A stream dictionary is an object of type
CStreamDictionary
. It maintains a list of two-way associations
between a UID and a stream ID.
Each TUid
and TStreamId
pair forms an entry
in an array. The CStreamDictionary
class provides member functions
to manage these entries, for example, to add a new entry or to change the
stream ID associated with a UID.
Applications often have a need to identify a stream associated with a particular purpose. That purpose is, itself, identified by UID. A stream dictionary allows the stream ID corresponding to a specific UID to be looked up.
The stream dictionary can be externalised. It is often externalised as the root stream of a store, after all the other streams have been written. When the store is opened, the stream dictionary can then be internalised from the root stream, and other streams looked up based on the associated UIDs.
System initialisation files use stream dictionaries