Pubsub: use gapic client (#3581)

* bump checkstyle version to build on Java 9

The version of checkstyle we currently use uses tools.jar
which is removed from Java 9 and above as part of Project Jigsaw.
This commit uses a newer version of checkstyle that does not
use tools.jar.

Running `mvn checkstyle:checkstyle` succeeded.�

* maybe this will be java 7 compat...?

* pubsub: use GAPIC stub

* fix merge

* pr comment

Author: pongad

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

@@ -16,8 +16,8 @@
 
 package com.google.cloud.pubsub.v1;
 
+import com.google.api.gax.rpc.ApiException;
 import io.grpc.Status;
-import io.grpc.StatusRuntimeException;
 
 /** Utilities for handling gRPC {@link Status}. */
 final class StatusUtil {
@@ -26,23 +26,20 @@ private StatusUtil() {
   }
 
   public static boolean isRetryable(Throwable error) {
-    if (!(error instanceof StatusRuntimeException)) {
+    if (!(error instanceof ApiException)) {
       return true;
     }
-    StatusRuntimeException statusRuntimeException = (StatusRuntimeException) error;
-    switch (statusRuntimeException.getStatus().getCode()) {
+    ApiException apiException = (ApiException) error;
+    switch (apiException.getStatusCode().getCode()) {
       case DEADLINE_EXCEEDED:
       case INTERNAL:
       case CANCELLED:
       case RESOURCE_EXHAUSTED:
       case ABORTED:
         return true;
       case UNAVAILABLE:
-        if (statusRuntimeException.getMessage().contains("Server shutdownNow invoked")) {
-          return false;
-        } else {
-          return true;
-        }
+        // TODO(pongad): check that ApiException propagate message properly.
+        return !apiException.getMessage().contains("Server shutdownNow invoked");
       default:
         return false;
     }

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

@@ -18,29 +18,31 @@
 
 import com.google.api.core.AbstractApiService;
 import com.google.api.core.ApiClock;
+import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutureCallback;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.InternalApi;
 import com.google.api.core.SettableApiFuture;
 import com.google.api.gax.batching.FlowController;
 import com.google.api.gax.core.Distribution;
+import com.google.api.gax.grpc.GrpcCallContext;
 import com.google.api.gax.grpc.GrpcStatusCode;
 import com.google.api.gax.rpc.ApiException;
 import com.google.api.gax.rpc.ApiExceptionFactory;
+import com.google.api.gax.rpc.ClientStream;
+import com.google.api.gax.rpc.ResponseObserver;
+import com.google.api.gax.rpc.StreamController;
 import com.google.cloud.pubsub.v1.MessageDispatcher.AckProcessor;
 import com.google.cloud.pubsub.v1.MessageDispatcher.PendingModifyAckDeadline;
+import com.google.cloud.pubsub.v1.stub.SubscriberStub;
 import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.protobuf.Empty;
 import com.google.pubsub.v1.AcknowledgeRequest;
 import com.google.pubsub.v1.ModifyAckDeadlineRequest;
 import com.google.pubsub.v1.StreamingPullRequest;
 import com.google.pubsub.v1.StreamingPullResponse;
-import com.google.pubsub.v1.SubscriberGrpc.SubscriberStub;
 import io.grpc.Status;
-import io.grpc.stub.ClientCallStreamObserver;
-import io.grpc.stub.ClientResponseObserver;
-import io.grpc.stub.StreamObserver;
 import java.util.ArrayList;
 import java.util.Deque;
 import java.util.List;
@@ -62,9 +64,9 @@ final class StreamingSubscriberConnection extends AbstractApiService implements
   private static final Duration INITIAL_CHANNEL_RECONNECT_BACKOFF = Duration.ofMillis(100);
   private static final Duration MAX_CHANNEL_RECONNECT_BACKOFF = Duration.ofSeconds(10);
   private static final int MAX_PER_REQUEST_CHANGES = 1000;
-  private static final Duration UNARY_TIMEOUT = Duration.ofSeconds(60);
 
   private final SubscriberStub stub;
+  private final int channelAffinity;
   private final String subscription;
   private final ScheduledExecutorService systemExecutor;
   private final MessageDispatcher messageDispatcher;
@@ -73,7 +75,7 @@ final class StreamingSubscriberConnection extends AbstractApiService implements
       new AtomicLong(INITIAL_CHANNEL_RECONNECT_BACKOFF.toMillis());
 
   private final Lock lock = new ReentrantLock();
-  private ClientCallStreamObserver<StreamingPullRequest> requestObserver;
+  private ClientStream<StreamingPullRequest> clientStream;
 
   public StreamingSubscriberConnection(
       String subscription,
@@ -82,6 +84,7 @@ public StreamingSubscriberConnection(
       Duration maxAckExtensionPeriod,
       Distribution ackLatencyDistribution,
       SubscriberStub stub,
+      int channelAffinity,
       FlowController flowController,
       Deque<MessageDispatcher.OutstandingMessageBatch> outstandingMessageBatches,
       ScheduledExecutorService executor,
@@ -90,6 +93,7 @@ public StreamingSubscriberConnection(
     this.subscription = subscription;
     this.systemExecutor = systemExecutor;
     this.stub = stub;
+    this.channelAffinity = channelAffinity;
     this.messageDispatcher =
         new MessageDispatcher(
             receiver,
@@ -118,15 +122,14 @@ protected void doStop() {
 
     lock.lock();
     try {
-      requestObserver.onError(Status.CANCELLED.asException());
+      clientStream.closeSendWithError(Status.CANCELLED.asException());
     } finally {
       lock.unlock();
       notifyStopped();
     }
   }
 
-  private class StreamingPullResponseObserver
-      implements ClientResponseObserver<StreamingPullRequest, StreamingPullResponse> {
+  private class StreamingPullResponseObserver implements ResponseObserver<StreamingPullResponse> {
 
     final SettableApiFuture<Void> errorFuture;
 
@@ -137,20 +140,21 @@ private class StreamingPullResponseObserver
      * the user can deal with -- so we save the request observer this response observer is "paired
      * with". If the stream has already errored, requesting more messages is a no-op.
      */
-    ClientCallStreamObserver<StreamingPullRequest> thisRequestObserver;
+    StreamController thisController;
 
     StreamingPullResponseObserver(SettableApiFuture<Void> errorFuture) {
       this.errorFuture = errorFuture;
     }
 
     @Override
-    public void beforeStart(ClientCallStreamObserver<StreamingPullRequest> requestObserver) {
-      thisRequestObserver = requestObserver;
-      requestObserver.disableAutoInboundFlowControl();
+    public void onStart(StreamController controller) {
+      thisController = controller;
+      thisController.disableAutoInboundFlowControl();
+      thisController.request(1);
     }
 
     @Override
-    public void onNext(StreamingPullResponse response) {
+    public void onResponse(StreamingPullResponse response) {
       channelReconnectBackoffMillis.set(INITIAL_CHANNEL_RECONNECT_BACKOFF.toMillis());
       messageDispatcher.processReceivedMessages(
           response.getReceivedMessagesList(),
@@ -163,7 +167,7 @@ public void run() {
               if (isAlive() && !errorFuture.isDone()) {
                 lock.lock();
                 try {
-                  thisRequestObserver.request(1);
+                  thisController.request(1);
                 } catch (Exception e) {
                   logger.log(Level.WARNING, "cannot request more messages", e);
                 } finally {
@@ -180,29 +184,30 @@ public void onError(Throwable t) {
     }
 
     @Override
-    public void onCompleted() {
+    public void onComplete() {
       logger.fine("Streaming pull terminated successfully!");
       errorFuture.set(null);
     }
   }
 
   private void initialize() {
     final SettableApiFuture<Void> errorFuture = SettableApiFuture.create();
-    final ClientResponseObserver<StreamingPullRequest, StreamingPullResponse> responseObserver =
+    final ResponseObserver<StreamingPullResponse> responseObserver =
         new StreamingPullResponseObserver(errorFuture);
-    final ClientCallStreamObserver<StreamingPullRequest> requestObserver =
-        (ClientCallStreamObserver<StreamingPullRequest>) (stub.streamingPull(responseObserver));
-    logger.log(
-        Level.FINER,
-        "Initializing stream to subscription {0}",subscription);
-        // We need to set streaming ack deadline, but it's not useful since we'll modack to send receipt anyway.
-        // Set to some big-ish value in case we modack late.
-    requestObserver.onNext(
+    ClientStream<StreamingPullRequest> initClientStream =
+        stub.streamingPullCallable()
+            .splitCall(
+                responseObserver,
+                GrpcCallContext.createDefault().withChannelAffinity(channelAffinity));
+
+    logger.log(Level.FINER, "Initializing stream to subscription {0}", subscription);
+    // We need to set streaming ack deadline, but it's not useful since we'll modack to send receipt
+    // anyway. Set to some big-ish value in case we modack late.
+    initClientStream.send(
         StreamingPullRequest.newBuilder()
             .setSubscription(subscription)
             .setStreamAckDeadlineSeconds(60)
             .build());
-    requestObserver.request(1);
 
     /**
      * Must make sure we do this after sending the subscription name and deadline. Otherwise, some
@@ -211,7 +216,7 @@ private void initialize() {
      */
     lock.lock();
     try {
-      this.requestObserver = requestObserver;
+      this.clientStream = initClientStream;
     } finally {
       lock.unlock();
     }
@@ -273,45 +278,43 @@ private boolean isAlive() {
   @Override
   public void sendAckOperations(
       List<String> acksToSend, List<PendingModifyAckDeadline> ackDeadlineExtensions) {
-    SubscriberStub timeoutStub =
-        stub.withDeadlineAfter(UNARY_TIMEOUT.toMillis(), TimeUnit.MILLISECONDS);
-    StreamObserver<Empty> loggingObserver = new StreamObserver<Empty>() {
-      @Override
-      public void onCompleted() {
-        // noop
-      }
-
-      @Override
-      public void onNext(Empty e) {
-        // noop
-      }
+    ApiFutureCallback<Empty> loggingCallback =
+        new ApiFutureCallback<Empty>() {
+          @Override
+          public void onSuccess(Empty empty) {
+            // noop
+          }
 
-      @Override
-      public void onError(Throwable t) {
-        Level level = isAlive() ? Level.WARNING : Level.FINER;
-        logger.log(level, "failed to send operations", t);
-      }
-    };
+          @Override
+          public void onFailure(Throwable t) {
+            Level level = isAlive() ? Level.WARNING : Level.FINER;
+            logger.log(level, "failed to send operations", t);
+          }
+        };
 
     for (PendingModifyAckDeadline modack : ackDeadlineExtensions) {
       for (List<String> idChunk : Lists.partition(modack.ackIds, MAX_PER_REQUEST_CHANGES)) {
-        timeoutStub.modifyAckDeadline(
-            ModifyAckDeadlineRequest.newBuilder()
-                .setSubscription(subscription)
-                .addAllAckIds(idChunk)
-                .setAckDeadlineSeconds(modack.deadlineExtensionSeconds)
-                .build(),
-            loggingObserver);
+        ApiFuture<Empty> future =
+            stub.modifyAckDeadlineCallable()
+                .futureCall(
+                    ModifyAckDeadlineRequest.newBuilder()
+                        .setSubscription(subscription)
+                        .addAllAckIds(idChunk)
+                        .setAckDeadlineSeconds(modack.deadlineExtensionSeconds)
+                        .build());
+        ApiFutures.addCallback(future, loggingCallback);
       }
     }
 
     for (List<String> idChunk : Lists.partition(acksToSend, MAX_PER_REQUEST_CHANGES)) {
-      timeoutStub.acknowledge(
-          AcknowledgeRequest.newBuilder()
-              .setSubscription(subscription)
-              .addAllAckIds(idChunk)
-              .build(),
-          loggingObserver);
+      ApiFuture<Empty> future =
+          stub.acknowledgeCallable()
+              .futureCall(
+                  AcknowledgeRequest.newBuilder()
+                      .setSubscription(subscription)
+                      .addAllAckIds(idChunk)
+                      .build());
+      ApiFutures.addCallback(future, loggingCallback);
     }
   }