1 /* 2 * Copyright (C) 2009, Google Inc. 3 * and other copyright owners as documented in the project's IP log. 4 * 5 * This program and the accompanying materials are made available 6 * under the terms of the Eclipse Distribution License v1.0 which 7 * accompanies this distribution, is reproduced below, and is 8 * available at http://www.eclipse.org/org/documents/edl-v10.php 9 * 10 * All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or 13 * without modification, are permitted provided that the following 14 * conditions are met: 15 * 16 * - Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials provided 22 * with the distribution. 23 * 24 * - Neither the name of the Eclipse Foundation, Inc. nor the 25 * names of its contributors may be used to endorse or promote 26 * products derived from this software without specific prior 27 * written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 42 */ 43 44 package org.eclipse.jgit.internal.storage.file; 45 46 import java.io.File; 47 import java.io.IOException; 48 49 import org.eclipse.jgit.lib.Constants; 50 import org.eclipse.jgit.util.FS; 51 import org.eclipse.jgit.util.FileUtils; 52 53 /** Keeps track of a {@link PackFile}'s associated <code>.keep</code> file. */ 54 public class PackLock { 55 private final File keepFile; 56 private final FS fs; 57 58 /** 59 * Create a new lock for a pack file. 60 * 61 * @param packFile 62 * location of the <code>pack-*.pack</code> file. 63 * @param fs 64 * the filesystem abstraction used by the repository. 65 */ 66 public PackLock(final File packFile, final FS fs) { 67 final File p = packFile.getParentFile(); 68 final String n = packFile.getName(); 69 keepFile = new File(p, n.substring(0, n.length() - 5) + ".keep"); //$NON-NLS-1$ 70 this.fs = fs; 71 } 72 73 /** 74 * Create the <code>pack-*.keep</code> file, with the given message. 75 * 76 * @param msg 77 * message to store in the file. 78 * @return true if the keep file was successfully written; false otherwise. 79 * @throws IOException 80 * the keep file could not be written. 81 */ 82 public boolean lock(String msg) throws IOException { 83 if (msg == null) 84 return false; 85 if (!msg.endsWith("\n")) //$NON-NLS-1$ 86 msg += "\n"; //$NON-NLS-1$ 87 final LockFile lf = new LockFile(keepFile, fs); 88 if (!lf.lock()) 89 return false; 90 lf.write(Constants.encode(msg)); 91 return lf.commit(); 92 } 93 94 /** 95 * Remove the <code>.keep</code> file that holds this pack in place. 96 * 97 * @throws IOException 98 * if deletion of .keep file failed 99 */ 100 public void unlock() throws IOException { 101 FileUtils.delete(keepFile); 102 } 103 }