DATAREDIS-1138 - Fix detection whether XREAD is blocking.

We now correctly check if a BLOCK option is configured using a timeout of zero or higher. Previously we only checked if the configured value is greater than zero and didn't consider that a timeout of zero blocks indefinitely.

Original Pull Request: #528

Author: mp911de

src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveStreamCommands.java

@@ -322,7 +322,7 @@ public Flux<CommandResponse<ReadCommand, Flux<ByteBufferRecord>>> read(Publisher
 
 			StreamReadOptions readOptions = command.getReadOptions();
 
-			if (readOptions.getBlock() != null && readOptions.getBlock() > 0) {
+			if (readOptions.isBlocking()) {
 				return new CommandResponse<>(command, connection.executeDedicated(cmd -> doRead(command, readOptions, cmd)));
 			}
 

src/main/java/org/springframework/data/redis/connection/lettuce/LettuceStreamCommands.java

@@ -516,7 +516,7 @@ public List<ByteRecord> xRead(StreamReadOptions readOptions, StreamOffset<byte[]
 		XReadArgs.StreamOffset<byte[]>[] streamOffsets = toStreamOffsets(streams);
 		XReadArgs args = StreamConverters.toReadArgs(readOptions);
 
-		if (isBlocking(readOptions)) {
+		if (readOptions.isBlocking()) {
 
 			try {
 				if (isPipelined()) {
@@ -568,7 +568,7 @@ public List<ByteRecord> xReadGroup(Consumer consumer, StreamReadOptions readOpti
 		XReadArgs args = StreamConverters.toReadArgs(readOptions);
 		io.lettuce.core.Consumer<byte[]> lettuceConsumer = toConsumer(consumer);
 
-		if (isBlocking(readOptions)) {
+		if (readOptions.isBlocking()) {
 
 			try {
 				if (isPipelined()) {
@@ -699,9 +699,6 @@ private DataAccessException convertLettuceAccessException(Exception ex) {
 		return connection.convertLettuceAccessException(ex);
 	}
 
-	private static boolean isBlocking(StreamReadOptions readOptions) {
-		return readOptions.getBlock() != null && readOptions.getBlock() > 0;
-	}
 
 	@SuppressWarnings("unchecked")
 	private static XReadArgs.StreamOffset<byte[]>[] toStreamOffsets(StreamOffset<byte[]>[] streams) {

src/main/java/org/springframework/data/redis/connection/stream/StreamReadOptions.java

@@ -105,4 +105,12 @@ public StreamReadOptions count(long count) {
 
 		return new StreamReadOptions(block, count, noack);
 	}
+
+	/**
+	 * @return {@literal true} if the arguments indicate a blocking read.
+	 * @since 2.3
+	 */
+	public boolean isBlocking() {
+		return getBlock() != null && getBlock() >= 0;
+	}
 }

src/test/java/org/springframework/data/redis/connection/stream/StreamReadOptionsUnitTests.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.connection.stream;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.time.Duration;
+
+import org.junit.Test;
+
+/**
+ * Unit tests for {@link StreamReadOptions}.
+ * 
+ * @author Mark Paluch
+ */
+public class StreamReadOptionsUnitTests {
+
+	@Test // DATAREDIS-1138
+	public void shouldConsiderBlocking() {
+
+		assertThat(StreamReadOptions.empty().isBlocking()).isFalse();
+		assertThat(StreamReadOptions.empty().block(Duration.ofSeconds(1)).isBlocking()).isTrue();
+		assertThat(StreamReadOptions.empty().block(Duration.ZERO).isBlocking()).isTrue();
+	}
+}