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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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*/
package org.apache.brooklyn.util.guava;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertNull;
import java.util.Map;
import java.util.Set;
import org.apache.brooklyn.util.guava.KeyTransformingLoadingCache;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import com.google.common.base.Function;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
public class KeyTransformingLoadingCacheTest {
LoadingCache<Integer, Integer> doublingCache;
LoadingCache<String, Integer> stringDoubler;
LoadingCache<Map<String, Integer>, Map<Integer, String>> keyValueSwapCache;
@BeforeMethod(alwaysRun = true)
public void setUp() {
// Doubles Integer inputs
doublingCache = CacheBuilder.newBuilder()
.recordStats()
.build(new CacheLoader<Integer, Integer>() {
@Override
public Integer load(Integer key) throws Exception {
return key * 2;
}
});
// Turns string to integer and doubles
stringDoubler = KeyTransformingLoadingCache.from(doublingCache,
new Function<String, Integer>(){
@Override
public Integer apply(String input) {
return Integer.valueOf(input);
}
});
// Swaps keys with values
keyValueSwapCache = CacheBuilder.newBuilder()
.recordStats()
.build(new CacheLoader<Map<String, Integer>, Map<Integer, String>>() {
@Override
public Map<Integer, String> load(Map<String, Integer> key) throws Exception {
Map<Integer, String> out = Maps.newHashMapWithExpectedSize(key.size());
for (Map.Entry<String, Integer> entry : key.entrySet()) {
out.put(entry.getValue(), entry.getKey());
}
return out;
}
});
}
@Test
public void testIdentityCache() {
assertEquals(stringDoubler.getUnchecked("10"), Integer.valueOf(20));
}
@Test
public void testGetIfPresent() {
assertNull(stringDoubler.getIfPresent("10"), "Cache should be empty");
assertEquals(stringDoubler.getUnchecked("10"), Integer.valueOf(20), "Cache should load value for '10'");
assertEquals(stringDoubler.getIfPresent("10"), Integer.valueOf(20), "Cache should load value for '10'");
assertNull(stringDoubler.getIfPresent("20"), "Cache should have no value for '20'");
assertNull(stringDoubler.getIfPresent(new Object()), "Cache should have no value for arbitrary Object");
}
@Test
public void testInvalidate() {
stringDoubler.getUnchecked("10");
assertEquals(stringDoubler.size(), 1);
stringDoubler.invalidate(new Object());
assertEquals(stringDoubler.size(), 1);
stringDoubler.invalidate("10");
assertEquals(stringDoubler.size(), 0, "Expected cache to be empty after sole entry was invalidated");
}
@Test
public void testSubsetOfMapKeys() {
final Set<String> validKeys = ImmutableSet.of("a", "b", "c");
LoadingCache<Map<String, Integer>, Map<Integer, String>> keySubset =
KeyTransformingLoadingCache.from(keyValueSwapCache, new Function<Map<String, Integer>, Map<String, Integer>>() {
@Override
public Map<String, Integer> apply(Map<String, Integer> input) {
Map<String, Integer> replacement = Maps.newHashMap(input);
replacement.keySet().retainAll(validKeys);
return replacement;
}
});
Map<Integer, String> output = keySubset.getUnchecked(ImmutableMap.of("a", 1, "b", 2, "d", 4));
assertEquals(output, ImmutableMap.of(1, "a", 2, "b"));
assertEquals(keySubset.size(), 1, "Expected cache to contain one value");
assertEquals(keySubset.stats().loadCount(), 1, "Expected cache to have loaded one value");
// Check input with different key reducing to same map gives same output
Map<Integer, String> output2 = keySubset.getUnchecked(ImmutableMap.of("a", 1, "b", 2, "z", 26));
assertEquals(output2, output);
assertEquals(keySubset.size(), 1, "Expected cache to contain one value");
assertEquals(keySubset.stats().loadCount(), 1, "Expected cache to have loaded one value");
// And
keySubset.getUnchecked(ImmutableMap.of("c", 3));
assertEquals(keySubset.size(), 2, "Expected cache to contain two values");
assertEquals(keySubset.stats().loadCount(), 2, "Expected cache to have loaded a second value");
}
}