cpp_message.py revision b0575e93e4c39dec69365b850088a1eb7f82c5b3 
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30
31"""Protocol message implementation hooks for C++ implementation.
32
33Contains helper functions used to create protocol message classes from
34Descriptor objects at runtime backed by the protocol buffer C++ API.
35"""
36
37__author__ = 'tibell@google.com (Johan Tibell)'
38
39from google.protobuf.pyext import _message
40
41
42class GeneratedProtocolMessageType(_message.MessageMeta):
43
44  """Metaclass for protocol message classes created at runtime from Descriptors.
45
46  The protocol compiler currently uses this metaclass to create protocol
47  message classes at runtime.  Clients can also manually create their own
48  classes at runtime, as in this example:
49
50  mydescriptor = Descriptor(.....)
51  class MyProtoClass(Message):
52    __metaclass__ = GeneratedProtocolMessageType
53    DESCRIPTOR = mydescriptor
54  myproto_instance = MyProtoClass()
55  myproto.foo_field = 23
56  ...
57
58  The above example will not work for nested types. If you wish to include them,
59  use reflection.MakeClass() instead of manually instantiating the class in
60  order to create the appropriate class structure.
61  """
62
63  # Must be consistent with the protocol-compiler code in
64  # proto2/compiler/internal/generator.*.
65  _DESCRIPTOR_KEY = 'DESCRIPTOR'
66