ZODB.Architecture.Storage Interface.pack

Documentation
Pack and/or garbage-collect the storage. If the storage does not support undo, then t is ignored. All records for objects that are not reachable from the system root object as of time t, or as of the current time, if undo is not supported, are removed from the storage.

A storage implementation may treat this method as ano-op. A storage implementation may also delay packing and return immediately. Storage documentation should define the behavior of this method.
Parameters
TypeNameDefaultDocumentation
TimeTimet the pack time. If the storage supports undo, then all non-current revisions written prior to t are removed.
Callablereferencesf a function that returns a sequence of object IDs for a given data string. This is used for garbage collection to determine which objects are reachable from the root.