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.utils;
  
  import java.io.*;
  import java.nio.MappedByteBuffer;
  import java.nio.channels.ClosedChannelException;
  import java.nio.channels.FileChannel;
  
  import com.google.common.base.Preconditions;
  
  import org.apache.cassandra.config.CassandraRelevantEnv;
  import org.apache.cassandra.config.CassandraRelevantProperties;
  import org.apache.cassandra.io.util.File;
  import org.apache.cassandra.utils.memory.MemoryUtil;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /*
   * A wrapper around various mechanisms for syncing files that makes it possible to intercept
   * and skip syncing. Useful for unit tests in certain environments where syncs can have outliers
   * bad enough to cause tests to run 10s of seconds longer.
   */
  public class SyncUtil
  {
      public static final boolean SKIP_SYNC;
      private static final Logger logger = LoggerFactory.getLogger(SyncUtil.class);
  
      static
      {
          //If skipping syncing is requested by any means then skip them.
          boolean skipSyncProperty = CassandraRelevantProperties.TEST_CASSANDRA_SKIP_SYNC.getBoolean();
          boolean skipSyncEnv = CassandraRelevantEnv.CASSANDRA_SKIP_SYNC.getBoolean();
          SKIP_SYNC = skipSyncProperty || skipSyncEnv;
          if (SKIP_SYNC)
          {
              logger.info("Skip fsync enabled due to property {} and environment {}", skipSyncProperty, skipSyncEnv);
          }
      }
  
      public static MappedByteBuffer force(MappedByteBuffer buf)
      {
          Preconditions.checkNotNull(buf);
          Object attachment = MemoryUtil.getAttachment(buf);
          if (attachment instanceof Runnable)
          {
              ((Runnable) attachment).run();
              return buf;
          }
          if (SKIP_SYNC)
          {
              return buf;
          }
          else
          {
              return buf.force();
          }
      }
      
      public static void sync(FileDescriptor fd) throws SyncFailedException
      {
          Preconditions.checkNotNull(fd);
          if (!SKIP_SYNC)
              fd.sync();
      }
  
      public static void force(FileChannel fc, boolean metaData) throws IOException
      {
          Preconditions.checkNotNull(fc);
          if (SKIP_SYNC)
          {
              if (!fc.isOpen())
                  throw new ClosedChannelException();
          }
          else
          {
              fc.force(metaData);
          }
      }
  
      public static void sync(FileOutputStream fos) throws IOException
      {
          Preconditions.checkNotNull(fos);
          sync(fos.getFD());
      }
  
      public static void trySync(int fd)
      {
          if (SKIP_SYNC)
              return;
  
          NativeLibrary.trySync(fd);
      }
  
      public static void trySyncDir(File dir)
      {
          if (SKIP_SYNC)
              return;
  
          int directoryFD = NativeLibrary.tryOpenDirectory(dir.path());
          try
          {
              trySync(directoryFD);
          }
          finally
          {
              NativeLibrary.tryCloseFD(directoryFD);
          }
      }
  }
  