reference_counted.cpp 3.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131
  1. //
  2. // reference_counted.cpp
  3. // ~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6. //
  7. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. #include <boost/asio.hpp>
  11. #include <boost/bind.hpp>
  12. #include <boost/enable_shared_from_this.hpp>
  13. #include <boost/shared_ptr.hpp>
  14. #include <iostream>
  15. #include <vector>
  16. using boost::asio::ip::tcp;
  17. // A reference-counted non-modifiable buffer class.
  18. class shared_const_buffer
  19. {
  20. public:
  21. // Construct from a std::string.
  22. explicit shared_const_buffer(const std::string& data)
  23. : data_(new std::vector<char>(data.begin(), data.end())),
  24. buffer_(boost::asio::buffer(*data_))
  25. {
  26. }
  27. // Implement the ConstBufferSequence requirements.
  28. typedef boost::asio::const_buffer value_type;
  29. typedef const boost::asio::const_buffer* const_iterator;
  30. const boost::asio::const_buffer* begin() const { return &buffer_; }
  31. const boost::asio::const_buffer* end() const { return &buffer_ + 1; }
  32. private:
  33. boost::shared_ptr<std::vector<char> > data_;
  34. boost::asio::const_buffer buffer_;
  35. };
  36. class session
  37. : public boost::enable_shared_from_this<session>
  38. {
  39. public:
  40. session(boost::asio::io_context& io_context)
  41. : socket_(io_context)
  42. {
  43. }
  44. tcp::socket& socket()
  45. {
  46. return socket_;
  47. }
  48. void start()
  49. {
  50. using namespace std; // For time_t, time and ctime.
  51. time_t now = time(0);
  52. shared_const_buffer buffer(ctime(&now));
  53. boost::asio::async_write(socket_, buffer,
  54. boost::bind(&session::handle_write, shared_from_this()));
  55. }
  56. void handle_write()
  57. {
  58. }
  59. private:
  60. // The socket used to communicate with the client.
  61. tcp::socket socket_;
  62. };
  63. typedef boost::shared_ptr<session> session_ptr;
  64. class server
  65. {
  66. public:
  67. server(boost::asio::io_context& io_context, short port)
  68. : io_context_(io_context),
  69. acceptor_(io_context, tcp::endpoint(tcp::v4(), port))
  70. {
  71. session_ptr new_session(new session(io_context_));
  72. acceptor_.async_accept(new_session->socket(),
  73. boost::bind(&server::handle_accept, this, new_session,
  74. boost::asio::placeholders::error));
  75. }
  76. void handle_accept(session_ptr new_session,
  77. const boost::system::error_code& error)
  78. {
  79. if (!error)
  80. {
  81. new_session->start();
  82. }
  83. new_session.reset(new session(io_context_));
  84. acceptor_.async_accept(new_session->socket(),
  85. boost::bind(&server::handle_accept, this, new_session,
  86. boost::asio::placeholders::error));
  87. }
  88. private:
  89. boost::asio::io_context& io_context_;
  90. tcp::acceptor acceptor_;
  91. };
  92. int main(int argc, char* argv[])
  93. {
  94. try
  95. {
  96. if (argc != 2)
  97. {
  98. std::cerr << "Usage: reference_counted <port>\n";
  99. return 1;
  100. }
  101. boost::asio::io_context io_context;
  102. using namespace std; // For atoi.
  103. server s(io_context, atoi(argv[1]));
  104. io_context.run();
  105. }
  106. catch (std::exception& e)
  107. {
  108. std::cerr << "Exception: " << e.what() << "\n";
  109. }
  110. return 0;
  111. }