INT-4507: Use UNLINK in RedisMessageStore if any

JIRA: https://jira.spring.io/browse/INT-4507

* Add `RedisUtils` with the `isUnlinkAvailable()` to check the Redis
server version to be sure that `UNLINK` is available or not
* Use `RedisUtils.isUnlinkAvailable()` in the `RedisMessageStore` and
`RedisLockRegistry` when a removal functionality is performed
* Add `AbstractKeyValueMessageStore.doRemoveAll(Collection<Object> ids)`
for optimization
* Implement `doRemoveAll()` in the `RedisMessageStore` and
`GemfireMessageStore`

**Cherry-pick to 5.0.x**

spring-integration-core/src/main/java/org/springframework/integration/store/AbstractKeyValueMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,8 +20,10 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Set;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 import org.springframework.jmx.export.annotation.ManagedAttribute;
 import org.springframework.messaging.Message;
@@ -243,11 +245,21 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 		if (mgm != null) {
 			Assert.isInstanceOf(MessageGroupMetadata.class, mgm);
 			MessageGroupMetadata messageGroupMetadata = (MessageGroupMetadata) mgm;
-			for (Message<?> messageToRemove : messages) {
-				UUID messageId = messageToRemove.getHeaders().getId();
-				messageGroupMetadata.remove(messageId);
-				doRemove(this.messagePrefix + messageId);
-			}
+
+			List<UUID> ids =
+					messages.stream()
+							.map(messageToRemove -> messageToRemove.getHeaders().getId())
+							.collect(Collectors.toList());
+
+			messageGroupMetadata.removeAll(ids);
+
+			List<Object> messageIds =
+					ids.stream()
+							.map(id -> this.messagePrefix + id)
+							.collect(Collectors.toList());
+
+			doRemoveAll(messageIds);
+
 			messageGroupMetadata.setLastModified(System.currentTimeMillis());
 			doStore(this.groupPrefix + groupId, messageGroupMetadata);
 		}
@@ -275,10 +287,13 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 			Assert.isInstanceOf(MessageGroupMetadata.class, mgm);
 			MessageGroupMetadata messageGroupMetadata = (MessageGroupMetadata) mgm;
 
-			Iterator<UUID> messageIds = messageGroupMetadata.messageIdIterator();
-			while (messageIds.hasNext()) {
-				removeMessage(messageIds.next());
-			}
+			List<Object> messageIds =
+					messageGroupMetadata.getMessageIds()
+							.stream()
+							.map(id -> this.messagePrefix + id)
+							.collect(Collectors.toList());
+
+			doRemoveAll(messageIds);
 		}
 	}
 
@@ -325,7 +340,7 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 	@Override
 	public Collection<Message<?>> getMessagesForGroup(Object groupId) {
 		MessageGroupMetadata groupMetadata = getGroupMetadata(groupId);
-		ArrayList<Message<?>> messages = new ArrayList<Message<?>>();
+		ArrayList<Message<?>> messages = new ArrayList<>();
 		if (groupMetadata != null) {
 			Iterator<UUID> messageIds = groupMetadata.messageIdIterator();
 			while (messageIds.hasNext()) {
@@ -345,7 +360,7 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 	}
 
 	private Collection<String> normalizeKeys(Collection<String> keys) {
-		Set<String> normalizedKeys = new HashSet<String>();
+		Set<String> normalizedKeys = new HashSet<>();
 		for (Object key : keys) {
 			String strKey = (String) key;
 			if (strKey.startsWith(this.groupPrefix)) {
@@ -378,6 +393,8 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 
 	protected abstract Object doRemove(Object id);
 
+	protected abstract void doRemoveAll(Collection<Object> ids);
+
 	protected abstract Collection<?> doListKeys(String keyPattern);
 
 	private final class MessageGroupIterator implements Iterator<MessageGroup> {

spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupMetadata.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.store;
 
 import java.io.Serializable;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
@@ -39,7 +40,7 @@ public class MessageGroupMetadata implements Serializable {
 
 	private static final long serialVersionUID = 1L;
 
-	private List<UUID> messageIds = new LinkedList<UUID>();
+	private List<UUID> messageIds = new LinkedList<>();
 
 	private long timestamp;
 
@@ -68,6 +69,10 @@ public class MessageGroupMetadata implements Serializable {
 		this.messageIds.remove(messageId);
 	}
 
+	public void removeAll(Collection<UUID> messageIds) {
+		this.messageIds.removeAll(messageIds);
+	}
+
 	boolean add(UUID messageId) {
 		return !this.messageIds.contains(messageId) && this.messageIds.add(messageId);
 	}