| // 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.impala.util; |
| |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| 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.RemoteIterator; |
| import org.apache.impala.util.FsPermissionChecker.Permissions; |
| |
| /** |
| * Simple non-thread-safe cache for resolved file permissions. This allows |
| * pre-caching permissions by listing the status of all files within a directory, |
| * and then using that cache to avoid round trips to the FileSystem for later |
| * queries of those paths. |
| */ |
| public class FsPermissionCache { |
| private static Configuration CONF = new Configuration(); |
| private Map<Path, Permissions> cache_ = new HashMap<>(); |
| |
| public Permissions getPermissions(Path location) throws IOException { |
| Permissions perms = cache_.get(location); |
| if (perms != null) return perms; |
| FsPermissionChecker checker = FsPermissionChecker.getInstance(); |
| FileSystem fs = location.getFileSystem(CONF); |
| perms = checker.getPermissions(fs, location); |
| cache_.put(location, perms); |
| return perms; |
| } |
| |
| public void precacheChildrenOf(FileSystem fs, Path p) |
| throws FileNotFoundException, IOException { |
| FsPermissionChecker checker = FsPermissionChecker.getInstance(); |
| RemoteIterator<FileStatus> iter = fs.listStatusIterator(p); |
| while (iter.hasNext()) { |
| FileStatus status = iter.next(); |
| Permissions perms = checker.getPermissions(fs, status); |
| cache_.put(status.getPath(), perms); |
| } |
| } |
| } |