Encoding a Series of Messages Using the C++ Control Class Interface

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A common application of BER encoding is the repetitive encoding of a series of the same type of message over and over again. For example, a TAP3 batch application might read billing data out of a database table and encode each of the records for a batch transmission.

If a user was to repeatedly instantiate and destroy the C++ objects involved in the encoding of a message, performance would suffer. This is not necessary however, because the C++ objects can be reused to allow multiple messages to be encoded. As example showing how to do this is as follows:

    #include employee.h         // include file generated by ASN1C
 

 
    main ()
 
    {
 
        const ASN1OCTET* msgptr;
 
        ASN1OCTET msgbuf[1024];
 
        int       msglen;
 

 
        ASN1BEREncodeBuffer encodeBuffer (msgbuf, sizeof(msgbuf));
 
        ASN1T_PersonnelRecord msgData;
 
        ASN1C_PersonnelRecord employee (encodeBuffer, msgData);
 

 
        // Encode loop starts here, this will repeatedly use the 
 
        // objects declared above to encode the messages
 

 
        for (;;) {
 

 
            // logic here to read record from some source (database, 
 
            // flat file, socket, etc.)..
 

            // populate structure with data to be encoded
 

 
            employee.msgData.name = "SMITH";
 
	      ...
 

 
            // invoke Encode method 
 

 
            if ((msglen = employee.Encode ()) > 0) {
 

 
                // encoding successful, get pointer to start of message
 

 
                msgptr = encodeBuffer.getMsgPtr();
 

 
                // do something with the encoded message
 

                ...
 
            }
 
            else
 
               error processing...
 

 
            // Call the init method on the encodeBuffer object to 
 
            // prepare the buffer for encoding another message..
 

 
            encodeBuffer.init();
 
        }
 
    }