text: /*
   * Copyright (c) 2015, Peter Thorson. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of the WebSocket++ Project nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #ifndef WEBSOCKETPP_TRANSPORT_ASIO_BASE_HPP
  #define WEBSOCKETPP_TRANSPORT_ASIO_BASE_HPP
  
  #include <websocketpp/common/asio.hpp>
  #include <websocketpp/common/cpp11.hpp>
  #include <websocketpp/common/functional.hpp>
  #include <websocketpp/common/system_error.hpp>
  #include <websocketpp/common/type_traits.hpp>
  
  #include <string>
  
  namespace websocketpp {
  namespace transport {
  /// Transport policy that uses asio
  /**
   * This policy uses a single asio io_service to provide transport
   * services to a WebSocket++ endpoint.
   */
  namespace asio {
  
  // Class to manage the memory to be used for handler-based custom allocation.
  // It contains a single block of memory which may be returned for allocation
  // requests. If the memory is in use when an allocation request is made, the
  // allocator delegates allocation to the global heap.
  class handler_allocator {
  public:
      static const size_t size = 1024;
      
      handler_allocator() : m_in_use(false) {}
  
  #ifdef _WEBSOCKETPP_DEFAULT_DELETE_FUNCTIONS_
  	handler_allocator(handler_allocator const & cpy) = delete;
  	handler_allocator & operator =(handler_allocator const &) = delete;
  #endif
  
      void * allocate(std::size_t memsize) {
          if (!m_in_use && memsize < size) {
              m_in_use = true;
              return static_cast<void*>(&m_storage);
          } else {
              return ::operator new(memsize);
          }
      }
  
      void deallocate(void * pointer) {
          if (pointer == &m_storage) {
              m_in_use = false;
          } else {
              ::operator delete(pointer);
          }
      }
  
  private:
      // Storage space used for handler-based custom memory allocation.
      lib::aligned_storage<size>::type m_storage;
  
      // Whether the handler-based custom allocation storage has been used.
      bool m_in_use;
  };
  
  // Wrapper class template for handler objects to allow handler memory
  // allocation to be customised. Calls to operator() are forwarded to the
  // encapsulated handler.
  template <typename Handler>
  class custom_alloc_handler {
  public:
      custom_alloc_handler(handler_allocator& a, Handler h)
        : allocator_(a),
          handler_(h)
      {}
  
      template <typename Arg1>
      void operator()(Arg1 arg1) {
          handler_(arg1);
      }
  
      template <typename Arg1, typename Arg2>
      void operator()(Arg1 arg1, Arg2 arg2) {
          handler_(arg1, arg2);
      }
  
      friend void* asio_handler_allocate(std::size_t size,
          custom_alloc_handler<Handler> * this_handler)
      {
          return this_handler->allocator_.allocate(size);
      }
  
      friend void asio_handler_deallocate(void* pointer, std::size_t /*size*/,
          custom_alloc_handler<Handler> * this_handler)
      {
          this_handler->allocator_.deallocate(pointer);
      }
  
  private:
      handler_allocator & allocator_;
      Handler handler_;
  };
  
  // Helper function to wrap a handler object to add custom allocation.
  template <typename Handler>
  inline custom_alloc_handler<Handler> make_custom_alloc_handler(
      handler_allocator & a, Handler h)
  {
      return custom_alloc_handler<Handler>(a, h);
  }
  
  
  
  
  
  
  
  // Forward declaration of class endpoint so that it can be friended/referenced
  // before being included.
  template <typename config>
  class endpoint;
  
  typedef lib::function<void (lib::asio::error_code const & ec,
      size_t bytes_transferred)> async_read_handler;
  
  typedef lib::function<void (lib::asio::error_code const & ec,
      size_t bytes_transferred)> async_write_handler;
  
  typedef lib::function<void (lib::error_code const & ec)> pre_init_handler;
  
  // handle_timer: dynamic parameters, multiple copies
  // handle_proxy_write
  // handle_proxy_read
  // handle_async_write
  // handle_pre_init
  
  
  /// Asio transport errors
  namespace error {
  enum value {
      /// Catch-all error for transport policy errors that don't fit in other
      /// categories
      general = 1,
  
      /// async_read_at_least call requested more bytes than buffer can store
      invalid_num_bytes,
  
      /// there was an error in the underlying transport library
      pass_through,
  
      /// The connection to the requested proxy server failed
      proxy_failed,
  
      /// Invalid Proxy URI
      proxy_invalid,
  
      /// Invalid host or service
      invalid_host_service
  };
  
  /// Asio transport error category
  class category : public lib::error_category {
  public:
      char const * name() const _WEBSOCKETPP_NOEXCEPT_TOKEN_ {
          return "websocketpp.transport.asio";
      }
  
      std::string message(int value) const {
          switch(value) {
              case error::general:
                  return "Generic asio transport policy error";
              case error::invalid_num_bytes:
                  return "async_read_at_least call requested more bytes than buffer can store";
              case error::pass_through:
                  return "Underlying Transport Error";
              case error::proxy_failed:
                  return "Proxy connection failed";
              case error::proxy_invalid:
                  return "Invalid proxy URI";
              case error::invalid_host_service:
                  return "Invalid host or service";
              default:
                  return "Unknown";
          }
      }
  };
  
  /// Get a reference to a static copy of the asio transport error category
  inline lib::error_category const & get_category() {
      static category instance;
      return instance;
  }
  
  /// Create an error code with the given value and the asio transport category
  inline lib::error_code make_error_code(error::value e) {
      return lib::error_code(static_cast<int>(e), get_category());
  }
  
  } // namespace error
  } // namespace asio
  } // namespace transport
  } // namespace websocketpp
  
  _WEBSOCKETPP_ERROR_CODE_ENUM_NS_START_
  template<> struct is_error_code_enum<websocketpp::transport::asio::error::value>
  {
      static bool const value = true;
  };
  _WEBSOCKETPP_ERROR_CODE_ENUM_NS_END_
  #endif // WEBSOCKETPP_TRANSPORT_ASIO_HPP
  