[xtext-dev] EMF Index - first shot

[Jan Köhnlein <jan.koehnlein@xxxxxxxxx>]

Hi,

I've checked in a first version of the EMF Index into the Xtext  
repository.

Currently, it roughly works as follows:
Backend:
- We store information on EPackages and EClasses, as well as  
Resources, EObjets and CrossReferences.
- We never store/return elements but rather descriptors that enable  
instantiation. E.g., an EObject can be instantiated from the  
EObjectDescriptor.getFragmentURI().
- The index storage backend (IIndexStore) is pluggable. Currently  
there is a single implementation for an in-memory index that is not  
persisting any information between workbench starts. Other backends  
should be easy to implement (Database, CDO,...)
- The information that is extracted for indexing is configurable by  
factories. The way these factories are registered is likely to change.
- The IIndexStore consists of one DAO per descriptor type that can be  
used to create generic queries. These generic queries can be  
configured using some kind of fluent API.
- Particular queries needed by the backend have extra creation methods  
in their respective DAOs, such that an IIndexStore implementor can  
provide optimized versions. A utility class maps these custom queries  
to generic ones, providing a default implementation for that query.
- An IndexFeeder is used to feed the information into the index store.

UI:
- A nature has to be added to all "watched projects"
- A builder updates the index on file changes. Deletion of files is  
not handled yet.
- An example UI action shows how to search for EClasses.
- At startup, the EPackage.Registry is indexed as well as all projects  
that have the EMF Index nature.

Issues:
- Lots of them :-)
- It currently has a dependency to Xtext, as we need the classpath URI  
protocol aware XtextResourceSet.
- The feeder needs more testing.

Next steps:
- Performance / memory analysis
- Integration Xtext services, such as with ScopeProvider, Navigation,  
etc.

I've also sent a mail to the EMO, requesting the creation review for  
the EMF Index project.

Best regards
Jan

--
Dr. Jan Köhnlein
Senior Software Architekt

Telefon: +49 (0) 431 / 5606-337
Mobile: +49 (0) 151 / 17396687
Telefax: +49 (0) 431 / 5606-339

http://www.itemis.de
jan.koehnlein@xxxxxxxxx

itemis AG
Niederlassung Kiel
Schauenburgerstr. 116
24118 Kiel
http://www.itemis.de/

Rechtlicher Hinweis:
Registergericht: Amtsgericht Dortmund HRB 20621
Sitz der Gesellschaft: Lünen
Vorstand: Wolfgang Neuhaus, Jens Wagener, Dr. Georg Pietrek
Aufsichtsrat: Prof. Dr. Burkhard Igel (Vorsitzender), Stephan  
Grollmann, Michael Neuhaus