From 59e968a114dfe1b513f31424211116f23525def8 Mon Sep 17 00:00:00 2001 From: Tsz-wo Sze Date: Mon, 25 Feb 2013 23:14:58 +0000 Subject: [PATCH] HDFS-4514. Add CLI for supporting snapshot rename, diff report, and snapshottable directory listing. Contributed by Jing Zhao git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2802@1449956 13f79535-47bb-0310-9956-ffa450edef68 --- .../java/org/apache/hadoop/fs/FileSystem.java | 13 +++ .../hadoop/fs/shell/SnapshotCommands.java | 60 +++++++++++-- .../hadoop-hdfs/CHANGES.HDFS-2802.txt | 3 + .../hadoop/hdfs/DistributedFileSystem.java | 22 +---- .../apache/hadoop/hdfs/client/HdfsAdmin.java | 16 ++++ .../hdfs/protocol/SnapshotDiffReport.java | 6 +- .../SnapshottableDirectoryStatus.java | 59 +++++++++++++ .../apache/hadoop/hdfs/tools/DFSAdmin.java | 30 +++++-- .../tools/snapshot/LsSnapshottableDir.java | 58 +++++++++++++ .../hdfs/tools/snapshot/SnapshotDiff.java | 86 +++++++++++++++++++ 10 files changed, 318 insertions(+), 35 deletions(-) create mode 100644 hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/LsSnapshottableDir.java create mode 100644 hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/SnapshotDiff.java diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java index 6732e149fc3..5762bdfb134 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java @@ -2241,6 +2241,19 @@ public abstract class FileSystem extends Configured implements Closeable { + " doesn't support createSnapshot"); } + /** + * Rename a snapshot + * @param path The directory path where the snapshot was taken + * @param snapshotOldName Old name of the snapshot + * @param snapshotNewName New name of the snapshot + * @throws IOException + */ + public void renameSnapshot(Path path, String snapshotOldName, + String snapshotNewName) throws IOException { + throw new UnsupportedOperationException(getClass().getSimpleName() + + " doesn't support renameSnapshot"); + } + /** * Delete a snapshot of a directory * @param path The directory that the to-be-deleted snapshot belongs to diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/SnapshotCommands.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/SnapshotCommands.java index 37f4cb08c07..e0621a739a6 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/SnapshotCommands.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/SnapshotCommands.java @@ -25,6 +25,8 @@ import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.fs.PathIsNotDirectoryException; +import com.google.common.base.Preconditions; + /** * Snapshot related operations */ @@ -34,10 +36,12 @@ import org.apache.hadoop.fs.PathIsNotDirectoryException; class SnapshotCommands extends FsCommand { private final static String CREATE_SNAPSHOT = "createSnapshot"; private final static String DELETE_SNAPSHOT = "deleteSnapshot"; + private final static String RENAME_SNAPSHOT = "renameSnapshot"; public static void registerCommands(CommandFactory factory) { factory.addClass(CreateSnapshot.class, "-" + CREATE_SNAPSHOT); factory.addClass(DeleteSnapshot.class, "-" + DELETE_SNAPSHOT); + factory.addClass(RenameSnapshot.class, "-" + RENAME_SNAPSHOT); } /** @@ -45,10 +49,10 @@ class SnapshotCommands extends FsCommand { */ public static class CreateSnapshot extends FsCommand { public static final String NAME = CREATE_SNAPSHOT; - public static final String USAGE = " "; + public static final String USAGE = " "; public static final String DESCRIPTION = "Create a snapshot on a directory"; - private static String snapshotName; + private String snapshotName; @Override protected void processPath(PathData item) throws IOException { @@ -62,7 +66,7 @@ class SnapshotCommands extends FsCommand { if (args.size() != 2) { throw new IOException("args number not 2:" + args.size()); } - snapshotName = args.removeFirst(); + snapshotName = args.removeLast(); // TODO: name length check } @@ -85,11 +89,11 @@ class SnapshotCommands extends FsCommand { */ public static class DeleteSnapshot extends FsCommand { public static final String NAME = DELETE_SNAPSHOT; - public static final String USAGE = " "; + public static final String USAGE = " "; public static final String DESCRIPTION = "Delete a snapshot from a directory"; - private static String snapshotName; + private String snapshotName; @Override protected void processPath(PathData item) throws IOException { @@ -103,7 +107,7 @@ class SnapshotCommands extends FsCommand { if (args.size() != 2) { throw new IOException("args number not 2: " + args.size()); } - snapshotName = args.removeFirst(); + snapshotName = args.removeLast(); // TODO: name length check } @@ -120,5 +124,49 @@ class SnapshotCommands extends FsCommand { sroot.fs.deleteSnapshot(sroot.path, snapshotName); } } + + /** + * Rename a snapshot + */ + public static class RenameSnapshot extends FsCommand { + public static final String NAME = RENAME_SNAPSHOT; + public static final String USAGE = " "; + public static final String DESCRIPTION = + "Rename a snapshot from oldName to newName"; + + private String oldName; + private String newName; + + @Override + protected void processPath(PathData item) throws IOException { + if (!item.stat.isDirectory()) { + throw new PathIsNotDirectoryException(item.toString()); + } + } + + @Override + protected void processOptions(LinkedList args) throws IOException { + if (args.size() != 3) { + throw new IOException("args number not 3: " + args.size()); + } + newName = args.removeLast(); + oldName = args.removeLast(); + + // TODO: new name length check + } + + @Override + protected void processArguments(LinkedList items) + throws IOException { + super.processArguments(items); + if (exitCode != 0) { // check for error collecting paths + return; + } + Preconditions.checkArgument(items.size() == 1); + PathData sroot = items.getFirst(); + sroot.fs.renameSnapshot(sroot.path, oldName, newName); + } + + } } diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-2802.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-2802.txt index 95933574d85..d25b36a06ed 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-2802.txt +++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-2802.txt @@ -173,3 +173,6 @@ Branch-2802 Snapshot (Unreleased) HDFS-4520. Support listing snapshots under a snapshottable directory using ls. (Jing Zhao via szetszwo) + + HDFS-4514. Add CLI for supporting snapshot rename, diff report, and + snapshottable directory listing. (Jing Zhao via szetszwo) diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java index 2f98f7b0953..4e411d06234 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java @@ -47,6 +47,7 @@ import org.apache.hadoop.fs.PathFilter; import org.apache.hadoop.fs.RemoteIterator; import org.apache.hadoop.fs.VolumeId; import org.apache.hadoop.fs.permission.FsPermission; +import org.apache.hadoop.hdfs.client.HdfsAdmin; import org.apache.hadoop.hdfs.client.HdfsDataInputStream; import org.apache.hadoop.hdfs.client.HdfsDataOutputStream; import org.apache.hadoop.hdfs.protocol.DatanodeInfo; @@ -906,21 +907,12 @@ public class DistributedFileSystem extends FileSystem { return setSafeMode(SafeModeAction.SAFEMODE_GET, true); } - /** - * Allow snapshot on a directory. - * - * @param path the directory to be taken snapshots - * @throws IOException - */ + /** @see HdfsAdmin#allowSnapshot(String) */ public void allowSnapshot(String path) throws IOException { dfs.allowSnapshot(path); } - /** - * Disallow snapshot on a directory. - * @param path the snapshottable directory. - * @throws IOException on error - */ + /** @see HdfsAdmin#disallowSnapshot(String) */ public void disallowSnapshot(String path) throws IOException { dfs.disallowSnapshot(path); } @@ -931,13 +923,7 @@ public class DistributedFileSystem extends FileSystem { dfs.createSnapshot(getPathName(path), snapshotName); } - /** - * Rename a snapshot - * @param path The directory path where the snapshot was taken - * @param snapshotOldName Old name of the snapshot - * @param snapshotNewName New name of the snapshot - * @throws IOException - */ + @Override public void renameSnapshot(Path path, String snapshotOldName, String snapshotNewName) throws IOException { dfs.renameSnapshot(getPathName(path), snapshotOldName, snapshotNewName); diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsAdmin.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsAdmin.java index 8975c955bbc..0fe9e96764d 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsAdmin.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/HdfsAdmin.java @@ -105,4 +105,20 @@ public class HdfsAdmin { public void clearSpaceQuota(Path src) throws IOException { dfs.setQuota(src, HdfsConstants.QUOTA_DONT_SET, HdfsConstants.QUOTA_RESET); } + + /** + * Allow snapshot on a directory. + * @param the path of the directory where snapshots will be taken + */ + public void allowSnapshot(String path) throws IOException { + dfs.allowSnapshot(path); + } + + /** + * Disallow snapshot on a directory. + * @param path of the snapshottable directory. + */ + public void disallowSnapshot(String path) throws IOException { + dfs.disallowSnapshot(path); + } } diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotDiffReport.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotDiffReport.java index 3a9256ebb8e..e0343a02f58 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotDiffReport.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotDiffReport.java @@ -106,9 +106,9 @@ public class SnapshotDiffReport { public String getRelativePathString() { String path = DFSUtil.bytes2String(relativePath); if (path.isEmpty()) { - return "."; + return Path.CUR_DIR; } else { - return "." + Path.SEPARATOR + path; + return Path.CUR_DIR + Path.SEPARATOR + path; } } @@ -183,7 +183,7 @@ public class SnapshotDiffReport { "current directory" : "snapshot " + fromSnapshot; String to = toSnapshot == null || toSnapshot.isEmpty() ? "current directory" : "snapshot " + toSnapshot; - str.append("Diffence between snapshot " + from + " and " + to + str.append("Difference between " + from + " and " + to + " under directory " + snapshotRoot + ":" + LINE_SEPARATOR); for (DiffReportEntry entry : diffList) { str.append(entry.toString() + LINE_SEPARATOR); diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshottableDirectoryStatus.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshottableDirectoryStatus.java index af40b5cc90b..5620d8cf6ca 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshottableDirectoryStatus.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshottableDirectoryStatus.java @@ -17,6 +17,10 @@ */ package org.apache.hadoop.hdfs.protocol; +import java.io.PrintStream; +import java.text.SimpleDateFormat; +import java.util.Date; + import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.permission.FsPermission; import org.apache.hadoop.hdfs.DFSUtil; @@ -85,4 +89,59 @@ public class SnapshottableDirectoryStatus { return parentFullPathStr == null ? new Path(dirStatus.getLocalName()) : new Path(parentFullPathStr, dirStatus.getLocalName()); } + + /** + * Print a list of {@link SnapshottableDirectoryStatus} out to a given stream. + * @param stats The list of {@link SnapshottableDirectoryStatus} + * @param out The given stream for printing. + */ + public static void print(SnapshottableDirectoryStatus[] stats, + PrintStream out) { + if (stats == null || stats.length == 0) { + out.println(); + return; + } + int maxRepl = 0, maxLen = 0, maxOwner = 0, maxGroup = 0; + int maxSnapshotNum = 0, maxSnapshotQuota = 0; + for (SnapshottableDirectoryStatus status : stats) { + maxRepl = maxLength(maxRepl, status.dirStatus.getReplication()); + maxLen = maxLength(maxLen, status.dirStatus.getLen()); + maxOwner = maxLength(maxOwner, status.dirStatus.getOwner()); + maxGroup = maxLength(maxGroup, status.dirStatus.getGroup()); + maxSnapshotNum = maxLength(maxSnapshotNum, status.snapshotNumber); + maxSnapshotQuota = maxLength(maxSnapshotQuota, status.snapshotQuota); + } + + StringBuilder fmt = new StringBuilder(); + fmt.append("%s%s "); // permission string + fmt.append("%" + maxRepl + "s "); + fmt.append((maxOwner > 0) ? "%-" + maxOwner + "s " : "%s"); + fmt.append((maxGroup > 0) ? "%-" + maxGroup + "s " : "%s"); + fmt.append("%" + maxLen + "s "); + fmt.append("%s "); // mod time + fmt.append("%" + maxSnapshotNum + "s "); + fmt.append("%" + maxSnapshotQuota + "s "); + fmt.append("%s"); // path + + String lineFormat = fmt.toString(); + SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm"); + + for (SnapshottableDirectoryStatus status : stats) { + String line = String.format(lineFormat, "d", + status.dirStatus.getPermission(), + status.dirStatus.getReplication(), + status.dirStatus.getOwner(), + status.dirStatus.getGroup(), + String.valueOf(status.dirStatus.getLen()), + dateFormat.format(new Date(status.dirStatus.getModificationTime())), + status.snapshotNumber, status.snapshotQuota, + status.getFullPath().toString() + ); + out.println(line); + } + } + + private static int maxLength(int n, Object value) { + return Math.max(n, String.valueOf(value).length()); + } } diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java index f7605ff9e98..e9363536f86 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java @@ -408,7 +408,7 @@ public class DFSAdmin extends FsShell { /** * Allow snapshot on a directory. - * Usage: java DFSAdmin -allowSnapshot + * Usage: java DFSAdmin -allowSnapshot snapshotDir * @param argv List of of command line parameters. * @exception IOException */ @@ -420,7 +420,7 @@ public class DFSAdmin extends FsShell { /** * Allow snapshot on a directory. - * Usage: java DFSAdmin -disallowSnapshot + * Usage: java DFSAdmin -disallowSnapshot snapshotDir * @param argv List of of command line parameters. * @exception IOException */ @@ -571,6 +571,8 @@ public class DFSAdmin extends FsShell { "\t[-deleteBlockPool datanodehost:port blockpoolId [force]]\n"+ "\t[-setBalancerBandwidth ]\n" + "\t[-fetchImage ]\n" + + "\t[-allowSnapshot ]\n" + + "\t[-disallowSnapshot ]\n" + "\t[-help [cmd]]\n"; String report ="-report: \tReports basic filesystem information and statistics.\n"; @@ -661,6 +663,12 @@ public class DFSAdmin extends FsShell { "\tDownloads the most recent fsimage from the Name Node and saves it in" + "\tthe specified local directory.\n"; + String allowSnapshot = "-allowSnapshot :\n" + + "\tAllow snapshots to be taken on a directory.\n"; + + String disallowSnapshot = "-disallowSnapshot :\n" + + "\tDo not allow snapshots to be taken on a directory any more.\n"; + String help = "-help [cmd]: \tDisplays help for the given command or all commands if none\n" + "\t\tis specified.\n"; @@ -704,6 +712,10 @@ public class DFSAdmin extends FsShell { System.out.println(setBalancerBandwidth); } else if ("fetchImage".equals(cmd)) { System.out.println(fetchImage); + } else if ("allowSnapshot".equalsIgnoreCase(cmd)) { + System.out.println(allowSnapshot); + } else if ("disallowSnapshot".equalsIgnoreCase(cmd)) { + System.out.println(disallowSnapshot); } else if ("help".equals(cmd)) { System.out.println(help); } else { @@ -728,6 +740,8 @@ public class DFSAdmin extends FsShell { System.out.println(deleteBlockPool); System.out.println(setBalancerBandwidth); System.out.println(fetchImage); + System.out.println(allowSnapshot); + System.out.println(disallowSnapshot); System.out.println(help); System.out.println(); ToolRunner.printGenericCommandUsage(System.out); @@ -906,10 +920,10 @@ public class DFSAdmin extends FsShell { + " [-safemode enter | leave | get | wait]"); } else if ("-allowSnapshot".equalsIgnoreCase(cmd)) { System.err.println("Usage: java DFSAdmin" - + " [-allowSnapshot ]"); - } else if ("-disallowsnapshot".equalsIgnoreCase(cmd)) { + + " [-allowSnapshot ]"); + } else if ("-disallowSnapshot".equalsIgnoreCase(cmd)) { System.err.println("Usage: java DFSAdmin" - + " [-disallowSnapshot ]"); + + " [-disallowSnapshot ]"); } else if ("-saveNamespace".equals(cmd)) { System.err.println("Usage: java DFSAdmin" + " [-saveNamespace]"); @@ -969,8 +983,8 @@ public class DFSAdmin extends FsShell { System.err.println("Note: Administrative commands can only be run as the HDFS superuser."); System.err.println(" [-report]"); System.err.println(" [-safemode enter | leave | get | wait]"); - System.err.println(" [-allowSnapshot ]"); - System.err.println(" [-disallowSnapshot ]"); + System.err.println(" [-allowSnapshot ]"); + System.err.println(" [-disallowSnapshot ]"); System.err.println(" [-saveNamespace]"); System.err.println(" [-rollEdits]"); System.err.println(" [-restoreFailedStorage true|false|check]"); @@ -1021,7 +1035,7 @@ public class DFSAdmin extends FsShell { return exitCode; } } else if ("-allowSnapshot".equalsIgnoreCase(cmd)) { - if (argv.length != 3) { + if (argv.length != 2) { printUsage(cmd); return exitCode; } diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/LsSnapshottableDir.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/LsSnapshottableDir.java new file mode 100644 index 00000000000..c8ac8611a31 --- /dev/null +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/LsSnapshottableDir.java @@ -0,0 +1,58 @@ +/** + * 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.hdfs.tools.snapshot; + +import java.io.IOException; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.hdfs.DistributedFileSystem; +import org.apache.hadoop.hdfs.protocol.SnapshottableDirectoryStatus; + +/** + * A tool used to list all snapshottable directories that are owned by the + * current user. The tool returns all the snapshottable directories if the user + * is a super user. + */ +@InterfaceAudience.Private +public class LsSnapshottableDir { + public static void main(String[] argv) throws IOException { + String description = "LsSnapshottableDir: \n" + + "\tGet the list of snapshottable directories that are owned by the current user.\n" + + "\tReturn all the snapshottable directories if the current user is a super user.\n"; + + if(argv.length != 0) { + System.err.println("Usage: \n" + description); + System.exit(1); + } + + Configuration conf = new Configuration(); + FileSystem fs = FileSystem.get(conf); + if (! (fs instanceof DistributedFileSystem)) { + System.err.println( + "LsSnapshottableDir can only be used in DistributedFileSystem"); + System.exit(1); + } + DistributedFileSystem dfs = (DistributedFileSystem) fs; + + SnapshottableDirectoryStatus[] stats = dfs.getSnapshottableDirListing(); + SnapshottableDirectoryStatus.print(stats, System.out); + } + +} diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/SnapshotDiff.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/SnapshotDiff.java new file mode 100644 index 00000000000..a80e1d76ebb --- /dev/null +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/snapshot/SnapshotDiff.java @@ -0,0 +1,86 @@ +/** + * 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.hdfs.tools.snapshot; + +import java.io.IOException; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.hdfs.DistributedFileSystem; +import org.apache.hadoop.hdfs.protocol.HdfsConstants; +import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport; + +/** + * A tool used to get the difference report between two snapshots, or between + * a snapshot and the current status of a directory. + * 
+ * Usage: SnapshotDiff snapshotDir from to
+ * For from/to, users can use "." to present the current status, and use 
+ * ".snapshot/snapshot_name" to present a snapshot, where ".snapshot/" can be 
+ * omitted.
+ *
+ */ +@InterfaceAudience.Private +public class SnapshotDiff { + private static String getSnapshotName(String name) { + if (Path.CUR_DIR.equals(name)) { // current directory + return ""; + } + if (name.startsWith(HdfsConstants.DOT_SNAPSHOT_DIR + Path.SEPARATOR) + || name.startsWith(Path.SEPARATOR + HdfsConstants.DOT_SNAPSHOT_DIR + + Path.SEPARATOR)) { + // get the snapshot name + int i = name.indexOf(HdfsConstants.DOT_SNAPSHOT_DIR); + return name.substring(i + HdfsConstants.DOT_SNAPSHOT_DIR.length() + 1); + } + return name; + } + + public static void main(String[] argv) throws IOException { + String description = "SnapshotDiff :\n" + + "\tGet the difference between two snapshots, \n" + + "\tor between a snapshot and the current tree of a directory.\n" + + "\tFor /, users can use \".\" to present the current status,\n" + + "\tand use \".snapshot/snapshot_name\" to present a snapshot,\n" + + "\twhere \".snapshot/\" can be omitted\n"; + + if(argv.length != 3) { + System.err.println("Usage: \n" + description); + System.exit(1); + } + + Configuration conf = new Configuration(); + FileSystem fs = FileSystem.get(conf); + if (! (fs instanceof DistributedFileSystem)) { + System.err.println( + "SnapshotDiff can only be used in DistributedFileSystem"); + System.exit(1); + } + DistributedFileSystem dfs = (DistributedFileSystem) fs; + + Path snapshotRoot = new Path(argv[0]); + String fromSnapshot = getSnapshotName(argv[1]); + String toSnapshot = getSnapshotName(argv[2]); + SnapshotDiffReport diffReport = dfs.getSnapshotDiffReport(snapshotRoot, + fromSnapshot, toSnapshot); + System.out.println(diffReport.toString()); + } + +}