| /** |
| * 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.shell; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.PathIsDirectoryException; |
| |
| import java.io.IOException; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| /** |
| * Truncates a file to a new size |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class Truncate extends FsCommand { |
| public static void registerCommands(CommandFactory factory) { |
| factory.addClass(Truncate.class, "-truncate"); |
| } |
| |
| public static final String NAME = "truncate"; |
| public static final String USAGE = "[-w] <length> <path> ..."; |
| public static final String DESCRIPTION = |
| "Truncate all files that match the specified file pattern to the " + |
| "specified length.\n" + |
| "-w: Requests that the command wait for block recovery to complete, " + |
| "if necessary."; |
| |
| protected long newLength = -1; |
| protected List<PathData> waitList = new LinkedList<>(); |
| protected boolean waitOpt = false; |
| |
| @Override |
| protected void processOptions(LinkedList<String> args) throws IOException { |
| CommandFormat cf = new CommandFormat(2, Integer.MAX_VALUE, "w"); |
| cf.parse(args); |
| waitOpt = cf.getOpt("w"); |
| |
| try { |
| newLength = Long.parseLong(args.removeFirst()); |
| } catch(NumberFormatException nfe) { |
| displayWarning("Illegal length, a non-negative integer expected"); |
| throw nfe; |
| } |
| if(newLength < 0) { |
| throw new IllegalArgumentException("length must be >= 0"); |
| } |
| } |
| |
| @Override |
| protected void processArguments(LinkedList<PathData> args) |
| throws IOException { |
| super.processArguments(args); |
| if (waitOpt) waitForRecovery(); |
| } |
| |
| @Override |
| protected void processPath(PathData item) throws IOException { |
| if(item.stat.isDirectory()) { |
| throw new PathIsDirectoryException(item.toString()); |
| } |
| long oldLength = item.stat.getLen(); |
| if(newLength > oldLength) { |
| throw new IllegalArgumentException( |
| "Cannot truncate to a larger file size. Current size: " + oldLength + |
| ", truncate size: " + newLength + "."); |
| } |
| if(item.fs.truncate(item.path, newLength)) { |
| out.println("Truncated " + item + " to length: " + newLength); |
| } |
| else if(waitOpt) { |
| waitList.add(item); |
| } |
| else { |
| out.println("Truncating " + item + " to length: " + newLength + ". " + |
| "Wait for block recovery to complete before further updating this " + |
| "file."); |
| } |
| } |
| |
| /** |
| * Wait for all files in waitList to have length equal to newLength. |
| */ |
| private void waitForRecovery() throws IOException { |
| for(PathData item : waitList) { |
| out.println("Waiting for " + item + " ..."); |
| out.flush(); |
| |
| for(;;) { |
| item.refreshStatus(); |
| if(item.stat.getLen() == newLength) break; |
| try {Thread.sleep(1000);} catch(InterruptedException ignored) {} |
| } |
| |
| out.println("Truncated " + item + " to length: " + newLength); |
| out.flush(); |
| } |
| } |
| } |