Disable reading from changes tables under notedb

Wrap ReviewDb with an implementation that disables all read access
methods on all Change-related tables. (Currently Changes itself is an
exception because those calls have not all been migrated yet.)

Change-Id: I60f585f5ef12c660aa9298c3676c1e5c95c945f4

gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/InMemoryTestingDatabaseModule.java

@@ -27,7 +27,10 @@ import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.config.TrackingFooters;
 import com.google.gerrit.server.config.TrackingFootersProvider;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.notedb.NotesMigration;
 import com.google.gerrit.server.schema.DataSourceType;
+import com.google.gerrit.server.schema.NotesMigrationSchemaFactory;
+import com.google.gerrit.server.schema.ReviewDbFactory;
 import com.google.gerrit.server.schema.SchemaModule;
 import com.google.gerrit.server.schema.SchemaVersion;
 import com.google.gerrit.testutil.InMemoryDatabase;
@@ -37,6 +40,7 @@ import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.OrmRuntimeException;
 import com.google.gwtorm.server.SchemaFactory;
 import com.google.inject.Inject;
+import com.google.inject.Key;
 import com.google.inject.Provides;
 import com.google.inject.Singleton;
 import com.google.inject.TypeLiteral;
@@ -71,9 +75,14 @@ class InMemoryTestingDatabaseModule extends LifecycleModule {
 
     bind(MetricMaker.class).to(DisabledMetricMaker.class);
     bind(DataSourceType.class).to(InMemoryH2Type.class);
+
+    bind(NotesMigration.class);
+    TypeLiteral<SchemaFactory<ReviewDb>> schemaFactory =
+        new TypeLiteral<SchemaFactory<ReviewDb>>() {};
+    bind(schemaFactory).to(NotesMigrationSchemaFactory.class);
+    bind(Key.get(schemaFactory, ReviewDbFactory.class))
+        .to(InMemoryDatabase.class);
     bind(InMemoryDatabase.class).in(SINGLETON);
-    bind(new TypeLiteral<SchemaFactory<ReviewDb>>() {})
-      .to(InMemoryDatabase.class);
 
     listener().to(CreateDatabase.class);
 

gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/server/ReviewDbWrapper.java

@@ -17,7 +17,12 @@ package com.google.gerrit.reviewdb.server;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.util.concurrent.CheckedFuture;
+import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.ChangeMessage;
+import com.google.gerrit.reviewdb.client.PatchLineComment;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.PatchSetApproval;
 import com.google.gwtorm.server.Access;
 import com.google.gwtorm.server.AtomicUpdate;
 import com.google.gwtorm.server.OrmException;
@@ -257,8 +262,7 @@ public class ReviewDbWrapper implements ReviewDb {
     }
 
     @Override
-    public Change atomicUpdate(Change.Id key, AtomicUpdate<Change> update)
-        throws OrmException {
+    public Change atomicUpdate(Change.Id key, AtomicUpdate<Change> update) throws OrmException {
       return delegate.atomicUpdate(key, update);
     }
 
@@ -272,4 +276,449 @@ public class ReviewDbWrapper implements ReviewDb {
       return delegate.all();
     }
   }
+
+  public static class PatchSetApprovalAccessWrapper
+      implements PatchSetApprovalAccess {
+    protected final PatchSetApprovalAccess delegate;
+
+    protected PatchSetApprovalAccessWrapper(PatchSetApprovalAccess delegate) {
+      this.delegate = delegate;
+    }
+
+    @Override
+    public String getRelationName() {
+      return delegate.getRelationName();
+    }
+
+    @Override
+    public int getRelationID() {
+      return delegate.getRelationID();
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> iterateAllEntities()
+        throws OrmException {
+      return delegate.iterateAllEntities();
+    }
+
+    @Override
+    public PatchSetApproval.Key primaryKey(PatchSetApproval entity) {
+      return delegate.primaryKey(entity);
+    }
+
+    @Override
+    public Map<PatchSetApproval.Key, PatchSetApproval> toMap(
+        Iterable<PatchSetApproval> c) {
+      return delegate.toMap(c);
+    }
+
+    @Override
+    public CheckedFuture<PatchSetApproval, OrmException> getAsync(
+        PatchSetApproval.Key key) {
+      return delegate.getAsync(key);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> get(Iterable<PatchSetApproval.Key> keys)
+        throws OrmException {
+      return delegate.get(keys);
+    }
+
+    @Override
+    public void insert(Iterable<PatchSetApproval> instances)
+        throws OrmException {
+      delegate.insert(instances);
+    }
+
+    @Override
+    public void update(Iterable<PatchSetApproval> instances)
+        throws OrmException {
+      delegate.update(instances);
+    }
+
+    @Override
+    public void upsert(Iterable<PatchSetApproval> instances)
+        throws OrmException {
+      delegate.upsert(instances);
+    }
+
+    @Override
+    public void deleteKeys(Iterable<PatchSetApproval.Key> keys)
+        throws OrmException {
+      delegate.deleteKeys(keys);
+    }
+
+    @Override
+    public void delete(Iterable<PatchSetApproval> instances)
+        throws OrmException {
+      delegate.delete(instances);
+    }
+
+    @Override
+    public void beginTransaction(PatchSetApproval.Key key) throws OrmException {
+      delegate.beginTransaction(key);
+    }
+
+    @Override
+    public PatchSetApproval atomicUpdate(PatchSetApproval.Key key,
+        AtomicUpdate<PatchSetApproval> update) throws OrmException {
+      return delegate.atomicUpdate(key, update);
+    }
+
+    @Override
+    public PatchSetApproval get(PatchSetApproval.Key key) throws OrmException {
+      return delegate.get(key);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> byChange(Change.Id id)
+        throws OrmException {
+      return delegate.byChange(id);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> byPatchSet(PatchSet.Id id)
+        throws OrmException {
+      return delegate.byPatchSet(id);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> byPatchSetUser(PatchSet.Id patchSet,
+        Account.Id account) throws OrmException {
+      return delegate.byPatchSetUser(patchSet, account);
+    }
+  }
+
+  public static class ChangeMessageAccessWrapper
+      implements ChangeMessageAccess {
+    protected final ChangeMessageAccess delegate;
+
+    protected ChangeMessageAccessWrapper(ChangeMessageAccess delegate) {
+      this.delegate = delegate;
+    }
+
+    @Override
+    public String getRelationName() {
+      return delegate.getRelationName();
+    }
+
+    @Override
+    public int getRelationID() {
+      return delegate.getRelationID();
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> iterateAllEntities() throws OrmException {
+      return delegate.iterateAllEntities();
+    }
+
+    @Override
+    public ChangeMessage.Key primaryKey(ChangeMessage entity) {
+      return delegate.primaryKey(entity);
+    }
+
+    @Override
+    public Map<ChangeMessage.Key, ChangeMessage> toMap(
+        Iterable<ChangeMessage> c) {
+      return delegate.toMap(c);
+    }
+
+    @Override
+    public CheckedFuture<ChangeMessage, OrmException> getAsync(
+        ChangeMessage.Key key) {
+      return delegate.getAsync(key);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> get(Iterable<ChangeMessage.Key> keys)
+        throws OrmException {
+      return delegate.get(keys);
+    }
+
+    @Override
+    public void insert(Iterable<ChangeMessage> instances) throws OrmException {
+      delegate.insert(instances);
+    }
+
+    @Override
+    public void update(Iterable<ChangeMessage> instances) throws OrmException {
+      delegate.update(instances);
+    }
+
+    @Override
+    public void upsert(Iterable<ChangeMessage> instances) throws OrmException {
+      delegate.upsert(instances);
+    }
+
+    @Override
+    public void deleteKeys(Iterable<ChangeMessage.Key> keys)
+        throws OrmException {
+      delegate.deleteKeys(keys);
+    }
+
+    @Override
+    public void delete(Iterable<ChangeMessage> instances) throws OrmException {
+      delegate.delete(instances);
+    }
+
+    @Override
+    public void beginTransaction(ChangeMessage.Key key) throws OrmException {
+      delegate.beginTransaction(key);
+    }
+
+    @Override
+    public ChangeMessage atomicUpdate(ChangeMessage.Key key,
+        AtomicUpdate<ChangeMessage> update) throws OrmException {
+      return delegate.atomicUpdate(key, update);
+    }
+
+    @Override
+    public ChangeMessage get(ChangeMessage.Key id) throws OrmException {
+      return delegate.get(id);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> byChange(Change.Id id) throws OrmException {
+      return delegate.byChange(id);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> byPatchSet(PatchSet.Id id)
+        throws OrmException {
+      return delegate.byPatchSet(id);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> all() throws OrmException {
+      return delegate.all();
+    }
+
+  }
+
+  public static class PatchSetAccessWrapper implements PatchSetAccess {
+    protected final PatchSetAccess delegate;
+
+    protected PatchSetAccessWrapper(PatchSetAccess delegate) {
+      this.delegate = delegate;
+    }
+
+    @Override
+    public String getRelationName() {
+      return delegate.getRelationName();
+    }
+
+    @Override
+    public int getRelationID() {
+      return delegate.getRelationID();
+    }
+
+    @Override
+    public ResultSet<PatchSet> iterateAllEntities() throws OrmException {
+      return delegate.iterateAllEntities();
+    }
+
+    @Override
+    public PatchSet.Id primaryKey(PatchSet entity) {
+      return delegate.primaryKey(entity);
+    }
+
+    @Override
+    public Map<PatchSet.Id, PatchSet> toMap(Iterable<PatchSet> c) {
+      return delegate.toMap(c);
+    }
+
+    @Override
+    public CheckedFuture<PatchSet, OrmException> getAsync(PatchSet.Id key) {
+      return delegate.getAsync(key);
+    }
+
+    @Override
+    public ResultSet<PatchSet> get(Iterable<PatchSet.Id> keys)
+        throws OrmException {
+      return delegate.get(keys);
+    }
+
+    @Override
+    public void insert(Iterable<PatchSet> instances) throws OrmException {
+      delegate.insert(instances);
+    }
+
+    @Override
+    public void update(Iterable<PatchSet> instances) throws OrmException {
+      delegate.update(instances);
+    }
+
+    @Override
+    public void upsert(Iterable<PatchSet> instances) throws OrmException {
+      delegate.upsert(instances);
+    }
+
+    @Override
+    public void deleteKeys(Iterable<PatchSet.Id> keys) throws OrmException {
+      delegate.deleteKeys(keys);
+    }
+
+    @Override
+    public void delete(Iterable<PatchSet> instances) throws OrmException {
+      delegate.delete(instances);
+    }
+
+    @Override
+    public void beginTransaction(PatchSet.Id key) throws OrmException {
+      delegate.beginTransaction(key);
+    }
+
+    @Override
+    public PatchSet atomicUpdate(PatchSet.Id key, AtomicUpdate<PatchSet> update)
+        throws OrmException {
+      return delegate.atomicUpdate(key, update);
+    }
+
+    @Override
+    public PatchSet get(PatchSet.Id id) throws OrmException {
+      return delegate.get(id);
+    }
+
+    @Override
+    public ResultSet<PatchSet> byChange(Change.Id id) throws OrmException {
+      return delegate.byChange(id);
+    }
+
+  }
+
+  public static class PatchLineCommentAccessWrapper
+      implements PatchLineCommentAccess {
+    protected PatchLineCommentAccess delegate;
+
+    protected PatchLineCommentAccessWrapper(PatchLineCommentAccess delegate) {
+      this.delegate = delegate;
+    }
+
+    @Override
+    public String getRelationName() {
+      return delegate.getRelationName();
+    }
+
+    @Override
+    public int getRelationID() {
+      return delegate.getRelationID();
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> iterateAllEntities()
+        throws OrmException {
+      return delegate.iterateAllEntities();
+    }
+
+    @Override
+    public PatchLineComment.Key primaryKey(PatchLineComment entity) {
+      return delegate.primaryKey(entity);
+    }
+
+    @Override
+    public Map<PatchLineComment.Key, PatchLineComment> toMap(
+        Iterable<PatchLineComment> c) {
+      return delegate.toMap(c);
+    }
+
+    @Override
+    public CheckedFuture<PatchLineComment, OrmException> getAsync(
+        PatchLineComment.Key key) {
+      return delegate.getAsync(key);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> get(Iterable<PatchLineComment.Key> keys)
+        throws OrmException {
+      return delegate.get(keys);
+    }
+
+    @Override
+    public void insert(Iterable<PatchLineComment> instances)
+        throws OrmException {
+      delegate.insert(instances);
+    }
+
+    @Override
+    public void update(Iterable<PatchLineComment> instances)
+        throws OrmException {
+      delegate.update(instances);
+    }
+
+    @Override
+    public void upsert(Iterable<PatchLineComment> instances)
+        throws OrmException {
+      delegate.upsert(instances);
+    }
+
+    @Override
+    public void deleteKeys(Iterable<PatchLineComment.Key> keys)
+        throws OrmException {
+      delegate.deleteKeys(keys);
+    }
+
+    @Override
+    public void delete(Iterable<PatchLineComment> instances)
+        throws OrmException {
+      delegate.delete(instances);
+    }
+
+    @Override
+    public void beginTransaction(PatchLineComment.Key key) throws OrmException {
+      delegate.beginTransaction(key);
+    }
+
+    @Override
+    public PatchLineComment atomicUpdate(PatchLineComment.Key key,
+        AtomicUpdate<PatchLineComment> update) throws OrmException {
+      return delegate.atomicUpdate(key, update);
+    }
+
+    @Override
+    public PatchLineComment get(PatchLineComment.Key id) throws OrmException {
+      return delegate.get(id);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> byChange(Change.Id id)
+        throws OrmException {
+      return delegate.byChange(id);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> byPatchSet(PatchSet.Id id)
+        throws OrmException {
+      return delegate.byPatchSet(id);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> publishedByChangeFile(Change.Id id,
+        String file) throws OrmException {
+      return delegate.publishedByChangeFile(id, file);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> publishedByPatchSet(PatchSet.Id patchset)
+        throws OrmException {
+      return delegate.publishedByPatchSet(patchset);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByPatchSetAuthor(
+        PatchSet.Id patchset, Account.Id author) throws OrmException {
+      return delegate.draftByPatchSetAuthor(patchset, author);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByChangeFileAuthor(Change.Id id,
+        String file, Account.Id author) throws OrmException {
+      return delegate.draftByChangeFileAuthor(id, file, author);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByAuthor(Account.Id author)
+        throws OrmException {
+      return delegate.draftByAuthor(author);
+    }
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraftChangeOp.java

@@ -30,6 +30,8 @@ import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.BatchUpdate.ChangeContext;
 import com.google.gerrit.server.git.BatchUpdate.RepoContext;
+import com.google.gerrit.server.git.BatchUpdateReviewDb;
+import com.google.gerrit.server.schema.DisabledChangesReviewDbWrapper;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 
@@ -46,6 +48,20 @@ class DeleteDraftChangeOp extends BatchUpdate.Op {
     return cfg.getBoolean("change", "allowDrafts", true);
   }
 
+  static ReviewDb unwrap(ReviewDb db) {
+    // This is special. We want to delete exactly the rows that are present in
+    // the database, even when reading everything else from notedb, so we need
+    // to bypass the write-only wrapper.
+    if (db instanceof BatchUpdateReviewDb) {
+      db = ((BatchUpdateReviewDb) db).unsafeGetDelegate();
+    }
+    if (db instanceof DisabledChangesReviewDbWrapper) {
+      db = ((DisabledChangesReviewDbWrapper) db).unsafeGetDelegate();
+    }
+    return db;
+  }
+
+
   private final PatchSetUtil psUtil;
   private final StarredChangesUtil starredChangesUtil;
   private final boolean allowDrafts;
@@ -71,7 +87,7 @@ class DeleteDraftChangeOp extends BatchUpdate.Op {
     Change change = ctx.getChange();
     id = change.getId();
 
-    ReviewDb db = ctx.getDb();
+    ReviewDb db = unwrap(ctx.getDb());
     if (change.getStatus() != Change.Status.DRAFT) {
       throw new ResourceConflictException("Change is not a draft: " + id);
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraftPatchSet.java

@@ -140,7 +140,7 @@ public class DeleteDraftPatchSet implements RestModifyView<RevisionResource, Inp
       // automatically filtered out when patch sets are deleted.
       psUtil.delete(ctx.getDb(), ctx.getUpdate(patchSet.getId()), patchSet);
 
-      ReviewDb db = ctx.getDb();
+      ReviewDb db = DeleteDraftChangeOp.unwrap(ctx.getDb());
       db.accountPatchReviews().delete(db.accountPatchReviews().byPatchSet(psId));
       db.changeMessages().delete(db.changeMessages().byPatchSet(psId));
       db.patchComments().delete(db.patchComments().byPatchSet(psId));

gerrit-server/src/main/java/com/google/gerrit/server/git/BatchUpdateReviewDb.java

@@ -20,7 +20,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.reviewdb.server.ReviewDbWrapper;
 import com.google.gwtorm.server.AtomicUpdate;
 
-class BatchUpdateReviewDb extends ReviewDbWrapper {
+public class BatchUpdateReviewDb extends ReviewDbWrapper {
   private final ChangeAccess changesWrapper;
 
   BatchUpdateReviewDb(ReviewDb delegate) {
@@ -28,6 +28,10 @@ class BatchUpdateReviewDb extends ReviewDbWrapper {
     changesWrapper = new BatchUpdateChanges(delegate.changes());
   }
 
+  public ReviewDb unsafeGetDelegate() {
+    return delegate;
+  }
+
   @Override
   public ChangeAccess changes() {
     return changesWrapper;

gerrit-server/src/main/java/com/google/gerrit/server/schema/DatabaseModule.java

@@ -18,17 +18,26 @@ import static com.google.inject.Scopes.SINGLETON;
 
 import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.notedb.NotesMigration;
 import com.google.gwtorm.jdbc.Database;
 import com.google.gwtorm.server.SchemaFactory;
+import com.google.inject.Key;
 import com.google.inject.TypeLiteral;
 
 /** Loads the database with standard dependencies. */
 public class DatabaseModule extends FactoryModule {
   @Override
   protected void configure() {
-    bind(new TypeLiteral<SchemaFactory<ReviewDb>>() {}).to(
-        new TypeLiteral<Database<ReviewDb>>() {}).in(SINGLETON);
-    bind(new TypeLiteral<Database<ReviewDb>>() {}).toProvider(
-        ReviewDbDatabaseProvider.class).in(SINGLETON);
+    TypeLiteral<SchemaFactory<ReviewDb>> schemaFactory =
+        new TypeLiteral<SchemaFactory<ReviewDb>>() {};
+    TypeLiteral<Database<ReviewDb>> database =
+        new TypeLiteral<Database<ReviewDb>>() {};
+
+    bind(NotesMigration.class);
+    bind(schemaFactory).to(NotesMigrationSchemaFactory.class);
+    bind(Key.get(schemaFactory, ReviewDbFactory.class))
+        .to(database)
+        .in(SINGLETON);
+    bind(database).toProvider(ReviewDbDatabaseProvider.class);
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/schema/DisabledChangesReviewDbWrapper.java

@@ -0,0 +1,256 @@
+// Copyright (C) 2016 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.schema;
+
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.ChangeMessage;
+import com.google.gerrit.reviewdb.client.PatchLineComment;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.PatchSetApproval;
+import com.google.gerrit.reviewdb.server.ChangeMessageAccess;
+import com.google.gerrit.reviewdb.server.PatchLineCommentAccess;
+import com.google.gerrit.reviewdb.server.PatchSetAccess;
+import com.google.gerrit.reviewdb.server.PatchSetApprovalAccess;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.reviewdb.server.ReviewDbWrapper;
+import com.google.gwtorm.server.OrmException;
+import com.google.gwtorm.server.ResultSet;
+
+public class DisabledChangesReviewDbWrapper extends ReviewDbWrapper {
+  private static final String MSG = "This table has been migrated to notedb";
+
+  private final DisabledPatchSetApprovalAccess patchSetApprovals;
+  private final DisabledChangeMessageAccess changeMessages;
+  private final DisabledPatchSetAccess patchSets;
+  private final DisabledPatchLineCommentAccess patchComments;
+
+  DisabledChangesReviewDbWrapper(ReviewDb db) {
+    super(db);
+    patchSetApprovals =
+        new DisabledPatchSetApprovalAccess(delegate.patchSetApprovals());
+    changeMessages = new DisabledChangeMessageAccess(delegate.changeMessages());
+    patchSets = new DisabledPatchSetAccess(delegate.patchSets());
+    patchComments =
+        new DisabledPatchLineCommentAccess(delegate.patchComments());
+  }
+
+  public ReviewDb unsafeGetDelegate() {
+    return delegate;
+  }
+
+  @Override
+  public PatchSetApprovalAccess patchSetApprovals() {
+    return patchSetApprovals;
+  }
+
+  @Override
+  public ChangeMessageAccess changeMessages() {
+    return changeMessages;
+  }
+
+  @Override
+  public PatchSetAccess patchSets() {
+    return patchSets;
+  }
+
+  @Override
+  public PatchLineCommentAccess patchComments() {
+    return patchComments;
+  }
+
+  private static class DisabledPatchSetApprovalAccess
+      extends PatchSetApprovalAccessWrapper {
+    DisabledPatchSetApprovalAccess(PatchSetApprovalAccess delegate) {
+      super(delegate);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> iterateAllEntities() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public CheckedFuture<PatchSetApproval, OrmException> getAsync(
+        PatchSetApproval.Key key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> get(
+        Iterable<PatchSetApproval.Key> keys) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public PatchSetApproval get(PatchSetApproval.Key key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> byChange(Change.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchSetApproval> byPatchSet(PatchSet.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+  }
+
+  private static class DisabledChangeMessageAccess
+      extends ChangeMessageAccessWrapper {
+    DisabledChangeMessageAccess(ChangeMessageAccess delegate) {
+      super(delegate);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> iterateAllEntities() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public CheckedFuture<ChangeMessage, OrmException> getAsync(
+        ChangeMessage.Key key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> get(Iterable<ChangeMessage.Key> keys) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ChangeMessage get(ChangeMessage.Key id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> byChange(Change.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> byPatchSet(PatchSet.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<ChangeMessage> all() {
+      throw new UnsupportedOperationException(MSG);
+    }
+  }
+
+  private static class DisabledPatchSetAccess extends PatchSetAccessWrapper {
+    DisabledPatchSetAccess(PatchSetAccess delegate) {
+      super(delegate);
+    }
+
+    @Override
+    public ResultSet<PatchSet> iterateAllEntities() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public CheckedFuture<PatchSet, OrmException> getAsync(PatchSet.Id key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchSet> get(Iterable<PatchSet.Id> keys) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public PatchSet get(PatchSet.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchSet> byChange(Change.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+  }
+
+  private static class DisabledPatchLineCommentAccess
+      extends PatchLineCommentAccessWrapper {
+    DisabledPatchLineCommentAccess(PatchLineCommentAccess delegate) {
+      super(delegate);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> iterateAllEntities() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public CheckedFuture<PatchLineComment, OrmException> getAsync(
+        PatchLineComment.Key key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> get(
+        Iterable<PatchLineComment.Key> keys) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public PatchLineComment get(PatchLineComment.Key id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> byChange(Change.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> byPatchSet(PatchSet.Id id) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> publishedByChangeFile(Change.Id id,
+        String file) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> publishedByPatchSet(
+        PatchSet.Id patchset) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByPatchSetAuthor(
+        PatchSet.Id patchset, Account.Id author) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByChangeFileAuthor(Change.Id id,
+        String file, Account.Id author) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<PatchLineComment> draftByAuthor(Account.Id author) {
+      throw new UnsupportedOperationException(MSG);
+    }
+  }
+}
+

gerrit-server/src/main/java/com/google/gerrit/server/schema/NotesMigrationSchemaFactory.java

@@ -0,0 +1,45 @@
+// Copyright (C) 2016 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.schema;
+
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.notedb.NotesMigration;
+import com.google.gwtorm.server.OrmException;
+import com.google.gwtorm.server.SchemaFactory;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+public class NotesMigrationSchemaFactory implements SchemaFactory<ReviewDb> {
+  private final SchemaFactory<ReviewDb> delegate;
+  private final boolean disableChangesTables;
+
+  @Inject
+  NotesMigrationSchemaFactory(
+      @ReviewDbFactory SchemaFactory<ReviewDb> delegate,
+      NotesMigration migration) {
+    this.delegate = delegate;
+    disableChangesTables = migration.readChanges();
+  }
+
+  @Override
+  public ReviewDb open() throws OrmException {
+    ReviewDb db = delegate.open();
+    if (!disableChangesTables) {
+      return db;
+    }
+    return new DisabledChangesReviewDbWrapper(db);
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/schema/ReviewDbFactory.java

@@ -0,0 +1,35 @@
+// Copyright (C) 2016 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.schema;
+
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import com.google.inject.BindingAnnotation;
+
+import java.lang.annotation.Retention;
+
+/**
+ * Marker on {@link com.google.gwtorm.server.SchemaFactory} implementation
+ * that talks to the underlying traditional {@link
+ * com.google.gerrit.reviewdb.server.ReviewDb} database.
+ * <p>
+ * During the migration to notedb, the actual {@code ReviewDb} will be a wrapper
+ * with certain tables enabled/disabled; this marker goes on the low-level
+ * implementation that has all tables.
+ */
+@Retention(RUNTIME)
+@BindingAnnotation
+public @interface ReviewDbFactory {
+}