DATAREDIS-542 - Polishing.

Prevent putIfAbsent from prolonging expiration time of existing keys having same value. Remove some trailing white spaces. Original Pull Request: spring-projects#224

Author: christophstrobl

src/main/java/org/springframework/data/redis/cache/RedisCache.java

@@ -76,7 +76,7 @@ public RedisCache(String name, byte[] prefix, RedisOperations<? extends Object,
 /**
  * Return the value to which this cache maps the specified key, generically specifying a type that return value will
  * be cast to.
- * 
+ *
  * @param key
  * @param type
  * @return
@@ -126,7 +126,7 @@ public <T> T get(final Object key, final Callable<T> valueLoader) {
 
 /**
  * Return the value to which this cache maps the specified key.
- * 
+ *
  * @param cacheKey the key whose associated value is to be returned via its binary representation.
  * @return the {@link RedisCacheElement} stored at given key or {@literal null} if no value found for key.
  * @since 1.5
@@ -162,7 +162,7 @@ public void put(final Object key, final Object value) {
  * Add the element by adding {@link RedisCacheElement#get()} at {@link RedisCacheElement#getKeyBytes()}. If the cache
  * previously contained a mapping for this {@link RedisCacheElement#getKeyBytes()}, the old value is replaced by
  * {@link RedisCacheElement#get()}.
- * 
+ *
  * @param element must not be {@literal null}.
  * @since 1.5
  */
@@ -188,7 +188,7 @@ public ValueWrapper putIfAbsent(Object key, final Object value) {
 /**
  * Add the element as long as no element exists at {@link RedisCacheElement#getKeyBytes()}. If a value is present for
  * {@link RedisCacheElement#getKeyBytes()} this one is returned.
- * 
+ *
  * @param element must not be {@literal null}.
  * @return
  * @since 1.5
@@ -256,7 +256,7 @@ private ValueWrapper toWrapper(Object value) {
 /**
  * Metadata required to maintain {@link RedisCache}. Keeps track of additional data structures required for processing
  * cache operations.
- * 
+ *
  * @author Christoph Strobl
  * @since 1.5
  */
@@ -294,7 +294,7 @@ public boolean usesKeyPrefix() {
 
 /**
  * Get the binary representation of the key prefix.
- * 
+ *
  * @return never {@literal null}.
  */
 public byte[] getKeyPrefix() {
@@ -303,7 +303,7 @@ public byte[] getKeyPrefix() {
 
 /**
  * Get the binary representation of the key identifying the data structure used to maintain known keys.
- * 
+ *
  * @return never {@literal null}.
  */
 public byte[] getSetOfKnownKeysKey() {
@@ -312,7 +312,7 @@ public byte[] getSetOfKnownKeysKey() {
 
 /**
  * Get the binary representation of the key identifying the data structure used to lock the cache.
- * 
+ *
  * @return never {@literal null}.
  */
 public byte[] getCacheLockKey() {
@@ -321,7 +321,7 @@ public byte[] getCacheLockKey() {
 
 /**
  * Get the name of the cache.
- * 
+ *
  * @return
  */
 public String getCacheName() {
@@ -330,7 +330,7 @@ public String getCacheName() {
 
 /**
  * Set the default expiration time in seconds
- * 
+ *
  * @param defaultExpiration
  */
 public void setDefaultExpiration(long seconds) {
@@ -339,7 +339,7 @@ public void setDefaultExpiration(long seconds) {
 
 /**
  * Get the default expiration time in seconds.
- * 
+ *
  * @return
  */
 public long getDefaultExpiration() {
@@ -721,26 +721,17 @@ public byte[] doInRedis(BinaryRedisCacheElement element, RedisConnection connect
 
 waitForLock(connection);
 
-byte existingValue[] = null;
-
-boolean keyMaintenance;
-
 byte[] keyBytes = element.getKeyBytes();
 byte[] value = element.get();
 
-if (connection.setNX(keyBytes, value)) {
-keyMaintenance = true;
-} else {
-existingValue = connection.get(keyBytes);
-keyMaintenance = ObjectUtils.nullSafeEquals(value, existingValue);
+if (!connection.setNX(keyBytes, value)) {
+return connection.get(keyBytes);
 }
 
-if (keyMaintenance) {
-processKeyExpiration(element, connection);
-maintainKnownKeys(element, connection);
-}
+maintainKnownKeys(element, connection);
+processKeyExpiration(element, connection);
 
-return existingValue;
+return null;
 }
 }
 

src/test/java/org/springframework/data/redis/cache/RedisCacheUnitTests.java

@@ -197,7 +197,7 @@ public void putIfAbsentShouldNotExpireWhenValueWasNotSetAndRedisContainsOtherDat
  * @see DATAREDIS-542
  */
 @Test
-public void putIfAbsentShouldExpireWhenValueWasNotSetAndRedisContainsSameData() {
+public void putIfAbsentShouldNotSetExpireWhenValueWasNotSetAndRedisContainsSameData() {
 
 when(connectionMock.setNX(KEY_BYTES, VALUE_BYTES)).thenReturn(false);
 when(connectionMock.get(KEY_BYTES)).thenReturn(VALUE_BYTES);
@@ -206,7 +206,7 @@ public void putIfAbsentShouldExpireWhenValueWasNotSetAndRedisContainsSameData()
 Cache.ValueWrapper valueWrapper = cache.putIfAbsent(KEY, VALUE);
 
 assertThat(valueWrapper, is(notNullValue()));
-verify(connectionMock).expire(eq(KEY_BYTES), anyLong());
+verify(connectionMock, never()).expire(eq(KEY_BYTES), anyLong());
 }
 
 /**