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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*.
z#robinson@google.com (Will Robinson)é )Úapi_implementation)ÚmessageZcpp)Ú cpp_message)Úpython_messagec C s t | ƒ}|ƒ }|j|ƒ |S )zêGenerate a new Message instance from this Descriptor and a byte string.
Args:
descriptor: Protobuf Descriptor object
byte_str: Serialized protocol buffer byte string
Returns:
Newly created protobuf Message object.
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descriptorZbyte_strZ result_classZnew_msg© r ú /usr/lib/python3.6/reflection.pyÚ ParseMessageC s
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c C sd | t krt | S i }x"| jjƒ D ]\}}t|ƒ||< q W | |tj< tt| jƒtj f|ƒ}|t | < |S )aŒ Construct a class object for a protobuf described by descriptor.
Composite descriptors are handled by defining the new class as a member of the
parent class, recursing as deep as necessary.
This is the dynamic equivalent to:
class Parent(message.Message):
__metaclass__ = GeneratedProtocolMessageType
DESCRIPTOR = descriptor
class Child(message.Message):
__metaclass__ = GeneratedProtocolMessageType
DESCRIPTOR = descriptor.nested_types[0]
Sample usage:
file_descriptor = descriptor_pb2.FileDescriptorProto()
file_descriptor.ParseFromString(proto2_string)
msg_descriptor = descriptor.MakeDescriptor(file_descriptor.message_type[0])
msg_class = reflection.MakeClass(msg_descriptor)
msg = msg_class()
Args:
descriptor: A descriptor.Descriptor object describing the protobuf.
Returns:
The Message class object described by the descriptor.
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__author__Zgoogle.protobuf.internalr Zgoogle.protobufr ZTypeZgoogle.protobuf.pyextr Z message_implr r
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