1 files changed, 81 insertions, 0 deletions
diff --git a/java/com/google/gerrit/pgm/util/PerThreadReviewDbModule.java b/java/com/google/gerrit/pgm/util/PerThreadReviewDbModule.java
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+++ b/java/com/google/gerrit/pgm/util/PerThreadReviewDbModule.java
@@ -0,0 +1,81 @@
+// Copyright (C) 2014 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.pgm.util;
+
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.lifecycle.LifecycleModule;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gwtorm.server.OrmException;
+import com.google.gwtorm.server.SchemaFactory;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.ProvisionException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Module to bind a single {@link ReviewDb} instance per thread.
+ *
+ * <p>New instances are opened on demand, but are closed only at shutdown.
+ */
+class PerThreadReviewDbModule extends LifecycleModule {
+  private final SchemaFactory<ReviewDb> schema;
+
+  @Inject
+  PerThreadReviewDbModule(SchemaFactory<ReviewDb> schema) {
+    this.schema = schema;
+  }
+
+  @Override
+  protected void configure() {
+    final List<ReviewDb> dbs = Collections.synchronizedList(new ArrayList<ReviewDb>());
+    final ThreadLocal<ReviewDb> localDb = new ThreadLocal<>();
+
+    bind(ReviewDb.class)
+        .toProvider(
+            new Provider<ReviewDb>() {
+              @Override
+              public ReviewDb get() {
+                ReviewDb db = localDb.get();
+                if (db == null) {
+                  try {
+                    db = schema.open();
+                    dbs.add(db);
+                    localDb.set(db);
+                  } catch (OrmException e) {
+                    throw new ProvisionException("unable to open ReviewDb", e);
+                  }
+                }
+                return db;
+              }
+            });
+    listener()
+        .toInstance(
+            new LifecycleListener() {
+              @Override
+              public void start() {
+                // Do nothing.
+              }
+
+              @Override
+              public void stop() {
+                for (ReviewDb db : dbs) {
+                  db.close();
+                }
+              }
+            });
+  }
+}