This might be obvious, but I'm having trouble figuring out how to write into the middl

Example of serializing into the middle of a buffer? about bitsery HOT 1 CLOSED

fraillt commented on August 18, 2024

Example of serializing into the middle of a buffer?

from bitsery.

Comments (1)

fraillt commented on August 18, 2024

Hello,
Good question and it certainly is not obvious how to make it work.
Writing to output buffer happens through OutputBufferAdapter class, and it has a currentWritePos method, which does what you need.
IMPORTANT: keep in mind that writtenBytesCount will return the final position in the buffer.
Example: if you set currentWritePos to 10 and write 4 bytes, writtenBytesCount will return 14, not 4.
Here, is a modified main function of basic_usage example.

int main() {
    //set some random data
    MyStruct data{8941, MyEnum::V2, {15.0f, -8.5f, 0.045f}};
    MyStruct res{};
    data.tmp.push_back(data);

    //create buffer to store data
    Buffer buffer;

    size_t my_offset = 10;
    // create adapter manually, that later will be moved into serialized (serialized/deserializer always owns adapter)
    OutputAdapter adapter{buffer};
    // set offset (which in turn resizes buffer is necessary)
    adapter.currentWritePos(my_offset);
    // minus my_offset from actual returned value
    auto writtenSize = bitsery::quickSerialization<OutputAdapter>(std::move(adapter), data) - my_offset;
    // add our offset
    auto beginIt = buffer.begin() + my_offset;

    auto state = bitsery::quickDeserialization<InputAdapter>({beginIt, writtenSize}, res);

    assert(state.first == bitsery::ReaderError::NoError && state.second);
    assert(data.fs == res.fs && data.i == res.i && data.e == res.e);
}