| /* |
| * Copyright (C) 2019, Matthias Sohn <matthias.sohn@sap.com> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.jgit.internal.storage.file; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| |
| import org.eclipse.jgit.lib.AnyObjectId; |
| import org.eclipse.jgit.lib.ObjectId; |
| |
| class PackFileSnapshot extends FileSnapshot { |
| |
| private static final ObjectId MISSING_CHECKSUM = ObjectId.zeroId(); |
| |
| /** |
| * Record a snapshot for a specific packfile path. |
| * <p> |
| * This method should be invoked before the packfile is accessed. |
| * |
| * @param path |
| * the path to later remember. The path's current status |
| * information is saved. |
| * @return the snapshot. |
| */ |
| public static PackFileSnapshot save(File path) { |
| return new PackFileSnapshot(path); |
| } |
| |
| private AnyObjectId checksum = MISSING_CHECKSUM; |
| |
| private boolean wasChecksumChanged; |
| |
| |
| PackFileSnapshot(File packFile) { |
| super(packFile); |
| } |
| |
| void setChecksum(AnyObjectId checksum) { |
| this.checksum = checksum; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean isModified(File packFile) { |
| if (!super.isModified(packFile)) { |
| return false; |
| } |
| if (wasSizeChanged() || wasFileKeyChanged() |
| || !wasLastModifiedRacilyClean()) { |
| return true; |
| } |
| return isChecksumChanged(packFile); |
| } |
| |
| boolean isChecksumChanged(File packFile) { |
| return wasChecksumChanged = checksum != MISSING_CHECKSUM |
| && !checksum.equals(readChecksum(packFile)); |
| } |
| |
| private AnyObjectId readChecksum(File packFile) { |
| try (RandomAccessFile fd = new RandomAccessFile(packFile, "r")) { //$NON-NLS-1$ |
| fd.seek(fd.length() - 20); |
| final byte[] buf = new byte[20]; |
| fd.readFully(buf, 0, 20); |
| return ObjectId.fromRaw(buf); |
| } catch (IOException e) { |
| return MISSING_CHECKSUM; |
| } |
| } |
| |
| boolean wasChecksumChanged() { |
| return wasChecksumChanged; |
| } |
| |
| @SuppressWarnings("nls") |
| @Override |
| public String toString() { |
| return "PackFileSnapshot [checksum=" + checksum + ", " |
| + super.toString() + "]"; |
| } |
| |
| } |