private FinishedTriggersBitSet readFinishedBits(ValueState<BitSet> state) {
if (!isFinishedSetNeeded()) {
// If no trigger in the tree will ever have finished bits, then we don't need to read them.
// So that the code can be agnostic to that fact, we create a BitSet that is all 0 (not
// finished) for each trigger in the tree.
return FinishedTriggersBitSet.emptyWithCapacity(rootTrigger.getFirstIndexAfterSubtree());
}
BitSet bitSet = state.read();
return bitSet == null
? FinishedTriggersBitSet.emptyWithCapacity(rootTrigger.getFirstIndexAfterSubtree())
: FinishedTriggersBitSet.fromBitSet(bitSet);
}
public TriggerStateMachineRunner(
ExecutableTriggerStateMachine rootTrigger,
TriggerStateMachineContextFactory<W> contextFactory) {
checkState(rootTrigger.getTriggerIndex() == 0);
this.rootTrigger = rootTrigger;
this.contextFactory = contextFactory;
}
/** Run the trigger logic to deal with a new value. */
public void processValue(W window, Instant timestamp, Timers timers, StateAccessor<?> state)
throws Exception {
// Clone so that we can detect changes and so that changes here don't pollute merging.
FinishedTriggersBitSet finishedSet = readFinishedBits(state.access(FINISHED_BITS_TAG)).copy();
TriggerStateMachine.OnElementContext triggerContext =
contextFactory.createOnElementContext(window, timers, timestamp, rootTrigger, finishedSet);
rootTrigger.invokeOnElement(triggerContext);
persistFinishedSet(state, finishedSet);
}
public void onFire(W window, Timers timers, StateAccessor<?> state) throws Exception {
// shouldFire should be false.
// However it is too expensive to assert.
FinishedTriggersBitSet finishedSet = readFinishedBits(state.access(FINISHED_BITS_TAG)).copy();
TriggerStateMachine.TriggerContext context =
contextFactory.base(window, timers, rootTrigger, finishedSet);
rootTrigger.invokeOnFire(context);
persistFinishedSet(state, finishedSet);
}
public void prefetchForMerge(
W window, Collection<W> mergingWindows, MergingStateAccessor<?, W> state) {
if (isFinishedSetNeeded()) {
for (ValueState<?> value : state.accessInEachMergingWindow(FINISHED_BITS_TAG).values()) {
value.readLater();
}
}
rootTrigger
.getSpec()
.prefetchOnMerge(
contextFactory.createMergingStateAccessor(window, mergingWindows, rootTrigger));
}
/** Run the trigger merging logic as part of executing the specified merge. */
public void onMerge(W window, Timers timers, MergingStateAccessor<?, W> state) throws Exception {
// Clone so that we can detect changes and so that changes here don't pollute merging.
FinishedTriggersBitSet finishedSet = readFinishedBits(state.access(FINISHED_BITS_TAG)).copy();
// And read the finished bits in each merging window.
ImmutableMap.Builder<W, FinishedTriggers> builder = ImmutableMap.builder();
for (Map.Entry<W, ValueState<BitSet>> entry :
state.accessInEachMergingWindow(FINISHED_BITS_TAG).entrySet()) {
// Don't need to clone these, since the trigger context doesn't allow modification
builder.put(entry.getKey(), readFinishedBits(entry.getValue()));
// Clear the underlying finished bits.
clearFinishedBits(entry.getValue());
}
ImmutableMap<W, FinishedTriggers> mergingFinishedSets = builder.build();
TriggerStateMachine.OnMergeContext mergeContext =
contextFactory.createOnMergeContext(
window, timers, rootTrigger, finishedSet, mergingFinishedSets);
// Run the merge from the trigger
rootTrigger.invokeOnMerge(mergeContext);
persistFinishedSet(state, finishedSet);
}
private boolean isFinishedSetNeeded() {
// TODO: If we know that no trigger in the tree will ever finish, we don't need to do the
// lookup. Right now, we special case this for the DefaultTrigger.
return !(rootTrigger.getSpec() instanceof DefaultTriggerStateMachine);
}
/**
* Clear the state used for executing triggers, but leave the finished set to indicate the window
* is closed.
*/
public void clearState(W window, Timers timers, StateAccessor<?> state) throws Exception {
// Don't need to clone, because we'll be clearing the finished bits anyways.
FinishedTriggers finishedSet = readFinishedBits(state.access(FINISHED_BITS_TAG));
rootTrigger.invokeClear(contextFactory.base(window, timers, rootTrigger, finishedSet));
}
public boolean shouldFire(W window, Timers timers, StateAccessor<?> state) throws Exception {
FinishedTriggers finishedSet = readFinishedBits(state.access(FINISHED_BITS_TAG)).copy();
TriggerStateMachine.TriggerContext context =
contextFactory.base(window, timers, rootTrigger, finishedSet);
return rootTrigger.invokeShouldFire(context);
}
public void prefetchShouldFire(W window, StateAccessor<?> state) {
prefetchIsClosed(state);
rootTrigger
.getSpec()
.prefetchShouldFire(contextFactory.createStateAccessor(window, rootTrigger));
}
public void prefetchForValue(W window, StateAccessor<?> state) {
prefetchIsClosed(state);
rootTrigger
.getSpec()
.prefetchOnElement(contextFactory.createStateAccessor(window, rootTrigger));
}