PackFileSnapshot.java
- /*
- * 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() + "]";
- }
- }