void get_URL( const string& host, const string& path )
{
  TCPSocket socket {};
  socket.connect( Address( host, "http" ) );
  string data_send = "GET " + path + " HTTP/1.1\r\nHost: " + host + "\r\n" + "Connection: close\r\n\r\n";
  socket.write( data_send );
  while ( !socket.eof() ) {
    string result;
    socket.read( result );
    cout << result;
  }
  socket.close();
  // cerr << "Function called: get_URL(" << host << ", " << path << ")\n";
  // cerr << "Warning: get_URL() has not been implemented yet.\n";
}

class ByteStream
{
public:
  explicit ByteStream( uint64_t capacity );

  // Helper functions (provided) to access the ByteStream's Reader and Writer interfaces
  Reader& reader();
  const Reader& reader() const;
  Writer& writer();
  const Writer& writer() const;

  void set_error() { error_ = true; };       // Signal that the stream suffered an error.
  bool has_error() const { return error_; }; // Has the stream had an error?

protected:
  // Please add any additional state to the ByteStream here, and not to the Writer and Reader interfaces.
  uint64_t capacity_;
  bool error_ {};
  std::string buffer_ {};
  size_t total_push_ {};
  size_t total_pop_ {};
  bool closed {};
};

void Writer::push( string data )
{
  // 计算写入字节数
  size_t writing_size = std::min( data.size(), available_capacity() );
  buffer_ += data.substr( 0, writing_size );
  total_push_ += writing_size;
}

void Writer::close()
{
  // Your code here.
  closed = true;
}

bool Writer::is_closed() const
{
  return closed;
}

uint64_t Writer::available_capacity() const
{
  return capacity_ - buffer_.size();
}

uint64_t Writer::bytes_pushed() const
{
  return total_push_;
}

string_view Reader::peek() const
{
  return string_view( buffer_.data(), buffer_.size() );
}

void Reader::pop( uint64_t len )
{
  buffer_ = buffer_.substr( len );
  total_pop_ += len;
}

bool Reader::is_finished() const
{
  return closed && buffer_.empty();
}

uint64_t Reader::bytes_buffered() const
{
  return buffer_.size();
}

uint64_t Reader::bytes_popped() const
{
  return total_pop_;
}