Reading a ringbuffer backwards in order to process the most recent data
first, is a very common operation. Nearly every dive computer backend
has its own implementation. Thus with a common implementation, the
amount of code duplication and complexity in the dive computer backends
can be greatly reduced.
The common algorithm is implemented as a simple ringbuffer stream, which
takes care of all the technical details like the ringbuffer boundaries,
alignment to the page size, using the optimal packet size and caching
the remaining data.
