def get_archiver_index(config, archiver):
root = pathlib.Path(config.cache_path) / archiver<EOL>with (root / "<STR_LIT>").open("<STR_LIT:r>") as index_f:<EOL><INDENT>index = json.load(index_f)<EOL><DEDENT>return index<EOL>
Get the contents of the archiver index file.

:param config: The configuration
:type  config: :class:`wily.config.WilyConfig`

:param archiver: The name of the archiver type (e.g. 'git')
:type  archiver: ``str``

:return: The index data
:rtype: ``dict``