在 C++ 中从原始字节解码协议缓冲区

Question

I need to work with a protocol buffer input in my c++ function which is in raw bytes form. The tutorials inhttps://developers.google.com/protocol-buffers/docs/cpptutorial only mention serializing and parsing data to/from files. This is not my use case.

How can I decode a protocol buffer from raw bytes? I only have a pointer to the data and the size to work with. Preferably I don't want the data to be copied.

Answer 1

Google protobufs has a type bytes you could use. If in your case you need to transform it to another scalar type, you'll have to do that before sending it to protobuffs as the library does some stuff behind the scenes to make sure it's in the right bight order at its destination.

Answer 2

seems to work now if I do it this way:

    uint8* buffer = (uint8*) theBytesPnt;

    CodedInputStream* codedStream = new CodedInputStream(buffer, nBytes );
    EquityPredParams* message = new myGeneratedProtoClass();

    bool_success = message->ParseFromCodedStream(codedStream);

    magicallyObtainedNum = message->people(1).id();

where the people class is defined in the .proto file as in the google tutorial.