Catalogs

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Catalogs

CatalogHook is the class which encapsulates the interaction of high level objects with the catalog system.

Catalog behavior:

There are two catalogs, the Active catalog and the File catalog. An item may be in one only or in both. CatalogHook provides two methods, update and downdate for updating these catalogs. update is called when the actual Table is initialized and adds the current CatalogHook to the Active list. downdate is called by the destructor, removes the CatalogHook from the Active catalog, and adds the CatalogHook to the File catalog if a filename is present in the Table header. (If the Table is constructed with a FileName, that Filename is also placed in the Table's header; if the Table is constructed with a Filename, the Table destructor writes the Table to disk before destruction.)

A third catalog, the Handle catalog, maps a Handle (an object's name as known to the user) into an ObjectID.

Next: Measurement Model Up: Orphaned Code to be Picked Up Previous: ObjectID