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.concurrent;
  
  import java.util.List;
  import java.util.concurrent.Callable;
  import java.util.concurrent.Executors; // checkstyle: permit this import
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.TimeUnit;
  
  import accord.utils.async.AsyncChain;
  import org.apache.cassandra.utils.WithResources;
  import org.apache.cassandra.utils.concurrent.AsyncPromise;
  import org.apache.cassandra.utils.concurrent.Future;
  
  import static com.google.common.primitives.Longs.max;
  import static java.util.concurrent.TimeUnit.NANOSECONDS;
  import static org.apache.cassandra.utils.Clock.Global.nanoTime;
  
  public class AdaptingScheduledExecutorPlus implements ScheduledExecutorPlus
  {
      private final ScheduledExecutorService delegate;
  
      public AdaptingScheduledExecutorPlus(ScheduledExecutorService delegate)
      {
          this.delegate = delegate;
      }
  
      protected ScheduledExecutorService delegate()
      {
          return delegate;
      }
  
      @Override
      public ScheduledFuture<?> scheduleSelfRecurring(Runnable run, long delay, TimeUnit units)
      {
          return schedule(run, delay, units);
      }
  
      @Override
      public ScheduledFuture<?> scheduleAt(Runnable run, long deadline)
      {
          return schedule(run, max(0, deadline - nanoTime()), NANOSECONDS);
      }
  
      @Override
      public ScheduledFuture<?> scheduleTimeoutAt(Runnable run, long deadline)
      {
          return scheduleTimeoutWithDelay(run, max(0, deadline - nanoTime()), NANOSECONDS);
      }
  
      @Override
      public ScheduledFuture<?> scheduleTimeoutWithDelay(Runnable run, long delay, TimeUnit units)
      {
          return schedule(run, delay, units);
      }
  
      @Override
      public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit)
      {
          return delegate().schedule(command, delay, unit);
      }
  
      @Override
      public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit)
      {
          return delegate().schedule(callable, delay, unit);
      }
  
      @Override
      public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit)
      {
          return delegate().scheduleAtFixedRate(command, initialDelay, period, unit);
      }
  
      @Override
      public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit)
      {
          return delegate().scheduleWithFixedDelay(command, initialDelay, delay, unit);
      }
  
      @Override
      public void shutdown()
      {
          delegate().shutdown();
      }
  
      @Override
      public List<Runnable> shutdownNow()
      {
          return delegate().shutdownNow();
      }
  
      @Override
      public boolean isShutdown()
      {
          return delegate().isShutdown();
      }
  
      @Override
      public boolean isTerminated()
      {
          return delegate().isTerminated();
      }
  
      @Override
      public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException
      {
          return delegate().awaitTermination(timeout, unit);
      }
  
      @Override
      public <T> Future<T> submit(Callable<T> task)
      {
          return wrap(delegate().submit(task));
      }
  
      @Override
      public <T> Future<T> submit(Runnable task, T result)
      {
          return wrap(delegate().submit(task, result));
      }
  
      @Override
      public Future<?> submit(Runnable task)
      {
          return wrap(delegate().submit(task));
      }
  
      @Override
      public void execute(WithResources withResources, Runnable task)
      {
          execute(TaskFactory.standard().toExecute(withResources, task));
      }
  
      @Override
      public <T> Future<T> submit(WithResources withResources, Callable<T> task)
      {
          class Catch { T value;}
          Catch c = new Catch();
          Runnable exec = TaskFactory.standard().toExecute(withResources, () -> {
              try
              {
                  c.value = task.call();
              }
              catch (Exception e)
              {
                  throw new RuntimeException(e);
              }
          });
          return submit(() -> {
              exec.run();
              return c.value;
          });
      }
  
      @Override
      public Future<?> submit(WithResources withResources, Runnable task)
      {
          return submit(TaskFactory.standard().toExecute(withResources, task));
      }
  
      @Override
      public <T> Future<T> submit(WithResources withResources, Runnable task, T result)
      {
          return submit(Executors.callable(TaskFactory.standard().toSubmit(withResources, task), result));
      }
  
      @Override
      public boolean inExecutor()
      {
          return false;
      }
  
      @Override
      public void execute(Runnable command)
      {
          delegate().execute(command);
      }
  
      @Override
      public int getCorePoolSize()
      {
          return 0;
      }
  
      @Override
      public void setCorePoolSize(int newCorePoolSize)
      {
  
      }
  
      @Override
      public int getMaximumPoolSize()
      {
          return 0;
      }
  
      @Override
      public void setMaximumPoolSize(int newMaximumPoolSize)
      {
  
      }
  
      @Override
      public int getActiveTaskCount()
      {
          return 0;
      }
  
      @Override
      public long getCompletedTaskCount()
      {
          return 0;
      }
  
      @Override
      public int getPendingTaskCount()
      {
          return 0;
      }
  
      private static <T> org.apache.cassandra.utils.concurrent.Future<T> wrap(java.util.concurrent.Future<T> future)
      {
          if (future instanceof org.apache.cassandra.utils.concurrent.Future)
              return (Future<T>) future;
          if (future instanceof AsyncChain)
          {
              AsyncChain<T> chain = (AsyncChain<T>) future;
              AsyncPromise<T> promise = new AsyncPromise<>();
              chain.begin((s, f) -> {
                  if (f != null) promise.setFailure(f);
                  else           promise.setSuccess(s);
              });
  
              return promise;
          }
          throw new IllegalStateException("Unexpected future type: " + future.getClass());
      }
  }
  