Re: [Discuss-gnuradio] adding new code

[Eric Blossom]

On Mon, Jan 17, 2005 at 02:39:38PM -0600, Suvda Myagmar wrote:
> I would like to my own code to gnuradio core library. A different 
> version of gr_buffer class, say files gr_mybuffer.cc and 
> gr_mybuffer.h. I would like to be able to use this new class when 
> allocating buffers in flow_graph.py, code line:
> 
>       from gnuradio_swig_python import buffer, buffer_add_reader, 
>       block_detail, \
>      single_threaded_scheduler
>       ....
>       return buffer (nitems, item_size)
> 
> How do I go about it? 

> How gr_buffer class relate to python class 
> 'buffer'? How I do make this connection?

The python gr.buffer object is just a swig generated wrapper around
the gr_buffer C++ class.  The swig interface file is gr_buffer.i
See the docs at www.swig.org

> To compile the new code, I just need to change the Makefile in the 
> gnuradio-core-2.x/src/lib/runtime and compile? Do I need to have the 
> gnuradio CVS code?
> Thanks

You don't have to work with the CVS build, but given what you're
trying to do I think it would be a good idea.

Most of the methods of gr_buffer are not virtual, so just subclassing
it probably won't get you what you want.  The rest of the C++ part of
the system will use the base class methods (most of which are inlined
for performance).

Assuming that your strategy is to create a new implementation of
gr_buffer, the easiest way would be to create the gr_mybuffer.{h,cc,i}
files, and make sure that the classes defined by them are called
gr_buffer and gr_buffer_reader.  Then edit
gnuradio-core/src/lib/runtime/Makefile.am replacing the references to
gr_buffer.{h,cc,i} with gr_mybuffer.{h,cc,i} and follow the directions
in the top level README for a CVS build.  When configuring be sure to 
use the --enable-maintainer-mode option or else the Makefile
generation rules aren't enabled.

If you haven't already, I suggest you get the CVS code to build on
your system.

Eric