code: /*
   * SPDX-License-Identifier: Apache-2.0
   * Copyright 2018-2020 The Feast Authors
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package feast.serving.connectors.redis.retriever;
  
  import io.lettuce.core.*;
  import io.lettuce.core.cluster.ClusterClientOptions;
  import io.lettuce.core.cluster.ClusterTopologyRefreshOptions;
  import io.lettuce.core.cluster.api.StatefulRedisClusterConnection;
  import io.lettuce.core.cluster.api.async.RedisAdvancedClusterAsyncCommands;
  import io.lettuce.core.codec.ByteArrayCodec;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  public class RedisClusterClient implements RedisClientAdapter {
  
    private final RedisAdvancedClusterAsyncCommands<byte[], byte[]> asyncCommands;
  
    @Override
    public RedisFuture<List<KeyValue<byte[], byte[]>>> hmget(byte[] key, byte[]... fields) {
      return asyncCommands.hmget(key, fields);
    }
  
    @Override
    public RedisFuture<Map<byte[], byte[]>> hgetall(byte[] key) {
      return asyncCommands.hgetall(key);
    }
  
    @Override
    public void flushCommands() {
      asyncCommands.flushCommands();
    }
  
    static class Builder {
      private final StatefulRedisClusterConnection<byte[], byte[]> connection;
  
      Builder(StatefulRedisClusterConnection<byte[], byte[]> connection) {
        this.connection = connection;
      }
  
      RedisClusterClient build() {
        return new RedisClusterClient(this);
      }
    }
  
    private RedisClusterClient(Builder builder) {
      this.asyncCommands = builder.connection.async();
  
      // allows reading from replicas
      this.asyncCommands.readOnly();
    }
  
    public static RedisClientAdapter create(RedisClusterStoreConfig config) {
      List<RedisURI> redisURIList =
          Arrays.stream(config.getConnectionString().split(","))
              .map(
                  hostPort -> {
                    String[] hostPortSplit = hostPort.trim().split(":");
                    RedisURI redisURI =
                        RedisURI.create(hostPortSplit[0], Integer.parseInt(hostPortSplit[1]));
                    if (!config.getPassword().isEmpty()) {
                      redisURI.setPassword(config.getPassword());
                    }
                    if (config.getSsl()) {
                      redisURI.setSsl(true);
                    }
                    redisURI.setTimeout(config.getTimeout());
                    return redisURI;
                  })
              .collect(Collectors.toList());
  
      io.lettuce.core.cluster.RedisClusterClient client =
          io.lettuce.core.cluster.RedisClusterClient.create(redisURIList);
      client.setOptions(
          ClusterClientOptions.builder()
              .socketOptions(SocketOptions.builder().keepAlive(true).tcpNoDelay(true).build())
              .timeoutOptions(TimeoutOptions.enabled(config.getTimeout()))
              .pingBeforeActivateConnection(true)
              .topologyRefreshOptions(
                  ClusterTopologyRefreshOptions.builder().enableAllAdaptiveRefreshTriggers().build())
              .build());
  
      StatefulRedisClusterConnection<byte[], byte[]> connection =
          client.connect(new ByteArrayCodec());
      connection.setReadFrom(config.getReadFrom());
  
      return new Builder(connection).build();
    }
  }
  