content: /*
   * Tencent is pleased to support the open source community by making Angel available.
   *
   * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
   *
   * Licensed 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
   *
   * https://opensource.org/licenses/Apache-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 com.tencent.angel.client.yarn;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.fs.permission.FsAction;
  import org.apache.hadoop.fs.permission.FsPermission;
  import org.apache.hadoop.yarn.api.records.LocalResource;
  import org.apache.hadoop.yarn.api.records.LocalResourceType;
  import org.apache.hadoop.yarn.api.records.LocalResourceVisibility;
  import org.apache.hadoop.yarn.util.ConverterUtils;
  import org.apache.hadoop.yarn.util.Records;
  
  import java.io.IOException;
  import java.net.URI;
  import java.util.Map;
  
  public class ClientDistributedCacheManager {
  
    public void addResource(FileSystem fs, Configuration conf, Path destPath,
      Map<String, LocalResource> localResources, LocalResourceType resourceType, String link,
      Map<URI, FileStatus> statCache, boolean appMasterOnly) throws IOException {
  
      FileStatus destStatus = fs.getFileStatus(destPath);
      LocalResource amJarRsrc = Records.newRecord(LocalResource.class);
      amJarRsrc.setType(resourceType);
  
      LocalResourceVisibility visibility = getVisibility(conf, destPath.toUri(), statCache);
      amJarRsrc.setVisibility(visibility);
      amJarRsrc.setResource(ConverterUtils.getYarnUrlFromPath(destPath));
      amJarRsrc.setTimestamp(destStatus.getModificationTime());
      amJarRsrc.setSize(destStatus.getLen());
  
      if (link == null || link.isEmpty())
        throw new IOException("You must specify a valid link name");
  
      localResources.put(link, amJarRsrc);
    }
  
    public LocalResourceVisibility getVisibility(Configuration conf, URI uri,
      Map<URI, FileStatus> statCache) throws IOException {
      if (isPublic(conf, uri, statCache)) {
        return LocalResourceVisibility.PUBLIC;
      } else {
        return LocalResourceVisibility.PRIVATE;
      }
    }
  
    public boolean isPublic(Configuration conf, URI uri, Map<URI, FileStatus> statCache)
      throws IOException {
      FileSystem fs = FileSystem.get(uri, conf);
      Path current = new Path(uri.getPath());
      // the leaf level file should be readable by others
      if (!checkPermissionOfOther(fs, current, FsAction.READ, statCache)) {
        return false;
      }
      return ancestorsHaveExecutePermissions(fs, current.getParent(), statCache);
    }
  
    public boolean ancestorsHaveExecutePermissions(FileSystem fs, Path path,
      Map<URI, FileStatus> statCache) throws IOException {
      Path current = path;
      while (current != null) {
        // the subdirs in the path should have execute permissions for
        // others
        if (!checkPermissionOfOther(fs, current, FsAction.EXECUTE, statCache)) {
          return false;
        }
        current = current.getParent();
      }
      return true;
    }
  
    /**
     * Checks for a given path whether the Other permissions on it imply the permission in the passed
     * FsAction
     *
     * @return true if the path in the uri is visible to all, false otherwise
     * @throws IOException
     */
    public boolean checkPermissionOfOther(FileSystem fs, Path path, FsAction action,
      Map<URI, FileStatus> statCache) throws IOException {
      FileStatus status = getFileStatus(fs, path.toUri(), statCache);
      FsPermission perms = status.getPermission();
      FsAction otherAction = perms.getOtherAction();
      return otherAction.implies(action);
    }
  
    public FileStatus getFileStatus(FileSystem fs, URI uri, Map<URI, FileStatus> statCache)
      throws IOException {
      FileStatus fstat = statCache.get(uri);
      if (fstat == null) {
        fstat = fs.getFileStatus(new Path(uri));
        statCache.put(uri, fstat);
      }
  
      return fstat;
    }
  }
  