Version Control (Git)

Table of Contents

• Naming conventions
• Popular subbranches

The project is hosted on the gitlab of the Leibniz Supercomputing Centre. You find the repository at https://gitlab.lrz.de/hpcsoftware/Peano. We try to give all interested colleagues access to the repository including some write permissions, but we do protect some branches.

• Our main branch is called p4, as we work with Peano 4. This one is protected and serves as our release branch.
• p4 has a couple of top-level branches which are editable by a few key users. Please assign merge requests to one of these key users if you want your changes to be merged.
  • particles
  • multigrid
  • exahype
  • applications
  • infrastructure
  • documentation
• Most of these branches are only writable by the PI, though some responsibilities for very few ranches are delegated.
• We have multiple subbranches under each top level branch. They are "owned" by various colleagues.

It is sometimes confusing to distinguish methodological extensions and applications: Very often, the application needs trigger the introduction of new numerical techniques or infrastructure features. However, we find it useful to maintain them in different branches, as infrastructure changes by definition often affect a lot of different applications, so we want people to be very careful.

Our merges happen exclusively along the branch tree, i.e. any modification should feed at one point into a top-level branch of above. Once we are happy with the status quo there, anybody can request a merge into p4 via a merge request. The other way round, updates into p4 are not automatically downstreamed into the top level branches. If you would like to see updates of the release branch before you branch from a top-level branch, please issue another MR and assign it to the PI.

Naming conventions

If you create a new branch, please follow the two naming approaches:

1. Create a hierarchical representation such as particles-taskgraph-bugfix which highlights that this branch is a subbranch of taskgraph which in turn is a subbranch of particles.
2. Use your username followed by a slash as name prefix.

The second version puts additional emphasis on who "owns" a certain branch, while the first one highlights the hierarchical relationships. Multi-user branches or top-level branches do not have a name prefix.

Popular subbranches

• documentation is a top-level branch which exclusively fixes documentation, tutorials, ... Nothing in here does actually "touch" real code besides inserting markers such that code sections can be cited.
• infrastructure-gpu is a subbranch of infrastructure and collects all the extensions we need to support various GPU back-ends.
• infrastructure-cmake and similar branches are used for tweaks around the build systems.
• infrastructure-ci and similar branches deal with continuous integration.
• particles hosts our SPH work, i.e. Swift 2.
• exahype hosts our work around ExaHyPE 2.
• multigrid hosts our multigrid work funded under the ExCALIBUR programme.