| /* |
| * 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.distributed.util; |
| |
| import java.net.InetAddress; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.concurrent.CopyOnWriteArrayList; |
| |
| import com.google.common.collect.Iterators; |
| |
| import com.datastax.driver.core.Cluster; |
| import com.datastax.driver.core.Host; |
| import com.datastax.driver.core.HostDistance; |
| import com.datastax.driver.core.Statement; |
| import com.datastax.driver.core.policies.LoadBalancingPolicy; |
| |
| /** |
| * A CQL driver {@link LoadBalancingPolicy} that only connects to a fixed host. |
| */ |
| public class SingleHostLoadBalancingPolicy implements LoadBalancingPolicy |
| { |
| private final InetAddress address; |
| private Host host; |
| |
| public SingleHostLoadBalancingPolicy(InetAddress address) |
| { |
| this.address = address; |
| } |
| |
| protected final List<Host> hosts = new CopyOnWriteArrayList<>(); |
| |
| @Override |
| public void init(Cluster cluster, Collection<Host> hosts) |
| { |
| host = hosts.stream() |
| .filter(h -> h.getBroadcastAddress().equals(address)).findFirst() |
| .orElseThrow(() -> new AssertionError("The host should be a contact point")); |
| this.hosts.add(host); |
| } |
| |
| @Override |
| public HostDistance distance(Host host) |
| { |
| return HostDistance.LOCAL; |
| } |
| |
| @Override |
| public Iterator<Host> newQueryPlan(String loggedKeyspace, Statement statement) |
| { |
| return Iterators.singletonIterator(host); |
| } |
| |
| @Override |
| public void onAdd(Host host) |
| { |
| // no-op |
| } |
| |
| @Override |
| public void onUp(Host host) |
| { |
| // no-op |
| } |
| |
| @Override |
| public void onDown(Host host) |
| { |
| // no-op |
| } |
| |
| @Override |
| public void onRemove(Host host) |
| { |
| // no-op |
| } |
| |
| @Override |
| public void close() |
| { |
| // no-op |
| } |
| } |