src/third_party/protobuf-3/python/google/protobuf/json_format.py - cobalt - Git at Google

 # 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)'

 import base64
 import json
 import math
 import six
 import sys

 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'


 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):
   """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.

   Returns:
     A string containing the JSON formatted protocol buffer message.
   """
   js = _MessageToJsonObject(message, including_default_value_fields)
   return json.dumps(js, indent=2)


 def _MessageToJsonObject(message, including_default_value_fields):
   """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 _WrapperMessageToJsonObject(message)
   if full_name in _WKTJSONMETHODS:
     return _WKTJSONMETHODS[full_name][0](
         message, including_default_value_fields)
   js = {}
   return _RegularMessageToJsonObject(
       message, js, including_default_value_fields)


 def _IsMapEntry(field):
   return (field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
           field.message_type.has_options and
           field.message_type.GetOptions().map_entry)


 def _RegularMessageToJsonObject(message, js, including_default_value_fields):
   """Converts normal message according to Proto3 JSON Specification."""
   fields = message.ListFields()
   include_default = including_default_value_fields

   try:
     for field, value in fields:
       name = field.camelcase_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] = _FieldToJsonObject(
               v_field, value[key], including_default_value_fields)
         js[name] = js_map
       elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
         # Convert a repeated field.
         js[name] = [_FieldToJsonObject(field, k, include_default)
                     for k in value]
       else:
         js[name] = _FieldToJsonObject(field, value, include_default)

     # Serialize default value if including_default_value_fields is True.
     if 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
         name = field.camelcase_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] = _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(
     field, value, including_default_value_fields=False):
   """Converts field value according to Proto3 JSON Specification."""
   if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
     return _MessageToJsonObject(value, including_default_value_fields)
   elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
     enum_value = field.enum_type.values_by_number.get(value, None)
     if enum_value is not None:
       return enum_value.name
     else:
       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(message, including_default):
   """Converts Any message according to Proto3 JSON Specification."""
   if not message.ListFields():
     return {}
   js = {}
   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'] = _WrapperMessageToJsonObject(sub_message)
     return js
   if full_name in _WKTJSONMETHODS:
     js['value'] = _WKTJSONMETHODS[full_name][0](sub_message, including_default)
     return js
   return _RegularMessageToJsonObject(sub_message, js, including_default)


 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 _GenericMessageToJsonObject(message, unused_including_default):
   """Converts message by ToJsonString 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(message, unused_including_default=False):
   """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 _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 _FieldToJsonObject(oneof_descriptor, value)


 def _ListValueMessageToJsonObject(message, unused_including_default=False):
   """Converts ListValue message according to Proto3 JSON Specification."""
   return [_ValueMessageToJsonObject(value)
           for value in message.values]


 def _StructMessageToJsonObject(message, unused_including_default=False):
   """Converts Struct message according to Proto3 JSON Specification."""
   fields = message.fields
   ret = {}
   for key in fields:
     ret[key] = _ValueMessageToJsonObject(fields[key])
   return ret


 def _IsWrapperMessage(message_descriptor):
   return message_descriptor.file.name == 'google/protobuf/wrappers.proto'


 def _WrapperMessageToJsonObject(message):
   return _FieldToJsonObject(
       message.DESCRIPTOR.fields_by_name['value'], message.value)


 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 Parse(text, message):
   """Parses a JSON representation of a protocol message into a message.

   Args:
     text: Message JSON representation.
     message: A protocol beffer message to merge into.

   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:
     if sys.version_info < (2, 7):
       # object_pair_hook is not supported before python2.7
       js = json.loads(text)
     else:
       js = json.loads(text, object_pairs_hook=_DuplicateChecker)
   except ValueError as e:
     raise ParseError('Failed to load JSON: {0}.'.format(str(e)))
   _ConvertMessage(js, message)
   return message


 def _ConvertFieldValuePair(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
   for name in js:
     try:
       field = message_descriptor.fields_by_camelcase_name.get(name, None)
       if not field:
         raise ParseError(
             'Message type "{0}" has no field named "{1}".'.format(
                 message_descriptor.full_name, name))
       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:
         message.ClearField(field.name)
         continue

       # Parse field value.
       if _IsMapEntry(field):
         message.ClearField(field.name)
         _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.')
             _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:
         sub_message = getattr(message, field.name)
         _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 _ConvertMessage(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):
     _ConvertWrapperMessage(value, message)
   elif full_name in _WKTJSONMETHODS:
     _WKTJSONMETHODS[full_name][1](value, message)
   else:
     _ConvertFieldValuePair(value, message)


 def _ConvertAnyMessage(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):
     _ConvertWrapperMessage(value['value'], sub_message)
   elif full_name in _WKTJSONMETHODS:
     _WKTJSONMETHODS[full_name][1](value['value'], sub_message)
   else:
     del value['@type']
     _ConvertFieldValuePair(value, sub_message)
   # Sets Any message
   message.value = sub_message.SerializeToString()
   message.type_url = type_url


 def _ConvertGenericMessage(value, message):
   """Convert a JSON representation into message with FromJsonString."""
   # Durantion, Timestamp, FieldMask have FromJsonString method to do the
   # convert. Users can also call the method directly.
   message.FromJsonString(value)


 _INT_OR_FLOAT = six.integer_types + (float,)


 def _ConvertValueMessage(value, message):
   """Convert a JSON representation into Value message."""
   if isinstance(value, dict):
     _ConvertStructMessage(value, message.struct_value)
   elif isinstance(value, list):
     _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(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:
     _ConvertValueMessage(item, message.values.add())


 def _ConvertStructMessage(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:
     _ConvertValueMessage(value[key], message.fields[key])
   return


 def _ConvertWrapperMessage(value, message):
   """Convert a JSON representation into Wrapper message."""
   field = message.DESCRIPTOR.fields_by_name['value']
   setattr(message, 'value', _ConvertScalarFieldValue(value, field))


 def _ConvertMapFieldValue(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:
       _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:
       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:
       raise ParseError(
           'Enum value must be a string literal with double quotes. '
           'Type "{0}" has no value named {1}.'.format(
               field.enum_type.full_name, value))
     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):
     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]
 }
	# 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)'

	import base64
	import json
	import math
	import six
	import sys

	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'


	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):
	"""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.

	Returns:
	A string containing the JSON formatted protocol buffer message.
	"""
	js = _MessageToJsonObject(message, including_default_value_fields)
	return json.dumps(js, indent=2)


	def _MessageToJsonObject(message, including_default_value_fields):
	"""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 _WrapperMessageToJsonObject(message)
	if full_name in _WKTJSONMETHODS:
	return _WKTJSONMETHODS[full_name][0](
	message, including_default_value_fields)
	js = {}
	return _RegularMessageToJsonObject(
	message, js, including_default_value_fields)


	def _IsMapEntry(field):
	return (field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
	field.message_type.has_options and
	field.message_type.GetOptions().map_entry)


	def _RegularMessageToJsonObject(message, js, including_default_value_fields):
	"""Converts normal message according to Proto3 JSON Specification."""
	fields = message.ListFields()
	include_default = including_default_value_fields

	try:
	for field, value in fields:
	name = field.camelcase_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] = _FieldToJsonObject(
	v_field, value[key], including_default_value_fields)
	js[name] = js_map
	elif field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
	# Convert a repeated field.
	js[name] = [_FieldToJsonObject(field, k, include_default)
	for k in value]
	else:
	js[name] = _FieldToJsonObject(field, value, include_default)

	# Serialize default value if including_default_value_fields is True.
	if 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
	name = field.camelcase_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] = _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(
	field, value, including_default_value_fields=False):
	"""Converts field value according to Proto3 JSON Specification."""
	if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
	return _MessageToJsonObject(value, including_default_value_fields)
	elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
	enum_value = field.enum_type.values_by_number.get(value, None)
	if enum_value is not None:
	return enum_value.name
	else:
	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(message, including_default):
	"""Converts Any message according to Proto3 JSON Specification."""
	if not message.ListFields():
	return {}
	js = {}
	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'] = _WrapperMessageToJsonObject(sub_message)
	return js
	if full_name in _WKTJSONMETHODS:
	js['value'] = _WKTJSONMETHODS[full_name][0](sub_message, including_default)
	return js
	return _RegularMessageToJsonObject(sub_message, js, including_default)


	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 _GenericMessageToJsonObject(message, unused_including_default):
	"""Converts message by ToJsonString 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(message, unused_including_default=False):
	"""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 _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 _FieldToJsonObject(oneof_descriptor, value)


	def _ListValueMessageToJsonObject(message, unused_including_default=False):
	"""Converts ListValue message according to Proto3 JSON Specification."""
	return [_ValueMessageToJsonObject(value)
	for value in message.values]


	def _StructMessageToJsonObject(message, unused_including_default=False):
	"""Converts Struct message according to Proto3 JSON Specification."""
	fields = message.fields
	ret = {}
	for key in fields:
	ret[key] = _ValueMessageToJsonObject(fields[key])
	return ret


	def _IsWrapperMessage(message_descriptor):
	return message_descriptor.file.name == 'google/protobuf/wrappers.proto'


	def _WrapperMessageToJsonObject(message):
	return _FieldToJsonObject(
	message.DESCRIPTOR.fields_by_name['value'], message.value)


	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 Parse(text, message):
	"""Parses a JSON representation of a protocol message into a message.

	Args:
	text: Message JSON representation.
	message: A protocol beffer message to merge into.

	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:
	if sys.version_info < (2, 7):
	# object_pair_hook is not supported before python2.7
	js = json.loads(text)
	else:
	js = json.loads(text, object_pairs_hook=_DuplicateChecker)
	except ValueError as e:
	raise ParseError('Failed to load JSON: {0}.'.format(str(e)))
	_ConvertMessage(js, message)
	return message


	def _ConvertFieldValuePair(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
	for name in js:
	try:
	field = message_descriptor.fields_by_camelcase_name.get(name, None)
	if not field:
	raise ParseError(
	'Message type "{0}" has no field named "{1}".'.format(
	message_descriptor.full_name, name))
	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:
	message.ClearField(field.name)
	continue

	# Parse field value.
	if _IsMapEntry(field):
	message.ClearField(field.name)
	_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.')
	_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:
	sub_message = getattr(message, field.name)
	_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 _ConvertMessage(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):
	_ConvertWrapperMessage(value, message)
	elif full_name in _WKTJSONMETHODS:
	_WKTJSONMETHODS[full_name][1](value, message)
	else:
	_ConvertFieldValuePair(value, message)


	def _ConvertAnyMessage(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):
	_ConvertWrapperMessage(value['value'], sub_message)
	elif full_name in _WKTJSONMETHODS:
	_WKTJSONMETHODS[full_name][1](value['value'], sub_message)
	else:
	del value['@type']
	_ConvertFieldValuePair(value, sub_message)
	# Sets Any message
	message.value = sub_message.SerializeToString()
	message.type_url = type_url


	def _ConvertGenericMessage(value, message):
	"""Convert a JSON representation into message with FromJsonString."""
	# Durantion, Timestamp, FieldMask have FromJsonString method to do the
	# convert. Users can also call the method directly.
	message.FromJsonString(value)


	_INT_OR_FLOAT = six.integer_types + (float,)


	def _ConvertValueMessage(value, message):
	"""Convert a JSON representation into Value message."""
	if isinstance(value, dict):
	_ConvertStructMessage(value, message.struct_value)
	elif isinstance(value, list):
	_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(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:
	_ConvertValueMessage(item, message.values.add())


	def _ConvertStructMessage(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:
	_ConvertValueMessage(value[key], message.fields[key])
	return


	def _ConvertWrapperMessage(value, message):
	"""Convert a JSON representation into Wrapper message."""
	field = message.DESCRIPTOR.fields_by_name['value']
	setattr(message, 'value', _ConvertScalarFieldValue(value, field))


	def _ConvertMapFieldValue(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:
	_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:
	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:
	raise ParseError(
	'Enum value must be a string literal with double quotes. '
	'Type "{0}" has no value named {1}.'.format(
	field.enum_type.full_name, value))
	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):
	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]
	}