Add option to skip deletion of non-existing files

For convenience provide an option to skip deletion of non-existing
files. Also add some tests for deletion methods in FileUtils.

Change-Id: I33e355cfcdc19367d50208150ee49a4a06394890
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/util/FileUtilTest.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2010, 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.util;
+
+import java.io.File;
+import java.io.IOException;
+
+import junit.framework.TestCase;
+
+public class FileUtilTest extends TestCase {
+	public void testDeleteFile() throws IOException {
+		File f = new File("test");
+		assertTrue(f.createNewFile());
+		FileUtils.delete(f);
+		assertFalse(f.exists());
+
+		try {
+			FileUtils.delete(f);
+			fail("deletion of non-existing file must fail");
+		} catch (IOException e) {
+			// expected
+		}
+
+		try {
+			FileUtils.delete(f, FileUtils.SKIP_MISSING);
+		} catch (IOException e) {
+			fail("deletion of non-existing file must not fail with option SKIP_MISSING");
+		}
+	}
+
+	public void testDeleteRecursive() throws IOException {
+		File f1 = new File("test/test/a");
+		f1.mkdirs();
+		f1.createNewFile();
+		File f2 = new File("test/test/b");
+		f2.createNewFile();
+		File d = new File("test");
+		FileUtils.delete(d, FileUtils.RECURSIVE);
+		assertFalse(d.exists());
+
+		try {
+			FileUtils.delete(d, FileUtils.RECURSIVE);
+			fail("recursive deletion of non-existing directory must fail");
+		} catch (IOException e) {
+			// expected
+		}
+
+		try {
+			FileUtils.delete(d, FileUtils.RECURSIVE | FileUtils.SKIP_MISSING);
+		} catch (IOException e) {
+			fail("recursive deletion of non-existing directory must not fail with option SKIP_MISSING");
+		}
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java

@@ -71,6 +71,11 @@ public class FileUtils {
 	 */
 	public static final int RETRY = 2;
 
+	/**
+	 * Option to skip deletion if file doesn't exist
+	 */
+	public static final int SKIP_MISSING = 4;
+
 	/**
 	 * Delete file or empty folder
 	 *
@@ -103,6 +108,9 @@ public class FileUtils {
 	 *             concurrent threads all try to delete the same file.
 	 */
 	public static void delete(final File f, int options) throws IOException {
+		if ((options & SKIP_MISSING) != 0 && !f.exists())
+			return;
+
 		if ((options & RECURSIVE) != 0 && f.isDirectory()) {
 			final File[] items = f.listFiles();
 			if (items != null) {