fix empty member bug in SerializedMappedSet

Author: drm

src/nl/melp/redis/collections/SerializedMappedSet.java

@@ -7,6 +7,36 @@
 import java.util.Collection;
 
 public class SerializedMappedSet<K, V> implements Map<K, Set<V>> {
+	private class SerializedMemberSet extends SerializedSet<V> {
+		private final K key;
+
+		public SerializedMemberSet(K key, ISerializer<V> serializer, Redis redis, String keyName) {
+			super(serializer, redis, keyName);
+			this.key = key;
+
+			if (size() > 0) {
+				keys.add(key);
+			}
+		}
+
+		@Override
+		public void clear() {
+			super.clear();
+			keys.remove(key);
+			cache.remove(key);
+		}
+
+		@Override
+		public boolean remove(Object o) {
+			boolean removed = super.remove(o);
+			if (removed && size() == 0) {
+				keys.remove(key);
+				cache.remove(key);
+			}
+			return removed;
+		}
+	}
+
 	private final byte[] prefix;
 	private final int prefixLength;
 
@@ -74,9 +104,8 @@ public Set<V> get(Object o) {
 		synchronized (redis) {
 			K key = (K)o;
 
-			this.keys.add(key);
 			if (!this.cache.containsKey(key)) {
-				this.cache.put(key, new SerializedSet<>(this.valueSerializer, this.redis, new String(this.withPrefix(this.keySerializer.serialize(key)))));
+				this.cache.put(key, new SerializedMemberSet(key, this.valueSerializer, this.redis, new String(this.withPrefix(this.keySerializer.serialize(key)))));
 			}
 			return this.cache.get(o);
 		}
@@ -96,6 +125,8 @@ public Set<V> put(K k, Set<V> vs) {
 	public Set<V> remove(Object o) {
 		synchronized (redis) {
 			Set<V> vs = this.get(o);
+			keys.remove(o);
+			cache.remove(o);
 			vs.clear();
 			return vs;
 		}

test/nl/melp/redis/collections/IntegrationTest.java

@@ -344,11 +344,7 @@ public void testSerializedMappedSetForInForEach() throws IOException {
 			}
 		}
 
-		map.forEach((k, v) -> {
-			v.forEach(s -> {
-				pairs2.add(k + "." + s);
-			});
-		});
+		map.forEach((k, v) -> v.forEach(s -> pairs2.add(k + "." + s)));
 
 		Assert.assertEquals(6, pairs.size());
 		for (String expected : new String[]{"A.1", "A.2", "A.3", "B.1", "B.2", "B.3",}) {
@@ -358,4 +354,14 @@ public void testSerializedMappedSetForInForEach() throws IOException {
 
 		map.clear();
 	}
+
+
+	@Test
+	public void testSerializedMappedSetKeySynchronization() throws IOException {
+		Map<String, Set<String>> map = new SerializedMappedSet<>(Serializers.of(String.class), Serializers.of(String.class), redis, keyName);
+		Assert.assertEquals(0, map.get("A").size());
+		Assert.assertEquals(0, map.size());
+		map.remove("A");
+		Assert.assertEquals(0, map.size());
+	}
 }