I need to serialize a thrift struct in C (glib) such that I can deserialize it in python. Note that I am using my own transport here.

Suppose I have a structed defined in thrift such as the following:

struct frame_header_s {
    1: required i32 pattern = FRAME_PATTERN,
    2: required i16 header_length,
    3: required i32 frame_index,
    4: required frame_type_e type,
    5: required i32 frame_length_bytes
}

I can serialize/deserialize this header in python as follows:

from thrift.TSerialization import serialize, deserialize
import gen.ttypes as gen_types

def ser_deser_bytes():
    hdr = gen_types.frame_header_s()
    hdr.pattern = 0x5a5a5a5a
    hdr.frame_index = 89
    hdr.type = gen_types.frame_type_e.T1
    hdr.frame_length_bytes = 1000
    tst = serialize(hdr)
    des = deserialize(gen_types.frame_header_s(), tst)
    assert des.pattern == hdr.pattern, 'test didnt work'
    assert des.frame_length_bytes == hdr.frame_length_bytes, 'test didnt work'
    print('test worked')

if __name__ == '__main__':
    ser_deser_bytes()

But when I try and use a naive approach of serializing the generated struct in C such as:

#include "gen-c_glib/gen.h"

frame_header_s *frame_header;

void server_test()
{
  frame_header = g_object_new(TYPE_FRAME_HEADER_S, NULL);
  frame_header->header_length = sizeof(frame_header_s);
  // TCP send
  int sent = send(fd, (uint8_T*)frame_header, sizeof(frame_header_s));
  // etc.
}

I get the following error when I attempt to deserialize the data on the client in python:

thrift.protocol.TProtocol.TProtocolException: invalid TType

I am sure I am doing something wrong in my naive serialization in C, but I can’t find any document for thrift that gives me the kind of detail that I need. I would really appreciate any insight.