@VisibleForTesting
public synchronized void acknowledge(String outputId, long sequenceId) {
Preconditions.checkNotNull(outputId, "outputId is null");
NamedQueue namedQueue = namedQueues.get(outputId);
if (namedQueue == null) {
throw new NoSuchBufferException(outputId, namedQueues.keySet());
}
if (state == QueueState.FINISHED) {
return;
}
// remove queue from set before calling getPages because getPages changes
// the sequence number of the queue which is used for identity comparison in the
// sorted set
openQueuesBySequenceId.remove(namedQueue);
// acknowledge the pages
namedQueue.acknowledge(sequenceId);
// only add back the queue if it is still open
if (!closed.get()) {
openQueuesBySequenceId.add(namedQueue);
} else {
namedQueue.setFinished();
}
updateState();
}
public synchronized void abort(String outputId) {
Preconditions.checkNotNull(outputId, "outputId is null");
NamedQueue namedQueue = namedQueues.get(outputId);
if (namedQueue == null || namedQueue.isFinished()) {
return;
}
namedQueue.setFinished();
openQueuesBySequenceId.remove(namedQueue);
updateState();
}
public synchronized SharedBufferInfo getInfo() {
ImmutableList.Builder<BufferInfo> infos = ImmutableList.builder();
for (NamedQueue namedQueue : namedQueues.values()) {
infos.add(
new BufferInfo(
namedQueue.getQueueId(),
namedQueue.isFinished(),
namedQueue.size(),
namedQueue.pagesRemoved()));
}
return new SharedBufferInfo(state, masterSequenceId, pagesAdded.get(), infos.build());
}
private synchronized void updateState() {
if (closed.get()) {
// remove all empty queues
for (Iterator<NamedQueue> iterator = openQueuesBySequenceId.iterator();
iterator.hasNext(); ) {
NamedQueue namedQueue = iterator.next();
if (namedQueue.isEmpty()) {
namedQueue.setFinished();
iterator.remove();
}
}
// discard queued pages (not officially in the buffer) and waiters
for (QueuedPage queuedPage : queuedPages) {
queuedPage.getFuture().set(null);
}
queuedPages.clear();
}
if (state == QueueState.NO_MORE_QUEUES && !openQueuesBySequenceId.isEmpty()) {
// advance master sequence id
long oldMasterSequenceId = masterSequenceId;
masterSequenceId = openQueuesBySequenceId.iterator().next().getSequenceId();
// drop consumed pages
int pagesToRemove = Ints.checkedCast(masterSequenceId - oldMasterSequenceId);
Preconditions.checkState(
pagesToRemove >= 0,
"Master sequence id moved backwards: oldMasterSequenceId=%s, newMasterSequenceId=%s",
oldMasterSequenceId,
masterSequenceId);
for (int i = 0; i < pagesToRemove; i++) {
Page page = masterQueue.removeFirst();
bufferedBytes -= page.getDataSize().toBytes();
}
// refill buffer from queued pages
while (!queuedPages.isEmpty() && bufferedBytes < maxBufferedBytes) {
QueuedPage queuedPage = queuedPages.removeFirst();
addInternal(queuedPage.getPage());
queuedPage.getFuture().set(null);
}
}
if (state == QueueState.NO_MORE_QUEUES && closed.get() && openQueuesBySequenceId.isEmpty()) {
destroy();
}
this.notifyAll();
}
/** Destroys the queue, discarding all pages. */
public synchronized void destroy() {
closed.set(true);
state = QueueState.FINISHED;
// drop all of the queues
for (NamedQueue namedQueue : openQueuesBySequenceId) {
namedQueue.setFinished();
}
openQueuesBySequenceId.clear();
// clear the buffer
masterQueue.clear();
bufferedBytes = 0;
// free queued page waiters
for (QueuedPage queuedPage : queuedPages) {
queuedPage.getFuture().set(null);
}
queuedPages.clear();
// notify readers that the buffer has been destroyed
this.notifyAll();
}
public synchronized BufferResult get(
String outputId, long startingSequenceId, DataSize maxSize, Duration maxWait)
throws InterruptedException {
Preconditions.checkNotNull(outputId, "outputId is null");
Preconditions.checkArgument(maxSize.toBytes() > 0, "maxSize must be at least 1 byte");
Preconditions.checkNotNull(maxWait, "maxWait is null");
NamedQueue namedQueue = namedQueues.get(outputId);
if (namedQueue == null) {
throw new NoSuchBufferException(outputId, namedQueues.keySet());
}
if (state == QueueState.FINISHED) {
return emptyResults(namedQueue.getSequenceId(), true);
}
// wait for pages to arrive
if (namedQueue.isEmpty()) {
long remainingNanos = maxWait.roundTo(NANOSECONDS);
long end = System.nanoTime() + remainingNanos;
while (remainingNanos > 0 && namedQueue.isEmpty() && !namedQueue.isFinished()) {
// wait for timeout or notification
NANOSECONDS.timedWait(this, remainingNanos);
remainingNanos = end - System.nanoTime();
}
}
// remove queue from set before calling getPages because getPages changes
// the sequence number of the queue which is used for identity comparison in the
// sorted set
openQueuesBySequenceId.remove(namedQueue);
// get the pages
BufferResult results = namedQueue.getPages(startingSequenceId, maxSize);
// only add back the queue if it is still open
if (!closed.get() || !results.isBufferClosed()) {
openQueuesBySequenceId.add(namedQueue);
} else {
namedQueue.setFinished();
}
updateState();
return results;
}
