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- /*
- * 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 java.io.File;
- import java.io.FileNotFoundException;
- import java.io.IOException;
- import java.text.MessageFormat;
-
- import org.eclipse.jgit.JGitText;
- import org.eclipse.jgit.errors.ConfigInvalidException;
- 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.IO;
- import org.eclipse.jgit.util.RawParseUtils;
-
- /**
- * The configuration file that is stored in the file of the file system.
- */
- public class FileBasedConfig extends StoredConfig {
- private final File configFile;
- private final FS fs;
- 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();
- }
-
- @Override
- protected boolean notifyUponTransientChanges() {
- // we will notify listeners upon save()
- return false;
- }
-
- /** @return location of the configuration file on disk */
- public final File getFile() {
- return configFile;
- }
-
- /**
- * 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.
- *
- * @throws IOException
- * the file could not be read (but does exist).
- * @throws ConfigInvalidException
- * the file is not a properly formatted configuration file.
- */
- @Override
- public void load() throws IOException, ConfigInvalidException {
- final FileSnapshot oldSnapshot = snapshot;
- final FileSnapshot newSnapshot = FileSnapshot.save(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 {
- fromText(RawParseUtils.decode(in));
- snapshot = newSnapshot;
- hash = newHash;
- }
- } catch (FileNotFoundException noFile) {
- clear();
- snapshot = newSnapshot;
- } catch (IOException e) {
- final IOException e2 = new IOException(MessageFormat.format(JGitText.get().cannotReadFile, getFile()));
- e2.initCause(e);
- throw e2;
- } catch (ConfigInvalidException e) {
- throw new ConfigInvalidException(MessageFormat.format(JGitText.get().cannotReadFile, getFile()), e);
- }
- }
-
- /**
- * 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.
- *
- * @throws IOException
- * the file could not be written.
- */
- public void save() throws IOException {
- final byte[] out = Constants.encode(toText());
- final LockFile lf = new LockFile(getFile(), fs);
- if (!lf.lock())
- throw new IOException(MessageFormat.format(JGitText.get().cannotLockFile, 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();
- }
-
- @Override
- public void clear() {
- hash = hash(new byte[0]);
- super.clear();
- }
-
- private static ObjectId hash(final byte[] rawText) {
- return ObjectId.fromRaw(Constants.newMessageDigest().digest(rawText));
- }
-
- @Override
- public String toString() {
- return getClass().getSimpleName() + "[" + getFile().getPath() + "]";
- }
-
- /**
- * @return returns true if the currently loaded configuration file is older
- * than the file on disk
- */
- public boolean isOutdated() {
- return snapshot.isModified(getFile());
- }
- }
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