Bug 456410

Description Pierre-Charles David 2014-12-31 05:14:25 EST

There are some common patterns for walking/searching inside EMF models that are repeated very often in Sirius, and which are implemented each time using the core EMF mechanisms. Beyond the code duplication, doing it this ways prevents any context-dependent optimizations.

For example, we often directly use eAllContents() or equivalent to search for elements of some kind. We could provide a higher-level service for this, which could be smarter than the "dumb" implementation (for example by not looking inside elements which can be proven statically to not contain the kind of elements we look for), and more importantly we could allow client code to provide custom implementations that are optimized for their context.

Examples of services/operations that could be abstracted:
* looking inside a model for elements of a given type. The "dumb and costly" way is a plain eAllcontenst() with calls to EClassifier.instanceOf().
* searching for inverse references towards a given element. The "dumb and costly" way is to maintain a complete inverse cross referencer.
* given a resource, knowing which other resources it references or that references it (i.e. the resource-level incoming and outgoing references). The "dumb and costly" is to load/resolve all the concerned resources and do a complete walk of all of them.