content: /*
   * 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 accord.impl.progresslog;
  
  // the phase of the distributed state machine
  public enum CoordinatePhase
  {
      /**
       * This replica is not known to be a home shard of the transaction
       */
      NotInitialised,
  
      /**
       * not durably decided; if eligible to take over coordination, should see if coordination is stalled and if so
       * take over recovery to ensure an execution decision is reached
       */
      Undecided,
  
      /**
       * durably decided but not ready to execute locally; no progress expected
       */
      Decided,
  
      /**
       * durably decided, but replicas may not be ready to execute; should wait until we can expect to successfully
       * execute the transaction before attempting recovery
       * TODO (expected): this state is not effectively used today, we only wait for the home shard to be ready to execute,
       * whereas we can perform a distributed wait using the WaitingState to ensure we can make progress
       */
      AwaitReadyToExecute,
  
      /**
       * some replicas of all shards ready to execute; we can expect that the transaction can be successfully executed,
       * and we should now try to ensure this happens when it is our turn to do so
       */
      ReadyToExecute,
  
      /**
       * The transaction has been durably executed at a majority of replicas of all shards (but not necessarily ourselves)
       */
      Done
      ;
  
      private static final CoordinatePhase[] lookup = values();
  
      boolean isAtMostReadyToExecute()
      {
          return compareTo(CoordinatePhase.ReadyToExecute) <= 0;
      }
  
      public static CoordinatePhase forOrdinal(int ordinal)
      {
          if (ordinal < 0 || ordinal > lookup.length)
              throw new IndexOutOfBoundsException(ordinal);
          return lookup[ordinal];
      }
  }
  