lianetm commented on code in PR #17035:
URL: https://github.com/apache/kafka/pull/17035#discussion_r1757119740
##########
clients/src/main/java/org/apache/kafka/clients/consumer/internals/FetchRequestManager.java:
##########
@@ -65,16 +67,59 @@ protected void maybeThrowAuthFailure(Node node) {
networkClientDelegate.maybeThrowAuthFailure(node);
}
+ /**
+ * Request that a fetch request be issued to the cluster to pull down the
next batch of records.
+ *
+ * <p/>
+ *
+ * The returned {@link CompletableFuture} is {@link
CompletableFuture#complete(Object) completed} when the
+ * fetch request(s) have been created and enqueued into the network
client's outgoing send buffer.
+ * It is <em>not completed</em> when the network client has received the
data.
+ *
+ * @return Future for which the caller can wait to ensure that the
requests have been enqueued
+ */
+ public CompletableFuture<Void> requestFetch() {
+ CompletableFuture<Void> future = new CompletableFuture<>();
+
+ if (pendingFetchRequestFuture != null) {
+ // In this case, we have an outstanding fetch request, so chain
the newly created future to be
+ // completed when the outstanding fetch request is completed.
+ pendingFetchRequestFuture.whenComplete((value, exception) -> {
+ if (exception != null) {
+ future.completeExceptionally(exception);
+ } else {
+ future.complete(value);
+ }
+ });
+ } else {
+ pendingFetchRequestFuture = future;
+ }
+
+ return future;
+ }
+
/**
* {@inheritDoc}
*/
@Override
public PollResult poll(long currentTimeMs) {
- return pollInternal(
+ if (pendingFetchRequestFuture == null) {
+ // If no explicit request for fetching has been issued, just
short-circuit.
+ return PollResult.EMPTY;
+ }
+
+ try {
+ return pollInternal(
prepareFetchRequests(),
this::handleFetchSuccess,
this::handleFetchFailure
- );
+ );
+ } finally {
+ // Completing the future here means that the caller knows that the
fetch request logic has been
Review Comment:
"the fetch request logic has been performed" seems confusingly vague (could
hint more that what we really do here I'm afraid). Maybe just saying that the
caller knows that the fetch request has been generated?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
