[flutter_tools] do not add events to closed sink in throttle transform (#66468)

The throttle duration could delay past the point where the destination sink was closed. Check if it is closed before adding an event. Fixes a crash on dev: StateError: Bad State: Stream is already closed.
This commit is contained in:
Jonah Williams 2020-09-23 10:40:39 -07:00 committed by GitHub
parent fc1e764264
commit 1d4e7cd52d
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2 changed files with 20 additions and 1 deletions

View File

@ -234,6 +234,7 @@ StreamTransformer<S, S> _throttle<S>({
S latestLine;
int lastExecution;
Future<void> throttleFuture;
bool done = false;
return StreamTransformer<S, S>
.fromHandlers(
@ -249,14 +250,20 @@ StreamTransformer<S, S> _throttle<S>({
final int nextExecutionTime = isFirstMessage || remainingTime > waitDuration.inMilliseconds
? 0
: waitDuration.inMilliseconds - remainingTime;
throttleFuture ??= Future<void>
.delayed(Duration(milliseconds: nextExecutionTime))
.whenComplete(() {
if (done) {
return;
}
sink.add(latestLine);
throttleFuture = null;
lastExecution = DateTime.now().millisecondsSinceEpoch;
});
},
handleDone: (EventSink<S> sink) {
done = true;
sink.close();
}
);
}

View File

@ -195,6 +195,18 @@ void main() {
expect('$uri', 'http://127.0.0.1:12345/PTwjm8Ii8qg=/');
});
testUsingContext('protocol discovery does not crash if the log reader is closed while delaying', () async {
initialize(devicePort: 12346, throttleDuration: const Duration(milliseconds: 10));
final Future<List<Uri>> results = discoverer.uris.toList();
logReader.addLine('I/flutter : Observatory listening on http://127.0.0.1:12346/PTwjm8Ii8qg=/');
logReader.addLine('I/flutter : Observatory listening on http://127.0.0.1:12346/PTwjm8Ii8qg=/');
await logReader.dispose();
// Give time for throttle to finish.
await Future<void>.delayed(const Duration(milliseconds: 11));
expect(await results, isEmpty);
});
testUsingContext('uris in the stream are throttled', () async {
const Duration kThrottleDuration = Duration(milliseconds: 10);