ceph/src/boost/libs/asio/example/cpp11/chat/chat_message.hpp

   1 //
   2 // chat_message.hpp
   3 // ~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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
  11 #ifndef CHAT_MESSAGE_HPP
  12 #define CHAT_MESSAGE_HPP
  13
  14 #include <cstdio>
  15 #include <cstdlib>
  16 #include <cstring>
  17
  18 class chat_message
  19 {
  20 public:
  21   enum { header_length = 4 };
  22   enum { max_body_length = 512 };
  23
  24   chat_message()
  25     : body_length_(0)
  26   {
  27   }
  28
  29   const char* data() const
  30   {
  31     return data_;
  32   }
  33
  34   char* data()
  35   {
  36     return data_;
  37   }
  38
  39   std::size_t length() const
  40   {
  41     return header_length + body_length_;
  42   }
  43
  44   const char* body() const
  45   {
  46     return data_ + header_length;
  47   }
  48
  49   char* body()
  50   {
  51     return data_ + header_length;
  52   }
  53
  54   std::size_t body_length() const
  55   {
  56     return body_length_;
  57   }
  58
  59   void body_length(std::size_t new_length)
  60   {
  61     body_length_ = new_length;
  62     if (body_length_ > max_body_length)
  63       body_length_ = max_body_length;
  64   }
  65
  66   bool decode_header()
  67   {
  68     char header[header_length + 1] = "";
  69     std::strncat(header, data_, header_length);
  70     body_length_ = std::atoi(header);
  71     if (body_length_ > max_body_length)
  72     {
  73       body_length_ = 0;
  74       return false;
  75     }
  76     return true;
  77   }
  78
  79   void encode_header()
  80   {
  81     char header[header_length + 1] = "";
  82     std::sprintf(header, "%4d", static_cast<int>(body_length_));
  83     std::memcpy(data_, header, header_length);
  84   }
  85
  86 private:
  87   char data_[header_length + max_body_length];
  88   std::size_t body_length_;
  89 };
  90
  91 #endif // CHAT_MESSAGE_HPP