Expose LongMap in util package

This is a useful primitive collection type like IntList.

Change-Id: I04b9b2ba25247df056eb3a1725602f1be6d3b440

1 files changed, 153 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/LongMapTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/LongMapTest.java
new file mode 100644
index 0000000000..054c61e2be
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/LongMapTest.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2009, Google Inc.
+ * 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 static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class LongMapTest {
+	private LongMap<Long> map;
+
+	@Before
+	public void setUp() throws Exception {
+		map = new LongMap<>();
+	}
+
+	@Test
+	public void testEmptyMap() {
+		assertFalse(map.containsKey(0));
+		assertFalse(map.containsKey(1));
+
+		assertNull(map.get(0));
+		assertNull(map.get(1));
+
+		assertNull(map.remove(0));
+		assertNull(map.remove(1));
+	}
+
+	@Test
+	public void testInsertMinValue() {
+		final Long min = Long.valueOf(Long.MIN_VALUE);
+		assertNull(map.put(Long.MIN_VALUE, min));
+		assertTrue(map.containsKey(Long.MIN_VALUE));
+		assertSame(min, map.get(Long.MIN_VALUE));
+		assertFalse(map.containsKey(Integer.MIN_VALUE));
+	}
+
+	@Test
+	public void testReplaceMaxValue() {
+		final Long min = Long.valueOf(Long.MAX_VALUE);
+		final Long one = Long.valueOf(1);
+		assertNull(map.put(Long.MAX_VALUE, min));
+		assertSame(min, map.get(Long.MAX_VALUE));
+		assertSame(min, map.put(Long.MAX_VALUE, one));
+		assertSame(one, map.get(Long.MAX_VALUE));
+	}
+
+	@Test
+	public void testRemoveOne() {
+		final long start = 1;
+		assertNull(map.put(start, Long.valueOf(start)));
+		assertEquals(Long.valueOf(start), map.remove(start));
+		assertFalse(map.containsKey(start));
+	}
+
+	@Test
+	public void testRemoveCollision1() {
+		// This test relies upon the fact that we always >>> 1 the value
+		// to derive an unsigned hash code. Thus, 0 and 1 fall into the
+		// same hash bucket. Further it relies on the fact that we add
+		// the 2nd put at the top of the chain, so removing the 1st will
+		// cause a different code path.
+		//
+		assertNull(map.put(0, Long.valueOf(0)));
+		assertNull(map.put(1, Long.valueOf(1)));
+		assertEquals(Long.valueOf(0), map.remove(0));
+
+		assertFalse(map.containsKey(0));
+		assertTrue(map.containsKey(1));
+	}
+
+	@Test
+	public void testRemoveCollision2() {
+		// This test relies upon the fact that we always >>> 1 the value
+		// to derive an unsigned hash code. Thus, 0 and 1 fall into the
+		// same hash bucket. Further it relies on the fact that we add
+		// the 2nd put at the top of the chain, so removing the 2nd will
+		// cause a different code path.
+		//
+		assertNull(map.put(0, Long.valueOf(0)));
+		assertNull(map.put(1, Long.valueOf(1)));
+		assertEquals(Long.valueOf(1), map.remove(1));
+
+		assertTrue(map.containsKey(0));
+		assertFalse(map.containsKey(1));
+	}
+
+	@Test
+	public void testSmallMap() {
+		final long start = 12;
+		final long n = 8;
+		for (long i = start; i < start + n; i++)
+			assertNull(map.put(i, Long.valueOf(i)));
+		for (long i = start; i < start + n; i++)
+			assertEquals(Long.valueOf(i), map.get(i));
+	}
+
+	@Test
+	public void testLargeMap() {
+		final long start = Integer.MAX_VALUE;
+		final long n = 100000;
+		for (long i = start; i < start + n; i++)
+			assertNull(map.put(i, Long.valueOf(i)));
+		for (long i = start; i < start + n; i++)
+			assertEquals(Long.valueOf(i), map.get(i));
+	}
+}