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 org.apache.cassandra.service.consensus.migration;
  
  import org.apache.cassandra.service.consensus.TransactionalMode;
  
  import static org.apache.cassandra.utils.LocalizeString.toLowerCaseLocalized;
  
  /**
   * This tracks the state of a migration either from Paxos -> Accord, Accord [interop mode a] -> Accord [interop mode b] or Accord -> Paxos.
   * The `TransactionalMode` associated with each transition from a system is how interoperability should be achieved during the migration with various performance/safety tradeoffs.
   */
  public enum TransactionalMigrationFromMode
  {
      none(null),  // No migration is in progress. The currently active transaction system could be either Accord or Paxos.
      off(TransactionalMode.off),
      mixed_reads(TransactionalMode.mixed_reads),
      full(TransactionalMode.full),
      test_unsafe(TransactionalMode.test_unsafe),
      test_unsafe_writes(TransactionalMode.test_unsafe_writes),
      test_interop_read(TransactionalMode.test_interop_read);
  
      public final TransactionalMode from;
  
      TransactionalMigrationFromMode(TransactionalMode from)
      {
          this.from = from;
      }
  
      public static TransactionalMigrationFromMode fromMode(TransactionalMode prev, TransactionalMode next)
      {
          if (next.accordIsEnabled == prev.accordIsEnabled)
              return none;
  
          switch (prev)
          {
              default: throw new IllegalArgumentException();
              case off: return off;
              case mixed_reads: return mixed_reads;
              case full: return full;
              case test_interop_read: return test_interop_read;
              case test_unsafe: return test_unsafe;
              case test_unsafe_writes: return test_unsafe_writes;
          }
      }
  
      public static TransactionalMigrationFromMode fromOrdinal(int ordinal)
      {
          return values()[ordinal];
      }
  
      public static TransactionalMigrationFromMode fromString(String name)
      {
          return valueOf(toLowerCaseLocalized(name));
      }
  
      public boolean migratingFromAccord()
      {
          return from != null && from.accordIsEnabled;
      }
  
      public boolean nonSerialWritesThroughAccord()
      {
          return from != null && from.nonSerialWritesThroughAccord;
      }
  
      public boolean readRepairsThroughAccord()
      {
          return from != null && from.blockingReadRepairThroughAccord;
      }
  
      public boolean nonSerialReadsThroughAccord()
      {
          return from != null && from.nonSerialReadsThroughAccord;
      }
  
      public boolean isMigrating()
      {
          return this != none;
      }
  
      public String asCqlParam()
      {
          return String.format("transactional_migration_from = '%s'", toLowerCaseLocalized(this.name()));
      }
  }
  