fix: update grpc based ReadObject rpcs to remove race condition between cancellation and message handling (#2708)

Update GapicUnbufferedReadableByteChannel to manage the grpc stream itself rather than using the stream iterator provided by gax. This allows us to ensure the cancellation is observed and our draining performs before returning from close().

As a side effect of not using the gax stream iterator, we now must handle stream restarts ourselves. GrpcStorageOptions.ReadObjectResumptionStrategy has been removed entirely, while RetryingDependencies and ResultRetryAlgorithm are now plumbed all the way down to the GapicUnbufferedReadableByteChannel.

Author: BenWhitehead

google-cloud-storage/src/main/java/com/google/cloud/storage/GapicDownloadSessionBuilder.java

@@ -20,8 +20,10 @@
 
 import com.google.api.core.ApiFutures;
 import com.google.api.core.SettableApiFuture;
+import com.google.api.gax.retrying.ResultRetryAlgorithm;
 import com.google.api.gax.rpc.ServerStreamingCallable;
 import com.google.cloud.storage.BufferedReadableByteChannelSession.BufferedReadableByteChannel;
+import com.google.cloud.storage.Retrying.RetryingDependencies;
 import com.google.cloud.storage.UnbufferedReadableByteChannelSession.UnbufferedReadableByteChannel;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.storage.v2.Object;
@@ -43,27 +45,32 @@ public static GapicDownloadSessionBuilder create() {
     return INSTANCE;
   }
 
-  /**
-   * Any retry capability must be defined within the provided ServerStreamingCallable. The
-   * ultimately produced channel will not do any retries of its own.
-   */
   public ReadableByteChannelSessionBuilder byteChannel(
       ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> read,
+      RetryingDependencies retryingDependencies,
+      ResultRetryAlgorithm<?> resultRetryAlgorithm,
       ResponseContentLifecycleManager responseContentLifecycleManager) {
-    return new ReadableByteChannelSessionBuilder(read, responseContentLifecycleManager);
+    return new ReadableByteChannelSessionBuilder(
+        read, retryingDependencies, resultRetryAlgorithm, responseContentLifecycleManager);
   }
 
   public static final class ReadableByteChannelSessionBuilder {
 
     private final ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> read;
+    private final RetryingDependencies retryingDependencies;
+    private final ResultRetryAlgorithm<?> resultRetryAlgorithm;
     private final ResponseContentLifecycleManager responseContentLifecycleManager;
     private boolean autoGzipDecompression;
     private Hasher hasher;
 
     private ReadableByteChannelSessionBuilder(
         ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> read,
+        RetryingDependencies retryingDependencies,
+        ResultRetryAlgorithm<?> resultRetryAlgorithm,
         ResponseContentLifecycleManager responseContentLifecycleManager) {
       this.read = read;
+      this.retryingDependencies = retryingDependencies;
+      this.resultRetryAlgorithm = resultRetryAlgorithm;
       this.responseContentLifecycleManager = responseContentLifecycleManager;
       this.hasher = Hasher.noop();
       this.autoGzipDecompression = false;
@@ -105,12 +112,24 @@ public UnbufferedReadableByteChannelSessionBuilder unbuffered() {
         if (autoGzipDecompression) {
           return new GzipReadableByteChannel(
               new GapicUnbufferedReadableByteChannel(
-                  resultFuture, read, object, hasher, responseContentLifecycleManager),
+                  resultFuture,
+                  read,
+                  object,
+                  hasher,
+                  retryingDependencies,
+                  resultRetryAlgorithm,
+                  responseContentLifecycleManager),
               ApiFutures.transform(
                   resultFuture, Object::getContentEncoding, MoreExecutors.directExecutor()));
         } else {
           return new GapicUnbufferedReadableByteChannel(
-              resultFuture, read, object, hasher, responseContentLifecycleManager);
+              resultFuture,
+              read,
+              object,
+              hasher,
+              retryingDependencies,
+              resultRetryAlgorithm,
+              responseContentLifecycleManager);
         }
       };
     }