doc/html/boost_asio/example/http/server2/request_parser.cpp

//
// request_parser.cpp
// ~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2010 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)
//

#include "request_parser.hpp"
#include "request.hpp"

namespace http {
	namespace server2 {

		request_parser::request_parser()
			: state_(method_start)
		{
		}

		void request_parser::reset()
		{
			state_ = method_start;
		}

		boost::tribool request_parser::consume(request& req, char input)
		{
			switch (state_)
			{
			case method_start:
				if (!is_char(input) || is_ctl(input) || is_tspecial(input))
				{
					return false;
				}
				else
				{
					state_ = method;
					req.method.push_back(input);
					return boost::indeterminate;
				}
			case method:
				if (input == ' ')
				{
					state_ = uri;
					return boost::indeterminate;
				}
				else if (!is_char(input) || is_ctl(input) || is_tspecial(input))
				{
					return false;
				}
				else
				{
					req.method.push_back(input);
					return boost::indeterminate;
				}
			case uri_start:
				if (is_ctl(input))
				{
					return false;
				}
				else
				{
					state_ = uri;
					req.uri.push_back(input);
					return boost::indeterminate;
				}
			case uri:
				if (input == ' ')
				{
					state_ = http_version_h;
					return boost::indeterminate;
				}
				else if (is_ctl(input))
				{
					return false;
				}
				else
				{
					req.uri.push_back(input);
					return boost::indeterminate;
				}
			case http_version_h:
				if (input == 'H')
				{
					state_ = http_version_t_1;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_t_1:
				if (input == 'T')
				{
					state_ = http_version_t_2;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_t_2:
				if (input == 'T')
				{
					state_ = http_version_p;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_p:
				if (input == 'P')
				{
					state_ = http_version_slash;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_slash:
				if (input == '/')
				{
					req.http_version_major = 0;
					req.http_version_minor = 0;
					state_ = http_version_major_start;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_major_start:
				if (is_digit(input))
				{
					req.http_version_major = req.http_version_major * 10 + input - '0';
					state_ = http_version_major;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_major:
				if (input == '.')
				{
					state_ = http_version_minor_start;
					return boost::indeterminate;
				}
				else if (is_digit(input))
				{
					req.http_version_major = req.http_version_major * 10 + input - '0';
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_minor_start:
				if (is_digit(input))
				{
					req.http_version_minor = req.http_version_minor * 10 + input - '0';
					state_ = http_version_minor;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case http_version_minor:
				if (input == '\r')
				{
					state_ = expecting_newline_1;
					return boost::indeterminate;
				}
				else if (is_digit(input))
				{
					req.http_version_minor = req.http_version_minor * 10 + input - '0';
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case expecting_newline_1:
				if (input == '\n')
				{
					state_ = header_line_start;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case header_line_start:
				if (input == '\r')
				{
					state_ = expecting_newline_3;
					return boost::indeterminate;
				}
				else if (!req.headers.empty() && (input == ' ' || input == '\t'))
				{
					state_ = header_lws;
					return boost::indeterminate;
				}
				else if (!is_char(input) || is_ctl(input) || is_tspecial(input))
				{
					return false;
				}
				else
				{
					req.headers.push_back(header());
					req.headers.back().name.push_back(input);
					state_ = header_name;
					return boost::indeterminate;
				}
			case header_lws:
				if (input == '\r')
				{
					state_ = expecting_newline_2;
					return boost::indeterminate;
				}
				else if (input == ' ' || input == '\t')
				{
					return boost::indeterminate;
				}
				else if (is_ctl(input))
				{
					return false;
				}
				else
				{
					state_ = header_value;
					req.headers.back().value.push_back(input);
					return boost::indeterminate;
				}
			case header_name:
				if (input == ':')
				{
					state_ = space_before_header_value;
					return boost::indeterminate;
				}
				else if (!is_char(input) || is_ctl(input) || is_tspecial(input))
				{
					return false;
				}
				else
				{
					req.headers.back().name.push_back(input);
					return boost::indeterminate;
				}
			case space_before_header_value:
				if (input == ' ')
				{
					state_ = header_value;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case header_value:
				if (input == '\r')
				{
					state_ = expecting_newline_2;
					return boost::indeterminate;
				}
				else if (is_ctl(input))
				{
					return false;
				}
				else
				{
					req.headers.back().value.push_back(input);
					return boost::indeterminate;
				}
			case expecting_newline_2:
				if (input == '\n')
				{
					state_ = header_line_start;
					return boost::indeterminate;
				}
				else
				{
					return false;
				}
			case expecting_newline_3:
				return (input == '\n');
			default:
				return false;
			}
		}

		bool request_parser::is_char(int c)
		{
			return c >= 0 && c <= 127;
		}

		bool request_parser::is_ctl(int c)
		{
			return (c >= 0 && c <= 31) || (c == 127);
		}

		bool request_parser::is_tspecial(int c)
		{
			switch (c)
			{
			case '(': case ')': case '<': case '>': case '@':
			case ',': case ';': case ':': case '\\': case '"':
			case '/': case '[': case ']': case '?': case '=':
			case '{': case '}': case ' ': case '\t':
				return true;
			default:
				return false;
			}
		}

		bool request_parser::is_digit(int c)
		{
			return c >= '0' && c <= '9';
		}

	} // namespace server2
} // namespace http