/*    Framer.h
 *
 *    Copyright (c) 1994-1995 by DataBeam Corporation, Lexington, KY
 *
 *    Abstract:
 *        This is the packet frame base class.  This class defines the behavior
 *        for other packet framers that inherit from this class.  Some packet
 *        framing definitions can be found in RFC1006 and Q.922
 *    
 *    Caveats:
 *
 *    Authors:
 *        James W. Lawwill
 */

#ifndef _PACKET_FRAME_H_
#define _PACKET_FRAME_H_


typedef enum
{
    PACKET_FRAME_NO_ERROR,
    PACKET_FRAME_DEST_BUFFER_TOO_SMALL,
    PACKET_FRAME_PACKET_DECODED,
    PACKET_FRAME_ILLEGAL_FLAG_FOUND,
    PACKET_FRAME_FATAL_ERROR
}
    PacketFrameError;


class PacketFrame
{
public:

        virtual    PacketFrameError    PacketEncode (
                                        PUChar        source_address, 
                                        UShort        source_length,
                                        PUChar        dest_address,
                                        UShort        dest_length,
                                        DBBoolean    prepend_flag,
                                        DBBoolean    append_flag,
                                        PUShort        packet_size) = 0;
                                    
        virtual    PacketFrameError    PacketDecode (
                                        PUChar        source_address,
                                        UShort        source_length,
                                        PUChar        dest_address,
                                        UShort        dest_length,
                                        PUShort        bytes_accepted,
                                        PUShort        packet_size,
                                        DBBoolean    continue_packet) = 0;
        virtual    Void                GetOverhead (
                                        UShort        original_packet_size,
                                        PUShort        max_packet_size) = 0;


};
typedef    PacketFrame    *    PPacketFrame;

#endif


/*    
 *    PacketFrameError    PacketFrame::PacketEncode (
 *                                        PUChar        source_address, 
 *                                        UShort        source_length,
 *                                        PUChar        dest_address,
 *                                        UShort        dest_length,
 *                                        DBBoolean    packet_start,
 *                                        DBBoolean    packet_end,
 *                                        PUShort        packet_size) = 0;
 *
 *    Functional Description
 *        This function receives takes the source data and encodes it.
 *
 *    Formal Parameters
 *        source_address    - (i)    Address of source buffer
 *        source_length    - (i)    Length of source buffer
 *        dest_address    - (i)    Address of destination buffer.
 *        dest_length        - (i)    Length of destination buffer.
 *        packet_start    - (i)    This is the beginning of a packet.
 *        packet_end        - (i)    This is the end of a packet.
 *        packet_size        - (o)    Size of packet after encoding
 *
 *    Return Value
 *        PACKET_FRAME_NO_ERROR                -    No error
 *        PACKET_FRAME_FATAL_ERROR            -    Fatal error during encode
 *        PACKET_FRAME_DEST_BUFFER_TOO_SMALL    -    Self-explanatory
 *
 *    Side Effects
 *        None
 *
 *    Caveats
 *        None
 */

/*    
 *    PacketFrameError    PacketFrame::PacketDecode (
 *                                        PUChar        source_address,
 *                                        UShort        source_length,
 *                                        PUChar        dest_address,
 *                                        UShort        dest_length,
 *                                        PUShort        bytes_accepted,
 *                                        PUShort        packet_size,
 *                                        DBBoolean    continue_packet) = 0;
 *
 *    Functional Description
 *        This function takes the stream data passed in and decodes it into a
 *        packet
 *        
 *    Formal Parameters
 *        source_address    - (i)    Address of source buffer.  If this parm is 
 *                                NULL, continue using the current address.
 *        source_length    - (i)    Length of source buffer
 *        dest_address    - (i)    Address of destination buffer.  If this address
 *                                is NULL, continue using current buffer.
 *        dest_length        - (i)    Length of destination buffer.
 *        bytes_accepted    - (o)    Number of bytes processed before return
 *        packet_size        - (o)    Size of packet after decoding
 *        continue_packet    - (i)    Restart decoding
 *
 *    Return Value
 *        PACKET_FRAME_NO_ERROR                -    No error
 *        PACKET_FRAME_FATAL_ERROR            -    Fatal error during encode
 *        PACKET_FRAME_DEST_BUFFER_TOO_SMALL    -    Self-explanatory
 *        PACKET_FRAME_PACKET_DECODED            -    Self-explanatory
 *
 *    Side Effects
 *        None
 *
 *    Caveats
 *        None
 *
 */

/*    
 *    Void    PacketFrame::GetOverhead (
 *                            UShort    original_packet_size,
 *                            PUShort    max_packet_size) = 0;
 *
 *    Functional Description
 *        This returns the new maximum packet size
 *
 *    Formal Parameters
 *        original_packet_size    - (i)
 *        max_packet_size            - (o)    new maximum packet size
 *
 *    Return Value
 *        PACKET_FRAME_NO_ERROR    -    No error
 *
 *    Side Effects
 *        None
 *
 *    Caveats
 *        None
 *
 */