TuringArena packs

A TuringArena pack is a collection of software components, which can be:

  • distributed, and
  • provided to TuringArena when performing operations.

Examples

  • A pack which defines one or more problems.
  • A pack which contains a library which can be used by other problems.
  • A pack which contains a private add-on for a public problem, providing the correct solutions needed for a full evaluation.

Format of packs

A pack is essentially a directory of files. More precisely, a pack is represented as a Git tree object and is identified by its SHA-1 hash.

Rationale

We use Git tree objects for packs for the following reasons.

  • Git tree objects represent the right subset of file metadata (filename, executable bit, symlinks) and are safe to distribute (no users/groups and other inode properties, as in tar).
  • The secure hashing can be used for caching purposes.
  • Git will probably be the most used tool to distribute packs, so the mapping to Git trees is natural.

Loading packs

When a pack is provided, the root directory of the pack is made available in the Python 3 path. In turn, the Python path is used (via the __path__ property of Python packages) when looking for specific files.

Rationale

Instead of developing a new module system used to identify, find and load different software components (in the form of files), the Python module system is exploited. Thanks to namespace packages of Python 3, no extra effort is required to map module names to directories in packs, and portions of the same package can be distributed in different packs.

Pack repositories

Some mechanisms are presented to load the content of a pack, identified by its SHA-1 hash, when it is not available. Such a mechanism is called a pack repository.

Git

A Git clone is performed with some specified parameters, including the following.

  • Git repository URL, required.
  • A Git ref, optional, the default is provided by the repository itself.
  • The clone depth, optional, defaulting to no depth (deep clone).

All the git tree objects present in the repository after the clone are made available as packs.

Archive

A provided file archive (e.g., tar or zip) is extracted. Then, the content of the archive is added to a Git index and a Git tree object is created. The tree object obtained and all of its subtrees are made available as packs.

Archive URL

An URL is used to download a file archive, which is then processed as above.