2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.data.impl.schema.tree;
10 import com.google.common.base.Optional;
11 import com.google.common.base.Preconditions;
12 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
13 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
14 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
15 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
16 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
18 import java.util.Collections;
21 * Internal utility class for an empty candidate. We instantiate this class
22 * for empty modifications, saving memory and processing speed. Instances
23 * of this class are explicitly recognized and processing of them is skipped.
25 final class NoopDataTreeCandidate extends AbstractDataTreeCandidate {
26 private static final DataTreeCandidateNode ROOT = new DataTreeCandidateNode() {
28 public ModificationType getModificationType() {
29 return ModificationType.UNMODIFIED;
33 public Iterable<DataTreeCandidateNode> getChildNodes() {
34 return Collections.emptyList();
38 public PathArgument getIdentifier() {
39 throw new IllegalStateException("Attempted to read identifier of the no-operation change");
43 public Optional<NormalizedNode<?, ?>> getDataAfter() {
44 return Optional.absent();
48 public Optional<NormalizedNode<?, ?>> getDataBefore() {
49 return Optional.absent();
53 protected NoopDataTreeCandidate(final InstanceIdentifier rootPath, final ModifiedNode modificationRoot) {
55 Preconditions.checkArgument(modificationRoot.getType() == ModificationType.UNMODIFIED);
59 public DataTreeCandidateNode getRootNode() {