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.repair.state;
  
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  
  import com.google.common.base.Throwables;
  
  import org.apache.cassandra.utils.Clock;
  
  public abstract class AbstractCompletable<I> implements Completable<I>
  {
      public enum Status { INIT, ACCEPTED, COMPLETED }
  
      private final long creationTimeMillis; // used to convert from nanos to millis
      private final long creationTimeNanos;
      protected final Clock clock;
      private final AtomicReference<Result> result = new AtomicReference<>(null);
      public final I id;
      protected volatile long lastUpdatedAtNs;
  
      public AbstractCompletable(Clock clock, I id)
      {
          this.creationTimeMillis = clock.currentTimeMillis();
          this.creationTimeNanos = clock.nanoTime();
          this.clock = clock;
          this.id = id;
      }
  
      public abstract boolean isAccepted();
  
      public Status getCompletionStatus()
      {
          Result result = getResult();
          if (result != null)
              return Status.COMPLETED;
          return isAccepted() ? Status.ACCEPTED : Status.INIT;
      }
  
      @Override
      public I getId()
      {
          return id;
      }
  
      @Override
      public long getInitializedAtMillis()
      {
          return nanosToMillis(creationTimeNanos);
      }
  
      @Override
      public long getInitializedAtNanos()
      {
          return creationTimeNanos;
      }
  
      @Override
      public long getLastUpdatedAtMillis()
      {
          return nanosToMillis(lastUpdatedAtNs);
      }
  
      @Override
      public long getLastUpdatedAtNanos()
      {
          return lastUpdatedAtNs;
      }
  
      @Override
      public Result getResult()
      {
          return result.get();
      }
  
      public void updated()
      {
          lastUpdatedAtNs = clock.nanoTime();
      }
  
      protected boolean tryResult(Result result)
      {
          if (!this.result.compareAndSet(null, result))
              return false;
          onComplete();
          lastUpdatedAtNs = clock.nanoTime();
          return true;
      }
  
      protected void onComplete() {}
  
      protected long nanosToMillis(long nanos)
      {
          // nanos - creationTimeNanos = delta since init
          return creationTimeMillis + TimeUnit.NANOSECONDS.toMillis(nanos - creationTimeNanos);
      }
  
      protected class BaseSkipPhase extends BasePhase
      {
          public void skip(String msg)
          {
              tryResult(Result.skip(msg));
          }
      }
  
      protected class BasePhase
      {
          public void success()
          {
              tryResult(Result.success());
          }
  
          public void success(String msg)
          {
              tryResult(Result.success(msg));
          }
  
          public void fail(Throwable e)
          {
              fail(e == null ? null : Throwables.getStackTraceAsString(e));
          }
  
          public void fail(String failureCause)
          {
              tryResult(Result.fail(failureCause));
          }
      }
  }
  