错误:块编码中的非法或丢失十六进制序列

Question

我正在编写我自己的http服务器，现在我正在尝试修改块传输编码。我的尝试是这样的：

void HttpServer::SendRespons(HttpServer::Connection &socket_) noexcept {
  int sent = 0;
  int counter = 0;
  int index = 0;
  std::size_t response_size_;
  std::ifstream t(this->conf_.GetRootPath() + socket_.data);
  socket_.respons = {(std::istreambuf_iterator<char>(t)),
                     std::istreambuf_iterator<char>()};
  t.clear();
  response_size_ = socket_.respons.size();
  std::vector<std::string> strVec;
  strVec.reserve(socket_.respons.size() / BUFSIZE + 2);
  strVec.push_back(
      "HTTP/1.1 200 OK\r\nServer: http\r\nContent-Type: "
      "text/html\r\nTransfer-Encoding: "
      "chunked\r\nConnection: Keep-Alive\r\n\r\n");
  while (index + 16374 < static_cast<int>(response_size_)) {
    strVec.push_back("3ff6\r\n" + socket_.respons.substr(index, 16374) +
                     "\r\n\r\n");
    index += 16374;
  }
  std::stringstream stream;
  stream << std::hex
         << std::atoi(std::to_string(response_size_ - index).c_str());
  strVec.push_back(stream.str() + "\r\n" +
                   socket_.respons.substr(index, response_size_ - index) +
                   "\r\n\r\n");
  strVec.push_back("0\r\n\r\n");
  index = 0;
  response_size_ += (strVec[0].size() + strVec[strVec.size() - 1].size());

  std::lock_guard<std::mutex> lg(this->connected_clients_mux_);
  while (index < static_cast<int>(strVec.size())) {
    int len =
        write(socket_.socket, (char *)&strVec[index][0], strVec[index].size());

    if (len < 0) {
      //...
      } else if ((errno == EPIPE) || (errno == ECONNRESET)) {
        std::cout << __FILE__ << " " << __func__
                  << " sent stop (epipe || econreset), len= " << len << " "
                  << "error #" << errno << std::endl;
        break;
      //...
    }
    ++index;
    sent += len;
    std::cout << __FILE__ << " " << __func__ << " sent " << len << " "
              << "packet #" << ++counter << std::endl;
  }
  std::cout << std::endl
            << __FILE__ << " " << __func__
            << " assumed length:" << response_size_
            << " sent:" << sent << " to: " << socket_.socket << std::endl;
}

上面的函数应该读取文件，将其分割成几个部分，然后一个一个地传递。据我所知，分片进行得很好，但当试图发送文件时：

curl -v http://localhost:8080/filename

我得到了：

*   Trying 127.0.0.1:8080...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /filename HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.68.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Server: http
< Content-Type: text/html
< Transfer-Encoding: chunked
< Connection: Keep-Alive
< 
//.... here is first chunk
* Illegal or missing hexadecimal sequence in chunked-encoding
* Closing connection 0
curl: (56) Illegal or missing hexadecimal sequence in chunked-encoding

如您所见，客户端接收响应的第一部分(头)并处理它们。之后-它期待消息的正文。收到它的第一部分后，连接被关闭。我知道错误就像在消息中以我自己的块的格式写的那样，但是我自己不知道确切的位置。我听从了encoding#Format的指示，但obv犯了一个错误。由于客户端没有输出它所期望的十六进制序列的任何内容，所以它接收并错误地考虑到的十六进制序列没有输出，因此我请求帮助。

Answer 1

我认为在这部分代码的末尾只需要一个\r\n。

    strVec.push_back("3ff6\r\n" + socket_.respons.substr(index, 16374) +
                     "\r\n\r\n");

不应该在前一个块和下一个块的十六进制大小之间插入空行。(最后一块也是如此)

您提供的维基百科页面在示例中的块之间插入空行，只是为了增加可读性，但实际上并不发送这些空行。