Merge pull request #3293 from ipalbeniz/feature-local-cache-null-values

Feature - Added option to allow null values in a local cache #3221

redisson/src/main/java/org/redisson/RedissonLocalCachedMap.java

@@ -61,6 +61,7 @@ public class RedissonLocalCachedMap<K, V> extends RedissonMap<K, V> implements R
     private int invalidateEntryOnChange;
     private SyncStrategy syncStrategy;
     private LocalCachedMapOptions.StoreMode storeMode;
+    private boolean storeCacheMiss;
 
     private LocalCacheListener listener;
     private LocalCacheView<K, V> localCacheView;
@@ -80,6 +81,7 @@ public class RedissonLocalCachedMap<K, V> extends RedissonMap<K, V> implements R
     private void init(String name, LocalCachedMapOptions<K, V> options, RedissonClient redisson, EvictionScheduler evictionScheduler) {
         syncStrategy = options.getSyncStrategy();
         storeMode = options.getStoreMode();
+        storeCacheMiss = options.isStoreCacheMiss();
 
         listener = new LocalCacheListener(name, commandExecutor, this, codec, options, cacheUpdateLogTime) {
             
@@ -212,7 +214,7 @@ public class RedissonLocalCachedMap<K, V> extends RedissonMap<K, V> implements R
 
         CacheKey cacheKey = localCacheView.toCacheKey(key);
         CacheValue cacheValue = cache.get(cacheKey);
-        if (cacheValue != null && cacheValue.getValue() != null) {
+        if (cacheValue != null && (storeCacheMiss || cacheValue.getValue() != null)) {
             return RedissonPromise.newSucceededFuture((V) cacheValue.getValue());
         }
 
@@ -226,7 +228,7 @@ public class RedissonLocalCachedMap<K, V> extends RedissonMap<K, V> implements R
                 return;
             }
             
-            if (value != null) {
+            if (storeCacheMiss || value != null) {
                 cachePut(cacheKey, key, value);
             }
         });
@@ -244,7 +246,7 @@ public class RedissonLocalCachedMap<K, V> extends RedissonMap<K, V> implements R
         return result;
     }
 
-    
+
     @Override
     protected RFuture<V> putOperationAsync(K key, V value) {
         ByteBuf mapKey = encodeMapKey(key);

redisson/src/main/java/org/redisson/api/LocalCachedMapOptions.java

@@ -136,6 +136,7 @@ public class LocalCachedMapOptions<K, V> extends MapOptions<K, V> {
     private long maxIdleInMillis;
     private CacheProvider cacheProvider;
     private StoreMode storeMode;
+    private boolean storeCacheMiss;
     
     protected LocalCachedMapOptions() {
     }
@@ -149,6 +150,7 @@ public class LocalCachedMapOptions<K, V> extends MapOptions<K, V> {
         this.maxIdleInMillis = copy.maxIdleInMillis;
         this.cacheProvider = copy.cacheProvider;
         this.storeMode = copy.storeMode;
+        this.storeCacheMiss = copy.storeCacheMiss;
     }
     
     /**
@@ -161,7 +163,8 @@ public class LocalCachedMapOptions<K, V> extends MapOptions<K, V> {
      *      .evictionPolicy(EvictionPolicy.NONE)
      *      .reconnectionStrategy(ReconnectionStrategy.NONE)
      *      .cacheProvider(CacheProvider.REDISSON)
-     *      .syncStrategy(SyncStrategy.INVALIDATE);
+     *      .syncStrategy(SyncStrategy.INVALIDATE)
+     *      .storeCacheMiss(false);
      * </pre>
      * 
      * @param <K> key type
@@ -177,7 +180,8 @@ public class LocalCachedMapOptions<K, V> extends MapOptions<K, V> {
                     .reconnectionStrategy(ReconnectionStrategy.NONE)
                     .cacheProvider(CacheProvider.REDISSON)
                     .storeMode(StoreMode.LOCALCACHE_REDIS)
-                    .syncStrategy(SyncStrategy.INVALIDATE);
+                    .syncStrategy(SyncStrategy.INVALIDATE)
+                    .storeCacheMiss(false);
     }
 
     public CacheProvider getCacheProvider() {
@@ -334,6 +338,21 @@ public class LocalCachedMapOptions<K, V> extends MapOptions<K, V> {
         return this;
     }
 
+    public boolean isStoreCacheMiss() {
+        return this.storeCacheMiss;
+    }
+
+    /**
+     * Defines whether to store a cache miss into the local cache.
+     *
+     * @param storeCacheMiss - whether to store a cache miss into the local cache
+     * @return LocalCachedMapOptions instance
+     */
+    public LocalCachedMapOptions<K, V> storeCacheMiss(boolean storeCacheMiss) {
+        this.storeCacheMiss = storeCacheMiss;
+        return this;
+    }
+
     @Override
     public LocalCachedMapOptions<K, V> writeBehindBatchSize(int writeBehindBatchSize) {
         return (LocalCachedMapOptions<K, V>) super.writeBehindBatchSize(writeBehindBatchSize);

redisson/src/test/java/org/redisson/RedissonLocalCachedMapTest.java

@@ -9,6 +9,8 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 
+import org.awaitility.Awaitility;
+import org.awaitility.Durations;
 import org.junit.Assert;
 import org.junit.Test;
 import org.redisson.api.LocalCachedMapOptions;
@@ -466,7 +468,29 @@ public class RedissonLocalCachedMapTest extends BaseMapTest {
         assertThat(map1.get("14")).isEqualTo(2);
         assertThat(map1.get("15")).isEqualTo(3);
     }
-    
+
+    @Test
+    public void testGetStoringCacheMiss() {
+        RLocalCachedMap<String, Integer> map = redisson.getLocalCachedMap("test", LocalCachedMapOptions.<String, Integer>defaults().storeCacheMiss(true));
+        Map<String, Integer> cache = map.getCachedMap();
+
+        assertThat(map.get("19")).isNull();
+
+        Awaitility.await().atMost(Durations.ONE_SECOND)
+                .untilAsserted(() -> assertThat(cache.size()).isEqualTo(1));
+    }
+
+    @Test
+    public void testGetNotStoringCacheMiss() {
+        RLocalCachedMap<String, Integer> map = redisson.getLocalCachedMap("test", LocalCachedMapOptions.<String, Integer>defaults().storeCacheMiss(false));
+        Map<String, Integer> cache = map.getCachedMap();
+
+        assertThat(map.get("19")).isNull();
+
+        Awaitility.await().atMost(Durations.ONE_SECOND)
+                .untilAsserted(() -> assertThat(cache.size()).isEqualTo(0));
+    }
+
     @Test
     public void testGetAllCache() {
         RLocalCachedMap<String, Integer> map = redisson.getLocalCachedMap("getAll", LocalCachedMapOptions.defaults());