Defines the interfaces for Space Manager module. This module is resposible for managing free space information within a Container.

A Raw Container as created by the {@link org.simpledbm.rss.io.StorageContainerFactory} interface is more or less a stream of bytes. The Space Manager module treats the Raw Container as an ordered collection of fixed size {@link org.simpledbm.rss.pm.Page Pages}. It also distinguishes between different types of pages. A container managed by the Space Manager module contains at least two types of pages. Firstly, special pages called Free Space Map Pages are used to track space allocation within the container. One or two bits are used to track space for each page within the container. Secondly, data pages are available for client modules to use. The type of the data page may be specified when creating a container.