read_until.ipp

Boost provides free peer-reviewed portable C++ source libraries. We emphasize libraries that work

        std::size_t bytes_transferred)
    {
      // Check for errors.
      if (ec)
      {
        std::size_t bytes = 0;
        handler_(ec, bytes);
        return;
      }

      // Commit received data to streambuf's get area.
      streambuf_.commit(bytes_transferred);

      // 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 = streambuf_.data();
      iterator begin = iterator::begin(buffers);
      iterator start = begin + next_search_start_;
      iterator end = iterator::end(buffers);

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

      // Check if buffer is full.
      if (streambuf_.size() == streambuf_.max_size())
      {
        std::size_t bytes = 0;
        boost::system::error_code ec(error::not_found);
        handler_(ec, bytes);
        return;
      }

      // Start a new asynchronous read operation to obtain more data.
      std::size_t bytes_available =
        std::min<std::size_t>(512, streambuf_.max_size() - streambuf_.size());
      stream_.async_read_some(streambuf_.prepare(bytes_available), *this);
    }

  //private:
    AsyncReadStream& stream_;
    boost::asio::basic_streambuf<Allocator>& streambuf_;
    boost::regex expr_;
    std::size_t next_search_start_;
    ReadHandler handler_;
  };

  template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
  inline void* asio_handler_allocate(std::size_t size,
      read_until_expr_handler<AsyncReadStream,
        Allocator, ReadHandler>* this_handler)
  {
    return boost_asio_handler_alloc_helpers::allocate(
        size, &this_handler->handler_);
  }

  template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
  inline void asio_handler_deallocate(void* pointer, std::size_t size,
      read_until_expr_handler<AsyncReadStream,
        Allocator, ReadHandler>* this_handler)
  {
    boost_asio_handler_alloc_helpers::deallocate(
        pointer, size, &this_handler->handler_);
  }

  template <typename Function, typename AsyncReadStream, typename Allocator,
      typename ReadHandler>
  inline void asio_handler_invoke(const Function& function,
      read_until_expr_handler<AsyncReadStream,
        Allocator, ReadHandler>* this_handler)
  {
    boost_asio_handler_invoke_helpers::invoke(
        function, &this_handler->handler_);
  }
} // namespace detail

template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
void async_read_until(AsyncReadStream& s,
    boost::asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
    ReadHandler handler)
{
  // 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 end = iterator::end(buffers);

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

  // Check if buffer is full.
  if (b.size() == b.max_size())
  {
    boost::system::error_code ec(error::not_found);
    s.get_io_service().post(detail::bind_handler(handler, ec, 0));
    return;
  }

  // Start a new asynchronous read operation to obtain more data.
  std::size_t bytes_available =
    std::min<std::size_t>(512, b.max_size() - b.size());
  s.async_read_some(b.prepare(bytes_available),
      detail::read_until_expr_handler<AsyncReadStream, Allocator, ReadHandler>(
        s, b, expr, next_search_start, handler));
}

namespace detail
{
  template <typename AsyncReadStream, typename Allocator,
      typename MatchCondition, typename ReadHandler>
  class read_until_match_handler
  {
  public:
    read_until_match_handler(AsyncReadStream& stream,
        boost::asio::basic_streambuf<Allocator>& streambuf,
        MatchCondition match_condition, std::size_t next_search_start,
        ReadHandler handler)
      : stream_(stream),
        streambuf_(streambuf),
        match_condition_(match_condition),
        next_search_start_(next_search_start),
        handler_(handler)
    {
    }

    void operator()(const boost::system::error_code& ec,
        std::size_t bytes_transferred)
    {
      // Check for errors.
      if (ec)
      {
        std::size_t bytes = 0;
        handler_(ec, bytes);
        return;
      }

      // Commit received data to streambuf's get area.
      streambuf_.commit(bytes_transferred);

      // 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 = streambuf_.data();
      iterator begin = iterator::begin(buffers);
      iterator start = begin + next_search_start_;
      iterator end = iterator::end(buffers);

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

      // Check if buffer is full.
      if (streambuf_.size() == streambuf_.max_size())
      {
        std::size_t bytes = 0;
        boost::system::error_code ec(error::not_found);
        handler_(ec, bytes);
        return;
      }

      // Start a new asynchronous read operation to obtain more data.
      std::size_t bytes_available =
        std::min<std::size_t>(512, streambuf_.max_size() - streambuf_.size());
      stream_.async_read_some(streambuf_.prepare(bytes_available), *this);
    }

  //private:
    AsyncReadStream& stream_;
    boost::asio::basic_streambuf<Allocator>& streambuf_;
    MatchCondition match_condition_;
    std::size_t next_search_start_;
    ReadHandler handler_;
  };

  template <typename AsyncReadStream, typename Allocator,
      typename MatchCondition, typename ReadHandler>
  inline void* asio_handler_allocate(std::size_t size,
      read_until_match_handler<AsyncReadStream,
        Allocator, MatchCondition, ReadHandler>* this_handler)
  {
    return boost_asio_handler_alloc_helpers::allocate(
        size, &this_handler->handler_);
  }

  template <typename AsyncReadStream, typename Allocator,
      typename MatchCondition, typename ReadHandler>
  inline void asio_handler_deallocate(void* pointer, std::size_t size,
      read_until_match_handler<AsyncReadStream,
        Allocator, MatchCondition, ReadHandler>* this_handler)
  {
    boost_asio_handler_alloc_helpers::deallocate(
        pointer, size, &this_handler->handler_);
  }

  template <typename Function, typename AsyncReadStream, typename Allocator,
      typename MatchCondition, typename ReadHandler>
  inline void asio_handler_invoke(const Function& function,
      read_until_match_handler<AsyncReadStream,
        Allocator, MatchCondition, ReadHandler>* this_handler)
  {
    boost_asio_handler_invoke_helpers::invoke(
        function, &this_handler->handler_);
  }
} // namespace detail

template <typename AsyncReadStream, typename Allocator,
    typename MatchCondition, typename ReadHandler>
void async_read_until(AsyncReadStream& s,
    boost::asio::basic_streambuf<Allocator>& b,
    MatchCondition match_condition, ReadHandler handler,
    typename boost::enable_if<is_match_condition<MatchCondition> >::type*)
{
  // 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 end = iterator::end(buffers);

  // Look for a match.
  std::size_t next_search_start;
  std::pair<iterator, bool> result = match_condition(begin, end);
  if (result.second)
  {
    // Full match. We're done.
    boost::system::error_code ec;
    std::size_t bytes = result.first - begin;
    s.get_io_service().post(detail::bind_handler(handler, ec, bytes));
    return;
  }
  else if (result.first != end)
  {
    // Partial match. Next search needs to start from beginning of match.
    next_search_start = result.first - begin;
  }
  else
  {
    // No match. Next search can start with the new data.
    next_search_start = end - begin;
  }

  // Check if buffer is full.
  if (b.size() == b.max_size())
  {
    boost::system::error_code ec(error::not_found);
    s.get_io_service().post(detail::bind_handler(handler, ec, 0));
    return;
  }

  // Start a new asynchronous read operation to obtain more data.
  std::size_t bytes_available =
    std::min<std::size_t>(512, b.max_size() - b.size());
  s.async_read_some(b.prepare(bytes_available),
      detail::read_until_match_handler<
        AsyncReadStream, Allocator, MatchCondition, ReadHandler>(
          s, b, match_condition, next_search_start, handler));
}

} // namespace asio
} // namespace boost

#include <boost/asio/detail/pop_options.hpp>

#endif // BOOST_ASIO_READ_UNTIL_IPP