content: /*
   * Copyright 2013-2023 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.
   * 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 com.alibaba.cloud.nacos.discovery;
  
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.ConcurrentHashMap;
  
  import com.alibaba.cloud.nacos.discovery.reactive.NacosReactiveDiscoveryClient;
  
  import org.springframework.cloud.client.ServiceInstance;
  
  /**
   * Service cache.
   * <p>
   * Cache serviceIds and corresponding instances in Nacos.
   * <p>
   * It's very useful to query services and instances on runtime, but it's not real-time,
   * depends on {@link NacosDiscoveryClient} or {@link NacosReactiveDiscoveryClient}
   * {@code getServices(), getInstances(..)} invoke.
   *
   * @author freeman
   * @since 2021.0.1.0
   */
  public final class ServiceCache {
  
  	private ServiceCache() {
  	}
  
  	private static List<String> services = Collections.emptyList();
  
  	private static Map<String, List<ServiceInstance>> instancesMap = new ConcurrentHashMap<>();
  
  	/**
  	 * Set instances for specific service.
  	 * @param serviceId service id
  	 * @param instances service instances
  	 */
  	public static void setInstances(String serviceId, List<ServiceInstance> instances) {
  		instancesMap.put(serviceId, Collections.unmodifiableList(instances));
  	}
  
  	/**
  	 * Get instances for specific service.
  	 * @param serviceId service id
  	 * @return service instances
  	 */
  	public static List<ServiceInstance> getInstances(String serviceId) {
  		return Optional.ofNullable(instancesMap.get(serviceId))
  				.orElse(Collections.emptyList());
  	}
  
  	/**
  	 * Set all services.
  	 * @param serviceIds all services
  	 * @deprecated since 2021.0.1.1, use {@link #setServiceIds(List)} instead.
  	 */
  	@Deprecated
  	public static void set(List<String> serviceIds) {
  		services = Collections.unmodifiableList(serviceIds);
  	}
  
  	/**
  	 * Set all services.
  	 * @param serviceIds all services
  	 * @since 2021.0.1.1
  	 */
  	public static void setServiceIds(List<String> serviceIds) {
  		services = Collections.unmodifiableList(serviceIds);
  	}
  
  	/**
  	 * Get all services.
  	 * @return all services
  	 * @deprecated since 2021.0.1.1, use {@link #getServiceIds()} instead.
  	 */
  	@Deprecated
  	public static List<String> get() {
  		return services;
  	}
  
  	/**
  	 * Get all services.
  	 * @return all services
  	 * @since 2021.0.1.1
  	 */
  	public static List<String> getServiceIds() {
  		return services;
  	}
  
  }
  