DATAREDIS-188 - Infinite loop renaming a non-existent Collection when using Lettuce.

We run into an infinite loop in org.springframework.data.redis.support.collections.CollectionUtils.rename(K, K, RedisOperations<K, ?>) if no value was associated with the key which leads to operations.hasKey(...) always returning false which prevents the actual renaming. RedisCollections will only send rename command if values are present as empty collections cannot be stored and therefor cannot be renamed.

Original pull request: #28

src/main/java/org/springframework/data/redis/core/BoundKeyOperations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2013 the original author or authors.
+ * Copyright 2011-2014 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.
@@ -28,6 +28,7 @@ import org.springframework.data.redis.connection.DataType;
  * </p>
  * 
  * @author Costin Leau
+ * @author Christoph Strobl
  */
 public interface BoundKeyOperations<K> {
 
@@ -77,7 +78,8 @@ public interface BoundKeyOperations<K> {
 	Boolean persist();
 
 	/**
-	 * Renames the key.
+	 * Renames the key. <br />
+	 * <b>Note:</b> The new name for empty collections will be propagated on add of first element.
 	 * 
 	 * @param newKey new key
 	 */

src/main/java/org/springframework/data/redis/support/collections/AbstractRedisCollection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2013 the original author or authors.
+ * Copyright 2011-2014 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.
@@ -27,6 +27,7 @@ import org.springframework.data.redis.core.RedisOperations;
  * works only with normal, non-pipeline/multi-exec connections as it requires a reply to be sent right away.
  * 
  * @author Costin Leau
+ * @author Christoph Strobl
  */
 public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> implements RedisCollection<E> {
 
@@ -48,6 +49,7 @@ public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> i
 		return operations;
 	}
 
+	@Override
 	public boolean addAll(Collection<? extends E> c) {
 		boolean modified = false;
 		for (E e : c) {
@@ -56,10 +58,7 @@ public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> i
 		return modified;
 	}
 
-	public abstract boolean add(E e);
-
-	public abstract void clear();
-
+	@Override
 	public boolean containsAll(Collection<?> c) {
 		boolean contains = true;
 		for (Object object : c) {
@@ -68,8 +67,7 @@ public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> i
 		return contains;
 	}
 
-	public abstract boolean remove(Object o);
-
+	@Override
 	public boolean removeAll(Collection<?> c) {
 		boolean modified = false;
 		for (Object object : c) {
@@ -78,6 +76,60 @@ public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> i
 		return modified;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.BoundKeyOperations#expire(long, java.util.concurrent.TimeUnit)
+	 */
+	@Override
+	public Boolean expire(long timeout, TimeUnit unit) {
+		return operations.expire(key, timeout, unit);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.BoundKeyOperations#expireAt(java.util.Date)
+	 */
+	@Override
+	public Boolean expireAt(Date date) {
+		return operations.expireAt(key, date);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.BoundKeyOperations#getExpire()
+	 */
+	@Override
+	public Long getExpire() {
+		return operations.getExpire(key);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.BoundKeyOperations#persist()
+	 */
+	@Override
+	public Boolean persist() {
+		return operations.persist(key);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.core.BoundKeyOperations#rename(java.lang.Object)
+	 */
+	@Override
+	public void rename(final String newKey) {
+		if (!this.isEmpty()) {
+			CollectionUtils.rename(key, newKey, operations);
+		}
+		key = newKey;
+	}
+
+	protected void checkResult(Object obj) {
+		if (obj == null) {
+			throw new IllegalStateException("Cannot read collection with Redis connection in pipeline/multi-exec mode");
+		}
+	}
+
 	public boolean equals(Object o) {
 		if (o == this)
 			return true;
@@ -105,30 +157,4 @@ public abstract class AbstractRedisCollection<E> extends AbstractCollection<E> i
 		return sb.toString();
 	}
 
-	public Boolean expire(long timeout, TimeUnit unit) {
-		return operations.expire(key, timeout, unit);
-	}
-
-	public Boolean expireAt(Date date) {
-		return operations.expireAt(key, date);
-	}
-
-	public Long getExpire() {
-		return operations.getExpire(key);
-	}
-
-	public Boolean persist() {
-		return operations.persist(key);
-	}
-
-	public void rename(final String newKey) {
-		CollectionUtils.rename(key, newKey, operations);
-		key = newKey;
-	}
-
-	protected void checkResult(Object obj) {
-		if (obj == null) {
-			throw new IllegalStateException("Cannot read collection with Redis connection in pipeline/multi-exec mode");
-		}
-	}
 }