Re: [dpdk-dev] [dpdk-users] [DISCUSSION] code snippet documentation

On Thu, Jul 22, 2021 at 1:29 PM Thomas Monjalon [off-list ref] wrote:

15/07/2021 09:01, Asaf Penso:

quoted

Hello DPDK community,

I would like to bring up a discussion about a way to have code snippets as an example for proper usage.
The DPDK tree is filled with great pieces of code that are well documented and maintained in high quality.
I feel we are a bit behind when we talk about usage examples.

One way, whenever we implement a new feature, is to extend one of the test-* under the "app" folder.
This, however, provides means to test but doesn't provide a good usage example.

Another way is to check the content of the "example" folder and whenever we have a BIG new feature it seems like a good place.
This, however, doesn't provide a good option when we talk about small features.
If, for example, we extend rte_flow with an extra action then providing a full-blown example application is somewhat an entry barrier.

A third option could be to document it in one of the .rst files we have.
Obviously, this requires high maintenance and no option to assure it still compiles.

I'd like to propose another approach that will address the main two issues: remove the entry barrier and assure compilation.
In this approach, inside the "examples" folder we'll create another folder for "snippets".
Inside "snippets" we'll have several files per category, for example, rte_flow_snippets.c
Each .c file will include a main function that calls the different use cases we want to give as an example.
The purpose is not to generate traffic nor read rx/tx packets from the DPDK ports.
The purpose is to have a good example that compiles properly.

Taking the rte_flow_snippets.c as an example its main function would look like this:

int
main(int argc, char **argv)
{
      rte_flow_snippet_match_5tuple_and_drop();
      rte_flow_snippet_match_geneve_ope_and_rss();
      ...
      Return 0;
}

I think we need to have a policy or justification about which snippet
is worth to have.
My thought is to avoid creating snippets which have no other value
than showing a function call.
I think there is a value if the context is not simple.

I agree. Otherwise it will be cluttered with snippets.

Please could you provide a more complex example?