| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 |
| * |
| * http://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 org.apache.cassandra.sidecar.utils; |
| |
| import com.google.inject.Inject; |
| import com.google.inject.Singleton; |
| import org.apache.cassandra.sidecar.cluster.InstancesConfig; |
| import org.apache.cassandra.sidecar.cluster.instance.InstanceMetadata; |
| import org.apache.cassandra.sidecar.common.CassandraAdapterDelegate; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * Helper class to retrieve instance information from an instanceId or hostname. |
| */ |
| @Singleton |
| public class InstanceMetadataFetcher |
| { |
| private final InstancesConfig instancesConfig; |
| |
| @Inject |
| public InstanceMetadataFetcher(InstancesConfig instancesConfig) |
| { |
| this.instancesConfig = instancesConfig; |
| } |
| |
| /** |
| * Returns the {@link InstanceMetadata} for the given {@code host}. When the {@code host} is {@code null}, |
| * returns the first instance from the list of configured instances. |
| * |
| * @param host the Cassandra instance host |
| * @return the {@link InstanceMetadata} for the given {@code host}, or the first instance when {@code host} is |
| * {@code null} |
| */ |
| public InstanceMetadata instance(@Nullable String host) |
| { |
| return host == null |
| ? firstInstance() |
| : instancesConfig.instanceFromHost(host); |
| } |
| |
| /** |
| * Returns the {@link InstanceMetadata} for the given {@code instanceId}, or the first instance when |
| * {@code instanceId} is {@code null}. |
| * |
| * @param instanceId the identifier for the Cassandra instance |
| * @return the {@link InstanceMetadata} for the given {@code instanceId}, or the first instance when |
| * {@code instanceId} is {@code null} |
| */ |
| public InstanceMetadata instance(int instanceId) |
| { |
| return instancesConfig.instanceFromId(instanceId); |
| } |
| |
| /** |
| * Returns the {@link CassandraAdapterDelegate} for the given {@code host}. When the {@code host} is {@code null}, |
| * returns the delegate for the first instance from the list of configured instances. |
| * |
| * @param host the Cassandra instance host |
| * @return the {@link CassandraAdapterDelegate} for the given {@code host}, or the first instance when {@code host} |
| * is {@code null} |
| */ |
| public CassandraAdapterDelegate delegate(String host) |
| { |
| return instance(host).delegate(); |
| } |
| |
| /** |
| * Returns the {@link CassandraAdapterDelegate} for the given {@code instanceId}, or the delegate for the first |
| * instance when {@code instanceId} is {@code null}. |
| * |
| * @param instanceId the identifier for the Cassandra instance |
| * @return the {@link CassandraAdapterDelegate} for the given {@code instanceId}, or the first instance when |
| * {@code instanceId} is {@code null} |
| */ |
| public CassandraAdapterDelegate delegate(int instanceId) |
| { |
| return instance(instanceId).delegate(); |
| } |
| |
| /** |
| * @return the first instance from the list of configured instances |
| * @throws IllegalStateException when there are no configured instances |
| */ |
| public InstanceMetadata firstInstance() |
| { |
| if (instancesConfig.instances().isEmpty()) |
| { |
| throw new IllegalStateException("There are no instances configured!"); |
| } |
| return instancesConfig.instances().get(0); |
| } |
| } |