Add ConcurrentHashMap.KeySetView serializer (#1183)

* Add ConcurrentHashMap.KeySetView serializer

Author: bergander

src/com/esotericsoftware/kryo/serializers/DefaultSerializers.java

@@ -62,6 +62,7 @@
 import java.util.TreeMap;
 import java.util.TreeSet;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentSkipListMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -852,6 +853,27 @@ private PriorityQueue createPriorityQueue (Class<? extends Collection> type, int
 		}
 	}
 
+	/** Serializer for {@link ConcurrentHashMap.KeySetView}.
+	 * @author Andreas Bergander */
+	public static class KeySetViewSerializer extends Serializer<ConcurrentHashMap.KeySetView> {
+		public void write (Kryo kryo, Output output, ConcurrentHashMap.KeySetView set) {
+			kryo.writeClassAndObject(output, set.getMap());
+			kryo.writeClassAndObject(output, set.getMappedValue());
+		}
+
+		public ConcurrentHashMap.KeySetView read (Kryo kryo, Input input, Class<? extends ConcurrentHashMap.KeySetView> type) {
+			return createKeySetView((ConcurrentHashMap)kryo.readClassAndObject(input), kryo.readClassAndObject(input));
+		}
+
+		public ConcurrentHashMap.KeySetView copy (Kryo kryo, ConcurrentHashMap.KeySetView original) {
+			return createKeySetView(kryo.copy(original.getMap()), kryo.copy(original.getMappedValue()));
+		}
+
+		private ConcurrentHashMap.KeySetView createKeySetView (ConcurrentHashMap map, Object mappedValue) {
+			return map.keySet(mappedValue);
+		}
+	}
+
 	/** Serializer for {@link Locale} (immutables).
 	 * @author Tumi <[email protected]> */
 	public static class LocaleSerializer extends ImmutableSerializer<Locale> {

test/com/esotericsoftware/kryo/serializers/DefaultSerializersTest.java

@@ -26,6 +26,7 @@
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
 import com.esotericsoftware.kryo.util.DefaultInstantiatorStrategy;
+import com.esotericsoftware.kryo.serializers.DefaultSerializers.KeySetViewSerializer;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -45,6 +46,7 @@
 import java.util.PriorityQueue;
 import java.util.TimeZone;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
@@ -246,7 +248,7 @@ void testTimestampSerializer () {
 		roundTrip(11, newTimestamp(-1234567, 1));
 		roundTrip(14, newTimestamp(-1234567, 123_456_789));
 	}
-	
+
 	private java.sql.Timestamp newTimestamp(long time, int nanos) {
 		java.sql.Timestamp t = new java.sql.Timestamp(time);
 		t.setNanos(nanos);
@@ -452,6 +454,53 @@ void testEmptyPriorityQueueSubclass () {
 		roundTrip(3, queue);
 	}
 
+	@Test
+	void testConcurrentHashMapKeySetView () {
+		ConcurrentHashMap.KeySetView<Integer, Boolean> set = ConcurrentHashMap.newKeySet();
+		set.add(12);
+		kryo.register(ConcurrentHashMap.KeySetView.class, new KeySetViewSerializer());
+		kryo.register(ConcurrentHashMap.class);
+		roundTrip(9, set);
+	}
+
+	@Test
+	void testConcurrentHashMapKeySetViewFromExistingMap () {
+		ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
+
+		map.put("1", 1);
+		map.put("2", 2);
+
+		ConcurrentHashMap.KeySetView<String, Integer> set = map.keySet(4);
+
+		kryo.register(ConcurrentHashMap.KeySetView.class, new KeySetViewSerializer());
+		kryo.register(ConcurrentHashMap.class);
+		roundTrip(15, set);
+	}
+
+	@Test
+	void testEmptyConcurrentHashMapKeySetView () {
+		ConcurrentHashMap.KeySetView set = ConcurrentHashMap.newKeySet();
+		kryo.register(ConcurrentHashMap.KeySetView.class, new KeySetViewSerializer());
+		kryo.register(ConcurrentHashMap.class);
+		roundTrip(5, set);
+	}
+
+	@Test
+	void testConcurrentHashMapKeySetViewCopy () {
+		ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
+
+		map.put("1", 1);
+		map.put("2", 2);
+
+		ConcurrentHashMap.KeySetView<String, Integer> set = map.keySet(4);
+
+		kryo.register(ConcurrentHashMap.KeySetView.class, new KeySetViewSerializer());
+		kryo.register(ConcurrentHashMap.class);
+		ConcurrentHashMap.KeySetView<String, Integer> copy = kryo.copy(set);
+		assertEquals(set.iterator().next(), copy.iterator().next());
+		assertEquals(set.getMappedValue(), copy.getMappedValue());
+	}
+
 	@Test
 	void testCalendar () {
 		kryo.setRegistrationRequired(false);
@@ -589,7 +638,7 @@ void testURISerializer () throws Exception {
 	@Test
 	void testUUIDSerializer () {
 		kryo.register(UUID.class, new DefaultSerializers.UUIDSerializer());
-		
+
 		roundTrip(17, UUID.fromString("e58ed763-928c-4155-bee9-fdbaaadc15f3"));
 	}