Fix call to block() in CouchbaseCallbackTransactionManager. (#1528)

Closes #1527.

Author: mikereiche

spring-data-couchbase/src/main/java/org/springframework/data/couchbase/core/TransactionalSupport.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.couchbase.core;
 
+import com.couchbase.client.core.transaction.threadlocal.TransactionMarker;
 import reactor.core.publisher.Mono;
 
 import java.util.Optional;
@@ -26,6 +27,7 @@
 import com.couchbase.client.core.error.transaction.TransactionOperationFailedException;
 import com.couchbase.client.core.transaction.CoreTransactionAttemptContext;
 import com.couchbase.client.core.transaction.threadlocal.TransactionMarkerOwner;
+import reactor.util.context.ContextView;
 
 /**
  * Utility methods to support transactions.
@@ -50,6 +52,14 @@ public static Mono<Optional<CouchbaseResourceHolder>> checkForTransactionInThrea
 		});
 	}
 
+	public static Optional<CouchbaseResourceHolder> checkForTransactionInThreadLocalStorage(ContextView ctx) {
+		return Optional.ofNullable(ctx.hasKey(TransactionMarker.class) ? new CouchbaseResourceHolder(ctx.get(TransactionMarker.class).context()) : null);
+	}
+
+	//public static Optional<CouchbaseResourceHolder> blockingCheckForTransactionInThreadLocalStorage() {
+	//		return TransactionMarkerOwner.marker;
+	//	}
+
 	public static Mono<Void> verifyNotInTransaction(String methodName) {
 		return checkForTransactionInThreadLocalStorage().flatMap(s -> {
 			if (s.isPresent()) {

spring-data-couchbase/src/main/java/org/springframework/data/couchbase/transaction/CouchbaseCallbackTransactionManager.java

@@ -44,6 +44,7 @@
 import com.couchbase.client.java.transactions.config.TransactionOptions;
 import com.couchbase.client.java.transactions.error.TransactionCommitAmbiguousException;
 import com.couchbase.client.java.transactions.error.TransactionFailedException;
+import reactor.util.context.ContextView;
 
 /**
  * The Couchbase transaction manager, providing support for @Transactional methods.
@@ -73,7 +74,7 @@ public CouchbaseCallbackTransactionManager(CouchbaseClientFactory couchbaseClien
 
 	@Override
 	public <T> T execute(TransactionDefinition definition, TransactionCallback<T> callback) throws TransactionException {
-		boolean createNewTransaction = handlePropagation(definition);
+		boolean createNewTransaction = handlePropagation(definition, null);
 
 		setOptionsFromDefinition(definition);
 
@@ -87,8 +88,8 @@ public <T> T execute(TransactionDefinition definition, TransactionCallback<T> ca
 	@Stability.Internal
 	<T> Flux<T> executeReactive(TransactionDefinition definition,
 			org.springframework.transaction.reactive.TransactionCallback<T> callback) {
-		return Flux.defer(() -> {
-			boolean createNewTransaction = handlePropagation(definition);
+		return Flux.deferContextual((ctx) -> {
+			boolean createNewTransaction = handlePropagation(definition, ctx);
 
 			setOptionsFromDefinition(definition);
 
@@ -187,8 +188,9 @@ public boolean isCompleted() {
 	}
 
 	// Propagation defines what happens when a @Transactional method is called from another @Transactional method.
-	private boolean handlePropagation(TransactionDefinition definition) {
-		boolean isExistingTransaction = TransactionalSupport.checkForTransactionInThreadLocalStorage().block().isPresent();
+	private boolean handlePropagation(TransactionDefinition definition, ContextView ctx) {
+		boolean isExistingTransaction = ctx != null ? TransactionalSupport.checkForTransactionInThreadLocalStorage(ctx).isPresent() :
+				TransactionalSupport.checkForTransactionInThreadLocalStorage().block().isPresent();
 
 		LOGGER.trace("Deciding propagation behaviour from {} and {}", definition.getPropagationBehavior(),
 				isExistingTransaction);