public ImmutableSet<WaveletId> lookupWavelets(WaveId waveId) throws WaveletStateException {
ListenableFuture<ImmutableSet<WaveletId>> future = waves.get(waveId).lookedupWavelets;
try {
return FutureUtil.getResultOrPropagateException(future, PersistenceException.class);
} catch (PersistenceException e) {
throw new WaveletStateException("Failed to look up wave " + waveId, e);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new WaveletStateException("Interrupted while looking up wave " + waveId, e);
}
}
private <T extends WaveletContainer> T getWavelet(
WaveletId waveletId, ConcurrentMap<WaveletId, T> waveletsMap) throws WaveletStateException {
ImmutableSet<WaveletId> storedWavelets;
try {
storedWavelets =
FutureUtil.getResultOrPropagateException(lookedupWavelets, PersistenceException.class);
} catch (PersistenceException e) {
throw new WaveletStateException(
"Failed to lookup wavelet " + WaveletName.of(waveId, waveletId), e);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new WaveletStateException(
"Interrupted looking up wavelet " + WaveletName.of(waveId, waveletId), e);
}
// Since waveletsMap is a computing map, we must call containsKey(waveletId)
// to tell if waveletId is mapped, we cannot test if get(waveletId) returns null.
if (!storedWavelets.contains(waveletId) && !waveletsMap.containsKey(waveletId)) {
return null;
} else {
T wavelet = waveletsMap.get(waveletId);
Preconditions.checkNotNull(wavelet, "computingMap returned null");
return wavelet;
}
}
