request_parser.hpp

//
// request_parser.hpp
// ~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef HTTP_SERVER3_REQUEST_PARSER_HPP
#define HTTP_SERVER3_REQUEST_PARSER_HPP

#include <boost/logic/tribool.hpp>
#include <boost/tuple/tuple.hpp>

namespace http
{
  namespace server
  {

    struct request;

/// Parser for incoming requests.
    class request_parser
    {
    public:
      /// Construct ready to parse the request method.
      request_parser();

      /// Reset to initial parser state.
      void
      reset();

      /// Parse some data. The tribool return value is true when a complete request
      /// has been parsed, false if the data is invalid, indeterminate when more
      /// data is required. The InputIterator return value indicates how much of the
      /// input has been consumed.
      template<typename InputIterator>
      boost::tuple<boost::tribool, InputIterator>
      parse(request& req, InputIterator begin, InputIterator end)
      {
        while (begin != end)
        {
          boost::tribool result = consume(req, *begin++);
          if (result || !result)
            return boost::make_tuple(result, begin);
        }
        boost::tribool result = boost::indeterminate;
        return boost::make_tuple(result, begin);
      }

    private:
      /// Handle the next character of input.
      boost::tribool
      consume(request& req, char input);

      /// Check if a byte is an HTTP character.
      static bool
      is_char(int c);

      /// Check if a byte is an HTTP control character.
      static bool
      is_ctl(int c);

      /// Check if a byte is defined as an HTTP tspecial character.
      static bool
      is_tspecial(int c);

      /// Check if a byte is a digit.
      static bool
      is_digit(int c);

      /// The current state of the parser.
      enum state
      {
        method_start,
        method,
        uri_start,
        uri,
        http_version_h,
        http_version_t_1,
        http_version_t_2,
        http_version_p,
        http_version_slash,
        http_version_major_start,
        http_version_major,
        http_version_minor_start,
        http_version_minor,
        expecting_newline_1,
        header_line_start,
        header_lws,
        header_name,
        space_before_header_value,
        header_value,
        expecting_newline_2,
        expecting_newline_3
      } state_;
    };

  } // namespace server3
} // namespace http

#endif // HTTP_SERVER3_REQUEST_PARSER_HPP