Pass-thru custom Redis commands using Lettuce.

We now accept unknown custom Redis commands when using the Lettuce driver. Previously, custom commands were required to exist in Lettuce's CommandType enumeration and unknown commands (such as modules) failed to run.

Closes #1979

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

@@ -36,10 +36,12 @@ import io.lettuce.core.output.*;
 import io.lettuce.core.protocol.Command;
 import io.lettuce.core.protocol.CommandArgs;
 import io.lettuce.core.protocol.CommandType;
+import io.lettuce.core.protocol.ProtocolKeyword;
 import io.lettuce.core.pubsub.StatefulRedisPubSubConnection;
 import io.lettuce.core.sentinel.api.StatefulRedisSentinelConnection;
 
 import java.lang.reflect.Constructor;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -389,7 +391,7 @@ public class LettuceConnection extends AbstractRedisConnection {
 		Assert.hasText(command, "a valid command needs to be specified");
 
 		String name = command.trim().toUpperCase();
-		CommandType commandType = CommandType.valueOf(name);
+		ProtocolKeyword commandType = getCommandType(name);
 
 		validateCommandIfRunningInTransactionMode(commandType, args);
 
@@ -1109,14 +1111,14 @@ public class LettuceConnection extends AbstractRedisConnection {
 		return io.lettuce.core.ScanCursor.of(Long.toString(cursorId));
 	}
 
-	private void validateCommandIfRunningInTransactionMode(CommandType cmd, byte[]... args) {
+	private void validateCommandIfRunningInTransactionMode(ProtocolKeyword cmd, byte[]... args) {
 
 		if (this.isQueueing()) {
 			validateCommand(cmd, args);
 		}
 	}
 
-	private void validateCommand(CommandType cmd, @Nullable byte[]... args) {
+	private void validateCommand(ProtocolKeyword cmd, @Nullable byte[]... args) {
 
 		RedisCommand redisCommand = RedisCommand.failsafeCommandLookup(cmd.name());
 		if (!RedisCommand.UNKNOWN.equals(redisCommand) && redisCommand.requiresArguments()) {
@@ -1128,6 +1130,15 @@ public class LettuceConnection extends AbstractRedisConnection {
 		}
 	}
 
+	private static ProtocolKeyword getCommandType(String name) {
+
+		try {
+			return CommandType.valueOf(name);
+		} catch (IllegalArgumentException e) {
+			return new CustomCommandType(name);
+		}
+	}
+
 	/**
 	 * {@link TypeHints} provide {@link CommandOutput} information for a given {@link CommandType}.
 	 *
@@ -1136,7 +1147,7 @@ public class LettuceConnection extends AbstractRedisConnection {
 	static class TypeHints {
 
 		@SuppressWarnings("rawtypes") //
-		private static final Map<CommandType, Class<? extends CommandOutput>> COMMAND_OUTPUT_TYPE_MAPPING = new HashMap<>();
+		private static final Map<ProtocolKeyword, Class<? extends CommandOutput>> COMMAND_OUTPUT_TYPE_MAPPING = new HashMap<>();
 
 		@SuppressWarnings("rawtypes") //
 		private static final Map<Class<?>, Constructor<CommandOutput>> CONSTRUCTORS = new ConcurrentHashMap<>();
@@ -1298,7 +1309,7 @@ public class LettuceConnection extends AbstractRedisConnection {
 		 * @return {@link ByteArrayOutput} as default when no matching {@link CommandOutput} available.
 		 */
 		@SuppressWarnings("rawtypes")
-		public CommandOutput getTypeHint(CommandType type) {
+		public CommandOutput getTypeHint(ProtocolKeyword type) {
 			return getTypeHint(type, new ByteArrayOutput<>(CODEC));
 		}
 
@@ -1309,7 +1320,7 @@ public class LettuceConnection extends AbstractRedisConnection {
 		 * @return
 		 */
 		@SuppressWarnings("rawtypes")
-		public CommandOutput getTypeHint(CommandType type, CommandOutput defaultType) {
+		public CommandOutput getTypeHint(ProtocolKeyword type, CommandOutput defaultType) {
 
 			if (type == null || !COMMAND_OUTPUT_TYPE_MAPPING.containsKey(type)) {
 				return defaultType;
@@ -1552,4 +1563,49 @@ public class LettuceConnection extends AbstractRedisConnection {
 			connection.setAutoFlushCommands(true);
 		}
 	}
+
+	/**
+	 * @since 2.3.8
+	 */
+	static class CustomCommandType implements ProtocolKeyword {
+
+		private final String name;
+
+		CustomCommandType(String name) {
+			this.name = name;
+		}
+
+		@Override
+		public byte[] getBytes() {
+			return name.getBytes(StandardCharsets.US_ASCII);
+		}
+
+		@Override
+		public String name() {
+			return name;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+
+			if (this == o) {
+				return true;
+			}
+			if (!(o instanceof CustomCommandType)) {
+				return false;
+			}
+			CustomCommandType that = (CustomCommandType) o;
+			return ObjectUtils.nullSafeEquals(name, that.name);
+		}
+
+		@Override
+		public int hashCode() {
+			return ObjectUtils.nullSafeHashCode(name);
+		}
+
+		@Override
+		public String toString() {
+			return name;
+		}
+	}
 }