Module
ZODB.FileStorage.fspack

FileStorage helper to perform pack.

A storage contains an ordered set of object revisions. When a storage is packed, object revisions that are not reachable as of the pack time are deleted. The notion of reachability is complicated by backpointers -- object revisions that point to earlier revisions of the same object.

An object revisions is reachable at a certain time if it is reachable from the revision of the root at that time or if it is reachable from a backpointer after that time.