05/01/1993 09:00 AM
Computer Science
Many applications must efficiently store and manipulate complex objects. Often sub-objects or entire objects are identical. Memory use can be decreased by the use of object handles which point to shared objects in place of actual objects. If the objects are hierarchical, sub-objects can also be represented with handles, allowing many operations to manipulate handles instead of whole objects. The copy-on-write and object registration techniques presented here reduce the cost of storing, copying, modifying, and matching hierarchical objects. Using object registration, identical objects are detected and shared, allowing objects to be uniquely identified by their location in memory. Copy-on-write object semantics allows increased sharing and reduced copying, while hierarchical copy-on-write objects using handles allows copies to have deep-copy behavior but shallow-copy cost.
