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.Collection;
14 import java.util.Collections;
15 import java.util.HashMap;
16 import java.util.Iterator;
17 import java.util.LinkedHashMap;
19 import javax.annotation.Nonnull;
20 import javax.annotation.concurrent.NotThreadSafe;
21 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
22 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
23 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
24 import org.opendaylight.yangtools.yang.data.api.schema.tree.StoreTreeNode;
25 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
28 * Node Modification Node and Tree
30 * Tree which structurally resembles data tree and captures client modifications
31 * to the data store tree.
33 * This tree is lazily created and populated via {@link #modifyChild(PathArgument)}
34 * and {@link TreeNode} which represents original state as tracked by {@link #getOriginal()}.
37 final class ModifiedNode extends NodeModification implements StoreTreeNode<ModifiedNode> {
38 static final Predicate<ModifiedNode> IS_TERMINAL_PREDICATE = new Predicate<ModifiedNode>() {
40 public boolean apply(@Nonnull final ModifiedNode input) {
41 Preconditions.checkNotNull(input);
42 switch (input.getOperation()) {
52 throw new IllegalArgumentException(String.format("Unhandled modification type %s", input.getOperation()));
56 private final Map<PathArgument, ModifiedNode> children;
57 private final Optional<TreeNode> original;
58 private final PathArgument identifier;
59 private LogicalOperation operation = LogicalOperation.NONE;
60 private Optional<TreeNode> snapshotCache;
61 private NormalizedNode<?, ?> value;
62 private ModificationType modType;
64 private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original, final ChildTrackingPolicy childPolicy) {
65 this.identifier = identifier;
66 this.original = original;
68 switch (childPolicy) {
70 children = Collections.emptyMap();
73 children = new LinkedHashMap<>();
76 children = new HashMap<>();
79 throw new IllegalArgumentException("Unsupported child tracking policy " + childPolicy);
84 * Return the value which was written to this node.
86 * @return Currently-written value
88 public NormalizedNode<?, ?> getWrittenValue() {
93 public PathArgument getIdentifier() {
98 Optional<TreeNode> getOriginal() {
103 LogicalOperation getOperation() {
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}
128 * @param child child identifier, may not be null
129 * @param childPolicy child tracking policy for the node we are looking for
130 * @return {@link ModifiedNode} for specified child, with {@link #getOriginal()}
131 * containing child metadata if child was present in original data.
133 ModifiedNode modifyChild(@Nonnull final PathArgument child, @Nonnull final ChildTrackingPolicy childPolicy) {
135 if (operation == LogicalOperation.NONE) {
136 updateOperationType(LogicalOperation.TOUCH);
138 final ModifiedNode potential = children.get(child);
139 if (potential != null) {
143 final Optional<TreeNode> currentMetadata;
144 if (original.isPresent()) {
145 final TreeNode orig = original.get();
146 currentMetadata = orig.getChild(child);
148 currentMetadata = Optional.absent();
151 final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childPolicy);
152 children.put(child, newlyCreated);
157 * Returns all recorded direct child modification
159 * @return all recorded direct child modifications
162 Collection<ModifiedNode> getChildren() {
163 return children.values();
167 * Records a delete for associated node.
170 final LogicalOperation newType;
175 // We need to record this delete.
176 newType = LogicalOperation.DELETE;
182 * We are canceling a previous modification. This is a bit tricky,
183 * as the original write may have just introduced the data, or it
184 * may have modified it.
186 * As documented in BUG-2470, a delete of data introduced in this
187 * transaction needs to be turned into a no-op.
189 newType = original.isPresent() ? LogicalOperation.DELETE : LogicalOperation.NONE;
192 throw new IllegalStateException("Unhandled deletion of node with " + operation);
198 updateOperationType(newType);
202 * Records a write for associated node.
206 void write(final NormalizedNode<?, ?> value) {
208 updateOperationType(LogicalOperation.WRITE);
213 void merge(final NormalizedNode<?, ?> value) {
215 updateOperationType(LogicalOperation.MERGE);
218 * Blind overwrite of any previous data is okay, no matter whether the node
219 * is simple or complex type.
221 * If this is a simple or complex type with unkeyed children, this merge will
222 * be turned into a write operation, overwriting whatever was there before.
224 * If this is a container with keyed children, there are two possibilities:
225 * - if it existed before, this value will never be consulted and the children
226 * will get explicitly merged onto the original data.
227 * - if it did not exist before, this value will be used as a seed write and
228 * children will be merged into it.
229 * In either case we rely on OperationWithModification to manipulate the children
230 * before calling this method, so unlike a write we do not want to clear them.
236 * Seal the modification node and prune any children which has not been
242 // Walk all child nodes and remove any children which have not
244 final Iterator<ModifiedNode> it = children.values().iterator();
245 while (it.hasNext()) {
246 final ModifiedNode child = it.next();
249 if (child.operation == LogicalOperation.NONE) {
254 // A TOUCH node without any children is a no-op
255 if (operation == LogicalOperation.TOUCH && children.isEmpty()) {
256 updateOperationType(LogicalOperation.NONE);
260 private void clearSnapshot() {
261 snapshotCache = null;
264 Optional<TreeNode> getSnapshot() {
265 return snapshotCache;
268 Optional<TreeNode> setSnapshot(final Optional<TreeNode> snapshot) {
269 snapshotCache = Preconditions.checkNotNull(snapshot);
273 private void updateOperationType(final LogicalOperation type) {
280 public String toString() {
281 return "NodeModification [identifier=" + identifier + ", modificationType="
282 + operation + ", childModification=" + children + "]";
285 void resolveModificationType(@Nonnull final ModificationType type) {
290 * Return the physical modification done to data. May return null if the
291 * operation has not been applied to the underlying tree. This is different
292 * from the logical operation in that it can actually be a no-op if the
293 * operation has no side-effects (like an empty merge on a container).
295 * @return Modification type.
297 ModificationType getModificationType() {
302 * Create a node which will reflect the state of this node, except it will behave as newly-written
303 * value. This is useful only for merge validation.
305 * @param value Value associated with the node
306 * @return An isolated node. This node should never reach a datatree.
308 ModifiedNode asNewlyWritten(final NormalizedNode<?, ?> value) {
310 * We are instantiating an "equivalent" of this node. Currently the only callsite does not care
311 * about the actual iteration order, so we do not have to specify the same tracking policy as
312 * we were instantiated with. Since this is the only time we need to know that policy (it affects
313 * only things in constructor), we do not want to retain it (saves some memory on per-instance
316 * We could reconstruct it using two instanceof checks (to undo what the constructor has done),
317 * which would give perfect results. The memory saving would be at most 32 bytes of a short-lived
318 * object, so let's not bother with that.
320 final ModifiedNode ret = new ModifiedNode(getIdentifier(), Optional.<TreeNode>absent(), ChildTrackingPolicy.UNORDERED);
325 public static ModifiedNode createUnmodified(final TreeNode metadataTree, final ChildTrackingPolicy childPolicy) {
326 return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), childPolicy);