Method getBytestream

plugins/e57/libE57Format/src/Packet.cpp:438–484

}

char *DataPacket::getBytestream( unsigned bytestreamNumber, unsigned &byteCount )
{
#ifdef E57_VERBOSE
   std::cout << "getBytestream called, bytestreamNumber=" << bytestreamNumber << std::endl;
#endif

   // Verify that packet is correct type
   if ( header.packetType != DATA_PACKET )
   {
      throw E57_EXCEPTION2( ErrorBadCVPacket, "packetType=" + toString( header.packetType ) );
   }

   // Check bytestreamNumber in bounds
   if ( bytestreamNumber >= header.bytestreamCount )
   {
      throw E57_EXCEPTION2( ErrorInternal,
                            "bytestreamNumber=" + toString( bytestreamNumber ) +
                               " bytestreamCount=" + toString( header.bytestreamCount ) );
   }

   // Calc positions in packet
   auto bsbLength = reinterpret_cast<uint16_t *>( &payload[0] );
   auto streamBase = reinterpret_cast<char *>( &bsbLength[header.bytestreamCount] );

   // Sum size of preceding stream buffers to get position
   unsigned totalPreceding = 0;
   for ( unsigned i = 0; i < bytestreamNumber; i++ )
   {
      totalPreceding += bsbLength[i];
   }

   byteCount = bsbLength[bytestreamNumber];

   // Double check buffer is completely within packet
   if ( ( sizeof( DataPacketHeader ) + 2 * header.bytestreamCount + totalPreceding + byteCount ) >
        header.packetLogicalLengthMinus1 + 1U )
   {
      throw E57_EXCEPTION2( ErrorInternal, "bytestreamCount=" + toString( header.bytestreamCount ) +
                                              " totalPreceding=" + toString( totalPreceding ) +
                                              " byteCount=" + toString( byteCount ) +
                                              " packetLogicalLengthMinus1=" +
                                              toString( header.packetLogicalLengthMinus1 ) );
   }

   // Return start of buffer
   return ( &streamBase[totalPreceding] );
}

unsigned DataPacket::getBytestreamBufferLength( unsigned bytestreamNumber )
{