1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15package com.google.common.cache;
16
17import static com.google.common.cache.TestingCacheLoaders.incrementingLoader;
18import static java.util.concurrent.TimeUnit.MILLISECONDS;
19
20import com.google.common.cache.TestingCacheLoaders.IncrementingLoader;
21import com.google.common.testing.FakeTicker;
22
23import junit.framework.TestCase;
24
25/**
26 * Tests relating to automatic cache refreshing.
27 *
28 * @author Charles Fry
29 */
30public class CacheRefreshTest extends TestCase {
31  public void testAutoRefresh() {
32    FakeTicker ticker = new FakeTicker();
33    IncrementingLoader loader = incrementingLoader();
34    LoadingCache<Integer, Integer> cache = CacheBuilder.newBuilder()
35        .refreshAfterWrite(3, MILLISECONDS)
36        .expireAfterWrite(6, MILLISECONDS)
37        .lenientParsing()
38        .ticker(ticker)
39        .build(loader);
40    int expectedLoads = 0;
41    int expectedReloads = 0;
42    for (int i = 0; i < 3; i++) {
43      assertEquals(Integer.valueOf(i), cache.getUnchecked(i));
44      expectedLoads++;
45      assertEquals(expectedLoads, loader.getLoadCount());
46      assertEquals(expectedReloads, loader.getReloadCount());
47      ticker.advance(1, MILLISECONDS);
48    }
49
50    assertEquals(Integer.valueOf(0), cache.getUnchecked(0));
51    assertEquals(Integer.valueOf(1), cache.getUnchecked(1));
52    assertEquals(Integer.valueOf(2), cache.getUnchecked(2));
53    assertEquals(expectedLoads, loader.getLoadCount());
54    assertEquals(expectedReloads, loader.getReloadCount());
55
56    // refresh 0
57    ticker.advance(1, MILLISECONDS);
58    assertEquals(Integer.valueOf(1), cache.getUnchecked(0));
59    expectedReloads++;
60    assertEquals(Integer.valueOf(1), cache.getUnchecked(1));
61    assertEquals(Integer.valueOf(2), cache.getUnchecked(2));
62    assertEquals(expectedLoads, loader.getLoadCount());
63    assertEquals(expectedReloads, loader.getReloadCount());
64
65    // write to 1 to delay its refresh
66    cache.asMap().put(1, -1);
67    ticker.advance(1, MILLISECONDS);
68    assertEquals(Integer.valueOf(1), cache.getUnchecked(0));
69    assertEquals(Integer.valueOf(-1), cache.getUnchecked(1));
70    assertEquals(Integer.valueOf(2), cache.getUnchecked(2));
71    assertEquals(expectedLoads, loader.getLoadCount());
72    assertEquals(expectedReloads, loader.getReloadCount());
73
74    // refresh 2
75    ticker.advance(1, MILLISECONDS);
76    assertEquals(Integer.valueOf(1), cache.getUnchecked(0));
77    assertEquals(Integer.valueOf(-1), cache.getUnchecked(1));
78    assertEquals(Integer.valueOf(3), cache.getUnchecked(2));
79    expectedReloads++;
80    assertEquals(expectedLoads, loader.getLoadCount());
81    assertEquals(expectedReloads, loader.getReloadCount());
82
83    ticker.advance(1, MILLISECONDS);
84    assertEquals(Integer.valueOf(1), cache.getUnchecked(0));
85    assertEquals(Integer.valueOf(-1), cache.getUnchecked(1));
86    assertEquals(Integer.valueOf(3), cache.getUnchecked(2));
87    assertEquals(expectedLoads, loader.getLoadCount());
88    assertEquals(expectedReloads, loader.getReloadCount());
89
90    // refresh 0 and 1
91    ticker.advance(1, MILLISECONDS);
92    assertEquals(Integer.valueOf(2), cache.getUnchecked(0));
93    expectedReloads++;
94    assertEquals(Integer.valueOf(0), cache.getUnchecked(1));
95    expectedReloads++;
96    assertEquals(Integer.valueOf(3), cache.getUnchecked(2));
97    assertEquals(expectedLoads, loader.getLoadCount());
98    assertEquals(expectedReloads, loader.getReloadCount());
99  }
100}
101