1 files changed, 263 insertions, 0 deletions
diff --git a/javatests/com/google/gerrit/server/cache/mem/DefaultMemoryCacheFactoryTest.java b/javatests/com/google/gerrit/server/cache/mem/DefaultMemoryCacheFactoryTest.java
new file mode 100644
index 0000000000..9e345c0af4
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+++ b/javatests/com/google/gerrit/server/cache/mem/DefaultMemoryCacheFactoryTest.java
@@ -0,0 +1,263 @@
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed 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 under the License.
+
+package com.google.gerrit.server.cache.mem;
+
+import static com.google.common.base.Functions.identity;
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import com.google.common.cache.RemovalNotification;
+import com.google.common.cache.Weigher;
+import com.google.common.collect.ImmutableMap;
+import com.google.gerrit.metrics.DisabledMetricMaker;
+import com.google.gerrit.server.cache.CacheBackend;
+import com.google.gerrit.server.cache.CacheDef;
+import com.google.gerrit.server.cache.ForwardingRemovalListener;
+import com.google.gerrit.server.git.WorkQueue;
+import com.google.gerrit.server.util.IdGenerator;
+import com.google.inject.Guice;
+import com.google.inject.TypeLiteral;
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+import org.apache.mina.util.ConcurrentHashSet;
+import org.eclipse.jgit.lib.Config;
+import org.junit.Before;
+import org.junit.Test;
+
+public class DefaultMemoryCacheFactoryTest {
+
+  private static final String TEST_CACHE = "test-cache";
+  private static final long TEST_TIMEOUT_SEC = 1;
+  private static final int TEST_CACHE_KEY = 1;
+  private static final int TEST_CACHE_VALUE = 2;
+
+  private DefaultMemoryCacheFactory memoryCacheFactory;
+  private DefaultMemoryCacheFactory memoryCacheFactoryDirectExecutor;
+  private DefaultMemoryCacheFactory memoryCacheFactoryWithThreadPool;
+  private Config memoryCacheConfig;
+  private Config memoryCacheConfigDirectExecutor;
+  private Config memoryCacheConfigWithThreadPool;
+  private CyclicBarrier cacheGetStarted;
+  private CyclicBarrier cacheGetCompleted;
+  private CyclicBarrier evictionReceived;
+  private ForwardingRemovalTrackerListener forwardingRemovalListener;
+  private WorkQueue workQueue;
+
+  @Before
+  public void setUp() {
+
+    IdGenerator idGenerator = Guice.createInjector().getInstance(IdGenerator.class);
+    workQueue = new WorkQueue(idGenerator, 10, new DisabledMetricMaker());
+
+    memoryCacheConfig = new Config();
+    memoryCacheConfigDirectExecutor = new Config();
+    memoryCacheConfigDirectExecutor.setInt("cache", null, "threads", 0);
+    memoryCacheConfigWithThreadPool = new Config();
+    memoryCacheConfigWithThreadPool.setInt("cache", null, "threads", 1);
+
+    forwardingRemovalListener = new ForwardingRemovalTrackerListener();
+    memoryCacheFactory =
+        new DefaultMemoryCacheFactory(
+            memoryCacheConfig, (cache) -> forwardingRemovalListener, workQueue);
+    memoryCacheFactoryDirectExecutor =
+        new DefaultMemoryCacheFactory(
+            memoryCacheConfigDirectExecutor, (cache) -> forwardingRemovalListener, workQueue);
+    memoryCacheFactoryWithThreadPool =
+        new DefaultMemoryCacheFactory(
+            memoryCacheConfigWithThreadPool, (cache) -> forwardingRemovalListener, workQueue);
+    cacheGetStarted = new CyclicBarrier(2);
+    cacheGetCompleted = new CyclicBarrier(2);
+    evictionReceived = new CyclicBarrier(2);
+  }
+
+  @Test
+  public void shouldRunEvictionListenerInBackgroundByDefault() throws Exception {
+    shouldRunEvictionListenerInThreadPool(memoryCacheFactory, "ForkJoinPool");
+  }
+
+  @Test
+  public void shouldRunEvictionListenerInThreadPool() throws Exception {
+    shouldRunEvictionListenerInThreadPool(
+        memoryCacheFactoryWithThreadPool, DefaultMemoryCacheFactory.CACHE_EXECUTOR_PREFIX);
+  }
+
+  private void shouldRunEvictionListenerInThreadPool(
+      DefaultMemoryCacheFactory cacheFactory, String threadPoolPrefix) throws Exception {
+    LoadingCache<Integer, Integer> cache =
+        cacheFactory.build(newCacheDef(1), newCacheLoader(identity()), CacheBackend.CAFFEINE);
+
+    cache.put(TEST_CACHE_KEY, TEST_CACHE_VALUE);
+    cache.invalidate(TEST_CACHE_KEY);
+
+    assertThat(forwardingRemovalListener.contains(TEST_CACHE_KEY, TEST_CACHE_VALUE)).isFalse();
+
+    evictionReceived.await(TEST_TIMEOUT_SEC, TimeUnit.SECONDS);
+
+    assertThat(forwardingRemovalListener.contains(TEST_CACHE_KEY, TEST_CACHE_VALUE)).isTrue();
+    assertThat(forwardingRemovalListener.removalThreadName(TEST_CACHE_KEY))
+        .startsWith(threadPoolPrefix);
+  }
+
+  @Test
+  public void shouldRunEvictionListenerWithDirectExecutor() throws Exception {
+    LoadingCache<Integer, Integer> cache =
+        memoryCacheFactoryDirectExecutor.build(
+            newCacheDef(1), newCacheLoader(identity()), CacheBackend.CAFFEINE);
+
+    cache.put(TEST_CACHE_KEY, TEST_CACHE_VALUE);
+    cache.invalidate(TEST_CACHE_KEY);
+
+    assertThat(forwardingRemovalListener.contains(TEST_CACHE_KEY, TEST_CACHE_VALUE)).isTrue();
+  }
+
+  @Test
+  public void shouldLoadAllKeysWithDisabledCache() throws Exception {
+    LoadingCache<Integer, Integer> disabledCache =
+        memoryCacheFactory.build(newCacheDef(0), newCacheLoader(identity()), CacheBackend.CAFFEINE);
+
+    List<Integer> keys = Arrays.asList(1, 2);
+    ImmutableMap<Integer, Integer> entries = disabledCache.getAll(keys);
+
+    assertThat(entries).containsExactly(1, 1, 2, 2);
+  }
+
+  private CacheLoader<Integer, Integer> newCacheLoader(Function<Integer, Integer> loadFunc) {
+    return new CacheLoader<Integer, Integer>() {
+
+      @Override
+      public Integer load(Integer n) throws Exception {
+        Integer v = 0;
+        try {
+          cacheGetStarted.await(TEST_TIMEOUT_SEC, TimeUnit.SECONDS);
+          v = loadFunc.apply(n);
+          cacheGetCompleted.await(TEST_TIMEOUT_SEC, TimeUnit.SECONDS);
+        } catch (TimeoutException | BrokenBarrierException e) {
+        }
+        return v;
+      }
+
+      @Override
+      public Map<Integer, Integer> loadAll(Iterable<? extends Integer> keys) throws Exception {
+        return StreamSupport.stream(keys.spliterator(), false)
+            .collect(Collectors.toMap(identity(), identity()));
+      }
+    };
+  }
+
+  private class ForwardingRemovalTrackerListener extends ForwardingRemovalListener<Object, Object> {
+    private final ConcurrentHashMap<Object, Set<Object>> removalEvents;
+    private final ConcurrentHashMap<Object, String> removalThreads;
+
+    public ForwardingRemovalTrackerListener() {
+      super(null, null);
+
+      removalEvents = new ConcurrentHashMap<>();
+      removalThreads = new ConcurrentHashMap<>();
+    }
+
+    @Override
+    public void onRemoval(RemovalNotification<Object, Object> notification) {
+      Set<Object> setOfValues =
+          removalEvents.computeIfAbsent(
+              notification.getKey(),
+              (key) -> {
+                Set<Object> elements = new ConcurrentHashSet<>();
+                return elements;
+              });
+      setOfValues.add(notification.getValue());
+
+      removalThreads.put(notification.getKey(), Thread.currentThread().getName());
+
+      try {
+        evictionReceived.await(TEST_TIMEOUT_SEC, TimeUnit.SECONDS);
+      } catch (InterruptedException | BrokenBarrierException | TimeoutException e) {
+        throw new IllegalStateException(e);
+      }
+    }
+
+    private boolean contains(Object key, Object value) {
+      return Optional.ofNullable(removalEvents.get(key))
+          .map(sv -> sv.contains(value))
+          .orElse(false);
+    }
+
+    private String removalThreadName(Object key) {
+      return removalThreads.get(key);
+    }
+  }
+
+  private CacheDef<Integer, Integer> newCacheDef(long maximumWeight) {
+    return new CacheDef<Integer, Integer>() {
+
+      @Override
+      public String name() {
+        return TEST_CACHE;
+      }
+
+      @Override
+      public String configKey() {
+        return TEST_CACHE;
+      }
+
+      @Override
+      public TypeLiteral<Integer> keyType() {
+        return null;
+      }
+
+      @Override
+      public TypeLiteral<Integer> valueType() {
+        return null;
+      }
+
+      @Override
+      public long maximumWeight() {
+        return maximumWeight;
+      }
+
+      @Override
+      public Duration expireAfterWrite() {
+        return null;
+      }
+
+      @Override
+      public Duration expireFromMemoryAfterAccess() {
+        return null;
+      }
+
+      @Override
+      public Weigher<Integer, Integer> weigher() {
+        return null;
+      }
+
+      @Override
+      public CacheLoader<Integer, Integer> loader() {
+        return null;
+      }
+    };
+  }
+}