This is the core read/write storage module in ORDF. Its purpose is to store RDF graphs in the filesystem in a specialised directory hierarchy known as a Pairtree. The reasoning behind this is explained in the RDF back-end Design section of this documentation.
Bases: ordf.handler.HandlerPlugin
When adding a Graph to this store the first thing that is done is its uri is normalised to the urn:uuid: namespace. If its idenfifier is already in that namespace, nothing is changed. If it is not, it is converted. The original identifier is stored in the filesystem for later retrieval so that when a read operation is performed, the result is a Graph with the correct uri identifier. This is done with the utility function ordf.utils.uuid().