Implement SHA-256 abstraction

The Large File Storage extension specified by GitHub [1] uses SHA-256 to
compute the ID of large files stored by the extension. Hence implement a
SHA-256 abstraction similar to the SHA-1 abstraction used by JGit.

[1] https://git-lfs.github.com/

Bug: 470333
Change-Id: I3a95954543c8570d73929e55f4a884b55dbf1b7a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

3 files changed, 1115 insertions, 0 deletions

diff --git a/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/AbbreviatedLongObjectIdTest.java b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/AbbreviatedLongObjectIdTest.java
new file mode 100644
index 0000000000..8938a7875d
--- /dev/null
+++ b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/AbbreviatedLongObjectIdTest.java
@@ -0,0 +1,596 @@
+/*
+ * Copyright (C) 2015, 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.lfs.lib;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import org.eclipse.jgit.lfs.test.LongObjectIdTestUtils;
+import org.junit.Test;
+
+/*
+ * Ported to SHA-256 from org.eclipse.jgit.lib.AbbreviatedObjectIdTest
+ */
+public class AbbreviatedLongObjectIdTest {
+	@Test
+	public void testEmpty_FromByteArray() {
+		final AbbreviatedLongObjectId i;
+		i = AbbreviatedLongObjectId.fromString(new byte[] {}, 0, 0);
+		assertNotNull(i);
+		assertEquals(0, i.length());
+		assertFalse(i.isComplete());
+		assertEquals("", i.name());
+	}
+
+	@Test
+	public void testEmpty_FromString() {
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId
+				.fromString("");
+		assertNotNull(i);
+		assertEquals(0, i.length());
+		assertFalse(i.isComplete());
+		assertEquals("", i.name());
+	}
+
+	@Test
+	public void testFull_FromByteArray() {
+		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final byte[] b = org.eclipse.jgit.lib.Constants.encodeASCII(s);
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(b,
+				0, b.length);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertTrue(i.isComplete());
+		assertEquals(s, i.name());
+
+		final LongObjectId f = i.toLongObjectId();
+		assertNotNull(f);
+		assertEquals(LongObjectId.fromString(s), f);
+		assertEquals(f.hashCode(), i.hashCode());
+	}
+
+	@Test
+	public void testFull_FromString() {
+		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertTrue(i.isComplete());
+		assertEquals(s, i.name());
+
+		final LongObjectId f = i.toLongObjectId();
+		assertNotNull(f);
+		assertEquals(LongObjectId.fromString(s), f);
+		assertEquals(f.hashCode(), i.hashCode());
+	}
+
+	@Test
+	public void test1_FromString() {
+		final String s = "2";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test2_FromString() {
+		final String s = "27";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test3_FromString() {
+		final String s = "27e";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test4_FromString() {
+		final String s = "27e1";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test5_FromString() {
+		final String s = "27e15";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test6_FromString() {
+		final String s = "27e15b";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test7_FromString() {
+		final String s = "27e15b7";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test8_FromString() {
+		final String s = "27e15b72";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test9_FromString() {
+		final String s = "27e15b729";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test15_FromString() {
+		final String s = "27e15b72937fc8f";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test16_FromString() {
+		final String s = "27e15b72937fc8f5";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test17_FromString() {
+		final String s = "27e15b72937fc8f55";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void test33_FromString() {
+		final String s = "27e15b72937fc8f558da24ac3d50ec203";
+		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
+		assertNotNull(i);
+		assertEquals(s.length(), i.length());
+		assertFalse(i.isComplete());
+		assertEquals(s, i.name());
+		assertNull(i.toLongObjectId());
+	}
+
+	@Test
+	public void testEquals_Short() {
+		final String s = "27e15b72";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
+		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
+		assertNotSame(a, b);
+		assertTrue(a.hashCode() == b.hashCode());
+		assertEquals(b, a);
+		assertEquals(a, b);
+	}
+
+	@Test
+	public void testEquals_Full() {
+		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
+		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
+		assertNotSame(a, b);
+		assertTrue(a.hashCode() == b.hashCode());
+		assertEquals(b, a);
+		assertEquals(a, b);
+	}
+
+	@Test
+	public void testNotEquals_SameLength() {
+		final String sa = "27e15b72";
+		final String sb = "27e15b7f";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
+				.fromString(sb);
+		assertFalse(a.equals(b));
+		assertFalse(b.equals(a));
+	}
+
+	@Test
+	public void testNotEquals_DiffLength() {
+		final String sa = "27e15b72abcd";
+		final String sb = "27e15b72";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
+				.fromString(sb);
+		assertFalse(a.equals(b));
+		assertFalse(b.equals(a));
+	}
+
+	@Test
+	public void testPrefixCompare_Full() {
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(s1);
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b11";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b0f";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testPrefixCompare_1() {
+		final String sa = "2";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "37e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "17e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testPrefixCompare_15() {
+		final String sa = "27e15b72937fc8f";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "27e15b72937fc90558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "27e15b72937fc8e558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testPrefixCompare_16() {
+		final String sa = "27e15b72937fc8f5";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "27e15b72937fc8f658da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "27e15b72937fc8f458da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testPrefixCompare_17() {
+		final String sa = "27e15b72937fc8f55";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "27e15b72937fc8f568da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "27e15b72937fc8f548da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testPrefixCompare_33() {
+		final String sa = "27e15b72937fc8f558da24ac3d50ec203";
+		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
+				.fromString(sa);
+
+		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i1 = LongObjectId.fromString(s1);
+		assertEquals(0, a.prefixCompare(i1));
+		assertTrue(i1.startsWith(a));
+
+		final String s2 = "27e15b72937fc8f558da24ac3d50ec20402a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i2 = LongObjectId.fromString(s2);
+		assertTrue(a.prefixCompare(i2) < 0);
+		assertFalse(i2.startsWith(a));
+
+		final String s3 = "27e15b72937fc8f558da24ac3d50ec20202a4cf21e33b87ae8e4ce90e89c4b10";
+		final LongObjectId i3 = LongObjectId.fromString(s3);
+		assertTrue(a.prefixCompare(i3) > 0);
+		assertFalse(i3.startsWith(a));
+	}
+
+	@Test
+	public void testIsId() {
+		// These are all too short.
+		assertFalse(AbbreviatedLongObjectId.isId(""));
+		assertFalse(AbbreviatedLongObjectId.isId("a"));
+
+		// These are too long.
+		assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
+				.fromString(
+						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
+				.name() + "0"));
+		assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
+				.fromString(
+						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
+				.name() + "c0ffee"));
+
+		// These contain non-hex characters.
+		assertFalse(AbbreviatedLongObjectId.isId("01notahexstring"));
+
+		// These should all work.
+		assertTrue(AbbreviatedLongObjectId.isId("ab"));
+		assertTrue(AbbreviatedLongObjectId.isId("abc"));
+		assertTrue(AbbreviatedLongObjectId.isId("abcd"));
+		assertTrue(AbbreviatedLongObjectId.isId("abcd0"));
+		assertTrue(AbbreviatedLongObjectId.isId("abcd09"));
+		assertTrue(AbbreviatedLongObjectId.isId(LongObjectId
+				.fromString(
+						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
+				.name()));
+	}
+
+	@Test
+	public void testAbbreviate() {
+		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
+		assertEquals(
+				"abbreviated id should match the id it was abbreviated from", 0,
+				id.abbreviate(10).prefixCompare(id));
+	}
+
+	@Test
+	public void testFromStringByteWrongLength() {
+		byte[] buf = new byte[65];
+		try {
+			AbbreviatedLongObjectId.fromString(buf, 0, 65);
+			fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
+		} catch (IllegalArgumentException e) {
+			// expected
+		}
+	}
+
+	@Test
+	public void testFromStringWrongLength() {
+		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
+		try {
+			AbbreviatedLongObjectId.fromString(id.name() + "c0ffee");
+			fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
+		} catch (IllegalArgumentException e) {
+			// expected
+		}
+	}
+
+	@Test
+	public void testFromLongObjectId() {
+		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
+		assertEquals(0,
+				AbbreviatedLongObjectId.fromLongObjectId(id).prefixCompare(id));
+	}
+
+	@Test
+	public void testPrefixCompareByte() {
+		AnyLongObjectId id = LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
+		byte[] buf = new byte[32];
+		id.copyRawTo(buf, 0);
+
+		AbbreviatedLongObjectId a = id.abbreviate(62);
+		assertEquals(0, a.prefixCompare(buf, 0));
+
+		a = LongObjectId
+				.fromString(
+						"0023456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
+				.abbreviate(16);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef0023456789abcdef0123456789abcdef0123456789abcdef")
+				.abbreviate(32);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef0123456789abcdef0023456789abcdef0123456789abcdef")
+				.abbreviate(48);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef0123456789abcdef0123456789abcdef0023456789abcdef")
+				.abbreviate(64);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+
+		a = LongObjectId
+				.fromString(
+						"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
+				.abbreviate(16);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef1123456789abcdef0123456789abcdef0123456789abcdef")
+				.abbreviate(32);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef0123456789abcdef1123456789abcdef0123456789abcdef")
+				.abbreviate(48);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = LongObjectId
+				.fromString(
+						"0123456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef")
+				.abbreviate(64);
+		assertEquals(1, a.prefixCompare(buf, 0));
+	}
+
+	@Test
+	public void testPrefixCompareLong() {
+		AnyLongObjectId id = new LongObjectId(1L, 2L, 3L, 4L);
+		long[] buf = new long[4];
+		id.copyRawTo(buf, 0);
+
+		AbbreviatedLongObjectId a = id.abbreviate(62);
+		assertEquals(0, a.prefixCompare(buf, 0));
+
+		a = new LongObjectId(0L, 2L, 3L, 4L).abbreviate(16);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 1L, 3L, 4L).abbreviate(32);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 2L, 2L, 4L).abbreviate(48);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 2L, 3L, 3L).abbreviate(64);
+		assertEquals(-1, a.prefixCompare(buf, 0));
+
+		a = new LongObjectId(2L, 2L, 3L, 4L).abbreviate(16);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 3L, 3L, 4L).abbreviate(32);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 2L, 4L, 4L).abbreviate(48);
+		assertEquals(1, a.prefixCompare(buf, 0));
+		a = new LongObjectId(1L, 2L, 3L, 5L).abbreviate(64);
+		assertEquals(1, a.prefixCompare(buf, 0));
+	}
+
+	@Test
+	public void testGetFirstByte() {
+		AnyLongObjectId id = LongObjectId.fromString(
+				"f423456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef");
+		AbbreviatedLongObjectId a = id.abbreviate(10);
+		assertEquals(0xf4, a.getFirstByte());
+		assertEquals(id.getFirstByte(), a.getFirstByte());
+	}
+
+	@Test
+	public void testNotEquals() {
+		AbbreviatedLongObjectId a = new LongObjectId(1L, 2L, 3L, 4L)
+				.abbreviate(10);
+		assertFalse(a.equals("different"));
+	}
+}
diff --git a/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java
new file mode 100644
index 0000000000..435a2a3c39
--- /dev/null
+++ b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java
@@ -0,0 +1,427 @@
+/*
+ * Copyright (C) 2015, 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.lfs.lib;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.eclipse.jgit.junit.JGitTestUtil;
+import org.eclipse.jgit.lfs.errors.InvalidLongObjectIdException;
+import org.eclipse.jgit.lfs.test.LongObjectIdTestUtils;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.util.FileUtils;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/*
+ * Ported to SHA-256 from org.eclipse.jgit.lib.ObjectIdTest
+ */
+public class LongObjectIdTest {
+	private static Path tmp;
+
+	@BeforeClass
+	public static void setup() throws IOException {
+		tmp = Files.createTempDirectory("jgit_test_");
+	}
+
+	@AfterClass
+	public static void tearDown() throws IOException {
+		FileUtils.delete(tmp.toFile(), FileUtils.RECURSIVE | FileUtils.RETRY);
+	}
+
+	@Test
+	public void test001_toString() {
+		final String x = "8367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2deb7ab0a";
+		final LongObjectId oid = LongObjectId.fromString(x);
+		assertEquals(x, oid.name());
+	}
+
+	@Test
+	public void test002_toString() {
+		final String x = "140ce71d628cceb78e3709940ba52a651a0c4a9c1400f2e15e998a1a43887edf";
+		final LongObjectId oid = LongObjectId.fromString(x);
+		assertEquals(x, oid.name());
+	}
+
+	@Test
+	public void test003_equals() {
+		final String x = "8367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2deb7ab0a";
+		final LongObjectId a = LongObjectId.fromString(x);
+		final LongObjectId b = LongObjectId.fromString(x);
+		assertEquals(a.hashCode(), b.hashCode());
+		assertEquals("a and b should be equal", b, a);
+	}
+
+	@Test
+	public void test004_isId() {
+		assertTrue("valid id", LongObjectId.isId(
+				"8367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2deb7ab0a"));
+	}
+
+	@Test
+	public void test005_notIsId() {
+		assertFalse("bob is not an id", LongObjectId.isId("bob"));
+	}
+
+	@Test
+	public void test006_notIsId() {
+		assertFalse("63 digits is not an id", LongObjectId.isId(
+				"8367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2deb7ab0"));
+	}
+
+	@Test
+	public void test007_isId() {
+		assertTrue("uppercase is accepted", LongObjectId.isId(
+				"8367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2dEb7ab0A"));
+	}
+
+	@Test
+	public void test008_notIsId() {
+		assertFalse("g is not a valid hex digit", LongObjectId.isId(
+				"g367b0edc81df80e6b42eb1b71f783111224e058cb3da37894d065d2deb7ab0a"));
+	}
+
+	@Test
+	public void test009_toString() {
+		final String x = "140ce71d628cceb78e3709940ba52a651a0c4a9c1400f2e15e998a1a43887edf";
+		final LongObjectId oid = LongObjectId.fromString(x);
+		assertEquals(x, LongObjectId.toString(oid));
+	}
+
+	@Test
+	public void test010_toString() {
+		final String x = "0000000000000000000000000000000000000000000000000000000000000000";
+		assertEquals(x, LongObjectId.toString(null));
+	}
+
+	@Test
+	public void test011_toString() {
+		final String x = "0123456789ABCDEFabcdef01234567890123456789ABCDEFabcdef0123456789";
+		final LongObjectId oid = LongObjectId.fromString(x);
+		assertEquals(x.toLowerCase(), oid.name());
+	}
+
+	@Test
+	public void testGetByte() {
+		byte[] raw = new byte[32];
+		for (int i = 0; i < 32; i++)
+			raw[i] = (byte) (0xa0 + i);
+		LongObjectId id = LongObjectId.fromRaw(raw);
+
+		assertEquals(raw[0] & 0xff, id.getFirstByte());
+		assertEquals(raw[0] & 0xff, id.getByte(0));
+		assertEquals(raw[1] & 0xff, id.getByte(1));
+		assertEquals(raw[1] & 0xff, id.getSecondByte());
+
+		for (int i = 2; i < 32; i++) {
+			assertEquals("index " + i, raw[i] & 0xff, id.getByte(i));
+		}
+		try {
+			id.getByte(32);
+			fail("LongObjectId has 32 byte only");
+		} catch (ArrayIndexOutOfBoundsException e) {
+			// expected
+		}
+	}
+
+	@Test
+	public void testSetByte() {
+		byte[] exp = new byte[32];
+		for (int i = 0; i < 32; i++) {
+			exp[i] = (byte) (0xa0 + i);
+		}
+
+		MutableLongObjectId id = new MutableLongObjectId();
+		id.fromRaw(exp);
+		assertEquals(LongObjectId.fromRaw(exp).name(), id.name());
+
+		id.setByte(0, 0x10);
+		assertEquals(0x10, id.getByte(0));
+		exp[0] = 0x10;
+		assertEquals(LongObjectId.fromRaw(exp).name(), id.name());
+
+		for (int p = 1; p < 32; p++) {
+			id.setByte(p, 0x10 + p);
+			assertEquals(0x10 + p, id.getByte(p));
+			exp[p] = (byte) (0x10 + p);
+			assertEquals(LongObjectId.fromRaw(exp).name(), id.name());
+		}
+
+		for (int p = 0; p < 32; p++) {
+			id.setByte(p, 0x80 + p);
+			assertEquals(0x80 + p, id.getByte(p));
+			exp[p] = (byte) (0x80 + p);
+			assertEquals(LongObjectId.fromRaw(exp).name(), id.name());
+		}
+	}
+
+	@Test
+	public void testZeroId() {
+		AnyLongObjectId zero = new LongObjectId(0L, 0L, 0L, 0L);
+		assertEquals(zero, LongObjectId.zeroId());
+		assertEquals(
+				"0000000000000000000000000000000000000000000000000000000000000000",
+				LongObjectId.zeroId().name());
+	}
+
+	@Test
+	public void testEquals() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		assertTrue("id should equal itself", id1.equals(id1));
+		AnyLongObjectId id2 = new LongObjectId(id1);
+		assertEquals("objects should be equals", id1, id2);
+
+		id2 = LongObjectIdTestUtils.hash("other");
+		assertNotEquals("objects should be not equal", id1, id2);
+	}
+
+	@Test
+	public void testCopyRawBytes() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		AnyLongObjectId id2 = new LongObjectId(id1);
+
+		byte[] buf = new byte[64];
+		id1.copyRawTo(buf, 0);
+		id2.copyRawTo(buf, 32);
+		assertTrue("objects should be equals",
+				LongObjectId.equals(buf, 0, buf, 32));
+	}
+
+	@Test
+	public void testCopyRawLongs() {
+		long[] a = new long[4];
+		a[0] = 1L;
+		a[1] = 2L;
+		a[2] = 3L;
+		a[3] = 4L;
+		AnyLongObjectId id1 = new LongObjectId(a[0], a[1], a[2], a[3]);
+		AnyLongObjectId id2 = LongObjectId.fromRaw(a);
+		assertEquals("objects should be equals", id1, id2);
+	}
+
+	@Test
+	public void testCopyFromStringInvalid() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		try {
+			LongObjectId.fromString(id1.name() + "01234");
+			fail("expected InvalidLongObjectIdException");
+		} catch (InvalidLongObjectIdException e) {
+			assertEquals("Invalid id: " + id1.name() + "01234",
+					e.getMessage());
+		}
+	}
+
+	@Test
+	public void testCopyFromStringByte() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		byte[] buf = new byte[64];
+		Charset cs = StandardCharsets.US_ASCII;
+		cs.encode(id1.name()).get(buf);
+		AnyLongObjectId id2 = LongObjectId.fromString(buf, 0);
+		assertEquals("objects should be equals", id1, id2);
+	}
+
+	@Test
+	public void testHashFile() throws IOException {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		Path f = tmp.resolve("test");
+		JGitTestUtil.write(f.toFile(), "test");
+		AnyLongObjectId id2 = LongObjectIdTestUtils.hash(f);
+		assertEquals("objects should be equals", id1, id2);
+	}
+
+	@Test
+	public void testCompareTo() {
+		AnyLongObjectId id1 = LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
+		assertEquals(0, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")));
+		assertEquals(0, id1.compareTo(id1));
+
+		assertEquals(-1, id1.compareTo(LongObjectId.fromString(
+				"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")));
+		assertEquals(-1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef1123456789abcdef0123456789abcdef0123456789abcdef")));
+		assertEquals(-1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef1123456789abcdef0123456789abcdef")));
+		assertEquals(-1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef")));
+
+		assertEquals(1, id1.compareTo(LongObjectId.fromString(
+				"0023456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")));
+		assertEquals(1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0023456789abcdef0123456789abcdef0123456789abcdef")));
+		assertEquals(1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0023456789abcdef0123456789abcdef")));
+		assertEquals(1, id1.compareTo(LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef0023456789abcdef")));
+	}
+
+	@Test
+	public void testCompareToByte() {
+		AnyLongObjectId id1 = LongObjectId.fromString(
+				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
+		byte[] buf = new byte[32];
+		id1.copyRawTo(buf, 0);
+		assertEquals(0, id1.compareTo(buf, 0));
+
+		LongObjectId
+				.fromString(
+						"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
+				.copyRawTo(buf, 0);
+		assertEquals(-1, id1.compareTo(buf, 0));
+
+		LongObjectId
+				.fromString(
+						"0023456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
+				.copyRawTo(buf, 0);
+		assertEquals(1, id1.compareTo(buf, 0));
+	}
+
+	@Test
+	public void testCompareToLong() {
+		AnyLongObjectId id1 = new LongObjectId(1L, 2L, 3L, 4L);
+		long[] buf = new long[4];
+		id1.copyRawTo(buf, 0);
+		assertEquals(0, id1.compareTo(buf, 0));
+
+		new LongObjectId(2L, 2L, 3L, 4L).copyRawTo(buf, 0);
+		assertEquals(-1, id1.compareTo(buf, 0));
+
+		new LongObjectId(0L, 2L, 3L, 4L).copyRawTo(buf, 0);
+		assertEquals(1, id1.compareTo(buf, 0));
+	}
+
+	@Test
+	public void testCopyToByte() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		byte[] buf = new byte[64];
+		id1.copyTo(buf, 0);
+		assertEquals(id1, LongObjectId.fromString(buf, 0));
+	}
+
+	@Test
+	public void testCopyRawToByteBuffer() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteBuffer buf = ByteBuffer.allocate(32);
+		id1.copyRawTo(buf);
+		assertEquals(id1, LongObjectId.fromRaw(buf.array(), 0));
+	}
+
+	@Test
+	public void testCopyToByteBuffer() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteBuffer buf = ByteBuffer.allocate(64);
+		id1.copyTo(buf);
+		assertEquals(id1, LongObjectId.fromString(buf.array(), 0));
+	}
+
+	@Test
+	public void testCopyRawToOutputStream() throws IOException {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteArrayOutputStream os = new ByteArrayOutputStream(32);
+		id1.copyRawTo(os);
+		assertEquals(id1, LongObjectId.fromRaw(os.toByteArray(), 0));
+	}
+
+	@Test
+	public void testCopyToOutputStream() throws IOException {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteArrayOutputStream os = new ByteArrayOutputStream(64);
+		id1.copyTo(os);
+		assertEquals(id1, LongObjectId.fromString(os.toByteArray(), 0));
+	}
+
+	@Test
+	public void testCopyToWriter() throws IOException {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteArrayOutputStream os = new ByteArrayOutputStream(64);
+		OutputStreamWriter w = new OutputStreamWriter(os, Constants.CHARSET);
+		id1.copyTo(w);
+		w.close();
+		assertEquals(id1, LongObjectId.fromString(os.toByteArray(), 0));
+	}
+
+	@Test
+	public void testCopyToWriterWithBuf() throws IOException {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		ByteArrayOutputStream os = new ByteArrayOutputStream(64);
+		OutputStreamWriter w = new OutputStreamWriter(os, Constants.CHARSET);
+		char[] buf = new char[64];
+		id1.copyTo(buf, w);
+		w.close();
+		assertEquals(id1, LongObjectId.fromString(os.toByteArray(), 0));
+	}
+
+	@Test
+	public void testCopyToStringBuilder() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		StringBuilder sb = new StringBuilder();
+		char[] buf = new char[64];
+		id1.copyTo(buf, sb);
+		assertEquals(id1, LongObjectId.fromString(sb.toString()));
+	}
+
+	@Test
+	public void testCopy() {
+		AnyLongObjectId id1 = LongObjectIdTestUtils.hash("test");
+		assertEquals(id1.copy(), id1);
+		MutableLongObjectId id2 = new MutableLongObjectId();
+		id2.fromObjectId(id1);
+		assertEquals(id1, id2.copy());
+	}
+}
diff --git a/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/MutableLongObjectIdTest.java b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/MutableLongObjectIdTest.java
new file mode 100644
index 0000000000..9bdc3ab0c0
--- /dev/null
+++ b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/MutableLongObjectIdTest.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015, 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.lfs.lib;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/*
+ * Ported to SHA-256 from org.eclipse.jgit.lib.MutableObjectIdTest
+ */
+public class MutableLongObjectIdTest {
+
+	@Test
+	public void testFromRawLong() {
+		MutableLongObjectId m = new MutableLongObjectId();
+		m.fromRaw(new long[] { 1L, 2L, 3L, 4L });
+		assertEquals(new LongObjectId(1L, 2L, 3L, 4L), m);
+	}
+
+	@Test
+	public void testFromString() {
+		AnyLongObjectId id = new LongObjectId(1L, 2L, 3L, 4L);
+		MutableLongObjectId m = new MutableLongObjectId();
+		m.fromString(id.name());
+		assertEquals(id, m);
+	}
+
+	@Test
+	public void testFromStringByte() {
+		AnyLongObjectId id = new LongObjectId(1L, 2L, 3L, 4L);
+		MutableLongObjectId m = new MutableLongObjectId();
+		byte[] buf = new byte[64];
+		id.copyTo(buf, 0);
+		m.fromString(buf, 0);
+		assertEquals(id, m);
+	}
+
+	@Test
+	public void testCopy() {
+		MutableLongObjectId m = new MutableLongObjectId();
+		m.fromRaw(new long[] { 1L, 2L, 3L, 4L });
+		assertEquals(m, new MutableLongObjectId(m));
+	}
+
+	@Test
+	public void testToObjectId() {
+		MutableLongObjectId m = new MutableLongObjectId();
+		m.fromRaw(new long[] { 1L, 2L, 3L, 4L });
+		assertEquals(m, m.toObjectId());
+	}
+}