| /* |
| * Copyright (C) 2017 Two Sigma Open Source and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.internal.storage.file; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.nio.file.NoSuchFileException; |
| import java.nio.file.attribute.FileTime; |
| import java.text.ParseException; |
| import java.time.Instant; |
| |
| import org.eclipse.jgit.api.errors.JGitInternalException; |
| import org.eclipse.jgit.lib.ConfigConstants; |
| import org.eclipse.jgit.util.FileUtils; |
| import org.eclipse.jgit.util.GitDateParser; |
| import org.eclipse.jgit.util.SystemReader; |
| |
| /** |
| * This class manages the gc.log file for a {@link FileRepository}. |
| */ |
| class GcLog { |
| private final FileRepository repo; |
| |
| private final File logFile; |
| |
| private final LockFile lock; |
| |
| private Instant gcLogExpire; |
| |
| private static final String LOG_EXPIRY_DEFAULT = "1.day.ago"; //$NON-NLS-1$ |
| |
| private boolean nonEmpty = false; |
| |
| /** |
| * Construct a GcLog object for a {@link FileRepository} |
| * |
| * @param repo |
| * the repository |
| */ |
| GcLog(FileRepository repo) { |
| this.repo = repo; |
| logFile = new File(repo.getDirectory(), "gc.log"); //$NON-NLS-1$ |
| lock = new LockFile(logFile); |
| } |
| |
| private Instant getLogExpiry() throws ParseException { |
| if (gcLogExpire == null) { |
| String logExpiryStr = repo.getConfig().getString( |
| ConfigConstants.CONFIG_GC_SECTION, null, |
| ConfigConstants.CONFIG_KEY_LOGEXPIRY); |
| if (logExpiryStr == null) { |
| logExpiryStr = LOG_EXPIRY_DEFAULT; |
| } |
| gcLogExpire = GitDateParser.parse(logExpiryStr, null, |
| SystemReader.getInstance().getLocale()).toInstant(); |
| } |
| return gcLogExpire; |
| } |
| |
| private boolean autoGcBlockedByOldLockFile() { |
| try { |
| FileTime lastModified = Files.getLastModifiedTime(FileUtils.toPath(logFile)); |
| if (lastModified.toInstant().compareTo(getLogExpiry()) > 0) { |
| // There is an existing log file, which is too recent to ignore |
| return true; |
| } |
| } catch (NoSuchFileException e) { |
| // No existing log file, OK. |
| } catch (IOException | ParseException e) { |
| throw new JGitInternalException(e.getMessage(), e); |
| } |
| return false; |
| } |
| |
| /** |
| * Lock the GC log file for updates |
| * |
| * @return {@code true} if we hold the lock |
| */ |
| boolean lock() { |
| try { |
| if (!lock.lock()) { |
| return false; |
| } |
| } catch (IOException e) { |
| throw new JGitInternalException(e.getMessage(), e); |
| } |
| if (autoGcBlockedByOldLockFile()) { |
| lock.unlock(); |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Unlock (roll back) the GC log lock |
| */ |
| void unlock() { |
| lock.unlock(); |
| } |
| |
| /** |
| * Commit changes to the gc log, if there have been any writes. Otherwise, |
| * just unlock and delete the existing file (if any) |
| * |
| * @return true if committing (or unlocking/deleting) succeeds. |
| */ |
| boolean commit() { |
| if (nonEmpty) { |
| return lock.commit(); |
| } |
| logFile.delete(); |
| lock.unlock(); |
| return true; |
| } |
| |
| /** |
| * Write to the pending gc log. Content will be committed upon a call to |
| * commit() |
| * |
| * @param content |
| * The content to write |
| * @throws IOException |
| */ |
| void write(String content) throws IOException { |
| if (content.length() > 0) { |
| nonEmpty = true; |
| } |
| lock.write(content.getBytes(UTF_8)); |
| } |
| } |