This week, I added a Base Sink template class. It will be common class for all sinks. Following are the updates of the week:

Current Status

Added a base sink

The motivation of this concept was to remove the redundancy of code between all various sinks. The task of base class will be to manage the data-buffer operations which are almost common in all sinks. Some of the examples are:

  1. work function of the sink - stores input stream in a buffer
  2. get_plot_data function of the sinks - create an array of values to be sent to Python

Following is proposed structure of base sink template class. The implementation of base-sink is available on base_sink_impl branch.
BaseSink Structure

The base class contains the complete implementations of the functions like work, get_plot_data, handle_pdus, constructor initializations related to data-buffers. The base class template also contains definition of virtual functions which are specific to the sink and are called from the functions defined in base class. Example of such functions are process_plot_data and work_other_buffers for processing the data just before sending to Python via get_plot_data and processing the buffers other than data (like tag buffers) in work function respectively.

The template class parameters class T and class U defines the type of values the sink will be working with. In a sink, the input data stream is of type T, and output data array (in function get_plot_data) is of type U.

In this structure, the base sink class is inherited as a virtual class instead of the sync_block class in standard GNU Radio block. The reason for change is: sequence of the constructors called when initializing object. The virtual inheritance slightly disturbs the natural flow of constructor calls. Although there is a change in standard block structure, the overall idea is still same as standard block.

As of now, the current struture can not integrate the AUTO and NORM triggers because of different styles of trigger checks in different sinks. I am trying find a good structured way of implementation. Feedback from the community would be grateful.

As of now, the base sink is integrated in time_sink_f sink only. The remaining 3 sinks implemented till now will be integrated by starting of next week.

Feedback required

To make these bokeh based GUI a bug-less software, we would like to have feedbacks from the community. You can now test using GRC.

As of now, the working implementations of sinks are on develop branch.

To follow implementation and integration of base sink class, follow base_sink_impl branch.

For any comments/feedbacks/suggestions, you can drop an email to discuss-gnuradio.

To-Do list for next week:

  1. Solve the bugs of TimeSink and FreqSink:
    I don’t believe my code is perfect. Kindly reinforce my belief! Add as much bugs as possible. It is now easier with GRC integration!
  2. Integration of base sink template class to remaining 3 sinks
  3. Implementing textbox and label widgets