The document provides tips for improving the responsiveness of Xtext-based IDEs, including making long operations cancelable, using priority read transactions to speed up content assist, fixing a blocking bug in job management, storing fully resolved models to disk to reduce build times, enabling parallel generation, using profilers to measure performance instead of system time, checking cancel indicators and progress monitors frequently, training grammars to avoid backtracking, preferring index-based validation to reduce complexity, avoiding long chains of binary operations in Xbase, using storage-aware resources, and enabling parallel code generation and reducing indexed elements to improve build times.

1. Jan Köhnlein
Improving
the
Responsiveness
of Your
Xtext-based
IDE

2. Xtext
Master
DOJO

3. • If you cannot parallelize, make it cancelable
• CancelableUnitOfWork
• OutdatedStateManager#checkOutdated
• OperationCanceledManager transforms exceptions
Cancelation

4. • IXtextDocument#priorityReadOnly
• for fast UI services, e.g. content assist
• cancels current document readers
• executes action
• restarts model listeners
Priority
Read
Transactions

5. • 10yo bug finally fixed in Mars
• JobManager#isBlocking didn’t consider thread jobs
• Auto-build no longer blocks a save operation
BUG
60964

6. • Store fully-resolved models to disk
• Node model, resolved x-refs, resolved types, index
data…
• Drastically reduces build times
• especially for Xbase languages
Storage
Aware
Resource

7. • ParallelBuilderParticipant
Parallel
Generation

8. WORKOUT
For Xtext
Kyus

9. • Don’t guess – measure!
• Use a profiler, not the system clock
• But don’t trust your measurements!
The
Profiling
Koan

10. • Check CancelIndicators and ProgressMonitors
frequently
• Avoid calculation in the UI thread
• Careful with ProgressMonitor progress reporting
• Use BackgroundOutlineTreeProvider
Mastering
the GUI

11. • Avoid backtracking
• Reduce lookahead by
• adding keywords, preferably as prefix
• adding syntactic predicates
• use first-token-set predicates in complicated
lookahead scenarios
Train
your
Grammar

12. • Keep an eye on algorithmic complexity
• Prefer index-based NamesAreUniqueValidator
• Avoid unnecessary loading of external resources
• Use CheckType.NORMAL
Validation
KUNG-FU

13. • Avoid using long chains of binary operations
• Explicitly state types when necessary
Xbase
Workout

14. • Avoid clustering – increase memory instead
• Use StorageAwareResource
• Reduce number of indexed elements
• Use parallel code generator
• Maven: Avoid composite update sites
Builder
Katas

15. THank
YOU