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.carbondata.core.locks;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  import org.apache.carbondata.common.logging.LogServiceFactory;
  import org.apache.carbondata.core.datastore.impl.FileFactory;
  import org.apache.carbondata.core.metadata.AbsoluteTableIdentifier;
  import org.apache.carbondata.core.util.path.CarbonTablePath;
  
  import org.apache.log4j.Logger;
  
  /**
   * This class is used to handle the S3 File locking.
   * This is achieved by using the concept of acquiring the data out stream using Append option.
   */
  public class S3FileLock extends AbstractCarbonLock {
  
    private static final Logger LOGGER =
        LogServiceFactory.getLogService(S3FileLock.class.getName());
  
    /**
     * lockFileDir is the directory of the lock file.
     */
    private String lockFileDir;
  
    private DataOutputStream dataOutputStream;
  
    /**
     * @param tableIdentifier
     * @param lockFile
     */
    public S3FileLock(AbsoluteTableIdentifier tableIdentifier, String lockFile) {
      this(tableIdentifier.getTablePath(), lockFile);
    }
  
    /**
     * @param lockFileLocation
     * @param lockFile
     */
    public S3FileLock(String lockFileLocation, String lockFile) {
      this.lockFileDir = CarbonTablePath.getLockFilesDirPath(lockFileLocation);
      this.lockFilePath = CarbonTablePath.getLockFilePath(lockFileLocation, lockFile);
      LOGGER.info("S3 lock path:" + this.lockFilePath);
      initRetry();
    }
  
    /* (non-Javadoc)
     * @see org.apache.carbondata.core.locks.ICarbonLock#unlock()
     */
    @Override
    public boolean unlock() {
      boolean status = false;
      if (null != dataOutputStream) {
        try {
          dataOutputStream.close();
          status = true;
        } catch (IOException e) {
          status = false;
        }
      }
      return status;
    }
  
    /* (non-Javadoc)
     * @see org.apache.carbondata.core.locks.ICarbonLock#lock()
     */
    @Override
    public boolean lock() {
      try {
        if (!FileFactory.isFileExist(lockFileDir)) {
          FileFactory.mkdirs(lockFileDir);
        }
        if (!FileFactory.isFileExist(lockFilePath)) {
          FileFactory.createNewLockFile(lockFilePath);
        }
        dataOutputStream =
            FileFactory.getDataOutputStreamUsingAppend(lockFilePath);
        return true;
      } catch (IOException e) {
        LOGGER.error(e.getMessage(), e);
        return false;
      }
    }
  
  }
  