From f0b46e1db47bfc11dc7f39b9cb4fc30a78ea7f16 Mon Sep 17 00:00:00 2001 From: David Pursehouse Date: Wed, 21 Feb 2018 12:40:47 +0900 Subject: [PATCH] Add ObjectIdSerializer This is based on the ObjectIdSerialization class written by Shawn Pearce for the Gerrit Code Review project in 2009 [1]. As mentioned in the commit message there, it should be part of core JGit. This implementation is slightly different to Shawn's version. Rather than having separate methods for null/non-null ids, single methods are implemented with @Nullable annotations. [1] https://gerrit-review.googlesource.com/c/gerrit/+/9792 Change-Id: I7599cf8bd1ecd546e2252783d6d672eb76804060 Signed-off-by: David Pursehouse Signed-off-by: Matthias Sohn --- .../jgit/lib/ObjectIdSerializerTest.java | 88 ++++++++++++++ .../eclipse/jgit/lib/ObjectIdSerializer.java | 107 ++++++++++++++++++ 2 files changed, 195 insertions(+) create mode 100644 org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdSerializerTest.java create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdSerializer.java diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdSerializerTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdSerializerTest.java new file mode 100644 index 000000000..24bc40eee --- /dev/null +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdSerializerTest.java @@ -0,0 +1,88 @@ +/* + * Copyright (C) 2018, David Pursehouse + * 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.lib; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertNull; + +import java.io.File; +import java.io.FileInputStream; +import java.io.FileOutputStream; +import java.io.InputStream; +import java.io.OutputStream; + +import org.junit.Test; + +public class ObjectIdSerializerTest { + @Test + public void serialize() throws Exception { + ObjectId original = new ObjectId(1, 2, 3, 4, 5); + ObjectId deserialized = writeAndReadBackFromTempFile(original); + assertEquals(original, deserialized); + } + + @Test + public void serializeZeroId() throws Exception { + ObjectId original = ObjectId.zeroId(); + ObjectId deserialized = writeAndReadBackFromTempFile(original); + assertEquals(original, deserialized); + } + + @Test + public void serializeNull() throws Exception { + ObjectId deserialized = writeAndReadBackFromTempFile(null); + assertNull(deserialized); + } + + private ObjectId writeAndReadBackFromTempFile(ObjectId objectId) + throws Exception { + File file = File.createTempFile("ObjectIdSerializerTest_", ""); + try (OutputStream out = new FileOutputStream(file)) { + ObjectIdSerializer.write(out, objectId); + } + try (InputStream in = new FileInputStream(file)) { + return ObjectIdSerializer.read(in); + } + } +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdSerializer.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdSerializer.java new file mode 100644 index 000000000..59da40830 --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdSerializer.java @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2009, The Android Open Source Project + * Copyright (C) 2009, Shawn O. Pearce + * Copyright (C) 2018, David Pursehouse + * 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.lib; + +import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; + +import org.eclipse.jgit.annotations.Nullable; +import org.eclipse.jgit.util.IO; + +/** + * Helper to serialize {@link ObjectId} instances. {@link ObjectId} is already + * serializable, but this class provides a more optimal implementation. It + * writes out a flag (0 or 1) followed by the object's words, or nothing if it + * was a null id. + * + * @since 4.11 + */ +public class ObjectIdSerializer { + /** + * @param out + * the output stream + * @param id + * the object id to serialize + * @throws IOException + * the stream writing failed + */ + public static void write(OutputStream out, @Nullable AnyObjectId id) + throws IOException { + if (id != null) { + out.write((byte) 1); + id.copyRawTo(out); + } else { + out.write((byte) 0); + } + } + + /** + * @param in + * the input stream + * @return the object id + * @throws IOException + * there was an error reading the stream + */ + @Nullable + public static ObjectId read(InputStream in) throws IOException { + switch (in.read()) { + case 0: + return null; + case 1: + final byte[] b = new byte[OBJECT_ID_LENGTH]; + IO.readFully(in, b, 0, OBJECT_ID_LENGTH); + return ObjectId.fromRaw(b); + default: + throw new IOException("Invalid flag before ObjectId"); //$NON-NLS-1$ + } + } + + private ObjectIdSerializer() { + } +}