Revert "Reduce chance of deadlock in account cache"

This reverts commit 00fc15ac00.

With Caffeine, accessing the cache from the cache loader is causing an
infinite loop [1]. Merging that change up to stable-2.15 exposed that
there is still at least one cache loader (PatchListLoader) accessing its
cache (PatchListCacheImpl).

The test going into an infinite loop on stable-2.15 is
RevisionDiffIT.rebaseHunksOneLineApartFromRegularHunkAreIdentified.

Revert the change until circular dependency is removed or a solution is
found to access the cache from the cache loader.

[1]https://github.com/ben-manes/caffeine/issues/89

Bug: Issue 8464
Change-Id: If65560b4a9bfcf0a03decaedd83ad000c6b28f4f

WORKSPACE

@@ -212,18 +212,6 @@ maven_jar(
     sha1 = GUAVA_BIN_SHA1,
 )
 
-maven_jar(
-    name = "caffeine",
-    artifact = "com.github.ben-manes.caffeine:caffeine:2.6.1",
-    sha1 = "fc7a29feda0a3c5aaf1ff55e0df5417025e6d5f4",
-)
-
-maven_jar(
-    name = "caffeine_guava",
-    artifact = "com.github.ben-manes.caffeine:guava:2.6.1",
-    sha1 = "e1fbe0d8c06639d6fee74404f687f00da25671eb",
-)
-
 maven_jar(
     name = "velocity",
     artifact = "org.apache.velocity:velocity:1.7",

gerrit-cache-h2/BUILD

@@ -8,8 +8,6 @@ java_library(
         "//gerrit-common:server",
         "//gerrit-extension-api:api",
         "//gerrit-server:server",
-        "//lib:caffeine",
-        "//lib:caffeine_guava",
         "//lib:guava",
         "//lib:h2",
         "//lib/guice",
@@ -24,8 +22,6 @@ junit_tests(
     deps = [
         ":cache-h2",
         "//gerrit-server:server",
-        "//lib:caffeine",
-        "//lib:caffeine_guava",
         "//lib:guava",
         "//lib:h2",
         "//lib:junit",

gerrit-cache-h2/src/main/java/com/google/gerrit/server/cache/h2/DefaultCacheFactory.java

@@ -14,16 +14,12 @@
 
 package com.google.gerrit.server.cache.h2;
 
-import com.github.benmanes.caffeine.cache.Caffeine;
-import com.github.benmanes.caffeine.cache.RemovalCause;
-import com.github.benmanes.caffeine.cache.RemovalListener;
-import com.github.benmanes.caffeine.cache.Weigher;
-import com.github.benmanes.caffeine.guava.CaffeinatedGuava;
 import com.google.common.base.Strings;
 import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
 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.gerrit.lifecycle.LifecycleModule;
 import com.google.gerrit.server.cache.CacheBinding;
 import com.google.gerrit.server.cache.ForwardingRemovalListener;
@@ -61,48 +57,35 @@ public class DefaultCacheFactory implements MemoryCacheFactory {
 
   @Override
   public <K, V> Cache<K, V> build(CacheBinding<K, V> def) {
-    return CaffeinatedGuava.build(create(def, false));
+    return create(def, false).build();
   }
 
   @Override
   public <K, V> LoadingCache<K, V> build(CacheBinding<K, V> def, CacheLoader<K, V> loader) {
-    return CaffeinatedGuava.build(create(def, false), loader);
+    return create(def, false).build(loader);
   }
 
   @SuppressWarnings("unchecked")
-  <K, V> Caffeine<K, V> create(CacheBinding<K, V> def, boolean unwrapValueHolder) {
-    Caffeine<K, V> builder = newCacheBuilder();
+  <K, V> CacheBuilder<K, V> create(CacheBinding<K, V> def, boolean unwrapValueHolder) {
+    CacheBuilder<K, V> builder = newCacheBuilder();
     builder.recordStats();
     builder.maximumWeight(cfg.getLong("cache", def.name(), "memoryLimit", def.maximumWeight()));
 
-    builder =
-        builder.removalListener(
-            new CaffeineToGuavaRemovalListener<K, V>(
-                forwardingRemovalListenerFactory.create(def.name())));
+    builder = builder.removalListener(forwardingRemovalListenerFactory.create(def.name()));
 
-    Weigher<K, V> weigher = null;
-    com.google.common.cache.Weigher<K, V> guavaWeigher = def.weigher();
-    if (guavaWeigher != null) {
-      if (unwrapValueHolder) {
-        weigher =
-            (Weigher<K, V>)
-                new Weigher<K, ValueHolder<V>>() {
-                  @Override
-                  public int weigh(K key, ValueHolder<V> value) {
-                    return guavaWeigher.weigh(key, value.value);
-                  }
-                };
-      } else {
-        weigher =
-            new Weigher<K, V>() {
-              @Override
-              public int weigh(K key, V value) {
-                return guavaWeigher.weigh(key, value);
-              }
-            };
-      }
-    } else {
-      weigher = Weigher.singletonWeigher();
+    Weigher<K, V> weigher = def.weigher();
+    if (weigher != null && unwrapValueHolder) {
+      final Weigher<K, V> impl = weigher;
+      weigher =
+          (Weigher<K, V>)
+              new Weigher<K, ValueHolder<V>>() {
+                @Override
+                public int weigh(K key, ValueHolder<V> value) {
+                  return impl.weigh(key, value.value);
+                }
+              };
+    } else if (weigher == null) {
+      weigher = unitWeight();
     }
     builder.weigher(weigher);
 
@@ -124,24 +107,16 @@ public class DefaultCacheFactory implements MemoryCacheFactory {
   }
 
   @SuppressWarnings("unchecked")
-  private static <K, V> Caffeine<K, V> newCacheBuilder() {
-    return (Caffeine<K, V>) Caffeine.newBuilder();
+  private static <K, V> CacheBuilder<K, V> newCacheBuilder() {
+    return (CacheBuilder<K, V>) CacheBuilder.newBuilder();
   }
 
-  private static class CaffeineToGuavaRemovalListener<K, V> implements RemovalListener<K, V> {
-
-    private com.google.common.cache.RemovalListener<K, V> guavalistener;
-
-    private CaffeineToGuavaRemovalListener(
-        com.google.common.cache.RemovalListener<K, V> guavalistener) {
-      this.guavalistener = guavalistener;
-    }
-
-    @Override
-    public void onRemoval(K key, V value, RemovalCause cause) {
-      guavalistener.onRemoval(
-          RemovalNotification.create(
-              key, value, com.google.common.cache.RemovalCause.valueOf(cause.name())));
-    }
+  private static <K, V> Weigher<K, V> unitWeight() {
+    return new Weigher<K, V>() {
+      @Override
+      public int weigh(K key, V value) {
+        return 1;
+      }
+    };
   }
 }

gerrit-cache-h2/src/main/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.cache.h2;
 
-import com.github.benmanes.caffeine.guava.CaffeinatedGuava;
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
@@ -169,7 +168,7 @@ class H2CacheFactory implements PersistentCacheFactory, LifecycleListener {
             executor,
             store,
             def.keyType(),
-            (Cache<K, ValueHolder<V>>) CaffeinatedGuava.build(defaultFactory.create(def, true)));
+            (Cache<K, ValueHolder<V>>) defaultFactory.create(def, true).build());
     synchronized (caches) {
       caches.add(cache);
     }
@@ -189,9 +188,9 @@ class H2CacheFactory implements PersistentCacheFactory, LifecycleListener {
         newSqlStore(def.name(), def.keyType(), limit, def.expireAfterWrite(TimeUnit.SECONDS));
     Cache<K, ValueHolder<V>> mem =
         (Cache<K, ValueHolder<V>>)
-            CaffeinatedGuava.build(
-                defaultFactory.create(def, true),
-                (CacheLoader<K, V>) new H2CacheImpl.Loader<>(executor, store, loader));
+            defaultFactory
+                .create(def, true)
+                .build((CacheLoader<K, V>) new H2CacheImpl.Loader<>(executor, store, loader));
     H2CacheImpl<K, V> cache = new H2CacheImpl<>(executor, store, def.keyType(), mem);
     caches.add(cache);
     return cache;

gerrit-plugin-api/BUILD

@@ -20,8 +20,6 @@ EXPORTS = [
     "//gerrit-gwtexpui:server",
     "//gerrit-reviewdb:server",
     "//gerrit-server/src/main/prolog:common",
-    "//lib:caffeine",
-    "//lib:caffeine_guava",
     "//lib/commons:dbcp",
     "//lib/commons:lang",
     "//lib/commons:lang3",

lib/BUILD

@@ -82,20 +82,6 @@ java_library(
     exports = ["@guava//jar"],
 )
 
-java_library(
-    name = "caffeine",
-    data = ["//lib:LICENSE-Apache2.0"],
-    visibility = ["//visibility:public"],
-    exports = ["@caffeine//jar"],
-)
-
-java_library(
-    name = "caffeine_guava",
-    data = ["//lib:LICENSE-Apache2.0"],
-    visibility = ["//visibility:public"],
-    exports = ["@caffeine_guava//jar"],
-)
-
 java_library(
     name = "velocity",
     data = ["//lib:LICENSE-Apache2.0"],