-/*
- * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.controller.md.sal.dom.store.impl.tree.data;
-
-import java.util.Collections;
-
-import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeCandidateNode;
-import org.opendaylight.controller.md.sal.dom.store.impl.tree.ModificationType;
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
-import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
-
-import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
-
-/**
- * Internal utility class for an empty candidate. We instantiate this class
- * for empty modifications, saving memory and processing speed. Instances
- * of this class are explicitly recognized and processing of them is skipped.
- */
-final class NoopDataTreeCandidate extends AbstractDataTreeCandidate {
- private static final DataTreeCandidateNode ROOT = new DataTreeCandidateNode() {
- @Override
- public ModificationType getModificationType() {
- return ModificationType.UNMODIFIED;
- }
-
- @Override
- public Iterable<DataTreeCandidateNode> getChildNodes() {
- return Collections.emptyList();
- }
-
- @Override
- public PathArgument getIdentifier() {
- throw new IllegalStateException("Attempted to read identifier of the no-operation change");
- }
-
- @Override
- public Optional<NormalizedNode<?, ?>> getDataAfter() {
- return Optional.absent();
- }
-
- @Override
- public Optional<NormalizedNode<?, ?>> getDataBefore() {
- return Optional.absent();
- }
- };
-
- protected NoopDataTreeCandidate(final InstanceIdentifier rootPath, final ModifiedNode modificationRoot) {
- super(rootPath);
- Preconditions.checkArgument(modificationRoot.getType() == ModificationType.UNMODIFIED);
- }
-
- @Override
- public DataTreeCandidateNode getRootNode() {
- return ROOT;
- }
-}