My First Experience on Raising a ns3-dev Merge-Request at GitLab

In this post, I want to share my first experience on ‘Raising a simple merge request at GitLab’ at https://gitlab.com/nsnam/ns-3-dev/-/merge_requests

You may find that specific request at – A Simple CircleMobilityModel (3D) for ns-3.

Contributing to ns-3

In fact, I want to incorporate the simple CircleMobilityModel that I developed for ns-3 with the ns-3-dev; so that the future distributions of ns-3 will contain my mobility model in the default installation of ns-3.

You may find the internal mechanism of my CircleMobilityModel in the following post :

Implementation of Circle Mobility Model for ns-3 and Visualizing it in 3D

I tried to learn the procedure of submitting a new contribution to ns-3 while writing an article on it.  The following is the link to that article :

Confusions in Contributing Our New Model to mainline ns-3. 

After making the model to ready for submission, I made a submission at ns3-dev with a comment explaining the model.

The following is the actual content of the comments that I made along with that merge request:

A Simple CircleMobilityModel (3D) for ns-3

I wish to add a Simple CircleMobilityModel (3D) in ns-3. I wrote this model by cloning the skeleton structure of ns-3’s “ConstantPositionMobilityModel” by Mathieu Lacage. Only a few standard declaration lines are directly handled from ConstantPositionMobilityModel code, and mostly, 90% of lines of this models were only rewritten by me. This model uses circle functions inspired from Circle Function Logic of Circle Mobility Model of Omnet++ by Andras Varga. The original Omnet++ version used radians and degree conversions in its implementation; but I handled angles only in degree.

This merge will add “circle-mobility-model.h” and “circle-mobility-model.cc” file under “src/mobility/models” and do the necessary modifications in wscript and CMakeLists.txt and other files to incorporate CircleMobilityModel in ns-3-dev. This will also add two simulation example scripts under src/mobility/examples and add the necessary test script under src/mobility/test. It will do the necessary changes in src/mobility/test/examples-to-run.py and src/mobility/examples/wscript to incorporate them with in ns-3-dev.

The following are the NetAnim outputs (captured as gif animation) for our example scripts : simple-3d-circle-mobility-example1.cc and simple-3d-circle-mobility-example2.cc

The first one is an Example with one node with CircleMobilityModel (simple-3d-circle-mobility-example1.cc).

 

The second one is an Example with one node with CircleMobilityModel along with 50 nodes having GaussMarkovMobilityModel (simple-3d-circle-mobility-example2.cc).

In fact, the above are 2D projections of 3D Network simulations on NetAnim, so that the output in 3D can be visualized using ns-3 extensions such as NetSimulyzer (this merge is not providng with NetSimulyzer version of simulation script since ns-3-dev doesn’t have those required modules/model).

The following is one such possibility of visualizing this ns-3 CircleMobilityModel Simulation with NetSimulyzer 3D visualization Tool. In the following examples, the boat moving (in the reverse direction? 🙂 ) on the water surface is using the proposed CircleMobilityModel.

Since the merge request was filed because of some minor errors that I made in the “comments” of code (No other syntax or logical errors were reported by that automated merge process), I tried to get Mr Tom in this regard.

My Mail to Mr. Tom

The following is the mail content that I sent to Mr.Tom for getting his help and comments on it :

Dear Mr. Tom,

I started to learn GitLab way of doing things. 🙂 
(Still, I am unable to understand it even for doing basic things – later I may try to post an ‘idiots guide for using GitHub for contributing to ns-3-dev if I will be successfully merging my MobilityModel with ns-3-dev)

ok.

I forked ns-3-dev and incorporated the necessary things to add my CircleMobilityModel in it. (after testing the same in a cloned ns-3-dev in my local drive)

I raised a merge request for my first contribution to ns-2.
https://gitlab.com/nsnam/ns-3-dev/-/merge_requests/821

First Merge Attempt:
In fact, for the first time, the pre-commit-compile-*  successfully compiled and tested everything.
But, while compiling documentation, except Doxygen, the other three got succeeded.

 Doxygen failed because of errors like :

src/mobility/model/circle-mobility-model.h:66: warning: argument ‘void’ of command @param is not found in the argument list of ns3::CircleMobilityModel::DoGetPosition(void) const
src/mobility/model/circle-mobility-model.h:68: warning: return type of member ns3::CircleMobilityModel::DoGetPosition is not documented

This process also consumed around 2 hours

Second Merge Attempt:
To resolve the errors in those comments, I only “editor” that particular comments in those files and retried the merge.

 

It started another fork of my project with those modified files and again started to do pre-commit-compile-* and then Doxygen. 
And failed at Doxygen with the same kind of ‘comment’ errors.
This process also consumed around 1.5 hours

Third Merge Attempt:
I removed that  (unexpected) fork, and resolve the errors in those comments, I uploaded edited versions of the same files (from local disk) and retried the merge.

 

It again started to do pre-commit-compile-* and will compile the Doxygen. 
And it may fail at Doxygen with the same kind of ‘comment’ errors.
This process not yet completed. But I think, it will also consume around an hour.

My Questions are:
1. Why Doxygen is not failing on other ns-3 header files where there were no Doxygen comments at all?.

2. Why it is running the all the test of other models again and again at the end  of  all pre-commit-compile-* ? 

3. Is this the ‘normal’ usual way we have to do things while merging after a “single line change in the comment line of the code?” 

    (I mean waiting for more than an hour for editing a single line of comment? 🙂 🙂 🙂 )

4. Is there any other way to quickly do the  pre-commit-compile-*  and Doxygen compile only on the edited files?

For your information, I think, I am provided with a “shared pipeline” (I have no idea about it) since I am using a free account.

the following image shows the running process of  pre-commit-compile-* after one line editing.

 

Note: if you insist me,  then  I may post my future questions at the group.

Charles Pandian,

Reply from Mr. Tom

After carefully examining the problems that I faced during submission (the merge request), Mr. Tom posted me the following reply :

Mr.Tom’s reply highlighted in ‘Bold Green Text‘