How to read partial message types generically from one proto to another proto.

[Manish Sharma]

I am trying to add a functionality to only save a small set of messages that are defined in a huge proto, where the definition of small set of messages will be defined by this another proto that the users will declare.

Example:

message LargeProto {

  optional int32 id = 1;     

  optional Type type = 2;

  optional Image img1 = 3;

  optional Image img2 = 4;

}

message SmallProto1 {

  optional int32 id = 1;     

  optional Type type = 2;

  optional Image img1 = 3;

}

message SmallProto2 {

  optional int32 id = 1;     

  optional Type type = 2;

  optional Image img2 = 4;

}

SmallProto1 = readFrom(LargeProto lp);

SmallProto2 = readFrom(LargeProto lp);

Do we have an already existing functionality that will allow us to only read specific messages from one proto to another proto without hardcoding all this in C++? Do we have some form of generic implementation available to do something as above?

[Manish Sharma]

Correction

SmallProto1 pr1 = readFrom(LargeProto lp);

SmallProto2 pr2 = readFrom(LargeProto lp);