Add intersectSize methods for SINTERCARD operation in Reactive APIs

Signed-off-by: Kiminni <imk0980@gmail.com>

Author: Kiminni

src/main/java/org/springframework/data/redis/connection/ReactiveSetCommands.java

@@ -43,6 +43,7 @@
  *
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Mingi Lee
  * @since 2.0
  */
 public interface ReactiveSetCommands {
@@ -775,6 +776,73 @@ default Mono<Long> sInterStore(ByteBuffer destinationKey, Collection<ByteBuffer>
 	 */
 	Flux<NumericResponse<SInterStoreCommand, Long>> sInterStore(Publisher<SInterStoreCommand> commands);
 
+	/**
+	 * {@code SINTERCARD} command parameters.
+	 *
+	 * @author Mingi Lee
+	 * @since 4.0
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 */
+	class SInterCardCommand implements Command {
+
+		private final List<ByteBuffer> keys;
+
+		private SInterCardCommand(List<ByteBuffer> keys) {
+			this.keys = keys;
+		}
+
+		/**
+		 * Creates a new {@link SInterCardCommand} given a {@link Collection} of keys.
+		 *
+		 * @param keys must not be {@literal null}.
+		 * @return a new {@link SInterCardCommand} for a {@link Collection} of keys.
+		 */
+		public static SInterCardCommand keys(Collection<ByteBuffer> keys) {
+
+			Assert.notNull(keys, "Keys must not be null");
+
+			return new SInterCardCommand(new ArrayList<>(keys));
+		}
+
+		@Override
+		public @Nullable ByteBuffer getKey() {
+			return null;
+		}
+
+		/**
+		 * @return never {@literal null}.
+		 */
+		public List<ByteBuffer> getKeys() {
+			return keys;
+		}
+	}
+
+	/**
+	 * Returns the cardinality of the set which would result from the intersection of all given sets at {@literal keys}.
+	 *
+	 * @param keys must not be {@literal null}.
+	 * @return
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 * @since 4.0
+	 */
+	default Mono<Long> sInterCard(Collection<ByteBuffer> keys) {
+
+		Assert.notNull(keys, "Keys must not be null");
+
+		return sInterCard(Mono.just(SInterCardCommand.keys(keys))).next().map(NumericResponse::getOutput);
+	}
+
+	/**
+	 * Returns the cardinality of the set which would result from the intersection of all given sets at
+	 * {@link SInterCardCommand#getKeys()}.
+	 *
+	 * @param commands must not be {@literal null}.
+	 * @return
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 * @since 4.0
+	 */
+	Flux<NumericResponse<SInterCardCommand, Long>> sInterCard(Publisher<SInterCardCommand> commands);
+
 	/**
 	 * {@code SUNION} command parameters.
 	 *

src/main/java/org/springframework/data/redis/connection/lettuce/LettuceReactiveSetCommands.java

@@ -36,6 +36,7 @@
 /**
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Mingi Lee
  * @since 2.0
  */
 class LettuceReactiveSetCommands implements ReactiveSetCommands {
@@ -175,6 +176,18 @@ public Flux<NumericResponse<SInterStoreCommand, Long>> sInterStore(Publisher<SIn
 		}));
 	}
 
+	@Override
+	public Flux<NumericResponse<SInterCardCommand, Long>> sInterCard(Publisher<SInterCardCommand> commands) {
+
+		return connection.execute(cmd -> Flux.from(commands).concatMap(command -> {
+
+			Assert.notNull(command.getKeys(), "Keys must not be null");
+
+			return cmd.sintercard(command.getKeys().toArray(new ByteBuffer[0]))
+					.map(value -> new NumericResponse<>(command, value));
+		}));
+	}
+
 	@Override
 	public Flux<CommandResponse<SUnionCommand, Flux<ByteBuffer>>> sUnion(Publisher<SUnionCommand> commands) {
 

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

@@ -41,6 +41,7 @@
  * @author Christoph Strobl
  * @author Roman Bezpalko
  * @author John Blum
+ * @author Mingi Lee
  * @since 2.0
  */
 class DefaultReactiveSetOperations<K, V> implements ReactiveSetOperations<K, V> {
@@ -213,6 +214,35 @@ public Mono<Long> intersectAndStore(Collection<K> keys, K destKey) {
 				.flatMap(rawKeys -> setCommands.sInterStore(rawKey(destKey), rawKeys)));
 	}
 
+	@Override
+	public Mono<Long> intersectSize(K key, K otherKey) {
+
+		Assert.notNull(key, "Key must not be null");
+		Assert.notNull(otherKey, "Other key must not be null");
+
+		return intersectSize(key, Collections.singleton(otherKey));
+	}
+
+	@Override
+	public Mono<Long> intersectSize(K key, Collection<K> otherKeys) {
+
+		Assert.notNull(key, "Key must not be null");
+		Assert.notNull(otherKeys, "Other keys must not be null");
+
+		return intersectSize(getKeys(key, otherKeys));
+	}
+
+	@Override
+	public Mono<Long> intersectSize(Collection<K> keys) {
+
+		Assert.notNull(keys, "Keys must not be null");
+
+		return createMono(setCommands -> Flux.fromIterable(keys) //
+				.map(this::rawKey) //
+				.collectList() //
+				.flatMap(setCommands::sInterCard));
+	}
+
 	@Override
 	public Flux<V> union(K key, K otherKey) {
 

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

@@ -33,6 +33,7 @@
  * @author Mark Paluch
  * @author Christoph Strobl
  * @author Roman Bezpalko
+ * @author Mingi Lee
  * @see <a href="https://redis.io/commands#set">Redis Documentation: Set Commands</a>
  * @since 2.0
  */
@@ -181,6 +182,38 @@ public interface ReactiveSetOperations<K, V> {
 	 */
 	Mono<Long> intersectAndStore(Collection<K> keys, K destKey);
 
+	/**
+	 * Returns the cardinality of the set which would result from the intersection of {@code key} and {@code otherKey}.
+	 *
+	 * @param key must not be {@literal null}.
+	 * @param otherKey must not be {@literal null}.
+	 * @return
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 * @since 4.0
+	 */
+	Mono<Long> intersectSize(K key, K otherKey);
+
+	/**
+	 * Returns the cardinality of the set which would result from the intersection of {@code key} and {@code otherKeys}.
+	 *
+	 * @param key must not be {@literal null}.
+	 * @param otherKeys must not be {@literal null}.
+	 * @return
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 * @since 4.0
+	 */
+	Mono<Long> intersectSize(K key, Collection<K> otherKeys);
+
+	/**
+	 * Returns the cardinality of the set which would result from the intersection of all given sets at {@code keys}.
+	 *
+	 * @param keys must not be {@literal null}.
+	 * @return
+	 * @see <a href="https://redis.io/commands/sintercard">Redis Documentation: SINTERCARD</a>
+	 * @since 4.0
+	 */
+	Mono<Long> intersectSize(Collection<K> keys);
+
 	/**
 	 * Union all sets at given {@code keys} and {@code otherKey}.
 	 *