content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master;
  
  import alluxio.grpc.NodeState;
  import alluxio.util.interfaces.Scoped;
  
  import java.net.InetSocketAddress;
  import java.util.function.Consumer;
  
  /**
   * A test primary selector which is always primary.
   */
  public final class AlwaysPrimaryPrimarySelector implements PrimarySelector {
    @Override
    public void start(InetSocketAddress localAddress) {
      // Nothing to do.
    }
  
    @Override
    public void stop() {
      // Nothing to do.
    }
  
    @Override
    public NodeState getState() {
      return NodeState.PRIMARY;
    }
  
    @Override
    public NodeState getStateUnsafe() {
      return NodeState.PRIMARY;
    }
  
    @Override
    public Scoped onStateChange(Consumer<NodeState> listener) {
      // State never changes.
      return () -> { };
    }
  
    @Override
    public void waitForState(NodeState state) throws InterruptedException {
      switch (state) {
        case PRIMARY:
          return;
        case STANDBY:
          // Never happening
          Thread.sleep(Long.MAX_VALUE);
          break;
        default:
          throw new IllegalStateException("Unknown primary selector state: " + state);
      }
    }
  }
  