- The commit refactors some modification trackers previously provided by
`KotlinModificationTrackerFactory` to a subscription-directed
mechanism implemented via `MessageBus` and `KotlinTopics`. The
following modification trackers are affected:
- Module out-of-block modification: The FE10 Analysis API doesn't use
these modification trackers, so the effect is limited to LL FIR.
- Module state: Likewise, FE10 doesn't use this modification tracker,
so again the effect is limited to LL FIR.
- Project and library modifications trackers remain, because many small
objects in e.g. light classes depend on these trackers (making
listener management unfeasible), and they are not relevant for
`LLFirSession` invalidation.
- This new API paves the way for a session invalidation service to
subscribe to out-of-block and module state changes as events. This
removes the need to iterate through modification trackers.
- Also note that the out-of-block modification provided by the new
subscription mechanism is intended to work for _any_ `KtModule`, as
long as it makes sense to have out-of-block modifications. For
example, the subscription should work for script modules. The OOB
modification tracker previously only supported `KtSourceModule`s,
which required separate single-file modification trackers for script
and not-under-content-root modules.
- `MessageBus` is a general utility provided by IntelliJ, but usually it
is retrieved from `project`. To keep these two concerns decoupled,
`project.messageBus` should not be used directly. Instead, the commit
adds a `KotlinMessageBusProvider`, which for now just provides the
project message bus with its standard implementation, but allows
swapping out the message bus implementation later.
- Global changes are also supported by the new subscription API. Such
global changes may for example occur during cache invalidation in
tests, on global PSI tree changes, or when an SDK is removed.
- Test-only invalidation has been moved from
`KotlinModificationTrackerFactory` to a new
`KotlinGlobalModificationService`. This creates one central service
for invalidation between tests, which is easier from an implementation
and a usage perspective than calling multiple scattered services and
providers.
Marco Pennekamp
0c94a3131c