Remove duplication between both index modules

Change-Id: I16d866bb1b4c5d7887a29827cbd71b7911d141e1

gerrit-server/src/main/java/com/google/gerrit/server/index/AbstractIndexModule.java

@@ -0,0 +1,88 @@
+// Copyright (C) 2018 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.index;
+
+import com.google.gerrit.lifecycle.LifecycleModule;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.index.account.AccountIndex;
+import com.google.gerrit.server.index.change.ChangeIndex;
+import com.google.gerrit.server.index.group.GroupIndex;
+import com.google.inject.AbstractModule;
+import com.google.inject.Provides;
+import com.google.inject.Singleton;
+import com.google.inject.assistedinject.FactoryModuleBuilder;
+import java.util.Map;
+import org.eclipse.jgit.lib.Config;
+
+public abstract class AbstractIndexModule extends AbstractModule {
+
+  private final int threads;
+  private final Map<String, Integer> singleVersions;
+
+  protected AbstractIndexModule(Map<String, Integer> singleVersions, int threads) {
+    this.singleVersions = singleVersions;
+    this.threads = threads;
+  }
+
+  @Override
+  protected void configure() {
+    install(
+        new FactoryModuleBuilder()
+            .implement(AccountIndex.class, getAccountIndex())
+            .build(AccountIndex.Factory.class));
+    install(
+        new FactoryModuleBuilder()
+            .implement(ChangeIndex.class, getChangeIndex())
+            .build(ChangeIndex.Factory.class));
+    install(
+        new FactoryModuleBuilder()
+            .implement(GroupIndex.class, getGroupIndex())
+            .build(GroupIndex.Factory.class));
+
+    install(new IndexModule(threads));
+    if (singleVersions == null) {
+      install(new MultiVersionModule());
+    } else {
+      install(new SingleVersionModule(singleVersions));
+    }
+  }
+
+  protected abstract Class<? extends AccountIndex> getAccountIndex();
+
+  protected abstract Class<? extends ChangeIndex> getChangeIndex();
+
+  protected abstract Class<? extends GroupIndex> getGroupIndex();
+
+  protected abstract Class<? extends AbstractVersionManager> getVersionManager();
+
+  @Provides
+  @Singleton
+  IndexConfig provideIndexConfig(@GerritServerConfig Config cfg) {
+    return getIndexConfig(cfg);
+  }
+
+  protected IndexConfig getIndexConfig(@GerritServerConfig Config cfg) {
+    return IndexConfig.fromConfig(cfg);
+  }
+
+  private class MultiVersionModule extends LifecycleModule {
+    @Override
+    public void configure() {
+      Class<? extends AbstractVersionManager> versionManagerClass = getVersionManager();
+      bind(AbstractVersionManager.class).to(versionManagerClass);
+      listener().to(versionManagerClass);
+    }
+  }
+}