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      1 # Protocol Buffers - Google's data interchange format
      2 # Copyright 2008 Google Inc.  All rights reserved.
      3 # https://developers.google.com/protocol-buffers/
      4 #
      5 # Redistribution and use in source and binary forms, with or without
      6 # modification, are permitted provided that the following conditions are
      7 # met:
      8 #
      9 #     * Redistributions of source code must retain the above copyright
     10 # notice, this list of conditions and the following disclaimer.
     11 #     * Redistributions in binary form must reproduce the above
     12 # copyright notice, this list of conditions and the following disclaimer
     13 # in the documentation and/or other materials provided with the
     14 # distribution.
     15 #     * Neither the name of Google Inc. nor the names of its
     16 # contributors may be used to endorse or promote products derived from
     17 # this software without specific prior written permission.
     18 #
     19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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     25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30 
     31 """Protocol message implementation hooks for C++ implementation.
     32 
     33 Contains helper functions used to create protocol message classes from
     34 Descriptor objects at runtime backed by the protocol buffer C++ API.
     35 """
     36 
     37 __author__ = 'tibell (at] google.com (Johan Tibell)'
     38 
     39 from google.protobuf.pyext import _message
     40 
     41 
     42 class 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