Allow passing an executor directly into IndexModule

Change-Id: I3e156cee30b231e54608ecbf08c4e64a0e4d9661

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

@@ -21,6 +21,7 @@ import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.git.WorkQueue;
 import com.google.gerrit.server.git.WorkQueue.Executor;
 import com.google.gerrit.server.query.change.ChangeQueryRewriter;
+import com.google.inject.AbstractModule;
 import com.google.inject.Injector;
 import com.google.inject.Key;
 import com.google.inject.Provides;
@@ -48,9 +49,16 @@ public class IndexModule extends LifecycleModule {
   }
 
   private final int threads;
+  private final ListeningScheduledExecutorService indexExecutor;
 
   public IndexModule(int threads) {
     this.threads = threads;
+    this.indexExecutor = null;
+  }
+
+  public IndexModule(ListeningScheduledExecutorService indexExecutor) {
+    this.threads = -1;
+    this.indexExecutor = indexExecutor;
   }
 
   @Override
@@ -62,6 +70,32 @@ public class IndexModule extends LifecycleModule {
     install(new FactoryModuleBuilder()
         .implement(ChangeIndexer.class, ChangeIndexerImpl.class)
         .build(ChangeIndexer.Factory.class));
+
+    if (indexExecutor != null) {
+      bind(ListeningScheduledExecutorService.class)
+          .annotatedWith(IndexExecutor.class)
+          .toInstance(indexExecutor);
+    } else {
+      install(new IndexExecutorModule(threads));
+    }
+  }
+
+  @Provides
+  ChangeIndexer getChangeIndexer(
+      ChangeIndexer.Factory factory,
+      IndexCollection indexes) {
+    return factory.create(indexes);
+  }
+
+  private static class IndexExecutorModule extends AbstractModule {
+    private final int threads;
+
+    private IndexExecutorModule(int threads) {
+      this.threads = threads;
+    }
+
+    @Override
+    public void configure() {
     }
 
     @Provides
@@ -82,11 +116,5 @@ public class IndexModule extends LifecycleModule {
       }
       return MoreExecutors.listeningDecorator(executor);
     }
-
-  @Provides
-  ChangeIndexer getChangeIndexer(
-      ChangeIndexer.Factory factory,
-      IndexCollection indexes) {
-    return factory.create(indexes);
   }
 }