Merge branch 'stable-3.4'

* stable-3.4:
  Test cache invalidation behaviour inside a Gerrit daemon

Change-Id: I7a65b8aace0beb977f1c8f3121c6f59362867097

src/test/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/ForwardedCacheEvictionHandlerIT.java

diff --git a/src/test/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/ForwardedCacheEvictionHandlerIT.java b/src/test/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/ForwardedCacheEvictionHandlerIT.java
new file mode 100644
index 0000000..5a0833f
--- /dev/null
+++ b/src/test/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/ForwardedCacheEvictionHandlerIT.java
@@ -0,0 +1,116 @@
+// Copyright (C) 2021 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.ericsson.gerrit.plugins.highavailability.forwarder.rest;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.ericsson.gerrit.plugins.highavailability.forwarder.CacheEntry;
+import com.ericsson.gerrit.plugins.highavailability.forwarder.ForwardedCacheEvictionHandler;
+import com.google.common.cache.RemovalNotification;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import com.google.gerrit.acceptance.*;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.registration.RegistrationHandle;
+import com.google.gerrit.server.cache.CacheRemovalListener;
+import com.google.gerrit.server.events.EventGson;
+import com.google.gerrit.server.project.ProjectCacheImpl;
+import com.google.gson.Gson;
+import com.google.inject.Inject;
+import java.time.Duration;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+@NoHttpd
+@UseSsh
+@TestPlugin(
+    name = "high-availability",
+    sysModule = "com.ericsson.gerrit.plugins.highavailability.Module",
+    httpModule = "com.ericsson.gerrit.plugins.highavailability.HttpModule")
+public class ForwardedCacheEvictionHandlerIT extends LightweightPluginDaemonTest {
+  private static final Duration CACHE_EVICTIONS_WAIT_TIMEOUT = Duration.ofMinutes(1);
+
+  @SuppressWarnings("rawtypes")
+  @Inject
+  private DynamicSet<CacheRemovalListener> cacheRemovalListeners;
+
+  @Inject @EventGson private Gson gson;
+  @Inject private ForwardedCacheEvictionHandler objectUnderTest;
+  @Inject private CacheKeyJsonParser gsonParser;
+
+  private CacheEvictionsTracker<?, ?> evictionsCacheTracker;
+  private RegistrationHandle cacheEvictionRegistrationHandle;
+
+  public static class CacheEvictionsTracker<K, V> implements CacheRemovalListener<K, V> {
+    private final Map<String, Set<Object>> trackedEvictions;
+    private final CountDownLatch allExpectedEvictionsArrived;
+
+    public CacheEvictionsTracker(int numExpectedEvictions) {
+      allExpectedEvictionsArrived = new CountDownLatch(numExpectedEvictions);
+      trackedEvictions = Maps.newHashMap();
+    }
+
+    public Set<Object> trackedEvictionsFor(String cacheName) {
+      return trackedEvictions.getOrDefault(cacheName, Collections.emptySet());
+    }
+
+    public void waitForExpectedEvictions() throws InterruptedException {
+      allExpectedEvictionsArrived.await(
+          CACHE_EVICTIONS_WAIT_TIMEOUT.toMillis(), TimeUnit.MILLISECONDS);
+    }
+
+    @Override
+    public void onRemoval(
+        String pluginName, String cacheName, RemovalNotification<K, V> notification) {
+      trackedEvictions.compute(
+          cacheName,
+          (k, v) -> {
+            if (v == null) {
+              return Sets.newHashSet(notification.getKey());
+            }
+            v.add(notification.getKey());
+            return v;
+          });
+      allExpectedEvictionsArrived.countDown();
+    }
+  }
+
+  @Before
+  public void startTrackingCacheEvictions() {
+    evictionsCacheTracker = new CacheEvictionsTracker<>(1);
+    cacheEvictionRegistrationHandle = cacheRemovalListeners.add("gerrit", evictionsCacheTracker);
+  }
+
+  @After
+  public void stopTrackingCacheEvictions() {
+    cacheEvictionRegistrationHandle.remove();
+  }
+
+  @Test
+  public void shouldEvictProjectCache() throws Exception {
+    Object parsedKey = gsonParser.fromJson(ProjectCacheImpl.CACHE_NAME, gson.toJson(project));
+    objectUnderTest.evict(CacheEntry.from(ProjectCacheImpl.CACHE_NAME, parsedKey));
+    evictionsCacheTracker.waitForExpectedEvictions();
+
+    assertThat(evictionsCacheTracker.trackedEvictionsFor(ProjectCacheImpl.CACHE_NAME))
+        .contains(project);
+  }
+}