org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java - jgit/jgit - Git at Google

 /*
  * Copyright (C) 2010, Google Inc.
  * Copyright (C) 2010, Matthias Sohn <matthias.sohn@sap.com>
  * Copyright (C) 2010, Jens Baumgart <jens.baumgart@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.util;

 import java.io.File;
 import java.io.IOException;
 import java.nio.channels.FileLock;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.jgit.internal.JGitText;

 /**
  * File Utilities
  */
 public class FileUtils {

 	/**
 	 * Option to delete given {@code File}
 	 */
 	public static final int NONE = 0;

 	/**
 	 * Option to recursively delete given {@code File}
 	 */
 	public static final int RECURSIVE = 1;

 	/**
 	 * Option to retry deletion if not successful
 	 */
 	public static final int RETRY = 2;

 	/**
 	 * Option to skip deletion if file doesn't exist
 	 */
 	public static final int SKIP_MISSING = 4;

 	/**
 	 * Option not to throw exceptions when a deletion finally doesn't succeed.
 	 * @since 2.0
 	 */
 	public static final int IGNORE_ERRORS = 8;

 	/**
 	 * Option to only delete empty directories. This option can be combined with
 	 * {@link #RECURSIVE}
 	 *
 	 * @since 3.0
 	 */
 	public static final int EMPTY_DIRECTORIES_ONLY = 16;

 	/**
 	 * Delete file or empty folder
 	 *
 	 * @param f
 	 *            {@code File} to be deleted
 	 * @throws IOException
 	 *             if deletion of {@code f} fails. This may occur if {@code f}
 	 *             didn't exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to delete the same file.
 	 */
 	public static void delete(final File f) throws IOException {
 		delete(f, NONE);
 	}

 	/**
 	 * Delete file or folder
 	 *
 	 * @param f
 	 *            {@code File} to be deleted
 	 * @param options
 	 *            deletion options, {@code RECURSIVE} for recursive deletion of
 	 *            a subtree, {@code RETRY} to retry when deletion failed.
 	 *            Retrying may help if the underlying file system doesn't allow
 	 *            deletion of files being read by another thread.
 	 * @throws IOException
 	 *             if deletion of {@code f} fails. This may occur if {@code f}
 	 *             didn't exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to delete the same file. This
 	 *             exception is not thrown when IGNORE_ERRORS is set.
 	 */
 	public static void delete(final File f, int options) throws IOException {
 		FS fs = FS.DETECTED;
 		if ((options & SKIP_MISSING) != 0 && !fs.exists(f))
 			return;

 		if ((options & RECURSIVE) != 0 && fs.isDirectory(f)) {
 			final File[] items = f.listFiles();
 			if (items != null) {
 				List<File> files = new ArrayList<File>();
 				List<File> dirs = new ArrayList<File>();
 				for (File c : items)
 					if (c.isFile())
 						files.add(c);
 					else
 						dirs.add(c);
 				// Try to delete files first, otherwise options
 				// EMPTY_DIRECTORIES_ONLY|RECURSIVE will delete empty
 				// directories before aborting, depending on order.
 				for (File file : files)
 					delete(file, options);
 				for (File d : dirs)
 					delete(d, options);
 			}
 		}

 		boolean delete = false;
 		if ((options & EMPTY_DIRECTORIES_ONLY) != 0) {
 			if (f.isDirectory()) {
 				delete = true;
 			} else {
 				if ((options & IGNORE_ERRORS) == 0)
 					throw new IOException(MessageFormat.format(
 							JGitText.get().deleteFileFailed,
 							f.getAbsolutePath()));
 			}
 		} else {
 			delete = true;
 		}

 		if (delete && !f.delete()) {
 			if ((options & RETRY) != 0 && fs.exists(f)) {
 				for (int i = 1; i < 10; i++) {
 					try {
 						Thread.sleep(100);
 					} catch (InterruptedException e) {
 						// ignore
 					}
 					if (f.delete())
 						return;
 				}
 			}
 			if ((options & IGNORE_ERRORS) == 0)
 				throw new IOException(MessageFormat.format(
 						JGitText.get().deleteFileFailed, f.getAbsolutePath()));
 		}
 	}

 	/**
 	 * Rename a file or folder. If the rename fails and if we are running on a
 	 * filesystem where it makes sense to repeat a failing rename then repeat
 	 * the rename operation up to 9 times with 100ms sleep time between two
 	 * calls. Furthermore if the destination exists and is directory hierarchy
 	 * with only directories in it, the whole directory hierarchy will be
 	 * deleted. If the target represents a non-empty directory structure, empty
 	 * subdirectories within that structure may or may not be deleted even if
 	 * the method fails. Furthermore if the destination exists and is a file
 	 * then the file will be deleted and then the rename is retried.
 	 * <p>
 	 * This operation is <em>not</me> atomic.
 	 *
 	 * @see FS#retryFailedLockFileCommit()
 	 * @param src
 	 *            the old {@code File}
 	 * @param dst
 	 *            the new {@code File}
 	 * @throws IOException
 	 *             if the rename has failed
 	 * @since 3.0
 	 */
 	public static void rename(final File src, final File dst)
 			throws IOException {
 		int attempts = FS.DETECTED.retryFailedLockFileCommit() ? 10 : 1;
 		while (--attempts >= 0) {
 			if (src.renameTo(dst))
 				return;
 			try {
 				if (!dst.delete())
 					delete(dst, EMPTY_DIRECTORIES_ONLY | RECURSIVE);
 				// On *nix there is no try, you do or do not
 				if (src.renameTo(dst))
 					return;
 			} catch (IOException e) {
 				// ignore and continue retry
 			}
 			try {
 				Thread.sleep(100);
 			} catch (InterruptedException e) {
 				throw new IOException(MessageFormat.format(
 						JGitText.get().renameFileFailed, src.getAbsolutePath(),
 						dst.getAbsolutePath()));
 			}
 		}
 		throw new IOException(MessageFormat.format(
 				JGitText.get().renameFileFailed, src.getAbsolutePath(),
 				dst.getAbsolutePath()));
 	}

 	/**
 	 * Creates the directory named by this abstract pathname.
 	 *
 	 * @param d
 	 *            directory to be created
 	 * @throws IOException
 	 *             if creation of {@code d} fails. This may occur if {@code d}
 	 *             did exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to create the same directory.
 	 */
 	public static void mkdir(final File d)
 			throws IOException {
 		mkdir(d, false);
 	}

 	/**
 	 * Creates the directory named by this abstract pathname.
 	 *
 	 * @param d
 	 *            directory to be created
 	 * @param skipExisting
 	 *            if {@code true} skip creation of the given directory if it
 	 *            already exists in the file system
 	 * @throws IOException
 	 *             if creation of {@code d} fails. This may occur if {@code d}
 	 *             did exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to create the same directory.
 	 */
 	public static void mkdir(final File d, boolean skipExisting)
 			throws IOException {
 		if (!d.mkdir()) {
 			if (skipExisting && d.isDirectory())
 				return;
 			throw new IOException(MessageFormat.format(
 					JGitText.get().mkDirFailed, d.getAbsolutePath()));
 		}
 	}

 	/**
 	 * Creates the directory named by this abstract pathname, including any
 	 * necessary but nonexistent parent directories. Note that if this operation
 	 * fails it may have succeeded in creating some of the necessary parent
 	 * directories.
 	 *
 	 * @param d
 	 *            directory to be created
 	 * @throws IOException
 	 *             if creation of {@code d} fails. This may occur if {@code d}
 	 *             did exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to create the same directory.
 	 */
 	public static void mkdirs(final File d) throws IOException {
 		mkdirs(d, false);
 	}

 	/**
 	 * Creates the directory named by this abstract pathname, including any
 	 * necessary but nonexistent parent directories. Note that if this operation
 	 * fails it may have succeeded in creating some of the necessary parent
 	 * directories.
 	 *
 	 * @param d
 	 *            directory to be created
 	 * @param skipExisting
 	 *            if {@code true} skip creation of the given directory if it
 	 *            already exists in the file system
 	 * @throws IOException
 	 *             if creation of {@code d} fails. This may occur if {@code d}
 	 *             did exist when the method was called. This can therefore
 	 *             cause IOExceptions during race conditions when multiple
 	 *             concurrent threads all try to create the same directory.
 	 */
 	public static void mkdirs(final File d, boolean skipExisting)
 			throws IOException {
 		if (!d.mkdirs()) {
 			if (skipExisting && d.isDirectory())
 				return;
 			throw new IOException(MessageFormat.format(
 					JGitText.get().mkDirsFailed, d.getAbsolutePath()));
 		}
 	}

 	/**
 	 * Atomically creates a new, empty file named by this abstract pathname if
 	 * and only if a file with this name does not yet exist. The check for the
 	 * existence of the file and the creation of the file if it does not exist
 	 * are a single operation that is atomic with respect to all other
 	 * filesystem activities that might affect the file.
 	 * <p>
 	 * Note: this method should not be used for file-locking, as the resulting
 	 * protocol cannot be made to work reliably. The {@link FileLock} facility
 	 * should be used instead.
 	 *
 	 * @param f
 	 *            the file to be created
 	 * @throws IOException
 	 *             if the named file already exists or if an I/O error occurred
 	 */
 	public static void createNewFile(File f) throws IOException {
 		if (!f.createNewFile())
 			throw new IOException(MessageFormat.format(
 					JGitText.get().createNewFileFailed, f));
 	}

 	/**
 	 * Create a symbolic link
 	 *
 	 * @param path
 	 * @param target
 	 * @throws IOException
 	 * @since 3.0
 	 */
 	public static void createSymLink(File path, String target)
 			throws IOException {
 		FS.DETECTED.createSymLink(path, target);
 	}

 	/**
 	 * @param path
 	 * @return the target of the symbolic link, or null if it is not a symbolic
 	 *         link
 	 * @throws IOException
 	 * @since 3.0
 	 */
 	public static String readSymLink(File path) throws IOException {
 		return FS.DETECTED.readSymLink(path);
 	}
 }
	/*
	* Copyright (C) 2010, Google Inc.
	* Copyright (C) 2010, Matthias Sohn <matthias.sohn@sap.com>
	* Copyright (C) 2010, Jens Baumgart <jens.baumgart@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.util;

	import java.io.File;
	import java.io.IOException;
	import java.nio.channels.FileLock;
	import java.text.MessageFormat;
	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.jgit.internal.JGitText;

	/**
	* File Utilities
	*/
	public class FileUtils {

	/**
	* Option to delete given {@code File}
	*/
	public static final int NONE = 0;

	/**
	* Option to recursively delete given {@code File}
	*/
	public static final int RECURSIVE = 1;

	/**
	* Option to retry deletion if not successful
	*/
	public static final int RETRY = 2;

	/**
	* Option to skip deletion if file doesn't exist
	*/
	public static final int SKIP_MISSING = 4;

	/**
	* Option not to throw exceptions when a deletion finally doesn't succeed.
	* @since 2.0
	*/
	public static final int IGNORE_ERRORS = 8;

	/**
	* Option to only delete empty directories. This option can be combined with
	* {@link #RECURSIVE}
	*
	* @since 3.0
	*/
	public static final int EMPTY_DIRECTORIES_ONLY = 16;

	/**
	* Delete file or empty folder
	*
	* @param f
	* {@code File} to be deleted
	* @throws IOException
	* if deletion of {@code f} fails. This may occur if {@code f}
	* didn't exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to delete the same file.
	*/
	public static void delete(final File f) throws IOException {
	delete(f, NONE);
	}

	/**
	* Delete file or folder
	*
	* @param f
	* {@code File} to be deleted
	* @param options
	* deletion options, {@code RECURSIVE} for recursive deletion of
	* a subtree, {@code RETRY} to retry when deletion failed.
	* Retrying may help if the underlying file system doesn't allow
	* deletion of files being read by another thread.
	* @throws IOException
	* if deletion of {@code f} fails. This may occur if {@code f}
	* didn't exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to delete the same file. This
	* exception is not thrown when IGNORE_ERRORS is set.
	*/
	public static void delete(final File f, int options) throws IOException {
	FS fs = FS.DETECTED;
	if ((options & SKIP_MISSING) != 0 && !fs.exists(f))
	return;

	if ((options & RECURSIVE) != 0 && fs.isDirectory(f)) {
	final File[] items = f.listFiles();
	if (items != null) {
	List<File> files = new ArrayList<File>();
	List<File> dirs = new ArrayList<File>();
	for (File c : items)
	if (c.isFile())
	files.add(c);
	else
	dirs.add(c);
	// Try to delete files first, otherwise options
	// EMPTY_DIRECTORIES_ONLY\|RECURSIVE will delete empty
	// directories before aborting, depending on order.
	for (File file : files)
	delete(file, options);
	for (File d : dirs)
	delete(d, options);
	}
	}

	boolean delete = false;
	if ((options & EMPTY_DIRECTORIES_ONLY) != 0) {
	if (f.isDirectory()) {
	delete = true;
	} else {
	if ((options & IGNORE_ERRORS) == 0)
	throw new IOException(MessageFormat.format(
	JGitText.get().deleteFileFailed,
	f.getAbsolutePath()));
	}
	} else {
	delete = true;
	}

	if (delete && !f.delete()) {
	if ((options & RETRY) != 0 && fs.exists(f)) {
	for (int i = 1; i < 10; i++) {
	try {
	Thread.sleep(100);
	} catch (InterruptedException e) {
	// ignore
	}
	if (f.delete())
	return;
	}
	}
	if ((options & IGNORE_ERRORS) == 0)
	throw new IOException(MessageFormat.format(
	JGitText.get().deleteFileFailed, f.getAbsolutePath()));
	}
	}

	/**
	* Rename a file or folder. If the rename fails and if we are running on a
	* filesystem where it makes sense to repeat a failing rename then repeat
	* the rename operation up to 9 times with 100ms sleep time between two
	* calls. Furthermore if the destination exists and is directory hierarchy
	* with only directories in it, the whole directory hierarchy will be
	* deleted. If the target represents a non-empty directory structure, empty
	* subdirectories within that structure may or may not be deleted even if
	* the method fails. Furthermore if the destination exists and is a file
	* then the file will be deleted and then the rename is retried.
	* <p>
	* This operation is <em>not</me> atomic.
	*
	* @see FS#retryFailedLockFileCommit()
	* @param src
	* the old {@code File}
	* @param dst
	* the new {@code File}
	* @throws IOException
	* if the rename has failed
	* @since 3.0
	*/
	public static void rename(final File src, final File dst)
	throws IOException {
	int attempts = FS.DETECTED.retryFailedLockFileCommit() ? 10 : 1;
	while (--attempts >= 0) {
	if (src.renameTo(dst))
	return;
	try {
	if (!dst.delete())
	delete(dst, EMPTY_DIRECTORIES_ONLY \| RECURSIVE);
	// On *nix there is no try, you do or do not
	if (src.renameTo(dst))
	return;
	} catch (IOException e) {
	// ignore and continue retry
	}
	try {
	Thread.sleep(100);
	} catch (InterruptedException e) {
	throw new IOException(MessageFormat.format(
	JGitText.get().renameFileFailed, src.getAbsolutePath(),
	dst.getAbsolutePath()));
	}
	}
	throw new IOException(MessageFormat.format(
	JGitText.get().renameFileFailed, src.getAbsolutePath(),
	dst.getAbsolutePath()));
	}

	/**
	* Creates the directory named by this abstract pathname.
	*
	* @param d
	* directory to be created
	* @throws IOException
	* if creation of {@code d} fails. This may occur if {@code d}
	* did exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to create the same directory.
	*/
	public static void mkdir(final File d)
	throws IOException {
	mkdir(d, false);
	}

	/**
	* Creates the directory named by this abstract pathname.
	*
	* @param d
	* directory to be created
	* @param skipExisting
	* if {@code true} skip creation of the given directory if it
	* already exists in the file system
	* @throws IOException
	* if creation of {@code d} fails. This may occur if {@code d}
	* did exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to create the same directory.
	*/
	public static void mkdir(final File d, boolean skipExisting)
	throws IOException {
	if (!d.mkdir()) {
	if (skipExisting && d.isDirectory())
	return;
	throw new IOException(MessageFormat.format(
	JGitText.get().mkDirFailed, d.getAbsolutePath()));
	}
	}

	/**
	* Creates the directory named by this abstract pathname, including any
	* necessary but nonexistent parent directories. Note that if this operation
	* fails it may have succeeded in creating some of the necessary parent
	* directories.
	*
	* @param d
	* directory to be created
	* @throws IOException
	* if creation of {@code d} fails. This may occur if {@code d}
	* did exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to create the same directory.
	*/
	public static void mkdirs(final File d) throws IOException {
	mkdirs(d, false);
	}

	/**
	* Creates the directory named by this abstract pathname, including any
	* necessary but nonexistent parent directories. Note that if this operation
	* fails it may have succeeded in creating some of the necessary parent
	* directories.
	*
	* @param d
	* directory to be created
	* @param skipExisting
	* if {@code true} skip creation of the given directory if it
	* already exists in the file system
	* @throws IOException
	* if creation of {@code d} fails. This may occur if {@code d}
	* did exist when the method was called. This can therefore
	* cause IOExceptions during race conditions when multiple
	* concurrent threads all try to create the same directory.
	*/
	public static void mkdirs(final File d, boolean skipExisting)
	throws IOException {
	if (!d.mkdirs()) {
	if (skipExisting && d.isDirectory())
	return;
	throw new IOException(MessageFormat.format(
	JGitText.get().mkDirsFailed, d.getAbsolutePath()));
	}
	}

	/**
	* Atomically creates a new, empty file named by this abstract pathname if
	* and only if a file with this name does not yet exist. The check for the
	* existence of the file and the creation of the file if it does not exist
	* are a single operation that is atomic with respect to all other
	* filesystem activities that might affect the file.
	* <p>
	* Note: this method should not be used for file-locking, as the resulting
	* protocol cannot be made to work reliably. The {@link FileLock} facility
	* should be used instead.
	*
	* @param f
	* the file to be created
	* @throws IOException
	* if the named file already exists or if an I/O error occurred
	*/
	public static void createNewFile(File f) throws IOException {
	if (!f.createNewFile())
	throw new IOException(MessageFormat.format(
	JGitText.get().createNewFileFailed, f));
	}

	/**
	* Create a symbolic link
	*
	* @param path
	* @param target
	* @throws IOException
	* @since 3.0
	*/
	public static void createSymLink(File path, String target)
	throws IOException {
	FS.DETECTED.createSymLink(path, target);
	}

	/**
	* @param path
	* @return the target of the symbolic link, or null if it is not a symbolic
	* link
	* @throws IOException
	* @since 3.0
	*/
	public static String readSymLink(File path) throws IOException {
	return FS.DETECTED.readSymLink(path);
	}
	}