Fix: Removed EnableExactlyOnceDelivery from Builders (#1052)

Removed EnableExactlyOnceDelivery from `Subscriber.Builder`, `StreamingSubscriberConnection.Builder`, and `MessageDispatcher.Builder`. Added comments to `AckReplyConsumerWithResponse` to be in line with `AckReplyConsumer`

Author: mmicatka

google-cloud-pubsub/clirr-ignored-differences.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- see http://www.mojohaus.org/clirr-maven-plugin/examples/ignored-differences.html -->
+<differences>
+ <!-- These should be removed after the next major release 1.117.x -->
+ <difference>
+ <differenceType>7002</differenceType>
+ <className>com/google/cloud/pubsub/v1/Subscriber$Builder</className>
+ <method>com.google.cloud.pubsub.v1.Subscriber$Builder setExactlyOnceDeliveryEnabled(boolean)</method>
+ </difference>
+ <difference>
+ <differenceType>7002</differenceType>
+ <className>com/google/cloud/pubsub/v1/StreamingSubscriberConnection$Builder</className>
+ <method>com.google.cloud.pubsub.v1.StreamingSubscriberConnection$Builder setExactlyOnceDeliveryEnabled(boolean)</method>
+ </difference>
+ <difference>
+ <differenceType>7002</differenceType>
+ <className>com/google/cloud/pubsub/v1/MessageDispatcher$Builder</className>
+ <method>com.google.cloud.pubsub.v1.MessageDispatcher$Builder setEnableExactlyOnceDelivery(boolean)</method>
+ </difference>
+</differences>

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/AckReplyConsumerWithResponse.java

@@ -18,8 +18,34 @@
 
 import java.util.concurrent.Future;
 
+/**
+ * Acknowledging a message in Pub/Sub means that you are done with it, and it will not be delivered
+ * to this subscription again. You should avoid acknowledging messages until you have *finished*
+ * processing them, so that in the event of a failure, you receive the message again.
+ *
+ * <p>If exactly-once delivery is enabled on the subscription, the future returned by the ack/nack
+ * methods track the state of acknowledgement operation by the server. If the future completes
+ * successfully, the message is guaranteed NOT to be re-delivered. Otherwise, the future will
+ * contain an exception with more details about the failure and the message may be re-delivered.
+ *
+ * <p>If exactly-once delivery is NOT enabled on the subscription, the future returns immediately
+ * with an AckResponse.SUCCESS. Because re-deliveries are possible, you should ensure that your
+ * processing code is idempotent, as you may receive any given message more than once.
+ */
 public interface AckReplyConsumerWithResponse {
+ /**
+ * Acknowledges that the message has been successfully processed. The service will not send the
+ * message again.
+ *
+ * <p>A future representing the server response is returned
+ */
  Future<AckResponse> ack();
 
+ /**
+ * Signals that the message has not been successfully processed. The service should resend the
+ * message.
+ *
+ * <p>A future representing the server response is returned
+ */
  Future<AckResponse> nack();
 }

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/MessageDispatcher.java

@@ -70,7 +70,7 @@ class MessageDispatcher {
 
  private final FlowController flowController;
 
- private AtomicBoolean enableExactlyOnceDelivery;
+ private AtomicBoolean exactlyOnceDeliveryEnabled = new AtomicBoolean(false);
 
  private final Waiter messagesWaiter;
 
@@ -198,7 +198,6 @@ private MessageDispatcher(Builder builder) {
 
  ackProcessor = builder.ackProcessor;
  flowController = builder.flowController;
- enableExactlyOnceDelivery = new AtomicBoolean(builder.enableExactlyOnceDelivery);
  ackLatencyDistribution = builder.ackLatencyDistribution;
  clock = builder.clock;
  jobLock = new ReentrantLock();
@@ -296,13 +295,13 @@ int getMessageDeadlineSeconds() {
  }
 
  @InternalApi
- void setEnableExactlyOnceDelivery(boolean enableExactlyOnceDelivery) {
- // Sanity check that we are changing the enableExactlyOnceDelivery state
- if (enableExactlyOnceDelivery == this.enableExactlyOnceDelivery.get()) {
+ void setExactlyOnceDeliveryEnabled(boolean exactlyOnceDeliveryEnabled) {
+ // Sanity check that we are changing the exactlyOnceDeliveryEnabled state
+ if (exactlyOnceDeliveryEnabled == this.exactlyOnceDeliveryEnabled.get()) {
  return;
  }
 
- this.enableExactlyOnceDelivery.set(enableExactlyOnceDelivery);
+ this.exactlyOnceDeliveryEnabled.set(exactlyOnceDeliveryEnabled);
 
  // If a custom value for minDurationPerAckExtension, we should respect that
  if (!minDurationPerAckExtensionDefaultUsed) {
@@ -313,7 +312,7 @@ void setEnableExactlyOnceDelivery(boolean enableExactlyOnceDelivery) {
  // maxDurationPerAckExtensionSeconds does not change
  int possibleNewMinAckDeadlineExtensionSeconds;
 
- if (enableExactlyOnceDelivery) {
+ if (exactlyOnceDeliveryEnabled) {
  possibleNewMinAckDeadlineExtensionSeconds =
  Math.toIntExact(
  Subscriber.DEFAULT_MIN_ACK_DEADLINE_EXTENSION_EXACTLY_ONCE_DELIVERY.getSeconds());
@@ -323,7 +322,7 @@ void setEnableExactlyOnceDelivery(boolean enableExactlyOnceDelivery) {
  }
 
  // If we are not using the default maxDurationAckExtension, check if the
- // minAckDeadlineExtensionExactlyOnce needs to be bounded by the set max
+ // minAckDeadlineExtensionExactlyOnceDelivery needs to be bounded by the set max
  if (!maxDurationPerAckExtensionDefaultUsed
  && (possibleNewMinAckDeadlineExtensionSeconds > maxDurationPerAckExtensionSeconds)) {
  minDurationPerAckExtensionSeconds = maxDurationPerAckExtensionSeconds;
@@ -580,7 +579,6 @@ public static final class Builder {
 
  private Distribution ackLatencyDistribution;
  private FlowController flowController;
- private boolean enableExactlyOnceDelivery;
 
  private Executor executor;
  private ScheduledExecutorService systemExecutor;
@@ -641,11 +639,6 @@ public Builder setFlowController(FlowController flowController) {
  return this;
  }
 
- public Builder setEnableExactlyOnceDelivery(boolean enableExactlyOnceDelivery) {
- this.enableExactlyOnceDelivery = enableExactlyOnceDelivery;
- return this;
- }
-
  public Builder setExecutor(Executor executor) {
  this.executor = executor;
  return this;

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/StreamingSubscriberConnection.java

@@ -103,12 +103,7 @@ private StreamingSubscriberConnection(Builder builder) {
  // We need to set the default stream ack deadline on the initial request, this will be
  // updated by modack requests in the message dispatcher
  if (builder.maxDurationPerAckExtensionDefaultUsed) {
- // If the default is used, check if exactly once is enabled and set appropriately
- if (builder.exactlyOnceDeliveryEnabled) {
- inititalStreamAckDeadline = Subscriber.STREAM_ACK_DEADLINE_EXACTLY_ONCE_DELIVERY_DEFAULT;
- } else {
- inititalStreamAckDeadline = Subscriber.STREAM_ACK_DEADLINE_DEFAULT;
- }
+ inititalStreamAckDeadline = Subscriber.STREAM_ACK_DEADLINE_DEFAULT;
  } else if (builder.maxDurationPerAckExtension.compareTo(Subscriber.MIN_STREAM_ACK_DEADLINE)
  < 0) {
  // We will not be able to extend more than the default minimum
@@ -123,7 +118,6 @@ private StreamingSubscriberConnection(Builder builder) {
 
  subscriberStub = builder.subscriberStub;
  channelAffinity = builder.channelAffinity;
- exactlyOnceDeliveryEnabled.set(builder.exactlyOnceDeliveryEnabled);
 
  MessageDispatcher.Builder messageDispatcherBuilder;
  if (builder.receiver != null) {
@@ -143,7 +137,6 @@ private StreamingSubscriberConnection(Builder builder) {
  .setMaxDurationPerAckExtensionDefaultUsed(builder.maxDurationPerAckExtensionDefaultUsed)
  .setAckLatencyDistribution(builder.ackLatencyDistribution)
  .setFlowController(builder.flowController)
- .setEnableExactlyOnceDelivery(builder.exactlyOnceDeliveryEnabled)
  .setExecutor(builder.executor)
  .setSystemExecutor(builder.systemExecutor)
  .setApiClock(builder.clock)
@@ -159,7 +152,7 @@ public StreamingSubscriberConnection setExactlyOnceDeliveryEnabled(
  return this;
  }
 
- public boolean isExactlyOnceDeliveryEnabled() {
+ public boolean getExactlyOnceDeliveryEnabled() {
  return exactlyOnceDeliveryEnabled.get();
  }
 
@@ -221,7 +214,7 @@ public void onResponse(StreamingPullResponse response) {
  response.getSubscriptionProperties().getExactlyOnceDeliveryEnabled();
 
  setExactlyOnceDeliveryEnabled(exactlyOnceDeliveryEnabledResponse);
- messageDispatcher.setEnableExactlyOnceDelivery(exactlyOnceDeliveryEnabledResponse);
+ messageDispatcher.setExactlyOnceDeliveryEnabled(exactlyOnceDeliveryEnabledResponse);
  messageDispatcher.processReceivedMessages(response.getReceivedMessagesList());
 
  // Only request more if we're not shutdown.
@@ -370,7 +363,7 @@ public void setResponseOutstandingMessages(AckResponse ackResponse) {
  private void setFailureFutureOutstandingMessages(Throwable t) {
  AckResponse ackResponse;
 
- if (isExactlyOnceDeliveryEnabled()) {
+ if (getExactlyOnceDeliveryEnabled()) {
  if (!(t instanceof ApiException)) {
  ackResponse = AckResponse.OTHER;
  }
@@ -518,7 +511,7 @@ public void onFailure(Throwable t) {
  // Remove from our pending operations
  ackOperationsWaiter.incrementPendingCount(-1);
 
- if (!isExactlyOnceDeliveryEnabled()) {
+ if (!getExactlyOnceDeliveryEnabled()) {
  Level level = isAlive() ? Level.WARNING : Level.FINER;
  logger.log(level, "failed to send operations", t);
  return;
@@ -609,7 +602,6 @@ public static final class Builder {
  private int channelAffinity;
  private FlowController flowController;
  private FlowControlSettings flowControlSettings;
- private boolean exactlyOnceDeliveryEnabled;
  private boolean useLegacyFlowControl;
  private ScheduledExecutorService executor;
  private ScheduledExecutorService systemExecutor;
@@ -690,11 +682,6 @@ public Builder setUseLegacyFlowControl(boolean useLegacyFlowControl) {
  return this;
  }
 
- public Builder setExactlyOnceDeliveryEnabled(boolean exactlyOnceDeliveryEnabled) {
- this.exactlyOnceDeliveryEnabled = exactlyOnceDeliveryEnabled;
- return this;
- }
-
  public Builder setExecutor(ScheduledExecutorService executor) {
  this.executor = executor;
  return this;

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Subscriber.java

@@ -134,7 +134,6 @@ public class Subscriber extends AbstractApiService implements SubscriberInterfac
  private SubscriberStub subscriberStub;
  private final SubscriberStubSettings subStubSettings;
  private final FlowController flowController;
- private boolean exactlyOnceDeliveryEnabled = false;
  private final int numPullers;
 
  private final MessageReceiver receiver;
@@ -166,8 +165,6 @@ private Subscriber(Builder builder) {
  .setLimitExceededBehavior(LimitExceededBehavior.Block)
  .build());
 
- exactlyOnceDeliveryEnabled = builder.exactlyOnceDeliveryEnabled;
-
  this.numPullers = builder.parallelPullCount;
 
  executorProvider = builder.executorProvider;
@@ -385,7 +382,6 @@ private void startStreamingConnections() {
  .setExecutor(executor)
  .setSystemExecutor(alarmsExecutor)
  .setClock(clock)
- .setExactlyOnceDeliveryEnabled(exactlyOnceDeliveryEnabled)
  .build();
 
  streamingSubscriberConnections.add(streamingSubscriberConnection);
@@ -479,8 +475,6 @@ public static final class Builder {
  private boolean useLegacyFlowControl = false;
  private FlowControlSettings flowControlSettings = DEFAULT_FLOW_CONTROL_SETTINGS;
 
- private boolean exactlyOnceDeliveryEnabled = false;
-
  private ExecutorProvider executorProvider = DEFAULT_EXECUTOR_PROVIDER;
  private ExecutorProvider systemExecutorProvider = null;
  private TransportChannelProvider channelProvider =
@@ -573,22 +567,6 @@ public Builder setUseLegacyFlowControl(boolean value) {
  return this;
  }
 
- /**
- * Enables/Disabled ExactlyOnceDelivery
- *
- * <p>Will update the minDurationPerAckExtension if a user-provided value is not set
- */
- public Builder setExactlyOnceDeliveryEnabled(boolean exactlyOnceDeliveryEnabled) {
- // If exactlyOnceDeliveryIsEnabled we want to update the default minAckDeadlineExtension if
- // applicable
- if (exactlyOnceDeliveryEnabled && this.minDurationPerAckExtensionDefaultUsed) {
- this.minDurationPerAckExtension = DEFAULT_MIN_ACK_DEADLINE_EXTENSION_EXACTLY_ONCE_DELIVERY;
- }
-
- this.exactlyOnceDeliveryEnabled = exactlyOnceDeliveryEnabled;
- return this;
- }
-
  /**
  * Set the maximum period a message ack deadline will be extended. Defaults to one hour.
  *

google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/it/ITPubSubTest.java

@@ -209,7 +209,6 @@ public void receiveMessage(
  receiveQueue.offer(MessageAndConsumer.create(message, consumer));
  }
  })
- .setExactlyOnceDeliveryEnabled(true)
  .build();
  subscriber.addListener(
  new Subscriber.Listener() {
@@ -282,7 +281,6 @@ public void receiveMessage(
  SubscriptionAdminSettings.defaultGrpcTransportProviderBuilder()
  .setMaxInboundMessageSize(MAX_INBOUND_MESSAGE_SIZE)
  .build())
- .setExactlyOnceDeliveryEnabled(false)
  .build();
  subscriber.addListener(
  new Subscriber.Listener() {
@@ -360,7 +358,6 @@ public void receiveMessage(
  SubscriptionAdminSettings.defaultGrpcTransportProviderBuilder()
  .setMaxInboundMessageSize(MAX_INBOUND_MESSAGE_SIZE)
  .build())
- .setExactlyOnceDeliveryEnabled(false)
  .build();
  subscriber.addListener(
  new Subscriber.Listener() {