C++ SyncReadStream::read_some方法代码示例

std::size_t read_until(SyncReadStream& s,
    boost::asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
    boost::system::error_code& ec)
{
  std::size_t search_position = 0;
  for (;;)
  {
    // Determine the range of the data to be searched.
    typedef typename boost::asio::basic_streambuf<
      Allocator>::const_buffers_type const_buffers_type;
    typedef boost::asio::buffers_iterator<const_buffers_type> iterator;
    const_buffers_type buffers = b.data();
    iterator begin = iterator::begin(buffers);
    iterator start_pos = begin + search_position;
    iterator end = iterator::end(buffers);

    // Look for a match.
    boost::match_results<iterator,
      typename std::vector<boost::sub_match<iterator> >::allocator_type>
        match_results;
    if (regex_search(start_pos, end, match_results, expr,
          boost::match_default | boost::match_partial))
    {
      if (match_results[0].matched)
      {
        // Full match. We're done.
        ec = boost::system::error_code();
        return match_results[0].second - begin;
      }
      else
      {
        // Partial match. Next search needs to start from beginning of match.
        search_position = match_results[0].first - begin;
      }
    }
    else
    {
      // No match. Next search can start with the new data.
      search_position = end - begin;
    }

    // Check if buffer is full.
    if (b.size() == b.max_size())
    {
      ec = error::not_found;
      return 0;
    }

    // Need more data.
    std::size_t bytes_to_read = read_size_helper(b, 65536);
    b.commit(s.read_some(b.prepare(bytes_to_read), ec));
    if (ec)
      return 0;
  }
}

std::size_t read_until(SyncReadStream& s,
    asio::basic_streambuf<Allocator>& b,
    MatchCondition match_condition, asio::error_code& ec,
    typename enable_if<is_match_condition<MatchCondition>::value>::type*)
{
  std::size_t search_position = 0;
  for (;;)
  {
    // Determine the range of the data to be searched.
    typedef typename asio::basic_streambuf<
      Allocator>::const_buffers_type const_buffers_type;
    typedef asio::buffers_iterator<const_buffers_type> iterator;
    const_buffers_type buffers = b.data();
    iterator begin = iterator::begin(buffers);
    iterator start_pos = begin + search_position;
    iterator end = iterator::end(buffers);

    // Look for a match.
    std::pair<iterator, bool> result = match_condition(start_pos, end);
    if (result.second)
    {
      // Full match. We're done.
      ec = asio::error_code();
      return result.first - begin;
    }
    else if (result.first != end)
    {
      // Partial match. Next search needs to start from beginning of match.
      search_position = result.first - begin;
    }
    else
    {
      // No match. Next search can start with the new data.
      search_position = end - begin;
    }

    // Check if buffer is full.
    if (b.size() == b.max_size())
    {
      ec = error::not_found;
      return 0;
    }

    // Need more data.
    std::size_t bytes_to_read = read_size_helper(b, 65536);
    b.commit(s.read_some(b.prepare(bytes_to_read), ec));
    if (ec)
      return 0;
  }
}

 std::size_t read_buffer_sequence(SyncReadStream& s,
     const MutableBufferSequence& buffers, const MutableBufferIterator&,
     CompletionCondition completion_condition, boost::system::error_code& ec)
 {
   ec = boost::system::error_code();
   boost::asio::detail::consuming_buffers<mutable_buffer,
       MutableBufferSequence, MutableBufferIterator> tmp(buffers);
   while (!tmp.empty())
   {
     if (std::size_t max_size = detail::adapt_completion_condition_result(
           completion_condition(ec, tmp.total_consumed())))
       tmp.consume(s.read_some(tmp.prepare(max_size), ec));
     else
       break;
   }
   return tmp.total_consumed();;
 }

std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers,
    CompletionCondition completion_condition, asio::error_code& ec)
{
  ec = asio::error_code();
  asio::detail::consuming_buffers<
    mutable_buffer, MutableBufferSequence> tmp(buffers);
  std::size_t total_transferred = 0;
  tmp.prepare(detail::adapt_completion_condition_result(
        completion_condition(ec, total_transferred)));
  while (tmp.begin() != tmp.end())
  {
    std::size_t bytes_transferred = s.read_some(tmp, ec);
    tmp.consume(bytes_transferred);
    total_transferred += bytes_transferred;
    tmp.prepare(detail::adapt_completion_condition_result(
          completion_condition(ec, total_transferred)));
  }
  return total_transferred;
}

void
send_cgi_response(
    SyncReadStream& input,
    SyncWriteStream& output,
    error_code& ec)
{
    static_assert(is_sync_read_stream<SyncReadStream>::value,
        "SyncReadStream requirements not met");

    static_assert(is_sync_write_stream<SyncWriteStream>::value,
        "SyncWriteStream requirements not met");

    using boost::asio::buffer_cast;
    using boost::asio::buffer_size;

    // Set up the response. We use the buffer_body type,
    // allowing serialization to use manually provided buffers.
    response<buffer_body> res;

    res.result(status::ok);
    res.version = 11;
    res.set(field::server, "Beast");
    res.set(field::transfer_encoding, "chunked");

    // No data yet, but we set more = true to indicate
    // that it might be coming later. Otherwise the
    // serializer::is_done would return true right after
    // sending the header.
    res.body.data = nullptr;
    res.body.more = true;

    // Create the serializer.
    response_serializer<buffer_body, fields> sr{res};

    // Send the header immediately.
    write_header(output, sr, ec);
    if(ec)
        return;

    // Alternate between reading from the child process
    // and sending all the process output until there
    // is no more output.
    do
    {
        // Read a buffer from the child process
        char buffer[2048];
        auto bytes_transferred = input.read_some(
            boost::asio::buffer(buffer, sizeof(buffer)), ec);
        if(ec == boost::asio::error::eof)
        {
            ec = {};

            // `nullptr` indicates there is no buffer
            res.body.data = nullptr;

            // `false` means no more data is coming
            res.body.more = false;
        }
        else
        {
            if(ec)
                return;

            // Point to our buffer with the bytes that
            // we received, and indicate that there may
            // be some more data coming
            res.body.data = buffer;
            res.body.size = bytes_transferred;
            res.body.more = true;
        }
            
        // Write everything in the body buffer
        write(output, sr, ec);

        // This error is returned by body_buffer during
        // serialization when it is done sending the data
        // provided and needs another buffer.
        if(ec == error::need_buffer)
        {
            ec = {};
            continue;
        }
        if(ec)
            return;
    }
    while(! sr.is_done());
}