTypeUrl(type_url):
    # TODO(jieluo): Should add a way that users can register the type resolver
    # instead of the default one.
    db = symbol_database.Default()
    type_name = type_url.split('/')[-1]
    try:
      message_descriptor = db.pool.FindMessageTypeByName(type_name)
    except KeyError:
      raise TypeError(
          'Can not find message descriptor by type_url: {0}.'.format(type_url))
    message_class = db.GetPrototype(message_descriptor)
    return message_class()
  
  
  def Parse(text, message, ignore_unknown_fields=False):
    """Parses a JSON representation of a protocol message into a message.
  
    Args:
      text: Message JSON representation.
      message: A protocol buffer message to merge into.
      ignore_unknown_fields: If True, do not raise errors for unknown fields.
  
    Returns:
      The same message passed as argument.
  
    Raises::
      ParseError: On JSON parsing problems.
    """
    if not isinstance(text, six.text_type): text = text.decode('utf-8')
    try:
      js = json.loads(text, object_pairs_hook=_DuplicateChecker)
    except ValueError as e:
      raise ParseError('Failed to load JSON: {0}.'.format(str(e)))
    return ParseDict(js, message, ignore_unknown_fields)
  
  
  def ParseDict(js_dict, message, ignore_unknown_fields=False):
    """Parses a JSON dictionary representation into a message.
  
    Args:
      js_dict: Dict representation of a JSON message.
      message: A protocol buffer message to merge into.
      ignore_unknown_fields: If True, do not raise errors for unknown fields.
  
    Returns:
      The same message passed as argument.
    """
    parser = _Parser(ignore_unknown_fields)
    parser.ConvertMessage(js_dict, message)
    return message
  
  
  _INT_OR_FLOAT = six.integer_types + (float,)
  
  
  class _Parser(object):
    """JSON format parser for protocol message."""
  
    def __init__(self,
                 ignore_unknown_fields):
      self.ignore_unknown_fields = ignore_unknown_fields
  
    def ConvertMessage(self, value, message):
      """Convert a JSON object into a message.
  
      Args:
        value: A JSON object.
        message: A WKT or regular protocol message to record the data.
  
      Raises:
        ParseError: In case of convert problems.
      """
      message_descriptor = message.DESCRIPTOR
      full_name = message_descriptor.full_name
      if _IsWrapperMessage(message_descriptor):
        self._ConvertWrapperMessage(value, message)
      elif full_name in _WKTJSONMETHODS:
        methodcaller(_WKTJSONMETHODS[full_name][1], value, message)(self)
      else:
        self._ConvertFieldValuePair(value, message)
  
    def _ConvertFieldValuePair(self, js, message):
      """Convert field value pairs into regular message.
  
      Args:
        js: A JSON object to convert the field value pairs.
        message: A regular protocol message to record the data.
  
      Raises:
        ParseError: In case of problems converting.
      """
      names = []
      message_descriptor = message.DESCRIPTOR
      fields_by_json_name = dict((f.json_name, f)
                                 for f in message_descriptor.fields)
      for name in js:
        try:
          field = fields_by_json_name.get(name, None)
          if not field:
            field = message_descriptor.fields_by_name.get(name, None)
          if not field and _VALID_EXTENSION_NAME.match(name):
            if not message_descriptor.is_extendable:
              raise ParseError('Message type {0} does not have extensions'.format(
                  message_descriptor.full_name))
            identifier = name[1:-1]  # strip [] brackets
            identifier = '.'.join(identifier.split('.')[:-1])
            # pylint: disable=protected-access
            field = message.Extensions._FindExtensionByName(identifier)
            # pylint: enable=protected-access
          if not field:
            if self.ignore_unknown_fields:
              continue
            raise ParseError(
                ('Message type "{0}" has no field named "{1}".\n'
                 ' Available Fields(except extensions): {2}').format(
                     message_descriptor.full_name, name,
                     [f.json_name for f in message_descriptor.fields]))
          if name in names:
            raise ParseError('Message type "{0}" should not have multiple '
                             '"{1}" fields.'.format(
                                 message.DESCRIPTOR.full_name, name))
          names.append(name)
          # Check no other oneof field is parsed.
          if field.containing_oneof is not None:
            oneof_name = field.containing_oneof.name
            if oneof_name in names:
              raise ParseError('Message type "{0}" should not have multiple '
                               '"{1}" oneof fields.'.format(
                                   message.DESCRIPTOR.full_name, oneof_name))
            names.append(oneof_name)
  
          value = js[name]
          if value is None:
            if (field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE
                and field.message_type.full_name == 'google.protobuf.Value'):
              sub_message = getattr(message, field.name)
              sub_message.null_value = 0
            else:
              message.ClearField(field.name)
            continue
  
          # Parse field value.
          if _IsMapEntry(field):
            message.ClearField(field.name)
            self._ConvertMapFieldValue(value, message, field)
          elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
            message.ClearField(field.name)
            if not isinstance(value, list):
              raise ParseError('repeated field {0} must be in [] which is '
                               '{1}.'.format(name, value))
            if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
              # Repeated message field.
              for item in value:
                sub_message = getattr(message, field.name).add()
                # None is a null_value in Value.
                if (item is None and
                    sub_message.DESCRIPTOR.full_name != 'google.protobuf.Value'):
                  raise ParseError('null is not allowed to be used as an element'
                                   ' in a repeated field.')
                self.ConvertMessage(item, sub_message)
            else:
              # Repeated scalar field.
              for item in value:
                if item is None:
                  raise ParseError('null is not allowed to be used as an element'
                                   ' in a repeated field.')
                getattr(message, field.name).append(
                    _ConvertScalarFieldValue(item, field))
          elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
            if field.is_extension:
              sub_message = message.Extensions[field]
            else:
              sub_message = getattr(message, field.name)
            sub_message.SetInParent()
            self.ConvertMessage(value, sub_message)
          else:
            setattr(message, field.name, _ConvertScalarFieldValue(value, field))
        except ParseError as e:
          if field and field.containing_oneof is None:
            raise ParseError('Failed to parse {0} field: {1}'.format(name, e))
          else:
            raise ParseError(str(e))
        except ValueError as e:
          raise ParseError('Failed to parse {0} field: {1}.'.format(name, e))
        except TypeError as e:
          raise ParseError('Failed to parse {0} field: {1}.'.format(name, e))
  
    def _ConvertAnyMessage(self, value, message):
      """Convert a JSON representation into Any message."""
      if isinstance(value, dict) and not value:
        return
      try:
        type_url = value['@type']
      except KeyError:
        raise ParseError('@type is missing when parsing any message.')
  
      sub_message = _CreateMessageFromTypeUrl(type_url)
      message_descriptor = sub_message.DESCRIPTOR
      full_name = message_descriptor.full_name
      if _IsWrapperMessage(message_descriptor):
        self._ConvertWrapperMessage(value['value'], sub_message)
      elif full_name in _WKTJSONMETHODS:
        methodcaller(
            _WKTJSONMETHODS[full_name][1], value['value'], sub_message)(self)
      else:
        del value['@type']
        self._ConvertFieldValuePair(value, sub_message)
      # Sets Any message
      message.value = sub_message.SerializeToString()
      message.type_url = type_url
  
    def _ConvertGenericMessage(self, value, message):
      """Convert a JSON representation into message with FromJsonString."""
      # Duration, Timestamp, FieldMask have a FromJsonString method to do the
      # conversion. Users can also call the method directly.
      message.FromJsonString(value)
  
    def _ConvertValueMessage(self, value, message):
      """Convert a JSON representation into Value message."""
      if isinstance(value, dict):
        self._ConvertStructMessage(value, message.struct_value)
      elif isinstance(value, list):
        self. _ConvertListValueMessage(value, message.list_value)
      elif value is None:
        message.null_value = 0
      elif isinstance(value, bool):
        message.bool_value = value
      elif isinstance(value, six.string_types):
        message.string_value = value
      elif isinstance(value, _INT_OR_FLOAT):
        message.number_value = value
      else:
        raise ParseError('Unexpected type for Value message.')
  
    def _ConvertListValueMessage(self, value, message):
      """Convert a JSON representation into ListValue message."""
      if not isinstance(value, list):
        raise ParseError(
            'ListValue must be in [] which is {0}.'.format(value))
      message.ClearField('values')
      for item in value:
        self._ConvertValueMessage(item, message.values.add())
  
    def _ConvertStructMessage(self, value, message):
      """Convert a JSON representation into Struct message."""
      if not isinstance(value, dict):
        raise ParseError(
            'Struct must be in a dict which is {0}.'.format(value))
      for key in value:
        self._ConvertValueMessage(value[key], message.fields[key])
      return
  
    def _ConvertWrapperMessage(self, value, message):
      """Convert a JSON representation into Wrapper message."""
      field = message.DESCRIPTOR.fields_by_name['value']
      setattr(message, 'value', _ConvertScalarFieldValue(value, field))
  
    def _ConvertMapFieldValue(self, value, message, field):
      """Convert map field value for a message map field.
  
      Args:
        value: A JSON object to convert the map field value.
        message: A protocol message to record the converted data.
        field: The descriptor of the map field to be converted.
  
      Raises:
        ParseError: In case of convert problems.
      """
      if not isinstance(value, dict):
        raise ParseError(
            'Map field {0} must be in a dict which is {1}.'.format(
                field.name, value))
      key_field = field.message_type.fields_by_name['key']
      value_field = field.message_type.fields_by_name['value']
      for key in value:
        key_value = _ConvertScalarFieldValue(key, key_field, True)
        if value_field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
          self.ConvertMessage(value[key], getattr(
              message, field.name)[key_value])
        else:
          getattr(message, field.name)[key_value] = _ConvertScalarFieldValue(
              value[key], value_field)
  
  
  def _ConvertScalarFieldValue(value, field, require_str=False):
    """Convert a single scalar field value.
  
    Args:
      value: A scalar value to convert the scalar field value.
      field: The descriptor of the field to convert.
      require_str: If True, the field value must be a str.
  
    Returns:
      The converted scalar field value
  
    Raises:
      ParseError: In case of convert problems.
    """
    if field.cpp_type in _INT_TYPES:
      return _ConvertInteger(value)
    elif field.cpp_type in _FLOAT_TYPES:
      return _ConvertFloat(value)
    elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_BOOL:
      return _ConvertBool(value, require_str)
    elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_STRING:
      if field.type == descriptor.FieldDescriptor.TYPE_BYTES:
        return base64.b64decode(value)
      else:
        # Checking for unpaired surrogates appears to be unreliable,
        # depending on the specific Python version, so we check manually.
        if _UNPAIRED_SURROGATE_PATTERN.search(value):
          raise ParseError('Unpaired surrogate')
        return value
    elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
      # Convert an enum value.
      enum_value = field.enum_type.values_by_name.get(value, None)
      if enum_value is None:
        try:
          number = int(value)
          enum_value = field.enum_type.values_by_number.get(number, None)
        except ValueError:
          raise ParseError('Invalid enum value {0} for enum type {1}.'.format(
              value, field.enum_type.full_name))
        if enum_value is None:
          if field.file.syntax == 'proto3':
            # Proto3 accepts unknown enums.
            return number
          raise ParseError('Invalid enum value {0} for enum type {1}.'.format(
              value, field.enum_type.full_name))
      return enum_value.number
  
  
  def _ConvertInteger(value):
    """Convert an integer.
  
    Args:
      value: A scalar value to convert.
  
    Returns:
      The integer value.
  
    Raises:
      ParseError: If an integer couldn't be consumed.
    """
    if isinstance(value, float) and not value.is_integer():
      raise ParseError('Couldn\'t parse integer: {0}.'.format(value))
  
    if isinstance(value, six.text_type) and value.find(' ') != -1:
      raise ParseError('Couldn\'t parse integer: "{0}".'.format(value))
  
    return int(value)
  
  
  def _ConvertFloat(value):
    """Convert an floating point number."""
    if value == 'nan':
      raise ParseError('Couldn\'t parse float "nan", use "NaN" instead.')
    try:
      # Assume Python compatible syntax.
      return float(value)
    except ValueError:
      # Check alternative spellings.
      if value == _NEG_INFINITY:
        return float('-inf')
      elif value == _INFINITY:
        return float('inf')
      elif value == _NAN:
        return float('nan')
      else:
        raise ParseError('Couldn\'t parse float: {0}.'.format(value))
  
  
  def _ConvertBool(value, require_str):
    """Convert a boolean value.
  
    Args:
      value: A scalar value to convert.
      require_str: If True, value must be a str.
  
    Returns:
      The bool parsed.
  
    Raises:
      ParseError: If a boolean value couldn't be consumed.
    """
    if require_str:
      if value == 'true':
        return True
      elif value == 'false':
        return False
      else:
        raise ParseError('Expected "true" or "false", not {0}.'.format(value))
  
    if not isinstance(value, bool):
      raise ParseError('Expected true or false without quotes.')
    return value
  
  _WKTJSONMETHODS = {
      'google.protobuf.Any': ['_AnyMessageToJsonObject',
                              '_ConvertAnyMessage'],
      'google.protobuf.Duration': ['_GenericMessageToJsonObject',
                                   '_ConvertGenericMessage'],
      'google.protobuf.FieldMask': ['_GenericMessageToJsonObject',
                                    '_ConvertGenericMessage'],
      'google.protobuf.ListValue': ['_ListValueMessageToJsonObject',
                                    '_ConvertListValueMessage'],
      'google.protobuf.Struct': ['_StructMessageToJsonObject',
                                 '_ConvertStructMessage'],
      'google.protobuf.Timestamp': ['_GenericMessageToJsonObject',
                                    '_ConvertGenericMessage'],
      'google.protobuf.Value': ['_ValueMessageToJsonObject',
                                '_ConvertValueMessage']
  }
  