The Software Heritage Loader Core is a low-level loading utilities and helpers used by :term:`loaders <loader>`.

The main entry points are classes: - :class:`swh.loader.core.loader.BaseLoader` for VCS loaders (e.g. svn) - :class:`swh.loader.core.loader.DVCSLoader` for DVCS loaders (e.g. git, ...) - :class:`swh.loader.core.loader.ContentLoader` for Content loader - :class:`swh.loader.core.loader.DirectoryLoader` for Directory loader - :class:`swh.loader.package.loader.PackageLoader` for Package loaders (e.g. PyPI, Npm, ...) - ...

This package also implements many package loaders directly, out of convenience, as they usually are quite similar and each fits in a single file.

They all roughly follow these steps, explained in the :py:meth:`swh.loader.package.loader.PackageLoader.load` documentation. See the :ref:`package-loader-tutorial` for details.

Unlike package loaders, VCS loaders remain in separate packages, as they often need more advanced conversions and very VCS-specific operations.

This usually involves getting the branches of a repository and recursively loading revisions in the history (and directory trees in these revisions), until a known revision is found