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1   /*
2    * Copyright (C) 2015, Google Inc.
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
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12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
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22   *   with the distribution.
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24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
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29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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42   */
43  
44  package org.eclipse.jgit.internal.storage.dfs;
45  
46  import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
47  import static org.junit.Assert.assertEquals;
48  import static org.junit.Assert.assertNotNull;
49  import static org.junit.Assert.assertNull;
50  import static org.junit.Assert.assertSame;
51  
52  import org.eclipse.jgit.internal.storage.dfs.DeltaBaseCache.Entry;
53  import org.eclipse.jgit.junit.TestRng;
54  import org.junit.Before;
55  import org.junit.Test;
56  
57  public class DeltaBaseCacheTest {
58  	private static final int SZ = 512;
59  
60  	private DfsPackKey key;
61  	private DeltaBaseCache cache;
62  	private TestRng rng;
63  
64  	@Before
65  	public void setUp() {
66  		key = new DfsPackKey();
67  		cache = new DeltaBaseCache(SZ);
68  		rng = new TestRng(getClass().getSimpleName());
69  	}
70  
71  	@Test
72  	public void testObjectLargerThanCacheDoesNotEvict() {
73  		byte[] obj12 = put(12, 32);
74  		put(24, SZ + 5);
75  		assertNull("does not store large object", cache.get(key, 24));
76  		get(obj12, 12);
77  	}
78  
79  	@Test
80  	public void testCacheLruExpires1() {
81  		byte[] obj1 = put(1, SZ / 4);
82  		put(2, SZ / 4);
83  		byte[] obj3 = put(3, SZ / 4);
84  		put(4, SZ / 4);
85  		assertEquals(SZ, cache.getMemoryUsed());
86  
87  		get(obj3, 3);
88  		get(obj1, 1);
89  		put(5, SZ / 2);
90  		assertEquals(SZ, cache.getMemoryUsed());
91  		assertEquals(SZ, cache.getMemoryUsedByTableForTest());
92  		assertEquals(SZ, cache.getMemoryUsedByLruChainForTest());
93  		assertNull(cache.get(key, 4));
94  		assertNull(cache.get(key, 2));
95  
96  		get(obj1, 1);
97  		get(obj3, 3);
98  	}
99  
100 	@Test
101 	public void testCacheLruExpires2() {
102 		int pos0 = (0 << 10) | 2;
103 		int pos1 = (1 << 10) | 2;
104 		int pos2 = (2 << 10) | 2;
105 		int pos5 = (5 << 10) | 2;
106 		int pos6 = (6 << 10) | 2;
107 
108 		put(pos0, SZ / 4);
109 		put(pos5, SZ / 4);
110 		byte[] obj1 = put(pos1, SZ / 4);
111 		byte[] obj2 = put(pos2, SZ / 4);
112 		assertEquals(SZ, cache.getMemoryUsed());
113 
114 		byte[] obj6 = put(pos6, SZ / 2);
115 		assertEquals(SZ, cache.getMemoryUsed());
116 		assertEquals(SZ, cache.getMemoryUsedByTableForTest());
117 		assertEquals(SZ, cache.getMemoryUsedByLruChainForTest());
118 		assertNull(cache.get(key, pos0));
119 		assertNull(cache.get(key, pos5));
120 
121 		get(obj1, pos1);
122 		get(obj2, pos2);
123 		get(obj6, pos6);
124 	}
125 
126 	@Test
127 	public void testCacheMemoryUsedConsistentWithExpectations() {
128 		put(1, 32);
129 		put(2, 32);
130 		put(3, 32);
131 
132 		assertNotNull(cache.get(key, 1));
133 		assertNotNull(cache.get(key, 1));
134 
135 		assertEquals(32 * 3, cache.getMemoryUsed());
136 		assertEquals(32 * 3, cache.getMemoryUsedByTableForTest());
137 		assertEquals(32 * 3, cache.getMemoryUsedByLruChainForTest());
138 	}
139 
140 	private void get(byte[] data, int position) {
141 		Entry e = cache.get(key, position);
142 		assertNotNull("expected entry at " + position, e);
143 		assertEquals("expected blob for " + position, OBJ_BLOB, e.type);
144 		assertSame("expected data for " + position, data, e.data);
145 	}
146 
147 	private byte[] put(int position, int sz) {
148 		byte[] data = rng.nextBytes(sz);
149 		cache.put(key, position, OBJ_BLOB, data);
150 		return data;
151 	}
152 }