socket.h

mgcp协议源代码。支持多种编码：g711

      int level = SOL_SOCKET  /// Level for option
    );

    /**Get options on the socket. These options are defined as Berkeley socket
       options of the class SOL_SOCKET.

       @return
       TRUE if the option was successfully retreived.
     */
    BOOL GetOption(
      int option,             /// Option to get.
      void * valuePtr,        /// Pointer to buffer for value.
      PINDEX valueSize,       /// Size of buffer to receive value.
      int level = SOL_SOCKET  /// Level for option
    );
  //@}

  /**@name Port/Service database functions */
  //@{
    /**Get the number of the protocol associated with the specified name.

       @return
       Number of protocol or 0 if the protocol was not found.
     */
    static WORD GetProtocolByName(
      const PString & name      /// Name of protocol
    );

    /**Get the name of the protocol number specified.

       @return
       Name of protocol or the number if the protocol was not found.
     */
    static PString GetNameByProtocol(
      WORD proto                /// Number of protocol
    );


    /**Get the port number for the specified service name. */
    virtual WORD GetPortByService(
      const PString & service   /// Name of service to get port number for.
    ) const;
    /**Get the port number for the specified service name.
    
       A name is a unique string contained in a system database. The parameter
       here may be either this unique name, an integer value or both separated
       by a space (name then integer). In the latter case the integer value is
       used if the name cannot be found in the database.
    
       The exact behviour of this function is dependent on whether TCP or UDP
       transport is being used. The #PTCPSocket# and #PUDPSocket#
       classes will implement this function.

       The static version of the function is independent of the socket type as
       its first parameter may be "tcp" or "udp", 

       @return
       Port number for service name, or 0 if service cannot be found.
     */
    static WORD GetPortByService(
      const char * protocol,     /// Protocol type for port lookup
      const PString & service    /// Name of service to get port number for.
    );

    /**Get the service name from the port number. */
    virtual PString GetServiceByPort(
      WORD port   /// Number for service to find name of.
    ) const;
    /**Get the service name from the port number.
    
       A service name is a unique string contained in a system database. The
       parameter here may be either this unique name, an integer value or both
       separated by a space (name then integer). In the latter case the
       integer value is used if the name cannot be found in the database.
    
       The exact behviour of this function is dependent on whether TCP or UDP
       transport is being used. The #PTCPSocket# and #PUDPSocket#
       classes will implement this function.

       The static version of the function is independent of the socket type as
       its first parameter may be "tcp" or "udp", 

       @return
       Service name for port number.
     */
    static PString GetServiceByPort(
      const char * protocol,  /// Protocol type for port lookup
      WORD port   /// Number for service to find name of.
    );


    /**Set the port number for the channel. */
    void SetPort(
      WORD port   /// New port number for the channel.
    );
    /**Set the port number for the channel. This a 16 bit number representing
       an agreed high level protocol type. The string version looks up a
       database of names to find the number for the string name.

       A service name is a unique string contained in a system database. The
       parameter here may be either this unique name, an integer value or both
       separated by a space (name then integer). In the latter case the
       integer value is used if the name cannot be found in the database.
    
       The port number may not be changed while the port is open and the
       function will assert if an attempt is made to do so.
     */
    void SetPort(
      const PString & service   /// Service name to describe the port number.
    );

    /**Get the port the TCP socket channel object instance is using.

       @return
       Port number.
     */
    WORD GetPort() const;

    /**Get a service name for the port number the TCP socket channel object
       instance is using.

       @return
       string service name or a string representation of the port number if no
       service with that number can be found.
     */
    PString GetService() const;
  //@}

  /**@name Multiple socket selection functions */
  //@{
    /// List of sockets used for #Select()# function
    class SelectList : public PSocketList
    {
      PCLASSINFO(SelectList, PSocketList)
      public:
        SelectList()
          { DisallowDeleteObjects(); }
        /** Add a socket to list .*/
        void operator+=(PSocket & sock /** Socket to add. */)
          { Append(&sock); }
        /** Remove a socket from list .*/
        void operator-=(PSocket & sock /** Socket to remove. */)
          { Remove(&sock); }
    };

    /**Select a socket with available data. */
    static int Select(
      PSocket & sock1,        /// First socket to check for readability.
      PSocket & sock2         /// Second socket to check for readability.
    );
    /**Select a socket with available data. */
    static int Select(
      PSocket & sock1,        /// First socket to check for readability.
      PSocket & sock2,        /// Second socket to check for readability.
      const PTimeInterval & timeout /// Timeout for wait on read/write data.
    );
    /**Select a socket with available data. */
    static Errors Select(
      SelectList & read       /// List of sockets to check for readability.
    );
    /**Select a socket with available data. */
    static Errors Select(
      SelectList & read,      /// List of sockets to check for readability.
      const PTimeInterval & timeout /// Timeout for wait on read/write data.
    );
    /**Select a socket with available data. */
    static Errors Select(
      SelectList & read,      /// List of sockets to check for readability.
      SelectList & write      /// List of sockets to check for writability.
    );
    /**Select a socket with available data. */
    static Errors Select(
      SelectList & read,      /// List of sockets to check for readability.
      SelectList & write,     /// List of sockets to check for writability.
      const PTimeInterval & timeout /// Timeout for wait on read/write data.
    );
    /**Select a socket with available data. */
    static Errors Select(
      SelectList & read,      /// List of sockets to check for readability.
      SelectList & write,     /// List of sockets to check for writability.
      SelectList & except     /// List of sockets to check for exceptions.
    );
    /**Select a socket with available data. This function will block until the
       timeout or data is available to be read or written to the specified
       sockets.

       The #read#, #write# and #except# lists
       are modified by the call so that only the sockets that have data
       available are present. If the call timed out then all of these lists
       will be empty.

       If no timeout is specified then the call will block until a socket
       has data available.

       @return
       TRUE if the select was successful or timed out, FALSE if an error
       occurred. If a timeout occurred then the lists returned will be empty.

       For the versions taking sockets directly instead of lists the integer
       returned is >0 for an error being a value from the PChannel::Errors
       enum, 0 for a timeout, -1 for the first socket having read data,
       -2 for the second socket and -3 for both.
     */
    static Errors Select(
      SelectList & read,      /// List of sockets to check for readability.
      SelectList & write,     /// List of sockets to check for writability.
      SelectList & except,    /// List of sockets to check for exceptions.
      const PTimeInterval & timeout /// Timeout for wait on read/write data.
    );
  //@}

  /**@name Integer conversion functions */
  //@{
    /// Convert from host to network byte order
    inline static WORD  Host2Net(WORD  v) { return htons(v); }
    /// Convert from host to network byte order
    inline static DWORD Host2Net(DWORD v) { return htonl(v); }

    /// Convert from network to host byte order
    inline static WORD  Net2Host(WORD  v) { return ntohs(v); }
    /// Convert from network to host byte order
    inline static DWORD Net2Host(DWORD v) { return ntohl(v); }
  //@}

  protected:
    /*This function calls os_socket() with the correct parameters for the
       socket protocol type.
     */
    virtual BOOL OpenSocket() = 0;

    /**This function returns the protocol name for the socket type.
     */
    virtual const char * GetProtocolName() const = 0;


    int os_close();
    int os_socket(int af, int type, int proto);
    int os_connect(
      struct sockaddr * sin,
      PINDEX size
    );
    int os_recvfrom(
      void * buf,
      PINDEX len,
      int flags,
      struct sockaddr * from,
      PINDEX * fromlen
    );
    int os_sendto(
      const void * buf,
      PINDEX len,
      int flags,
      struct sockaddr * to,
      PINDEX tolen
    );
    int os_accept(
      int sock,
      struct sockaddr * addr,
      PINDEX * size,
      const PTimeInterval & timeout
    );
    static int os_select(
      int maxfds,
      fd_set & readfds,
      fd_set & writefds,
      fd_set & exceptfds,
      const PIntArray & allfds,
      const PTimeInterval & timeout
    );


  // Member variables
    /// Port to be used by the socket when opening the channel.
    WORD port;

#ifdef DOC_PLUS_PLUS
};
#endif

// Class declaration continued in platform specific header file ///////////////