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 static java.util.Objects.requireNonNull;
12 import java.util.Collection;
14 import java.util.Optional;
15 import java.util.function.Predicate;
16 import javax.annotation.Nonnull;
17 import javax.annotation.concurrent.NotThreadSafe;
18 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
19 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
20 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodeContainer;
21 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
22 import org.opendaylight.yangtools.yang.data.api.schema.tree.StoreTreeNode;
23 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
24 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNodeFactory;
25 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version;
28 * Node Modification Node and Tree.
31 * Tree which structurally resembles data tree and captures client modifications to the data store tree. This tree is
32 * lazily created and populated via {@link #modifyChild(PathArgument, ModificationApplyOperation, Version)} and
33 * {@link TreeNode} which represents original state as tracked by {@link #getOriginal()}.
36 * The contract is that the state information exposed here preserves the temporal ordering of whatever modifications
37 * were executed. A child's effects pertain to data node as modified by its ancestors. This means that in order to
38 * reconstruct the effective data node presentation, it is sufficient to perform a depth-first pre-order traversal of
42 final class ModifiedNode extends NodeModification implements StoreTreeNode<ModifiedNode> {
43 static final Predicate<ModifiedNode> IS_TERMINAL_PREDICATE = input -> {
44 requireNonNull(input);
45 switch (input.getOperation()) {
54 throw new IllegalArgumentException("Unhandled modification type " + input.getOperation());
58 private final Map<PathArgument, ModifiedNode> children;
59 private final Optional<TreeNode> original;
60 private final PathArgument identifier;
61 private LogicalOperation operation = LogicalOperation.NONE;
62 private Optional<TreeNode> snapshotCache;
63 private NormalizedNode<?, ?> value;
64 private ModificationType modType;
66 // Alternative history introduced in WRITE nodes. Instantiated when we touch any child underneath such a node.
67 private TreeNode writtenOriginal;
69 // Internal cache for TreeNodes created as part of validation
70 private SchemaAwareApplyOperation validatedOp;
71 private Optional<TreeNode> validatedCurrent;
72 private TreeNode validatedNode;
74 private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original,
75 final ChildTrackingPolicy childPolicy) {
76 this.identifier = identifier;
77 this.original = original;
78 this.children = childPolicy.createMap();
82 public PathArgument getIdentifier() {
87 LogicalOperation getOperation() {
92 Optional<TreeNode> getOriginal() {
97 * Return the value which was written to this node. The returned object is only valid for
98 * {@link LogicalOperation#MERGE} and {@link LogicalOperation#WRITE}.
99 * operations. It should only be consulted when this modification is going to end up being
100 * {@link ModificationType#WRITE}.
102 * @return Currently-written value
104 NormalizedNode<?, ?> getWrittenValue() {
109 * Returns child modification if child was modified.
111 * @return Child modification if direct child or it's subtree was modified.
114 public Optional<ModifiedNode> getChild(final PathArgument child) {
115 return Optional.ofNullable(children.get(child));
118 private Optional<TreeNode> metadataFromSnapshot(@Nonnull final PathArgument child) {
119 return original.isPresent() ? original.get().getChild(child) : Optional.empty();
122 private Optional<TreeNode> metadataFromData(@Nonnull final PathArgument child, final Version modVersion) {
123 if (writtenOriginal == null) {
124 // Lazy instantiation, as we do not want do this for all writes. We are using the modification's version
125 // here, as that version is what the SchemaAwareApplyOperation will see when dealing with the resulting
127 writtenOriginal = TreeNodeFactory.createTreeNode(value, modVersion);
130 return writtenOriginal.getChild(child);
134 * Determine the base tree node we are going to apply the operation to. This is not entirely trivial because
135 * both DELETE and WRITE operations unconditionally detach their descendants from the original snapshot, so we need
136 * to take the current node's operation into account.
138 * @param child Child we are looking to modify
139 * @param modVersion Version allocated by the calling {@link InMemoryDataTreeModification}
140 * @return Before-image tree node as observed by that child.
142 private Optional<TreeNode> findOriginalMetadata(@Nonnull final PathArgument child, final Version modVersion) {
145 // DELETE implies non-presence
146 return Optional.empty();
150 return metadataFromSnapshot(child);
152 // WRITE implies presence based on written data
153 return metadataFromData(child, modVersion);
155 throw new IllegalStateException("Unhandled node operation " + operation);
160 * Returns child modification if child was modified, creates {@link ModifiedNode}
161 * for child otherwise. If this node's {@link ModificationType} is {@link ModificationType#UNMODIFIED}
162 * changes modification type to {@link ModificationType#SUBTREE_MODIFIED}.
164 * @param child child identifier, may not be null
165 * @param childOper Child operation
166 * @param modVersion Version allocated by the calling {@link InMemoryDataTreeModification}
167 * @return {@link ModifiedNode} for specified child, with {@link #getOriginal()}
168 * containing child metadata if child was present in original data.
170 ModifiedNode modifyChild(@Nonnull final PathArgument child, @Nonnull final ModificationApplyOperation childOper,
171 @Nonnull final Version modVersion) {
173 if (operation == LogicalOperation.NONE) {
174 updateOperationType(LogicalOperation.TOUCH);
176 final ModifiedNode potential = children.get(child);
177 if (potential != null) {
181 final Optional<TreeNode> currentMetadata = findOriginalMetadata(child, modVersion);
184 final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childOper.getChildPolicy());
185 if (operation == LogicalOperation.MERGE && value != null) {
187 * We are attempting to modify a previously-unmodified part of a MERGE node. If the
188 * value contains this component, we need to materialize it as a MERGE modification.
190 @SuppressWarnings({ "rawtypes", "unchecked" })
191 final Optional<NormalizedNode<?, ?>> childData = ((NormalizedNodeContainer)value).getChild(child);
192 if (childData.isPresent()) {
193 childOper.mergeIntoModifiedNode(newlyCreated, childData.get(), modVersion);
197 children.put(child, newlyCreated);
202 * Returns all recorded direct child modifications.
204 * @return all recorded direct child modifications
207 Collection<ModifiedNode> getChildren() {
208 return children.values();
212 * Records a delete for associated node.
215 final LogicalOperation newType;
220 // We need to record this delete.
221 newType = LogicalOperation.DELETE;
224 // In case of merge - delete needs to be recored and must not to be changed into NONE, because lazy
225 // expansion of parent MERGE node would reintroduce it again.
226 newType = LogicalOperation.DELETE;
231 * We are canceling a previous modification. This is a bit tricky, as the original write may have just
232 * introduced the data, or it may have modified it.
234 * As documented in BUG-2470, a delete of data introduced in this transaction needs to be turned into
237 newType = original.isPresent() ? LogicalOperation.DELETE : LogicalOperation.NONE;
240 throw new IllegalStateException("Unhandled deletion of node with " + operation);
246 updateOperationType(newType);
250 * Records a write for associated node.
252 * @param value new value
254 void write(final NormalizedNode<?, ?> value) {
255 updateValue(LogicalOperation.WRITE, value);
260 * Seal the modification node and prune any children which has not been modified.
262 * @param schema associated apply operation
263 * @param version target version
265 void seal(final ModificationApplyOperation schema, final Version version) {
267 writtenOriginal = null;
271 // A TOUCH node without any children is a no-op
272 if (children.isEmpty()) {
273 updateOperationType(LogicalOperation.NONE);
277 // A WRITE can collapse all of its children
278 if (!children.isEmpty()) {
279 value = schema.apply(this, getOriginal(), version).get().getData();
283 schema.verifyStructure(value, true);
290 private void clearSnapshot() {
291 snapshotCache = null;
294 Optional<TreeNode> getSnapshot() {
295 return snapshotCache;
298 Optional<TreeNode> setSnapshot(final Optional<TreeNode> snapshot) {
299 snapshotCache = requireNonNull(snapshot);
303 void updateOperationType(final LogicalOperation type) {
307 // Make sure we do not reuse previously-instantiated data-derived metadata
308 writtenOriginal = null;
313 public String toString() {
314 return "NodeModification [identifier=" + identifier + ", modificationType="
315 + operation + ", childModification=" + children + "]";
318 void resolveModificationType(@Nonnull final ModificationType type) {
323 * Update this node's value and operation type without disturbing any of its child modifications.
325 * @param type New operation type
326 * @param value New node value
328 void updateValue(final LogicalOperation type, final NormalizedNode<?, ?> value) {
329 this.value = requireNonNull(value);
330 updateOperationType(type);
334 * Return the physical modification done to data. May return null if the
335 * operation has not been applied to the underlying tree. This is different
336 * from the logical operation in that it can actually be a no-op if the
337 * operation has no side-effects (like an empty merge on a container).
339 * @return Modification type.
341 ModificationType getModificationType() {
345 public static ModifiedNode createUnmodified(final TreeNode metadataTree, final ChildTrackingPolicy childPolicy) {
346 return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), childPolicy);
349 void setValidatedNode(final SchemaAwareApplyOperation op, final Optional<TreeNode> current, final TreeNode node) {
350 this.validatedOp = requireNonNull(op);
351 this.validatedCurrent = requireNonNull(current);
352 this.validatedNode = requireNonNull(node);
355 TreeNode getValidatedNode(final SchemaAwareApplyOperation op, final Optional<TreeNode> current) {
356 return op.equals(validatedOp) && current.equals(validatedCurrent) ? validatedNode : null;