DATAREDIS-1062 - Polishing.

We now select the database on dedicated connection acquisition only if the current database is different from the default database. Database connections are expected to use the default database index when they are acquired so the database index may be changed for the duration when a connection is in use. We also reset dedicated connections to use the default database index on connection cleanup to bring the connection back into its initial state. Add author tag and tests. Original pull request: spring-projects#496.

Author: mp911de

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

@@ -84,6 +84,7 @@
  * @author David Liu
  * @author Mark Paluch
  * @author Ninad Divadkar
+ * @author Tamil Selvan
  */
 public class LettuceConnection extends AbstractRedisConnection {
 
@@ -451,6 +452,9 @@ public void close() throws DataAccessException {
 
 if (asyncDedicatedConn != null) {
 try {
+if (customizedDatabaseIndex()) {
+potentiallySelectDatabase(defaultDbIndex);
+}
 connectionProvider.release(asyncDedicatedConn);
 } catch (RuntimeException ex) {
 throw convertLettuceAccessException(ex);
@@ -946,12 +950,7 @@ private RedisAsyncCommands<byte[], byte[]> getAsyncDedicatedRedisCommands() {
 protected RedisClusterAsyncCommands<byte[], byte[]> getAsyncDedicatedConnection() {
 
 if (asyncDedicatedConn == null) {
-
 asyncDedicatedConn = doGetAsyncDedicatedConnection();
-
-if (asyncDedicatedConn instanceof StatefulRedisConnection) {
-((StatefulRedisConnection<byte[], byte[]>) asyncDedicatedConn).sync().select(dbIndex);
-}
 }
 
 if (asyncDedicatedConn instanceof StatefulRedisConnection) {
@@ -965,6 +964,16 @@ protected RedisClusterAsyncCommands<byte[], byte[]> getAsyncDedicatedConnection(
 String.format("%s is not a supported connection type.", asyncDedicatedConn.getClass().getName()));
 }
 
+private boolean customizedDatabaseIndex() {
+return defaultDbIndex != dbIndex;
+}
+
+private void potentiallySelectDatabase(int dbIndex) {
+if (asyncDedicatedConn instanceof StatefulRedisConnection) {
+((StatefulRedisConnection<byte[], byte[]>) asyncDedicatedConn).sync().select(dbIndex);
+}
+}
+
 @SuppressWarnings("unchecked")
 private RedisCommands<byte[], byte[]> getDedicatedRedisCommands() {
 return (RedisCommands) getDedicatedConnection();
@@ -973,15 +982,7 @@ private RedisCommands<byte[], byte[]> getDedicatedRedisCommands() {
 RedisClusterCommands<byte[], byte[]> getDedicatedConnection() {
 
 if (asyncDedicatedConn == null) {
-
 asyncDedicatedConn = doGetAsyncDedicatedConnection();
-
-if (asyncDedicatedConn instanceof StatefulRedisConnection && dbIndex > 0) {
-((StatefulRedisConnection<byte[], byte[]>) asyncDedicatedConn).sync().select(dbIndex);
-}
-else if (asyncDedicatedConn instanceof StatefulRedisConnection) {
-((StatefulRedisConnection<byte[], byte[]>) asyncDedicatedConn).sync();
-}
 }
 
 if (asyncDedicatedConn instanceof StatefulRedisConnection) {
@@ -997,7 +998,14 @@ else if (asyncDedicatedConn instanceof StatefulRedisConnection) {
 
 @SuppressWarnings("unchecked")
 protected StatefulConnection<byte[], byte[]> doGetAsyncDedicatedConnection() {
-return connectionProvider.getConnection(StatefulConnection.class);
+
+StatefulConnection connection = connectionProvider.getConnection(StatefulConnection.class);
+
+if (customizedDatabaseIndex()) {
+potentiallySelectDatabase(dbIndex);
+}
+
+return connection;
 }
 
 io.lettuce.core.ScanCursor getScanCursor(long cursorId) {

src/test/java/org/springframework/data/redis/connection/lettuce/LettuceConnectionIntegrationTests.java

@@ -26,6 +26,7 @@
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -213,18 +214,33 @@ public void testCloseReturnBrokenResourceToPool() {
 pool.destroy();
 }
 
-@Test
+@Test // DATAREDIS-1062
 public void testSelectNotShared() {
 DefaultLettucePool pool = new DefaultLettucePool(SettingsUtils.getHost(), SettingsUtils.getPort());
+GenericObjectPoolConfig config = new GenericObjectPoolConfig();
+config.setMaxTotal(1);
+config.setMaxIdle(1);
+pool.setPoolConfig(config);
 pool.setClientResources(LettuceTestClientResources.getSharedClientResources());
 pool.afterPropertiesSet();
 LettuceConnectionFactory factory2 = new LettuceConnectionFactory(pool);
+factory2.setDatabase(0);
 factory2.setShutdownTimeout(0);
 factory2.setShareNativeConnection(false);
 factory2.afterPropertiesSet();
 RedisConnection connection = factory2.getConnection();
+
 connection.select(2);
+connection.rPush("key".getBytes(), "value1".getBytes(), "value2".getBytes());
+List<byte[]> bytes = connection.bLPop(1, "key".getBytes());
+assertThat(bytes).hasSize(2);
 connection.close();
+
+connection = factory2.getConnection();
+assertThat(connection.lLen("key".getBytes())).isEqualTo(0);
+connection.select(2);
+assertThat(connection.lLen("key".getBytes())).isEqualTo(1);
+
 factory2.destroy();
 pool.destroy();
 }