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.LinkedHashMap;
18 import javax.annotation.Nonnull;
19 import javax.annotation.concurrent.NotThreadSafe;
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(@Nonnull final ModifiedNode input) {
40 Preconditions.checkNotNull(input);
41 switch (input.getOperation()) {
51 throw new IllegalArgumentException(String.format("Unhandled modification type %s", input.getOperation()));
55 private final Map<PathArgument, ModifiedNode> children;
56 private final Optional<TreeNode> original;
57 private final PathArgument identifier;
58 private LogicalOperation operation = LogicalOperation.NONE;
59 private Optional<TreeNode> snapshotCache;
60 private NormalizedNode<?, ?> value;
61 private ModificationType modType;
63 private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original, final ChildTrackingPolicy childPolicy) {
64 this.identifier = identifier;
65 this.original = original;
67 switch (childPolicy) {
69 children = Collections.emptyMap();
72 children = new LinkedHashMap<>();
75 children = new HashMap<>();
78 throw new IllegalArgumentException("Unsupported child tracking policy " + childPolicy);
83 * Return the value which was written to this node.
85 * @return Currently-written value
87 public NormalizedNode<?, ?> getWrittenValue() {
92 public PathArgument getIdentifier() {
97 Optional<TreeNode> getOriginal() {
102 LogicalOperation getOperation() {
108 * Returns child modification if child was modified
110 * @return Child modification if direct child or it's subtree
115 public Optional<ModifiedNode> getChild(final PathArgument child) {
116 return Optional.<ModifiedNode> fromNullable(children.get(child));
121 * Returns child modification if child was modified, creates {@link ModifiedNode}
122 * for child otherwise.
124 * If this node's {@link ModificationType} is {@link ModificationType#UNMODIFIED}
125 * changes modification type to {@link ModificationType#SUBTREE_MODIFIED}
127 * @param child child identifier, may not be null
128 * @param childPolicy child tracking policy for the node we are looking for
129 * @return {@link ModifiedNode} for specified child, with {@link #getOriginal()}
130 * containing child metadata if child was present in original data.
132 ModifiedNode modifyChild(@Nonnull final PathArgument child, @Nonnull final ChildTrackingPolicy childPolicy) {
134 if (operation == LogicalOperation.NONE) {
135 updateOperationType(LogicalOperation.TOUCH);
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 final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childPolicy);
151 children.put(child, newlyCreated);
156 * Returns all recorded direct child modification
158 * @return all recorded direct child modifications
161 Collection<ModifiedNode> getChildren() {
162 return children.values();
166 * Records a delete for associated node.
169 final LogicalOperation newType;
174 // We need to record this delete.
175 newType = LogicalOperation.DELETE;
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() ? LogicalOperation.DELETE : LogicalOperation.NONE;
191 throw new IllegalStateException("Unhandled deletion of node with " + operation);
197 updateOperationType(newType);
201 * Records a write for associated node.
205 void write(final NormalizedNode<?, ?> value) {
207 updateOperationType(LogicalOperation.WRITE);
212 void merge(final NormalizedNode<?, ?> value) {
214 updateOperationType(LogicalOperation.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.
240 // A TOUCH node without any children is a no-op
241 if (operation == LogicalOperation.TOUCH && children.isEmpty()) {
242 updateOperationType(LogicalOperation.NONE);
246 private void clearSnapshot() {
247 snapshotCache = null;
250 Optional<TreeNode> getSnapshot() {
251 return snapshotCache;
254 Optional<TreeNode> setSnapshot(final Optional<TreeNode> snapshot) {
255 snapshotCache = Preconditions.checkNotNull(snapshot);
259 private void updateOperationType(final LogicalOperation type) {
266 public String toString() {
267 return "NodeModification [identifier=" + identifier + ", modificationType="
268 + operation + ", childModification=" + children + "]";
271 void resolveModificationType(@Nonnull final ModificationType type) {
276 * Return the physical modification done to data. May return null if the
277 * operation has not been applied to the underlying tree. This is different
278 * from the logical operation in that it can actually be a no-op if the
279 * operation has no side-effects (like an empty merge on a container).
281 * @return Modification type.
283 ModificationType getModificationType() {
288 * Create a node which will reflect the state of this node, except it will behave as newly-written
289 * value. This is useful only for merge validation.
291 * @param value Value associated with the node
292 * @return An isolated node. This node should never reach a datatree.
294 ModifiedNode asNewlyWritten(final NormalizedNode<?, ?> value) {
296 * We are instantiating an "equivalent" of this node. Currently the only callsite does not care
297 * about the actual iteration order, so we do not have to specify the same tracking policy as
298 * we were instantiated with. Since this is the only time we need to know that policy (it affects
299 * only things in constructor), we do not want to retain it (saves some memory on per-instance
302 * We could reconstruct it using two instanceof checks (to undo what the constructor has done),
303 * which would give perfect results. The memory saving would be at most 32 bytes of a short-lived
304 * object, so let's not bother with that.
306 final ModifiedNode ret = new ModifiedNode(getIdentifier(), Optional.<TreeNode>absent(), ChildTrackingPolicy.UNORDERED);
311 public static ModifiedNode createUnmodified(final TreeNode metadataTree, final ChildTrackingPolicy childPolicy) {
312 return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), childPolicy);