| /** |
| * 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.hadoop.fs.viewfs; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.FsConstants; |
| import org.apache.hadoop.fs.FsStatus; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.UnsupportedFileSystemException; |
| import org.apache.hadoop.fs.viewfs.ViewFileSystem.MountPoint; |
| |
| /** |
| * Utility APIs for ViewFileSystem. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public final class ViewFileSystemUtil { |
| |
| private ViewFileSystemUtil() { |
| // Private Constructor |
| } |
| |
| /** |
| * Check if the FileSystem is a ViewFileSystem. |
| * |
| * @param fileSystem |
| * @return true if the fileSystem is ViewFileSystem |
| */ |
| public static boolean isViewFileSystem(final FileSystem fileSystem) { |
| return fileSystem.getScheme().equals(FsConstants.VIEWFS_SCHEME); |
| } |
| |
| /** |
| * Check if the FileSystem is a ViewFileSystemOverloadScheme. |
| * |
| * @param fileSystem |
| * @return true if the fileSystem is ViewFileSystemOverloadScheme |
| */ |
| public static boolean isViewFileSystemOverloadScheme( |
| final FileSystem fileSystem) { |
| return fileSystem instanceof ViewFileSystemOverloadScheme; |
| } |
| |
| /** |
| * Get FsStatus for all ViewFsMountPoints matching path for the given |
| * ViewFileSystem. |
| * |
| * Say ViewFileSystem has following mount points configured |
| * (1) hdfs://NN0_host:port/sales mounted on /dept/sales |
| * (2) hdfs://NN1_host:port/marketing mounted on /dept/marketing |
| * (3) hdfs://NN2_host:port/eng_usa mounted on /dept/eng/usa |
| * (4) hdfs://NN3_host:port/eng_asia mounted on /dept/eng/asia |
| * |
| * For the above config, here is a sample list of paths and their matching |
| * mount points while getting FsStatus |
| * |
| * Path Description Matching MountPoint |
| * |
| * "/" Root ViewFileSystem lists all (1), (2), (3), (4) |
| * mount points. |
| * |
| * "/dept" Not a mount point, but a valid (1), (2), (3), (4) |
| * internal dir in the mount tree |
| * and resolved down to "/" path. |
| * |
| * "/dept/sales" Matches a mount point (1) |
| * |
| * "/dept/sales/india" Path is over a valid mount point (1) |
| * and resolved down to |
| * "/dept/sales" |
| * |
| * "/dept/eng" Not a mount point, but a valid (1), (2), (3), (4) |
| * internal dir in the mount tree |
| * and resolved down to "/" path. |
| * |
| * "/erp" Doesn't match or leads to or |
| * over any valid mount points None |
| * |
| * |
| * @param fileSystem - ViewFileSystem on which mount point exists |
| * @param path - URI for which FsStatus is requested |
| * @return Map of ViewFsMountPoint and FsStatus |
| */ |
| public static Map<MountPoint, FsStatus> getStatus( |
| FileSystem fileSystem, Path path) throws IOException { |
| if (!(isViewFileSystem(fileSystem) |
| || isViewFileSystemOverloadScheme(fileSystem))) { |
| throw new UnsupportedFileSystemException("FileSystem '" |
| + fileSystem.getUri() + "'is not a ViewFileSystem."); |
| } |
| ViewFileSystem viewFileSystem = (ViewFileSystem) fileSystem; |
| String viewFsUriPath = viewFileSystem.getUriPath(path); |
| boolean isPathOverMountPoint = false; |
| boolean isPathLeadingToMountPoint = false; |
| boolean isPathIncludesAllMountPoint = false; |
| Map<MountPoint, FsStatus> mountPointMap = new HashMap<>(); |
| for (MountPoint mountPoint : viewFileSystem.getMountPoints()) { |
| String[] mountPointPathComponents = InodeTree.breakIntoPathComponents( |
| mountPoint.getMountedOnPath().toString()); |
| String[] incomingPathComponents = |
| InodeTree.breakIntoPathComponents(viewFsUriPath); |
| |
| int pathCompIndex; |
| for (pathCompIndex = 0; pathCompIndex < mountPointPathComponents.length && |
| pathCompIndex < incomingPathComponents.length; pathCompIndex++) { |
| if (!mountPointPathComponents[pathCompIndex].equals( |
| incomingPathComponents[pathCompIndex])) { |
| break; |
| } |
| } |
| |
| if (pathCompIndex >= mountPointPathComponents.length) { |
| // Patch matches or over a valid mount point |
| isPathOverMountPoint = true; |
| mountPointMap.clear(); |
| updateMountPointFsStatus(viewFileSystem, mountPointMap, mountPoint, |
| new Path(viewFsUriPath)); |
| break; |
| } else { |
| if (pathCompIndex > 1) { |
| // Path is in the mount tree |
| isPathLeadingToMountPoint = true; |
| } else if (incomingPathComponents.length <= 1) { |
| // Special case of "/" path |
| isPathIncludesAllMountPoint = true; |
| } |
| updateMountPointFsStatus(viewFileSystem, mountPointMap, mountPoint, |
| mountPoint.getMountedOnPath()); |
| } |
| } |
| |
| if (!isPathOverMountPoint && !isPathLeadingToMountPoint && |
| !isPathIncludesAllMountPoint) { |
| throw new NotInMountpointException(path, "getStatus"); |
| } |
| return mountPointMap; |
| } |
| |
| /** |
| * Update FsStatus for the given the mount point. |
| * |
| * @param viewFileSystem |
| * @param mountPointMap |
| * @param mountPoint |
| * @param path |
| */ |
| private static void updateMountPointFsStatus( |
| final ViewFileSystem viewFileSystem, |
| final Map<MountPoint, FsStatus> mountPointMap, |
| final MountPoint mountPoint, final Path path) throws IOException { |
| FsStatus fsStatus = viewFileSystem.getStatus(path); |
| mountPointMap.put(mountPoint, fsStatus); |
| } |
| |
| } |