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 com.google.common.base.Predicate;
13 import java.util.HashMap;
14 import java.util.Iterator;
15 import java.util.LinkedHashMap;
17 import javax.annotation.Nonnull;
18 import javax.annotation.concurrent.NotThreadSafe;
19 import org.opendaylight.yangtools.concepts.Identifiable;
20 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
21 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
22 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
23 import org.opendaylight.yangtools.yang.data.api.schema.tree.StoreTreeNode;
24 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
27 * Node Modification Node and Tree
29 * Tree which structurally resembles data tree and captures client modifications
30 * to the data store tree.
32 * This tree is lazily created and populated via {@link #modifyChild(PathArgument)}
33 * and {@link TreeNode} which represents original state as tracked by {@link #getOriginal()}.
36 final class ModifiedNode extends NodeModification implements StoreTreeNode<ModifiedNode> {
37 static final Predicate<ModifiedNode> IS_TERMINAL_PREDICATE = new Predicate<ModifiedNode>() {
39 public boolean apply(final @Nonnull ModifiedNode input) {
40 Preconditions.checkNotNull(input);
41 switch (input.getType()) {
46 case SUBTREE_MODIFIED:
51 throw new IllegalArgumentException(String.format("Unhandled modification type %s", input.getType()));
55 private final Map<PathArgument, ModifiedNode> children;
56 private final Optional<TreeNode> original;
57 private final PathArgument identifier;
58 private ModificationType modificationType = ModificationType.UNMODIFIED;
59 private Optional<TreeNode> snapshotCache;
60 private NormalizedNode<?, ?> value;
62 private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original, final boolean isOrdered) {
63 this.identifier = identifier;
64 this.original = original;
67 children = new LinkedHashMap<>();
69 children = new HashMap<>();
74 * Return the value which was written to this node.
76 * @return Currently-written value
78 public NormalizedNode<?, ?> getWrittenValue() {
83 public PathArgument getIdentifier() {
89 * Returns original store metadata
90 * @return original store metadata
93 Optional<TreeNode> getOriginal() {
98 * Returns modification type
100 * @return modification type
103 ModificationType getType() {
104 return modificationType;
109 * Returns child modification if child was modified
111 * @return Child modification if direct child or it's subtree
116 public Optional<ModifiedNode> getChild(final PathArgument child) {
117 return Optional.<ModifiedNode> fromNullable(children.get(child));
122 * Returns child modification if child was modified, creates {@link ModifiedNode}
123 * for child otherwise.
125 * If this node's {@link ModificationType} is {@link ModificationType#UNMODIFIED}
126 * changes modification type to {@link ModificationType#SUBTREE_MODIFIED}
129 * @return {@link ModifiedNode} for specified child, with {@link #getOriginal()}
130 * containing child metadata if child was present in original data.
132 ModifiedNode modifyChild(final PathArgument child, final boolean isOrdered) {
134 if (modificationType == ModificationType.UNMODIFIED) {
135 updateModificationType(ModificationType.SUBTREE_MODIFIED);
137 final ModifiedNode potential = children.get(child);
138 if (potential != null) {
142 final Optional<TreeNode> currentMetadata;
143 if (original.isPresent()) {
144 final TreeNode orig = original.get();
145 currentMetadata = orig.getChild(child);
147 currentMetadata = Optional.absent();
150 ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, isOrdered);
151 children.put(child, newlyCreated);
156 * Returns all recorded direct child modification
158 * @return all recorded direct child modifications
161 Iterable<ModifiedNode> getChildren() {
162 return children.values();
166 * Records a delete for associated node.
169 final ModificationType newType;
171 switch (modificationType) {
174 // We need to record this delete.
175 newType = ModificationType.DELETE;
178 case SUBTREE_MODIFIED:
181 * We are canceling a previous modification. This is a bit tricky,
182 * as the original write may have just introduced the data, or it
183 * may have modified it.
185 * As documented in BUG-2470, a delete of data introduced in this
186 * transaction needs to be turned into a no-op.
188 newType = original.isPresent() ? ModificationType.DELETE : ModificationType.UNMODIFIED;
191 throw new IllegalStateException("Unhandled deletion of node with " + modificationType);
197 updateModificationType(newType);
201 * Records a write for associated node.
205 void write(final NormalizedNode<?, ?> value) {
207 updateModificationType(ModificationType.WRITE);
212 void merge(final NormalizedNode<?, ?> value) {
214 updateModificationType(ModificationType.MERGE);
217 * Blind overwrite of any previous data is okay, no matter whether the node
218 * is simple or complex type.
220 * If this is a simple or complex type with unkeyed children, this merge will
221 * be turned into a write operation, overwriting whatever was there before.
223 * If this is a container with keyed children, there are two possibilities:
224 * - if it existed before, this value will never be consulted and the children
225 * will get explicitly merged onto the original data.
226 * - if it did not exist before, this value will be used as a seed write and
227 * children will be merged into it.
228 * In either case we rely on OperationWithModification to manipulate the children
229 * before calling this method, so unlike a write we do not want to clear them.
235 * Seal the modification node and prune any children which has not been
241 // Walk all child nodes and remove any children which have not
243 final Iterator<ModifiedNode> it = children.values().iterator();
244 while (it.hasNext()) {
245 final ModifiedNode child = it.next();
248 if (child.modificationType == ModificationType.UNMODIFIED) {
253 // A SUBTREE_MODIFIED node without any children is a no-op
254 if (modificationType == ModificationType.SUBTREE_MODIFIED && children.isEmpty()) {
255 updateModificationType(ModificationType.UNMODIFIED);
259 private void clearSnapshot() {
260 snapshotCache = null;
263 Optional<TreeNode> getSnapshot() {
264 return snapshotCache;
267 Optional<TreeNode> setSnapshot(final Optional<TreeNode> snapshot) {
268 snapshotCache = Preconditions.checkNotNull(snapshot);
272 private void updateModificationType(final ModificationType type) {
273 modificationType = type;
278 public String toString() {
279 return "NodeModification [identifier=" + identifier + ", modificationType="
280 + modificationType + ", childModification=" + children + "]";
284 * Create a node which will reflect the state of this node, except it will behave as newly-written
285 * value. This is useful only for merge validation.
287 * @param value Value associated with the node
288 * @return An isolated node. This node should never reach a datatree.
290 ModifiedNode asNewlyWritten(final NormalizedNode<?, ?> value) {
291 final ModifiedNode ret = new ModifiedNode(getIdentifier(), Optional.<TreeNode>absent(), false);
296 public static ModifiedNode createUnmodified(final TreeNode metadataTree, final boolean isOrdered) {
297 return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), isOrdered);