SocketHandle.ih

Go to the documentation of this file.

//
// Copyright (c) 2020 Fraunhofer Institute for Applied Information Technology (FIT)
//                    Network Research Group (NET)
//                    Schloss Birlinghoven, 53754 Sankt Augustin, GERMANY
//                    Contact: support@wiback.org
//
// This file is part of the SENF code tree.
// It is licensed under the 3-clause BSD License (aka New BSD License).
// See LICENSE.txt in the top level directory for details or visit
// https://opensource.org/licenses/BSD-3-Clause
//


/** \file
    \brief SocketHandle internal header
 */

#ifndef IH_SENF_Socket_SocketHandle_
#define IH_SENF_Socket_SocketHandle_ 1

// Custom includes
#include <map>
#include <string>
#include <boost/scoped_ptr.hpp>
#include "FileHandle.hh"

//-/////////////////////////////////////////////////////////////////////////////////////////////////

namespace senf {


    class SocketProtocol;

    namespace detail {

        /** \brief String supporting automatic type conversion

            The StreamableString class is used to simplify creating a text representation of
            arbitrary values. StreamableString is an ordinary string with an additional constructor
            which allows constructing the string from any arbitrary, streamable type.

            \note It is generally not advisable to derive from the standard library container
            classes. However, in this concrete case, the derivation is safe since only the
            additional functionality is added. It is absolutely safe to convert the derived class
            back to the base type.
         */
        class StreamableString : public std::string
        {
        public:
            using std::string::operator=;

            template <class T>
            StreamableString & operator<<(T const & other);
                                        ///< Value assignment
                                        /**< This operator will assign the string from any
                                             arbitrary type. It will use boost::lexical_cast to
                                             convert the argument to its string representation.

                                             If the string is non-empty, an additional separating
                                             comma is added to the string. */

            StreamableString & operator<<(bool v);  ///< Bool assignment
                                        /**< The bool assignment is defined explicitly to use a
                                             specialized representation (the strings 'true' and
                                             'false'). */
        };

    }

    typedef std::map<std::string, detail::StreamableString> SocketStateMap;

    namespace detail {
        /** \brief Helper to convert SocketStateMap to multiline string representation
            \internal
         */
        std::string dumpState(SocketStateMap const & map);
    }

    template <class Policy, class Self> class ConcreteSocketProtocol;

    /** \brief SocketHandle referenced body

        \internal

        senf::SocketBody is the extended (relatively to senf::FileBody) body of
        senf::SocketHandle. Every SocketHandle must have a SocketBody as it's body (and not a simple
        FileBody). The casting and conversion operators defined will ensure this if used
        properly. If this invariant is violated, your Program will probably crash.
     */
    class SocketBody
        : public FileBody
    {
    public:
        //-/////////////////////////////////////////////////////////////////////////////////////////
        // Types

        typedef boost::intrusive_ptr<SocketBody> ptr;

        //-/////////////////////////////////////////////////////////////////////////////////////////
        ///\name Structors and default members
        //\{

        SocketBody(bool isServer);      /**< \param isServer \c true, if this socket is a server
                                             socket, false otherwise */
        SocketBody(bool isServer, int fd);
                                        /**< \param isServer \c true, if this socket is a server
                                             socket, false otherwise
                                             \param fd socket file descriptor */

        // no copy
        // no conversion constructors

        //\}
        //-/////////////////////////////////////////////////////////////////////////////////////////

        SocketProtocol & protocol() const; ///< Access the protocol instance

        bool isServer();                ///< Check socket type
                                        /**< \return \c true, if this is a server socket, \c false
                                           otherwise */

        void state(SocketStateMap & map, unsigned lod);

        std::unique_ptr<SocketBody> clone(bool isServer) const;
        std::unique_ptr<SocketBody> clone(int fd, bool isServer) const;

    private:
        virtual void v_close();         ///< Close socket
                                        /**< This override will automatically \c shutdown() the
                                           socket whenever it is closed.
                                           \throws senf::SystemException */
        virtual void v_terminate();     ///< Forcibly close socket
                                        /**< This override will automatically \c shutdown() the
                                           socket whenever it is called. Additionally it will
                                           disable SO_LINGER to ensure, that v_terminate will not
                                           block. Like the overridden method, this member will
                                           ignore failures and will never throw. It therefore
                                           safe to be called from a destructor. */
        virtual bool v_eof() const;     ///< Check for eof condition
                                        /**< Since the eof check for sockets is very protocol
                                           dependent, this member will forward the call to
                                           senf::SocketPolicy::eof() */

        virtual SocketProtocol const & v_protocol() const = 0;
        virtual std::string v_protocolName() const = 0;

        bool isServer_;
    };

    template <class SProtocol>
    class ProtocolSocketBody
        : public SocketBody,
          private SProtocol,
          public senf::pool_alloc_mixin< ProtocolSocketBody<SProtocol> >
    {
    public:
        typedef SProtocol Protocol;

        using senf::pool_alloc_mixin< ProtocolSocketBody<SProtocol> >::operator new;
        using senf::pool_alloc_mixin< ProtocolSocketBody<SProtocol> >::operator delete;

        ProtocolSocketBody(bool isServer); /**< \param isServer \c true, if this socket is a server
                                             socket, false otherwise */
        ProtocolSocketBody(bool isServer, int fd);
                                        /**< \param isServer \c true, if this socket is a server
                                             socket, false otherwise
                                             \param fd socket file descriptor */

    private:
        virtual SocketProtocol const & v_protocol() const;
        virtual std::string v_protocolName() const;

        friend class ConcreteSocketProtocol<typename SProtocol::Policy, SProtocol>;
    };

}

//-/////////////////////////////////////////////////////////////////////////////////////////////////
#endif


// Local Variables:
// mode: c++
// fill-column: 100
// c-file-style: "senf"
// indent-tabs-mode: nil
// ispell-local-dictionary: "american"
// compile-command: "scons -u test"
// comment-column: 40
// End: