Datapkg Design¶
Overview¶
The following diagram gives a conceptual overview of the datapkg system. Most, though not all, of the classes indicated already exist within datapkg.
The central object in datapkg is a Package. A Package consists of:
- metadata
- payload
One important thing to emphasize is that in datapkg the payload is often not directly available (since it may be very large) but is virtual, being represented by, for example, links to the payload or a listing of the items in the payload (the manifest). In addition to the basic metadata about a package (name, version, title, description etc) we also need to record things like dependencies. Thus a Package main attributes become:
- basic
- dependencies
- manifest
Distributions are serialized Package on disk (or elsewhere) and handle all serialization and deserialization of packages.
- Other people can provide plugins (datapkg.distribution)
- These are tried in turn when loading from disk
Tools include downloaders, unpacking and the command line interface.
An Index represents a list of packages whether locally (like DbIndex) or remotely (like CkanIndex). A Repository is an Index plus storage/installation capacity.