content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.job.plan.transform.format;
  
  import alluxio.client.ReadType;
  import alluxio.client.WriteType;
  import alluxio.conf.PropertyKey;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Objects;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.security.UserGroupInformation;
  
  import java.io.IOException;
  import java.net.URI;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * Implementation of {@link Path} that has a cache for getting file system.
   */
  public class JobPath extends Path {
    private static final long serialVersionUID = 1427341926575998813L;
    private static final ConcurrentHashMap<FileSystemKey, FileSystem> CACHE =
        new ConcurrentHashMap<>();
  
    /**
     * Calls {@link FileSystem}.get, created to make testing easier.
     * @param uri the uri
     * @param conf the conf
     * @return the file system
     * @throws IOException
     */
    @VisibleForTesting
    public static FileSystem fileSystemGet(URI uri, Configuration conf) throws IOException {
      return FileSystem.get(uri, conf);
    }
  
    private static class FileSystemKey {
  
      final String mScheme;
      final String mAuthority;
      final UserGroupInformation mUgi;
      final ReadType mReadType;
      final WriteType mWriteType;
  
      public FileSystemKey(JobPath path, Configuration conf) throws IOException {
        URI uri = path.toUri();
        mScheme = uri.getScheme() == null ? "" : uri.getScheme().toLowerCase();
        mAuthority = uri.getAuthority() == null ? "" : uri.getAuthority().toLowerCase();
        mUgi = UserGroupInformation.getCurrentUser();
        mReadType = conf.getEnum(PropertyKey.USER_FILE_READ_TYPE_DEFAULT.getName(),
            alluxio.conf.Configuration.getEnum(
                PropertyKey.USER_FILE_READ_TYPE_DEFAULT, ReadType.class));
        mWriteType = conf.getEnum(PropertyKey.USER_FILE_WRITE_TYPE_DEFAULT.getName(),
            alluxio.conf.Configuration.getEnum(
                PropertyKey.USER_FILE_WRITE_TYPE_DEFAULT, WriteType.class));
      }
  
      @Override
      public int hashCode() {
        return Objects.hashCode(mScheme, mAuthority, mUgi, mReadType, mWriteType);
      }
  
      @Override
      public boolean equals(Object o) {
        if (o == null) {
          return false;
        }
        if (this == o) {
          return true;
        }
        if (!(o instanceof FileSystemKey)) {
          return false;
        }
  
        FileSystemKey that = (FileSystemKey) o;
        return Objects.equal(mScheme, that.mScheme)
            && Objects.equal(mAuthority, that.mAuthority)
            && Objects.equal(mUgi, that.mUgi)
            && Objects.equal(mReadType, that.mReadType)
            && Objects.equal(mWriteType, that.mWriteType);
      }
    }
  
    /**
     * Copy of the constructor in {@link Path}.
     * @param scheme the scheme
     * @param authority the authority
     * @param path the path
     */
    public JobPath(String scheme, String authority, String path) {
      super(scheme, authority, path);
    }
  
    @Override
    public FileSystem getFileSystem(Configuration conf) throws IOException {
      try {
        return CACHE.computeIfAbsent(new FileSystemKey(this, conf), (key) -> {
          try {
            return fileSystemGet(this.toUri(), conf);
          } catch (IOException e) {
            throw new RuntimeException(e);
          }
        });
      } catch (RuntimeException e) {
        Throwable cause = e.getCause();
        if (cause instanceof IOException) {
          throw (IOException) cause;
        }
        throw e;
      }
    }
  }
  