Disable reading from Changes table under notedb

The only places where we still want to access the Changes table is in
ChangeNotes.Factory, BatchUpdate and RebuildNoteDb. Here we need to
unwrap ReviewDb.

Change-Id: I90e6dc89825383757f7f84507eba177445483630

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

@@ -21,6 +21,7 @@ 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.ChangeAccess;
 import com.google.gerrit.reviewdb.server.ChangeMessageAccess;
 import com.google.gerrit.reviewdb.server.PatchLineCommentAccess;
 import com.google.gerrit.reviewdb.server.PatchSetAccess;
@@ -33,6 +34,7 @@ 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 DisabledChangeAccess changes;
   private final DisabledPatchSetApprovalAccess patchSetApprovals;
   private final DisabledChangeMessageAccess changeMessages;
   private final DisabledPatchSetAccess patchSets;
@@ -40,6 +42,7 @@ public class DisabledChangesReviewDbWrapper extends ReviewDbWrapper {
 
   DisabledChangesReviewDbWrapper(ReviewDb db) {
     super(db);
+    changes = new DisabledChangeAccess(delegate.changes());
     patchSetApprovals =
         new DisabledPatchSetApprovalAccess(delegate.patchSetApprovals());
     changeMessages = new DisabledChangeMessageAccess(delegate.changeMessages());
@@ -52,6 +55,11 @@ public class DisabledChangesReviewDbWrapper extends ReviewDbWrapper {
     return delegate;
   }
 
+  @Override
+  public ChangeAccess changes() {
+    return changes;
+  }
+
   @Override
   public PatchSetApprovalAccess patchSetApprovals() {
     return patchSetApprovals;
@@ -72,6 +80,38 @@ public class DisabledChangesReviewDbWrapper extends ReviewDbWrapper {
     return patchComments;
   }
 
+  private static class DisabledChangeAccess extends ChangeAccessWrapper {
+
+    protected DisabledChangeAccess(ChangeAccess delegate) {
+      super(delegate);
+    }
+
+    @Override
+    public ResultSet<Change> iterateAllEntities() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public CheckedFuture<Change, OrmException> getAsync(Change.Id key) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<Change> get(Iterable<Change.Id> keys) {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public Change get(Change.Id id) throws OrmException {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ResultSet<Change> all() throws OrmException {
+      throw new UnsupportedOperationException(MSG);
+    }
+  }
+
   private static class DisabledPatchSetApprovalAccess
       extends PatchSetApprovalAccessWrapper {
     DisabledPatchSetApprovalAccess(PatchSetApprovalAccess delegate) {