73 lines
2.4 KiB
Python
73 lines
2.4 KiB
Python
|
# Protocol Buffers - Google's data interchange format
|
||
|
|
# Copyright 2008 Google Inc. All rights reserved.
|
||
|
|
#
|
||
|
|
# Use of this source code is governed by a BSD-style
|
||
|
|
# license that can be found in the LICENSE file or at
|
||
|
|
# https://developers.google.com/open-source/licenses/bsd
|
||
|
|
|
||
|
|
# This code is meant to work on Python 2.4 and above only.
|
||
|
|
|
||
|
|
"""Contains a metaclass and helper functions used to create
|
||
|
|
protocol message classes from Descriptor objects at runtime.
|
||
|
|
|
||
|
|
Recall that a metaclass is the "type" of a class.
|
||
|
|
(A class is to a metaclass what an instance is to a class.)
|
||
|
|
|
||
|
|
In this case, we use the GeneratedProtocolMessageType metaclass
|
||
|
|
to inject all the useful functionality into the classes
|
||
|
|
output by the protocol compiler at compile-time.
|
||
|
|
|
||
|
|
The upshot of all this is that the real implementation
|
||
|
|
details for ALL pure-Python protocol buffers are *here in
|
||
|
|
this file*.
|
||
|
|
"""
|
||
|
|
|
||
|
|
__author__ = 'robinson@google.com (Will Robinson)'
|
||
|
|
|
||
|
|
|
||
|
|
from google.protobuf import message_factory
|
||
|
|
from google.protobuf import symbol_database
|
||
|
|
|
||
|
|
# The type of all Message classes.
|
||
|
|
# Part of the public interface, but normally only used by message factories.
|
||
|
|
GeneratedProtocolMessageType = message_factory._GENERATED_PROTOCOL_MESSAGE_TYPE
|
||
|
|
|
||
|
|
MESSAGE_CLASS_CACHE = {}
|
||
|
|
|
||
|
|
|
||
|
|
# Deprecated. Please NEVER use reflection.ParseMessage().
|
||
|
|
def ParseMessage(descriptor, byte_str):
|
||
|
|
"""Generate a new Message instance from this Descriptor and a byte string.
|
||
|
|
|
||
|
|
DEPRECATED: ParseMessage is deprecated because it is using MakeClass().
|
||
|
|
Please use MessageFactory.GetPrototype() instead.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
descriptor: Protobuf Descriptor object
|
||
|
|
byte_str: Serialized protocol buffer byte string
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
Newly created protobuf Message object.
|
||
|
|
"""
|
||
|
|
result_class = MakeClass(descriptor)
|
||
|
|
new_msg = result_class()
|
||
|
|
new_msg.ParseFromString(byte_str)
|
||
|
|
return new_msg
|
||
|
|
|
||
|
|
|
||
|
|
# Deprecated. Please NEVER use reflection.MakeClass().
|
||
|
|
def MakeClass(descriptor):
|
||
|
|
"""Construct a class object for a protobuf described by descriptor.
|
||
|
|
|
||
|
|
DEPRECATED: use MessageFactory.GetPrototype() instead.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
descriptor: A descriptor.Descriptor object describing the protobuf.
|
||
|
|
Returns:
|
||
|
|
The Message class object described by the descriptor.
|
||
|
|
"""
|
||
|
|
# Original implementation leads to duplicate message classes, which won't play
|
||
|
|
# well with extensions. Message factory info is also missing.
|
||
|
|
# Redirect to message_factory.
|
||
|
|
return message_factory.GetMessageClass(descriptor)
|