| /* |
| * Copyright (C) 2009, Constantine Plotnikov <constantine.plotnikov@gmail.com> |
| * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com> |
| * Copyright (C) 2009, Google Inc. |
| * Copyright (C) 2009, JetBrains s.r.o. |
| * Copyright (C) 2008-2009, Robin Rosenberg <robin.rosenberg@dewire.com> |
| * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> |
| * Copyright (C) 2008, Thad Hughes <thadh@thad.corp.google.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.storage.file; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.text.MessageFormat; |
| |
| import org.eclipse.jgit.errors.ConfigInvalidException; |
| import org.eclipse.jgit.errors.LockFailedException; |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.internal.storage.file.FileSnapshot; |
| import org.eclipse.jgit.internal.storage.file.LockFile; |
| import org.eclipse.jgit.lib.Config; |
| import org.eclipse.jgit.lib.Constants; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.lib.StoredConfig; |
| import org.eclipse.jgit.util.FS; |
| import org.eclipse.jgit.util.FileUtils; |
| import org.eclipse.jgit.util.IO; |
| import org.eclipse.jgit.util.RawParseUtils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * The configuration file that is stored in the file of the file system. |
| */ |
| public class FileBasedConfig extends StoredConfig { |
| private final static Logger LOG = LoggerFactory |
| .getLogger(FileBasedConfig.class); |
| |
| private final File configFile; |
| |
| private final FS fs; |
| |
| private boolean utf8Bom; |
| |
| private volatile FileSnapshot snapshot; |
| |
| private volatile ObjectId hash; |
| |
| /** |
| * Create a configuration with no default fallback. |
| * |
| * @param cfgLocation |
| * the location of the configuration file on the file system |
| * @param fs |
| * the file system abstraction which will be necessary to perform |
| * certain file system operations. |
| */ |
| public FileBasedConfig(File cfgLocation, FS fs) { |
| this(null, cfgLocation, fs); |
| } |
| |
| /** |
| * The constructor |
| * |
| * @param base |
| * the base configuration file |
| * @param cfgLocation |
| * the location of the configuration file on the file system |
| * @param fs |
| * the file system abstraction which will be necessary to perform |
| * certain file system operations. |
| */ |
| public FileBasedConfig(Config base, File cfgLocation, FS fs) { |
| super(base); |
| configFile = cfgLocation; |
| this.fs = fs; |
| this.snapshot = FileSnapshot.DIRTY; |
| this.hash = ObjectId.zeroId(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected boolean notifyUponTransientChanges() { |
| // we will notify listeners upon save() |
| return false; |
| } |
| |
| /** |
| * Get location of the configuration file on disk |
| * |
| * @return location of the configuration file on disk |
| */ |
| public final File getFile() { |
| return configFile; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * Load the configuration as a Git text style configuration file. |
| * <p> |
| * If the file does not exist, this configuration is cleared, and thus |
| * behaves the same as though the file exists, but is empty. |
| */ |
| @Override |
| public void load() throws IOException, ConfigInvalidException { |
| final int maxRetries = 5; |
| int retryDelayMillis = 20; |
| int retries = 0; |
| while (true) { |
| final FileSnapshot oldSnapshot = snapshot; |
| final FileSnapshot newSnapshot; |
| // don't use config in this snapshot to avoid endless recursion |
| newSnapshot = FileSnapshot.saveNoConfig(getFile()); |
| try { |
| final byte[] in = IO.readFully(getFile()); |
| final ObjectId newHash = hash(in); |
| if (hash.equals(newHash)) { |
| if (oldSnapshot.equals(newSnapshot)) { |
| oldSnapshot.setClean(newSnapshot); |
| } else { |
| snapshot = newSnapshot; |
| } |
| } else { |
| final String decoded; |
| if (isUtf8(in)) { |
| decoded = RawParseUtils.decode(UTF_8, |
| in, 3, in.length); |
| utf8Bom = true; |
| } else { |
| decoded = RawParseUtils.decode(in); |
| } |
| fromText(decoded); |
| snapshot = newSnapshot; |
| hash = newHash; |
| } |
| return; |
| } catch (FileNotFoundException noFile) { |
| // might be locked by another process (see exception Javadoc) |
| if (retries < maxRetries && configFile.exists()) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug(MessageFormat.format( |
| JGitText.get().configHandleMayBeLocked, |
| Integer.valueOf(retries)), noFile); |
| } |
| try { |
| Thread.sleep(retryDelayMillis); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| } |
| retries++; |
| retryDelayMillis *= 2; // max wait 1260 ms |
| continue; |
| } |
| if (configFile.exists()) { |
| throw noFile; |
| } |
| clear(); |
| snapshot = newSnapshot; |
| return; |
| } catch (IOException e) { |
| if (FileUtils.isStaleFileHandle(e) |
| && retries < maxRetries) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug(MessageFormat.format( |
| JGitText.get().configHandleIsStale, |
| Integer.valueOf(retries)), e); |
| } |
| retries++; |
| continue; |
| } |
| throw new IOException(MessageFormat |
| .format(JGitText.get().cannotReadFile, getFile()), e); |
| } catch (ConfigInvalidException e) { |
| throw new ConfigInvalidException(MessageFormat |
| .format(JGitText.get().cannotReadFile, getFile()), e); |
| } |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * Save the configuration as a Git text style configuration file. |
| * <p> |
| * <b>Warning:</b> Although this method uses the traditional Git file |
| * locking approach to protect against concurrent writes of the |
| * configuration file, it does not ensure that the file has not been |
| * modified since the last read, which means updates performed by other |
| * objects accessing the same backing file may be lost. |
| */ |
| @Override |
| public void save() throws IOException { |
| final byte[] out; |
| final String text = toText(); |
| if (utf8Bom) { |
| final ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
| bos.write(0xEF); |
| bos.write(0xBB); |
| bos.write(0xBF); |
| bos.write(text.getBytes(UTF_8)); |
| out = bos.toByteArray(); |
| } else { |
| out = Constants.encode(text); |
| } |
| |
| final LockFile lf = new LockFile(getFile()); |
| if (!lf.lock()) |
| throw new LockFailedException(getFile()); |
| try { |
| lf.setNeedSnapshot(true); |
| lf.write(out); |
| if (!lf.commit()) |
| throw new IOException(MessageFormat.format(JGitText.get().cannotCommitWriteTo, getFile())); |
| } finally { |
| lf.unlock(); |
| } |
| snapshot = lf.getCommitSnapshot(); |
| hash = hash(out); |
| // notify the listeners |
| fireConfigChangedEvent(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void clear() { |
| hash = hash(new byte[0]); |
| super.clear(); |
| } |
| |
| private static ObjectId hash(byte[] rawText) { |
| return ObjectId.fromRaw(Constants.newMessageDigest().digest(rawText)); |
| } |
| |
| /** {@inheritDoc} */ |
| @SuppressWarnings("nls") |
| @Override |
| public String toString() { |
| return getClass().getSimpleName() + "[" + getFile().getPath() + "]"; |
| } |
| |
| /** |
| * Whether the currently loaded configuration file is outdated |
| * |
| * @return returns true if the currently loaded configuration file is older |
| * than the file on disk |
| */ |
| public boolean isOutdated() { |
| return snapshot.isModified(getFile()); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * @since 4.10 |
| */ |
| @Override |
| protected byte[] readIncludedConfig(String relPath) |
| throws ConfigInvalidException { |
| final File file; |
| if (relPath.startsWith("~/")) { //$NON-NLS-1$ |
| file = fs.resolve(fs.userHome(), relPath.substring(2)); |
| } else { |
| file = fs.resolve(configFile.getParentFile(), relPath); |
| } |
| |
| if (!file.exists()) { |
| return null; |
| } |
| |
| try { |
| return IO.readFully(file); |
| } catch (IOException ioe) { |
| throw new ConfigInvalidException(MessageFormat |
| .format(JGitText.get().cannotReadFile, relPath), ioe); |
| } |
| } |
| } |