code: public void setTraceMemory(String dataDirectory, long memoryBufferSize) {
  		TraceState state = (TraceState)ivTrace.clone();
  		state.ivStorageType = MEMORYBUFFER_TYPE;
  		state.ivDataDirectory = dataDirectory;
  		state.ivMemoryBufferSize = memoryBufferSize;
  		
  		updateTraceConfiguration(state);
  		
  		state.copyTo(ivTrace);
  	}
docs: Modify the trace to use a memory buffer
  @param dataDirectory directory where buffer will be dumped if requested
  @param memoryBufferSize amount of memory (in Mb) to be used for this circular buffer