def get_http_chunk(params, offset):
    for i in range(MAX_RETRIES_ON_404):
        try:
            link = generate_link(params)
            http_response = do_http_request(link, headers = { "Range": "bytes={}-".format(offset) })
            total_length = get_total_length_from_content_range_header(http_response)
            return http_response.data(), total_length
        except HttpError as e:
            if e.code != 404:
                 raise
    raise NuNeSmogla()

def get_file(params):
    data = bytearray()
    for i in range(MAX_DOWNLOAD_ATTEMPTS):
        new_data, total_length = get_http_chunk(params, offset=len(data))
        data.append(new_data)
        if len(data) == total_length:
            return data
    raise NuNeSmogla()

for ( result = read_internet_file(generate_link()); 
      result == http_code::not_found; 
      result = read_internet_file(generate_link()) )
{ 
  log( "Yet another try..." ); 
}

if ( result != http_code::ok200 )
  throw http_exception( result );

J>void f()
J>{
J>    // declare collect & progress var's

J>repeat:

J>    generate_link()

J>    try
J>    {
J>        read_internet_file(link)
J>    }

J>    catch (web_exception& e)
J>    {
J>        if (e.code == http_code::not_found)
J>        {
J>            goto repeat;
J>        }
J>        throw;
J>    }
J>}
J>

enum ReadInternetFileResult
{
  eNotFound,
  eSuccess
};


ReadInternetFileResult ReadInternetFile(LinkType& link)
{
    try
    {
        read_internet_file(link)
    }
    catch (web_exception& e)
    {
        if (e.code == http_code::not_found)
        {
            return eNotFound;
        }
        throw;
    }
    return eSuccess;
}


void f()
{
    // declare collect & progress var's

    do
    {
        generate_link();

    }while(eNotFound == ReadInternetFile(link));
}

EP>>Если тебе нравится вариант с goto, если тебе он кажется более понятным — используй его, не комплексуй (конечно если в твоей команде нет каких-то жёстких guidelines на эту тему).

repeat_until_whatever([&]
{
    generate_link();
    read_internet_file(link);
});

void f()
{
    // declare collect & progress var's

repeat:

    generate_link()

    try
    {
        read_internet_file(link)
    }

    catch (web_exception& e)
    {
        if (e.code == http_code::not_found)
        {
            goto repeat;
        }
        throw;
    }
}

void f()
{
    // declare collect & progress var's

    for (;;)
    {
        generate_link()

        try
        {
            read_internet_file(link)
            break
        }

        catch (web_exception& e)
        {
            if (e.code == http_code::not_found)
            {
                continue;
            }
            throw;
        }
    }
}

bool g(link)
{
    try
    {
        read_internet_file(link);
    }
    catch (web_exception& e)
    {
        if (e.code == http_code::not_found)
        {
            return false;
        }
        throw;
    }

    return true;
}

void f()
{
    // declare collect & progress var's

    for (;;)
    {
        generate_link();
        if (g(link))
            break;
    }
}

bool f(web_error *err)
{
  for (;;)
  {
    generate_link();
    if (read_internet_file(link, err))
      return true;
    else if (err->code==http_code::not_found)
      continue; 
    else
      return false;  
  }
  return true;
}

// ПОКА ФАЙЛ НЕ ПОЛУЧЕН
{
   // СГЕНЕРИТЬ ССЫЛКУ
   // ЗАПРОСИТЬ ФАЙЛ
}

SVZ>void f()
SVZ>{
SVZ>    // declare collect & progress var's

SVZ>    do
SVZ>    {
SVZ>        generate_link();
SVZ>        
SVZ>    } while (!read_internet_file(link));
SVZ>}
SVZ>

/**
Returns
true if file was read
false if file cannot be reached by generated link (error 404)
throws exception in case of other problem
*/
bool generate_and_read()
{
  auto link = generate_link();
  try
  {
    read_internet_file(link);
    return true;
  }
  catch (web_exception& e)
  {
    if (e.code == http_code::not_found)
      return false;
    throw;
  }

  //unreachable code
  return true;
}

void f()
{
  //here we can add limit for attempt number
   while (!generate_and_read())
   {
     //empty body
   }
}

void f()
{
    // declare collect & progress var's

    do
    {
        generate_link()

    } while (!read(link))

    auto read = []()
    {
        try
        {
            read_internet_file(link)
            return true
        }

        catch (web_exception& e)
        {
            if (e.code != http_code::not_found)
                throw
        }
        return false
    }
}

  if(! load_from_url( get_cur_url() ) ) {
    while( make_alterntive_url() && try_to_load_rest_of_file_from( get_cur_url() ) )
      ;
  }