SDL_RWread and SDL2 Mixer Loading entire file into memory

Question

I am reading WAVE files into memory and then playing them whenever needed

I wrote this implementation for loading the file into memory:

SDL_RWops* RawData = SDL_RWFromFile("Demo.wav", "rb");

    if (!RawData)
    {
        Error::Set("Could not read music file");
        return;
    }

    const Sint64 DataSize = SDL_RWsize(RawData);

    Data = malloc(DataSize);

    if (!Data)
    {
        Error::Set("Failed to load music file");
        return;
    }

    SDL_RWread(RawData, Data, DataSize, 1);

    SDL_RWclose(RawData);

    music = Mix_LoadMUSType_RW(SDL_RWFromConstMem(Data, DataSize), MUS_NONE, true);

However I found a code example to load an entire file into memory and the code is a bit different:

SDL_RWops *rw = SDL_RWFromFile(filename, "rb");
    if (rw == NULL) return NULL;

    Sint64 res_size = SDL_RWsize(rw);
    char* res = (char*)malloc(res_size + 1);

    Sint64 nb_read_total = 0, nb_read = 1;
    char* buf = res;
    while (nb_read_total < res_size && nb_read != 0) {
        nb_read = SDL_RWread(rw, buf, 1, (res_size - nb_read_total));
        nb_read_total += nb_read;
        buf += nb_read;
    }
    SDL_RWclose(rw);
    if (nb_read_total != res_size) {
        free(res);
        return NULL;
    }

    res[nb_read_total] = '\0';
    return res;

Testing both of the codes.. I found that my implementation uses slightly more memory but both of them work ( Music is played )

So I want to know if there is any difference in both of them

And is my first method to load entire file into memory is right

Ref: https://wiki.libsdl.org/SDL_RWread